Bump to 5.2.174 (#5721)

Co-authored-by: ClementPasteau <ClementPasteau@users.noreply.github.com>

.circleci/config.yml

@@ -62,9 +62,10 @@ jobs:
 
       # Build GDevelop IDE (seems like we need to allow Node.js to use more space than usual)
       # Note: Code signing is done using CSC_LINK (see https://www.electron.build/code-signing).
+      # To test signing the code in the CI, add "export CSC_FOR_PULL_REQUEST=true && " before the command.
       - run:
           name: Build GDevelop IDE
-          command: export NODE_OPTIONS="--max-old-space-size=7168" && cd newIDE/electron-app && CI=false npm run build -- --mac --publish=never
+          command: export CSC_FOR_PULL_REQUEST=true && export NODE_OPTIONS="--max-old-space-size=7168" && cd newIDE/electron-app && CI=false npm run build -- --mac --publish=never
 
       - run:
           name: Clean dist folder to keep only installers/binaries.

.github/workflows/extract-translations.yml

@@ -26,7 +26,7 @@ jobs:
         run: sudo apt update && sudo apt install gettext -y
 
       - name: Install newIDE dependencies
-        run: npm install
+        run: npm ci
         working-directory: newIDE/app
 
       - name: Extract translations

CMakeLists.txt

@@ -60,7 +60,7 @@ if("${CMAKE_BUILD_TYPE}" STREQUAL "Release" AND NOT WIN32 AND CMAKE_COMPILER_IS_
 endif()
 
 #Activate C++11
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 11) # Upgrading to C++17 would need to remove usage of bind2nd (should be easy).
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # Mark some warnings as errors
@@ -77,7 +77,8 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 		-Wno-unused-private-field
 
 		# Make as much warnings considered as errors as possible (only one for now).
-		-Werror=return-stack-address)
+		-Werror=return-stack-address
+		-Werror=return-type)
 endif()
 
 # Define common directories:

Core/GDCore/Events/Builtin/ForEachChildVariableEvent.cpp

@@ -45,10 +45,39 @@ ForEachChildVariableEvent::GetAllActionsVectors() const {
   return allActions;
 }
 
+vector<pair<gd::Expression*, gd::ParameterMetadata> >
+    ForEachChildVariableEvent::GetAllExpressionsWithMetadata() {
+  vector<pair<gd::Expression*, gd::ParameterMetadata> >
+      allExpressionsWithMetadata;
+  auto metadata = gd::ParameterMetadata().SetType("scenevar");
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&iterableVariableName, metadata));
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&valueIteratorVariableName, metadata));
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&keyIteratorVariableName, metadata));
+
+  return allExpressionsWithMetadata;
+}
+vector<pair<const gd::Expression*, const gd::ParameterMetadata> >
+    ForEachChildVariableEvent::GetAllExpressionsWithMetadata() const {
+  vector<pair<const gd::Expression*, const gd::ParameterMetadata> >
+      allExpressionsWithMetadata;
+  auto metadata = gd::ParameterMetadata().SetType("scenevar");
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&iterableVariableName, metadata));
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&valueIteratorVariableName, metadata));
+  allExpressionsWithMetadata.push_back(
+      std::make_pair(&keyIteratorVariableName, metadata));
+
+  return allExpressionsWithMetadata;
+}
+
 void ForEachChildVariableEvent::SerializeTo(SerializerElement& element) const {
-  element.AddChild("iterableVariableName").SetValue(iterableVariableName);
-  element.AddChild("valueIteratorVariableName").SetValue(valueIteratorVariableName);
-  element.AddChild("keyIteratorVariableName").SetValue(keyIteratorVariableName);
+  element.AddChild("iterableVariableName").SetValue(iterableVariableName.GetPlainString());
+  element.AddChild("valueIteratorVariableName").SetValue(valueIteratorVariableName.GetPlainString());
+  element.AddChild("keyIteratorVariableName").SetValue(keyIteratorVariableName.GetPlainString());
   gd::EventsListSerialization::SerializeInstructionsTo(
       conditions, element.AddChild("conditions"));
   gd::EventsListSerialization::SerializeInstructionsTo(

Core/GDCore/Events/Builtin/ForEachChildVariableEvent.h

@@ -8,6 +8,7 @@
 #define FOREACHCHILDVARIABLEEVENT_H
 #include "GDCore/Events/Event.h"
 #include "GDCore/Events/EventsList.h"
+#include "GDCore/Events/Expression.h"
 namespace gd {
 class Instruction;
 class Project;
@@ -44,7 +45,7 @@ class GD_CORE_API ForEachChildVariableEvent : public gd::BaseEvent {
    *
    * It is the structure variable that will be iterated on.
    */
-  const gd::String& GetIterableVariableName() const { return iterableVariableName; };
+  const gd::String& GetIterableVariableName() const { return iterableVariableName.GetPlainString(); };
 
   /**
    * \brief Set the iterable variable name attached to the event.
@@ -56,15 +57,15 @@ class GD_CORE_API ForEachChildVariableEvent : public gd::BaseEvent {
   /**
    * \brief Get the value iterator variable attached to the event.
    *
-   * It is the variable that will contain the value of the 
+   * It is the variable that will contain the value of the
    * iterable's child being iterated on.
    */
-  const gd::String& GetValueIteratorVariableName() const { return valueIteratorVariableName; };
+  const gd::String& GetValueIteratorVariableName() const { return valueIteratorVariableName.GetPlainString(); };
 
   /**
    * \brief Set the value iterator variable attached to the event.
    *
-   * It is the variable that will contain the value of the 
+   * It is the variable that will contain the value of the
    * iterable's child being iterated on.
    */
   void SetValueIteratorVariableName(gd::String newName) { valueIteratorVariableName = newName; };
@@ -72,15 +73,15 @@ class GD_CORE_API ForEachChildVariableEvent : public gd::BaseEvent {
   /**
    * \brief Get the key iterator variable attached to the event.
    *
-   * It is the variable that will contain the name of the 
+   * It is the variable that will contain the name of the
    * iterable's child being iterated on.
    */
-  const gd::String& GetKeyIteratorVariableName() const { return keyIteratorVariableName; };
+  const gd::String& GetKeyIteratorVariableName() const { return keyIteratorVariableName.GetPlainString(); };
 
   /**
    * \brief Set the key iterator variable attached to the event.
    *
-   * It is the variable that will contain the name of the 
+   * It is the variable that will contain the name of the
    * iterable's child being iterated on.
    */
   void SetKeyIteratorVariableName(gd::String newName) { keyIteratorVariableName = newName; };
@@ -92,14 +93,19 @@ class GD_CORE_API ForEachChildVariableEvent : public gd::BaseEvent {
   virtual std::vector<gd::InstructionsList*> GetAllConditionsVectors();
   virtual std::vector<gd::InstructionsList*> GetAllActionsVectors();
 
+  virtual std::vector<std::pair<const gd::Expression*, const gd::ParameterMetadata> >
+        GetAllExpressionsWithMetadata() const;
+  virtual std::vector<std::pair<gd::Expression*, gd::ParameterMetadata> >
+        GetAllExpressionsWithMetadata();
+
   virtual void SerializeTo(SerializerElement& element) const;
   virtual void UnserializeFrom(gd::Project& project,
                                const SerializerElement& element);
 
  private:
-  gd::String valueIteratorVariableName;
-  gd::String keyIteratorVariableName;
-  gd::String iterableVariableName;
+  gd::Expression valueIteratorVariableName;
+  gd::Expression keyIteratorVariableName;
+  gd::Expression iterableVariableName;
   gd::InstructionsList conditions;
   gd::InstructionsList actions;
   gd::EventsList events;

Core/GDCore/Events/Builtin/ForEachEvent.h

@@ -64,12 +64,6 @@ class GD_CORE_API ForEachEvent : public gd::BaseEvent {
   virtual void UnserializeFrom(gd::Project& project,
                                const SerializerElement& element);
 
-  std::vector<gd::Expression*> GetAllObjectExpressions() {
-    std::vector<gd::Expression*> allObjectExpressions;
-    allObjectExpressions.push_back(&objectsToPick);
-    return allObjectExpressions;
-  }
-
  private:
   gd::Expression objectsToPick;
   gd::InstructionsList conditions;

Core/GDCore/Events/Builtin/LinkEvent.cpp

@@ -131,30 +131,36 @@ void LinkEvent::SerializeTo(SerializerElement& element) const {
 
 void LinkEvent::UnserializeFrom(gd::Project& project,
                                 const SerializerElement& element) {
-  SerializerElement& includeElement = element.GetChild("include", 0, "Limites");
-
   SetTarget(element.GetChild("target", 0, "Scene").GetValue().GetString());
 
-  if (includeElement.HasAttribute("includeAll")) {
-    // Compatibility with GDevelop <= 4.0.92
-    if (includeElement.GetBoolAttribute("includeAll", true)) {
-      SetIncludeAllEvents();
+  // Compatibility with GD <= 5
+  if (element.HasChild("include", "Limites")) {
+    SerializerElement& includeElement = element.GetChild("include", 0, "Limites");
+    if (includeElement.HasAttribute("includeAll")) {
+      // Compatibility with GDevelop <= 4.0.92
+      if (includeElement.GetBoolAttribute("includeAll", true)) {
+        SetIncludeAllEvents();
+      } else {
+        SetIncludeStartAndEnd(includeElement.GetIntAttribute("start"),
+                              includeElement.GetIntAttribute("end"));
+      }
     } else {
-      SetIncludeStartAndEnd(includeElement.GetIntAttribute("start"),
-                            includeElement.GetIntAttribute("end"));
+      // GDevelop > 4.0.92
+      IncludeConfig config = static_cast<IncludeConfig>(
+          includeElement.GetIntAttribute("includeConfig", 0));
+      if (config == INCLUDE_ALL)
+        SetIncludeAllEvents();
+      else if (config == INCLUDE_EVENTS_GROUP)
+        SetIncludeEventsGroup(includeElement.GetStringAttribute("eventsGroup"));
+      else if (config == INCLUDE_BY_INDEX)
+        SetIncludeStartAndEnd(includeElement.GetIntAttribute("start"),
+                              includeElement.GetIntAttribute("end"));
     }
   } else {
-    // GDevelop > 4.0.92
-    IncludeConfig config = static_cast<IncludeConfig>(
-        includeElement.GetIntAttribute("includeConfig", 0));
-    if (config == INCLUDE_ALL)
-      SetIncludeAllEvents();
-    else if (config == INCLUDE_EVENTS_GROUP)
-      SetIncludeEventsGroup(includeElement.GetStringAttribute("eventsGroup"));
-    else if (config == INCLUDE_BY_INDEX)
-      SetIncludeStartAndEnd(includeElement.GetIntAttribute("start"),
-                            includeElement.GetIntAttribute("end"));
+    // Since GDevelop 5, links always include all events.
+    SetIncludeAllEvents();
   }
+  // end of compatibility code
 }
 
 bool LinkEvent::AcceptVisitor(gd::EventVisitor &eventVisitor) {

Core/GDCore/Events/Builtin/RepeatEvent.cpp

@@ -35,7 +35,7 @@ vector<pair<gd::Expression*, gd::ParameterMetadata> >
     RepeatEvent::GetAllExpressionsWithMetadata() {
   vector<pair<gd::Expression*, gd::ParameterMetadata> >
       allExpressionsWithMetadata;
-  auto metadata = gd::ParameterMetadata().SetType("expression");
+  auto metadata = gd::ParameterMetadata().SetType("number");
   allExpressionsWithMetadata.push_back(
       std::make_pair(&repeatNumberExpression, metadata));
 
@@ -61,7 +61,7 @@ vector<pair<const gd::Expression*, const gd::ParameterMetadata> >
     RepeatEvent::GetAllExpressionsWithMetadata() const {
   vector<pair<const gd::Expression*, const gd::ParameterMetadata> >
       allExpressionsWithMetadata;
-  auto metadata = gd::ParameterMetadata().SetType("expression");
+  auto metadata = gd::ParameterMetadata().SetType("number");
   allExpressionsWithMetadata.push_back(
       std::make_pair(&repeatNumberExpression, metadata));
 

Core/GDCore/Events/CodeGeneration/EventsCodeGenerator.cpp

@@ -16,6 +16,7 @@
 #include "GDCore/Extensions/PlatformExtension.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/ObjectsContainer.h"
+#include "GDCore/Project/ObjectsContainersList.h"
 #include "GDCore/Project/Project.h"
 
 using namespace std;
@@ -295,16 +296,10 @@ gd::String EventsCodeGenerator::GenerateConditionCode(
       gd::String objectInParameter =
           condition.GetParameter(pNb).GetPlainString();
 
-      if (!GetObjectsAndGroups().HasObjectNamed(objectInParameter) &&
-          !GetGlobalObjectsAndGroups().HasObjectNamed(objectInParameter) &&
-          !GetObjectsAndGroups().GetObjectGroups().Has(objectInParameter) &&
-          !GetGlobalObjectsAndGroups().GetObjectGroups().Has(
-              objectInParameter)) {
+      if (!GetObjectsContainersList().HasObjectOrGroupNamed(objectInParameter)) {
         return "/* Unknown object - skipped. */";
       } else if (!instrInfos.parameters[pNb].GetExtraInfo().empty() &&
-                 gd::GetTypeOfObject(GetGlobalObjectsAndGroups(),
-                                     GetObjectsAndGroups(),
-                                     objectInParameter) !=
+                GetObjectsContainersList().GetTypeOfObject(objectInParameter) !=
                      instrInfos.parameters[pNb].GetExtraInfo()) {
         return "/* Mismatched object type - skipped. */";
       }
@@ -315,11 +310,10 @@ gd::String EventsCodeGenerator::GenerateConditionCode(
     gd::String objectName = condition.GetParameter(0).GetPlainString();
     if (!objectName.empty() && !instrInfos.parameters.empty()) {
       std::vector<gd::String> realObjects =
-          ExpandObjectsName(objectName, context);
+          GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
       for (std::size_t i = 0; i < realObjects.size(); ++i) {
         // Set up the context
-        gd::String objectType = gd::GetTypeOfObject(
-            GetGlobalObjectsAndGroups(), GetObjectsAndGroups(), realObjects[i]);
+        gd::String objectType = GetObjectsContainersList().GetTypeOfObject(realObjects[i]);
         const ObjectMetadata& objInfo =
             MetadataProvider::GetObjectMetadata(platform, objectType);
 
@@ -343,13 +337,10 @@ gd::String EventsCodeGenerator::GenerateConditionCode(
     }
   } else if (instrInfos.IsBehaviorInstruction()) {
     gd::String objectName = condition.GetParameter(0).GetPlainString();
-    gd::String behaviorType =
-        gd::GetTypeOfBehavior(GetGlobalObjectsAndGroups(),
-                              GetObjectsAndGroups(),
-                              condition.GetParameter(1).GetPlainString());
+    gd::String behaviorType = GetObjectsContainersList().GetTypeOfBehavior(condition.GetParameter(1).GetPlainString());
     if (instrInfos.parameters.size() >= 2) {
       std::vector<gd::String> realObjects =
-          ExpandObjectsName(objectName, context);
+          GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
       for (std::size_t i = 0; i < realObjects.size(); ++i) {
         // Setup context
         const BehaviorMetadata& autoInfo =
@@ -479,16 +470,10 @@ gd::String EventsCodeGenerator::GenerateActionCode(
   for (std::size_t pNb = 0; pNb < instrInfos.parameters.size(); ++pNb) {
     if (ParameterMetadata::IsObject(instrInfos.parameters[pNb].GetType())) {
       gd::String objectInParameter = action.GetParameter(pNb).GetPlainString();
-      if (!GetObjectsAndGroups().HasObjectNamed(objectInParameter) &&
-          !GetGlobalObjectsAndGroups().HasObjectNamed(objectInParameter) &&
-          !GetObjectsAndGroups().GetObjectGroups().Has(objectInParameter) &&
-          !GetGlobalObjectsAndGroups().GetObjectGroups().Has(
-              objectInParameter)) {
+      if (!GetObjectsContainersList().HasObjectOrGroupNamed(objectInParameter)) {
         return "/* Unknown object - skipped. */";
       } else if (!instrInfos.parameters[pNb].GetExtraInfo().empty() &&
-                 gd::GetTypeOfObject(GetGlobalObjectsAndGroups(),
-                                     GetObjectsAndGroups(),
-                                     objectInParameter) !=
+                 GetObjectsContainersList().GetTypeOfObject(objectInParameter) !=
                      instrInfos.parameters[pNb].GetExtraInfo()) {
         return "/* Mismatched object type - skipped. */";
       }
@@ -501,11 +486,10 @@ gd::String EventsCodeGenerator::GenerateActionCode(
 
     if (!instrInfos.parameters.empty()) {
       std::vector<gd::String> realObjects =
-          ExpandObjectsName(objectName, context);
+          GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
       for (std::size_t i = 0; i < realObjects.size(); ++i) {
         // Setup context
-        gd::String objectType = gd::GetTypeOfObject(
-            GetGlobalObjectsAndGroups(), GetObjectsAndGroups(), realObjects[i]);
+        gd::String objectType = GetObjectsContainersList().GetTypeOfObject(realObjects[i]);
         const ObjectMetadata& objInfo =
             MetadataProvider::GetObjectMetadata(platform, objectType);
 
@@ -529,14 +513,11 @@ gd::String EventsCodeGenerator::GenerateActionCode(
     }
   } else if (instrInfos.IsBehaviorInstruction()) {
     gd::String objectName = action.GetParameter(0).GetPlainString();
-    gd::String behaviorType =
-        gd::GetTypeOfBehavior(GetGlobalObjectsAndGroups(),
-                              GetObjectsAndGroups(),
-                              action.GetParameter(1).GetPlainString());
+    gd::String behaviorType = GetObjectsContainersList().GetTypeOfBehavior(action.GetParameter(1).GetPlainString());
 
     if (instrInfos.parameters.size() >= 2) {
       std::vector<gd::String> realObjects =
-          ExpandObjectsName(objectName, context);
+          GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
       for (std::size_t i = 0; i < realObjects.size(); ++i) {
         // Setup context
         const BehaviorMetadata& autoInfo =
@@ -912,41 +893,6 @@ gd::String EventsCodeGenerator::ConvertToStringExplicit(
   return "\"" + ConvertToString(plainString) + "\"";
 }
 
-std::vector<gd::String> EventsCodeGenerator::ExpandObjectsName(
-    const gd::String& objectName,
-    const EventsCodeGenerationContext& context) const {
-  // Note: this logic is duplicated in EventsContextAnalyzer::ExpandObjectsName
-  std::vector<gd::String> realObjects;
-  if (globalObjectsAndGroups.GetObjectGroups().Has(objectName))
-    realObjects = globalObjectsAndGroups.GetObjectGroups()
-                      .Get(objectName)
-                      .GetAllObjectsNames();
-  else if (objectsAndGroups.GetObjectGroups().Has(objectName))
-    realObjects =
-        objectsAndGroups.GetObjectGroups().Get(objectName).GetAllObjectsNames();
-  else
-    realObjects.push_back(objectName);
-
-  // If current object is present, use it and only it.
-  if (find(realObjects.begin(),
-           realObjects.end(),
-           context.GetCurrentObject()) != realObjects.end()) {
-    realObjects.clear();
-    realObjects.push_back(context.GetCurrentObject());
-  }
-
-  // Ensure that all returned objects actually exists.
-  for (std::size_t i = 0; i < realObjects.size();) {
-    if (!objectsAndGroups.HasObjectNamed(realObjects[i]) &&
-        !globalObjectsAndGroups.HasObjectNamed(realObjects[i]))
-      realObjects.erase(realObjects.begin() + i);
-    else
-      ++i;
-  }
-
-  return realObjects;
-}
-
 void EventsCodeGenerator::DeleteUselessEvents(gd::EventsList& events) {
   for (std::size_t eId = events.size() - 1; eId < events.size(); --eId) {
     if (events[eId].CanHaveSubEvents())  // Process sub events, if any
@@ -963,6 +909,8 @@ void EventsCodeGenerator::DeleteUselessEvents(gd::EventsList& events) {
  */
 void EventsCodeGenerator::PreprocessEventList(gd::EventsList& listEvent) {
   for (std::size_t i = 0; i < listEvent.GetEventsCount(); ++i) {
+    if (listEvent[i].IsDisabled()) continue;
+
     listEvent[i].Preprocess(*this, listEvent, i);
     if (i <
         listEvent.GetEventsCount()) {  // Be sure that that there is still an
@@ -1260,12 +1208,24 @@ gd::String EventsCodeGenerator::GenerateArgumentsList(
   return argumentsStr;
 }
 
+gd::String EventsCodeGenerator::GeneratePropertyGetter(const gd::PropertiesContainer& propertiesContainer,
+                                                       const gd::NamedPropertyDescriptor& property,
+                                                       const gd::String& type,
+                                                       gd::EventsCodeGenerationContext& context) {
+  return "getProperty" + property.GetName() + "()";
+}
+
+gd::String EventsCodeGenerator::GenerateParameterGetter(const gd::ParameterMetadata& parameter,
+                                                        const gd::String& type,
+                                                        gd::EventsCodeGenerationContext& context) {
+  return "getParameter" + parameter.GetName() + "()";
+}
+
 EventsCodeGenerator::EventsCodeGenerator(const gd::Project& project_,
                                          const gd::Layout& layout,
                                          const gd::Platform& platform_)
     : platform(platform_),
-      globalObjectsAndGroups(project_),
-      objectsAndGroups(layout),
+      projectScopedContainers(gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project_, layout)),
       hasProjectAndLayout(true),
       project(&project_),
       scene(&layout),
@@ -1277,11 +1237,9 @@ EventsCodeGenerator::EventsCodeGenerator(const gd::Project& project_,
 
 EventsCodeGenerator::EventsCodeGenerator(
     const gd::Platform& platform_,
-    const gd::ObjectsContainer& globalObjectsAndGroups_,
-    const gd::ObjectsContainer& objectsAndGroups_)
+    const gd::ProjectScopedContainers& projectScopedContainers_)
     : platform(platform_),
-      globalObjectsAndGroups(globalObjectsAndGroups_),
-      objectsAndGroups(objectsAndGroups_),
+      projectScopedContainers(projectScopedContainers_),
       hasProjectAndLayout(false),
       project(nullptr),
       scene(nullptr),

Core/GDCore/Events/CodeGeneration/EventsCodeGenerator.h

@@ -13,12 +13,14 @@
 #include "GDCore/Events/Event.h"
 #include "GDCore/Events/Instruction.h"
 #include "GDCore/String.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 namespace gd {
 class EventsList;
 class Expression;
 class Project;
 class Layout;
 class ObjectsContainer;
+class ObjectsContainersList;
 class ExternalEvents;
 class ParameterMetadata;
 class ObjectMetadata;
@@ -57,8 +59,7 @@ class GD_CORE_API EventsCodeGenerator {
    * objects/groups and platform
    */
   EventsCodeGenerator(const gd::Platform& platform,
-                      const gd::ObjectsContainer& globalObjectsAndGroups_,
-                      const gd::ObjectsContainer& objectsAndGroups_);
+                      const gd::ProjectScopedContainers& projectScopedContainers_);
   virtual ~EventsCodeGenerator(){};
 
   /**
@@ -326,18 +327,12 @@ class GD_CORE_API EventsCodeGenerator {
    */
   bool ErrorOccurred() const { return errorOccurred; };
 
-  /**
-   * \brief Get the global objects/groups used for code generation.
-   */
-  const gd::ObjectsContainer& GetGlobalObjectsAndGroups() const {
-    return globalObjectsAndGroups;
-  }
+  const gd::ObjectsContainersList& GetObjectsContainersList() const {
+    return projectScopedContainers.GetObjectsContainersList();
+  };
 
-  /**
-   * \brief Get the objects/groups used for code generation.
-   */
-  const gd::ObjectsContainer& GetObjectsAndGroups() const {
-    return objectsAndGroups;
+  const gd::ProjectScopedContainers& GetProjectScopedContainers() const {
+    return projectScopedContainers;
   }
 
   /**
@@ -363,22 +358,6 @@ class GD_CORE_API EventsCodeGenerator {
    */
   const gd::Platform& GetPlatform() const { return platform; }
 
-  /**
-   * \brief Convert a group name to the full list of objects contained in the
-   * group.
-   *
-   * Get a list containing the "real" objects name when the events refers to \a
-   * objectName :<br> If \a objectName is really an object, the list will only
-   * contains \a objectName unchanged.<br> If \a objectName is a group, the list
-   * will contains all the objects of the group.<br> If \a objectName is the
-   * "current" object in the context ( i.e: The object being used for launching
-   * an action... ), none of the two rules below apply, and the list will only
-   * contains the context "current" object name.
-   */
-  std::vector<gd::String> ExpandObjectsName(
-      const gd::String& objectName,
-      const EventsCodeGenerationContext& context) const;
-
   /**
    * \brief Get the maximum depth of custom conditions reached during code
    * generation.
@@ -566,6 +545,10 @@ class GD_CORE_API EventsCodeGenerator {
     return ".getChild(" + ConvertToStringExplicit(childName) + ")";
   };
 
+  virtual gd::String GenerateVariableValueAs(const gd::String& type) {
+    return type == "string" ? ".getAsString()" : ".getAsNumber()";
+  }
+
   /**
    * \brief Generate the code to get the child of a variable,
    * using generated the expression.
@@ -594,6 +577,15 @@ class GD_CORE_API EventsCodeGenerator {
     return "fakeObjectListOf_" + objectName;
   }
 
+  virtual gd::String GeneratePropertyGetter(const gd::PropertiesContainer& propertiesContainer,
+                                            const gd::NamedPropertyDescriptor& property,
+                                            const gd::String& type,
+                                            gd::EventsCodeGenerationContext& context);
+
+  virtual gd::String GenerateParameterGetter(const gd::ParameterMetadata& parameter,
+                                             const gd::String& type,
+                                             gd::EventsCodeGenerationContext& context);
+
   /**
    * \brief Generate the code to reference an object which is
    * in an empty/null state.
@@ -777,8 +769,7 @@ class GD_CORE_API EventsCodeGenerator {
 
   const gd::Platform& platform;  ///< The platform being used.
 
-  const gd::ObjectsContainer& globalObjectsAndGroups;
-  const gd::ObjectsContainer& objectsAndGroups;
+  gd::ProjectScopedContainers projectScopedContainers;
 
   bool hasProjectAndLayout;  ///< true only if project and layout are valid
                              ///< references. If false, they should not be used.

Core/GDCore/Events/CodeGeneration/ExpressionCodeGenerator.cpp

@@ -7,6 +7,7 @@
 
 #include <memory>
 #include <vector>
+#include <vector>
 
 #include "GDCore/CommonTools.h"
 #include "GDCore/Events/CodeGeneration/EventsCodeGenerationContext.h"
@@ -25,6 +26,9 @@
 #include "GDCore/IDE/Events/ExpressionValidator.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/VariablesContainersList.h"
+#include "GDCore/Project/ObjectsContainersList.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/IDE/Events/ExpressionTypeFinder.h"
 #include "GDCore/IDE/Events/ExpressionVariableOwnerFinder.h"
 
@@ -47,8 +51,7 @@ gd::String ExpressionCodeGenerator::GenerateExpressionCode(
   }
 
   gd::ExpressionValidator validator(codeGenerator.GetPlatform(),
-                                    codeGenerator.GetGlobalObjectsAndGroups(),
-                                    codeGenerator.GetObjectsAndGroups(),
+                                    codeGenerator.GetProjectScopedContainers(),
                                     rootType);
   node->Visit(validator);
   if (!validator.GetFatalErrors().empty()) {
@@ -100,34 +103,94 @@ void ExpressionCodeGenerator::OnVisitVariableNode(VariableNode& node) {
   // This "translation" from the type to an enum could be avoided
   // if all types were moved to an enum.
   auto type = gd::ExpressionTypeFinder::GetType(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootType,
                                             node);
-  EventsCodeGenerator::VariableScope scope =
-      type == "globalvar"
-          ? gd::EventsCodeGenerator::PROJECT_VARIABLE
-          : ((type == "scenevar")
-                 ? gd::EventsCodeGenerator::LAYOUT_VARIABLE
-                 : gd::EventsCodeGenerator::OBJECT_VARIABLE);
-  auto objectName = gd::ExpressionVariableOwnerFinder::GetObjectName(codeGenerator.GetPlatform(),
-                                        codeGenerator.GetGlobalObjectsAndGroups(),
-                                        codeGenerator.GetObjectsAndGroups(),
-                                        rootObjectName,
-                                        node);
-  output += codeGenerator.GenerateGetVariable(
-      node.name, scope, context, objectName);
-  if (node.child) node.child->Visit(*this);
+
+  if (gd::ParameterMetadata::IsExpression("variable", type)) {
+    // The node is a variable inside an expression waiting for a *variable* to be returned, not its value.
+    EventsCodeGenerator::VariableScope scope =
+        type == "globalvar"
+            ? gd::EventsCodeGenerator::PROJECT_VARIABLE
+            : ((type == "scenevar")
+                  ? gd::EventsCodeGenerator::LAYOUT_VARIABLE
+                  : gd::EventsCodeGenerator::OBJECT_VARIABLE);
+
+    auto objectName = gd::ExpressionVariableOwnerFinder::GetObjectName(codeGenerator.GetPlatform(),
+                                          codeGenerator.GetObjectsContainersList(),
+                                          rootObjectName,
+                                          node);
+    output += codeGenerator.GenerateGetVariable(
+        node.name, scope, context, objectName);
+    if (node.child) node.child->Visit(*this);
+  } else {
+    // The node represents a variable or an object variable in an expression waiting for its *value* to be returned.
+
+    codeGenerator.GetProjectScopedContainers().MatchIdentifierWithName<void>(node.name, [&](){
+      // Generate the code to access the object variables.
+
+      // Defer generation of the access to the object and variable to the child,
+      // once we know the name of the variable.
+      objectNameToUseForVariableAccessor = node.name;
+      if (node.child) node.child->Visit(*this);
+      objectNameToUseForVariableAccessor = "";
+
+      output += codeGenerator.GenerateVariableValueAs(type);
+    }, [&]() {
+      if (!codeGenerator.HasProjectAndLayout()) {
+        gd::LogWarning("Tried to generate access to a variable without a project/scene - the code generator only works for global and scene variables for now.");
+        output += GenerateDefaultValue(type);
+        return;
+      }
+
+      // This could be adapted in the future if more scopes are supported.
+      EventsCodeGenerator::VariableScope scope = gd::EventsCodeGenerator::PROJECT_VARIABLE;
+      if (codeGenerator.GetProjectScopedContainers().GetVariablesContainersList().GetBottomMostVariablesContainer()->Has(node.name)) {
+        scope = gd::EventsCodeGenerator::LAYOUT_VARIABLE;
+      }
+
+      output += codeGenerator.GenerateGetVariable(node.name, scope, context, "");
+      if (node.child) node.child->Visit(*this);
+      output += codeGenerator.GenerateVariableValueAs(type);
+    }, [&]() {
+      // Properties are not supported.
+      output += GenerateDefaultValue(type);
+    }, [&]() {
+      // Parameters are not supported.
+      output += GenerateDefaultValue(type);
+    }, [&]() {
+      // The identifier does not represents a variable (or a child variable), or not at least an existing
+      // one, nor an object variable. It's invalid.
+      output += GenerateDefaultValue(type);
+    });
+  }
 }
 
 void ExpressionCodeGenerator::OnVisitVariableAccessorNode(
     VariableAccessorNode& node) {
-  output += codeGenerator.GenerateVariableAccessor(node.name);
+    if (!objectNameToUseForVariableAccessor.empty()) {
+      // Use the name of the object passed by the parent, as we need both to access an object variable.
+      output += codeGenerator.GenerateGetVariable(node.name,
+          gd::EventsCodeGenerator::OBJECT_VARIABLE, context, objectNameToUseForVariableAccessor);
+
+      // We have accessed an object variable, from now we can continue accessing the child variables
+      // (including using the bracket notation).
+      objectNameToUseForVariableAccessor = "";
+    } else {
+        output += codeGenerator.GenerateVariableAccessor(node.name);
+    }
   if (node.child) node.child->Visit(*this);
 }
 
 void ExpressionCodeGenerator::OnVisitVariableBracketAccessorNode(
     VariableBracketAccessorNode& node) {
+  if (!objectNameToUseForVariableAccessor.empty()) {
+    // Bracket notation can't be used to directly access a variable of an object (`MyObject["MyVariable"]`).
+    // This would be rejected by the ExpressionValidator.
+    output += codeGenerator.GenerateBadVariable();
+    return;
+  }
+
   ExpressionCodeGenerator generator("string", "", codeGenerator, context);
   node.expression->Visit(generator);
   output +=
@@ -137,10 +200,10 @@ void ExpressionCodeGenerator::OnVisitVariableBracketAccessorNode(
 
 void ExpressionCodeGenerator::OnVisitIdentifierNode(IdentifierNode& node) {
   auto type = gd::ExpressionTypeFinder::GetType(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootType,
                                             node);
+
   if (gd::ParameterMetadata::IsObject(type)) {
     output +=
         codeGenerator.GenerateObject(node.identifierName, type, context);
@@ -153,8 +216,7 @@ void ExpressionCodeGenerator::OnVisitIdentifierNode(IdentifierNode& node) {
                     : gd::EventsCodeGenerator::OBJECT_VARIABLE);
 
       auto objectName = gd::ExpressionVariableOwnerFinder::GetObjectName(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootObjectName,
                                             node);
       output += codeGenerator.GenerateGetVariable(
@@ -162,30 +224,60 @@ void ExpressionCodeGenerator::OnVisitIdentifierNode(IdentifierNode& node) {
       if (!node.childIdentifierName.empty()) {
         output += codeGenerator.GenerateVariableAccessor(node.childIdentifierName);
       }
-  } else if (node.childIdentifierName.empty()) {
-    output += "/* Error during generation, unrecognized identifier type: " +
-              codeGenerator.ConvertToString(type) + " with value " +
-              codeGenerator.ConvertToString(node.identifierName) + " */ " +
-              codeGenerator.ConvertToStringExplicit(node.identifierName);
-  }
-  else {
-    // This is for function names that are put in IdentifierNode
-    // because the type is needed to tell them apart from variables.
-    output += GenerateDefaultValue(type);
+  } else {
+    const auto& variablesContainersList = codeGenerator.GetProjectScopedContainers().GetVariablesContainersList();
+    const auto& propertiesContainersList = codeGenerator.GetProjectScopedContainers().GetPropertiesContainersList();
+    const auto& parametersVectorsList = codeGenerator.GetProjectScopedContainers().GetParametersVectorsList();
+
+    // The node represents a variable, property, parameter or an object.
+    codeGenerator.GetProjectScopedContainers().MatchIdentifierWithName<void>(node.identifierName, [&]() {
+      // Generate the code to access the object variable.
+      output += codeGenerator.GenerateGetVariable(
+        node.childIdentifierName, gd::EventsCodeGenerator::OBJECT_VARIABLE, context, node.identifierName);
+      output += codeGenerator.GenerateVariableValueAs(type);
+    }, [&]() {
+      if (!codeGenerator.HasProjectAndLayout()) {
+        gd::LogWarning("Tried to generate access to a variable without a project/scene - the code generator only works for global and scene variables for now.");
+        output += GenerateDefaultValue(type);
+        return;
+      }
+
+      // This could be adapted in the future if more scopes are supported at runtime.
+      EventsCodeGenerator::VariableScope scope = gd::EventsCodeGenerator::PROJECT_VARIABLE;
+      if (variablesContainersList.GetBottomMostVariablesContainer()->Has(node.identifierName)) {
+        scope = gd::EventsCodeGenerator::LAYOUT_VARIABLE;
+      }
+
+      output += codeGenerator.GenerateGetVariable(node.identifierName, scope, context, "");
+      if (!node.childIdentifierName.empty()) {
+        output += codeGenerator.GenerateVariableAccessor(node.childIdentifierName);
+      }
+      output += codeGenerator.GenerateVariableValueAs(type);
+    }, [&]() {
+      const auto& propertiesContainerAndProperty = propertiesContainersList.Get(node.identifierName);
+
+      output += codeGenerator.GeneratePropertyGetter(
+        propertiesContainerAndProperty.first, propertiesContainerAndProperty.second, type, context);
+    }, [&]() {
+      const auto& parameter = gd::ParameterMetadataTools::Get(parametersVectorsList, node.identifierName);
+      output += codeGenerator.GenerateParameterGetter(parameter, type, context);
+    }, [&]() {
+      // The identifier does not represents a variable (or a child variable), or not at least an existing
+      // one, nor an object variable. It's invalid.
+      output += GenerateDefaultValue(type);
+    });
   }
 }
 
 void ExpressionCodeGenerator::OnVisitFunctionCallNode(FunctionCallNode& node) {
   auto type = gd::ExpressionTypeFinder::GetType(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootType,
                                             node);
 
   const gd::ExpressionMetadata &metadata = MetadataProvider::GetFunctionCallMetadata(
       codeGenerator.GetPlatform(),
-      codeGenerator.GetGlobalObjectsAndGroups(),
-      codeGenerator.GetObjectsAndGroups(),
+      codeGenerator.GetObjectsContainersList(),
       node);
 
   if (gd::MetadataProvider::IsBadExpressionMetadata(metadata)) {
@@ -236,11 +328,6 @@ gd::String ExpressionCodeGenerator::GenerateObjectFunctionCode(
     const gd::String& objectName,
     const std::vector<std::unique_ptr<ExpressionNode>>& parameters,
     const ExpressionMetadata& expressionMetadata) {
-  const gd::ObjectsContainer& globalObjectsAndGroups =
-      codeGenerator.GetGlobalObjectsAndGroups();
-  const gd::ObjectsContainer& objectsAndGroups =
-      codeGenerator.GetObjectsAndGroups();
-
   codeGenerator.AddIncludeFiles(
       expressionMetadata.GetIncludeFiles());
 
@@ -261,12 +348,11 @@ gd::String ExpressionCodeGenerator::GenerateObjectFunctionCode(
 
   // Get object(s) concerned by function call
   std::vector<gd::String> realObjects =
-      codeGenerator.ExpandObjectsName(objectName, context);
+      codeGenerator.GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
   for (std::size_t i = 0; i < realObjects.size(); ++i) {
     context.ObjectsListNeeded(realObjects[i]);
 
-    gd::String objectType = gd::GetTypeOfObject(
-        globalObjectsAndGroups, objectsAndGroups, realObjects[i]);
+    gd::String objectType = codeGenerator.GetObjectsContainersList().GetTypeOfObject(realObjects[i]);
     const ObjectMetadata& objInfo = MetadataProvider::GetObjectMetadata(
         codeGenerator.GetPlatform(), objectType);
 
@@ -288,11 +374,6 @@ gd::String ExpressionCodeGenerator::GenerateBehaviorFunctionCode(
     const gd::String& behaviorName,
     const std::vector<std::unique_ptr<ExpressionNode>>& parameters,
     const ExpressionMetadata& expressionMetadata) {
-  const gd::ObjectsContainer& globalObjectsAndGroups =
-      codeGenerator.GetGlobalObjectsAndGroups();
-  const gd::ObjectsContainer& objectsAndGroups =
-      codeGenerator.GetObjectsAndGroups();
-
   codeGenerator.AddIncludeFiles(
       expressionMetadata.GetIncludeFiles());
 
@@ -311,12 +392,11 @@ gd::String ExpressionCodeGenerator::GenerateBehaviorFunctionCode(
 
   // Get object(s) concerned by function call
   std::vector<gd::String> realObjects =
-      codeGenerator.ExpandObjectsName(objectName, context);
+      codeGenerator.GetObjectsContainersList().ExpandObjectName(objectName, context.GetCurrentObject());
 
   gd::String functionOutput = GenerateDefaultValue(type);
 
-  gd::String behaviorType = gd::GetTypeOfBehavior(
-      globalObjectsAndGroups, objectsAndGroups, behaviorName);
+  gd::String behaviorType = codeGenerator.GetObjectsContainersList().GetTypeOfBehavior(behaviorName);
   const BehaviorMetadata& autoInfo = MetadataProvider::GetBehaviorMetadata(
       codeGenerator.GetPlatform(), behaviorType);
 
@@ -352,8 +432,7 @@ gd::String ExpressionCodeGenerator::GenerateParametersCodes(
     if (!parameterMetadata.IsCodeOnly()) {
       if (nonCodeOnlyParameterIndex < parameters.size()) {
         auto objectName = gd::ExpressionVariableOwnerFinder::GetObjectName(codeGenerator.GetPlatform(),
-                                              codeGenerator.GetGlobalObjectsAndGroups(),
-                                              codeGenerator.GetObjectsAndGroups(),
+                                              codeGenerator.GetObjectsContainersList(),
                                               rootObjectName,
                                               *parameters[nonCodeOnlyParameterIndex].get());
         ExpressionCodeGenerator generator(parameterMetadata.GetType(), objectName, codeGenerator, context);
@@ -423,8 +502,7 @@ gd::String ExpressionCodeGenerator::GenerateDefaultValue(
 
 void ExpressionCodeGenerator::OnVisitEmptyNode(EmptyNode& node) {
   auto type = gd::ExpressionTypeFinder::GetType(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootType,
                                             node);
   output += GenerateDefaultValue(type);
@@ -433,8 +511,7 @@ void ExpressionCodeGenerator::OnVisitEmptyNode(EmptyNode& node) {
 void ExpressionCodeGenerator::OnVisitObjectFunctionNameNode(
     ObjectFunctionNameNode& node) {
   auto type = gd::ExpressionTypeFinder::GetType(codeGenerator.GetPlatform(),
-                                            codeGenerator.GetGlobalObjectsAndGroups(),
-                                            codeGenerator.GetObjectsAndGroups(),
+                                            codeGenerator.GetObjectsContainersList(),
                                             rootType,
                                             node);
   output += GenerateDefaultValue(type);

Core/GDCore/Events/CodeGeneration/ExpressionCodeGenerator.h

@@ -102,6 +102,7 @@ class GD_CORE_API ExpressionCodeGenerator : public ExpressionParser2NodeWorker {
       const std::vector<std::unique_ptr<ExpressionNode>>& parameters);
 
   gd::String output;
+  gd::String objectNameToUseForVariableAccessor;
   EventsCodeGenerator& codeGenerator;
   EventsCodeGenerationContext& context;
   const gd::String rootType;

Core/GDCore/Events/Event.h

@@ -240,7 +240,7 @@ class GD_CORE_API BaseEvent {
    */
   virtual void UnserializeFrom(gd::Project& project,
                                const SerializerElement& element){};
-  
+
   virtual bool AcceptVisitor(gd::EventVisitor& eventVisitor);
   virtual void AcceptVisitor(gd::ReadOnlyEventVisitor& eventVisitor) const;
   ///@}
@@ -281,15 +281,6 @@ class GD_CORE_API BaseEvent {
    * \brief True if the event should be folded in the events editor.
    */
   bool IsFolded() const { return folded; }
-
-  /**
-   * \brief Return a list of all objects linked to the event.
-   */
-  virtual std::vector<gd::Expression*> GetAllObjectExpressions() {
-    std::vector<gd::Expression*> allObjectExpressions;
-    return allObjectExpressions;
-  }
-
   ///@}
 
   std::weak_ptr<gd::BaseEvent>

Core/GDCore/Events/Parsers/ExpressionParser2.h

@@ -47,14 +47,9 @@ class GD_CORE_API ExpressionParser2 {
   virtual ~ExpressionParser2(){};
 
   /**
-   * Parse the given expression with the specified type.
+   * Parse the given expression into a tree of nodes.
    *
-   * \param type Type of the expression: "string", "number",
-   * type supported by gd::ParameterMetadata::IsObject, types supported by
-   * gd::ParameterMetadata::IsExpression or "unknown".
-   * \param expression The expression to parse
-   * \param objectName Specify the object name, only for the
-   * case of "objectvar" type.
+   * \param expression The expression to parse.
    *
    * \return The node representing the expression as a parsed tree.
    */
@@ -267,12 +262,11 @@ class GD_CORE_API ExpressionParser2 {
     } else if (CheckIfChar(IsDot)) {
       ExpressionParserLocation dotLocation = SkipChar();
       SkipAllWhitespaces();
-      return ObjectFunctionOrBehaviorFunction(
+      return ObjectFunctionOrBehaviorFunctionOrVariable(
           name, nameLocation, dotLocation);
     } else if (CheckIfChar(IsOpeningSquareBracket)) {
       return Variable(name, nameLocation);
-    }
-    else {
+    } else {
       auto identifier = gd::make_unique<IdentifierNode>(name);
       identifier->location = ExpressionParserLocation(
           nameLocation.GetStartPosition(), GetCurrentPosition());
@@ -318,7 +312,7 @@ class GD_CORE_API ExpressionParser2 {
       auto dotLocation = SkipChar();
       SkipAllWhitespaces();
 
-      auto identifierAndLocation = ReadIdentifierName();
+      auto identifierAndLocation = ReadIdentifierName(/*allowDeprecatedSpacesInName=*/ false);
       auto child =
           gd::make_unique<VariableAccessorNode>(identifierAndLocation.name);
       child->child = VariableAccessorOrVariableBracketAccessor();
@@ -358,11 +352,11 @@ class GD_CORE_API ExpressionParser2 {
   }
 
   std::unique_ptr<IdentifierOrFunctionCallOrObjectFunctionNameOrEmptyNode>
-  ObjectFunctionOrBehaviorFunction(
+  ObjectFunctionOrBehaviorFunctionOrVariable(
       const gd::String &parentIdentifier,
       const ExpressionParserLocation &parentIdentifierLocation,
       const ExpressionParserLocation &parentIdentifierDotLocation) {
-    auto childIdentifierAndLocation = ReadIdentifierName();
+    auto childIdentifierAndLocation = ReadIdentifierName(/*allowDeprecatedSpacesInName=*/ false);
     const gd::String &childIdentifierName = childIdentifierAndLocation.name;
     const auto &childIdentifierNameLocation =
         childIdentifierAndLocation.location;
@@ -420,12 +414,6 @@ class GD_CORE_API ExpressionParser2 {
 
     auto node = gd::make_unique<IdentifierNode>(
         parentIdentifier, childIdentifierName);
-    if (!CheckIfChar(IsParameterSeparator) && !CheckIfChar(IsClosingParenthesis) && !IsEndReached()) {
-      node->diagnostic = RaiseSyntaxError(
-          _("An opening parenthesis (for an object expression), a double colon "
-            "(:: for a behavior expression), a dot or an opening bracket (for "
-            "a child variable) where expected."));
-    }
     node->location = ExpressionParserLocation(
         parentIdentifierLocation.GetStartPosition(), GetCurrentPosition());
     node->identifierNameLocation = parentIdentifierLocation;
@@ -625,13 +613,13 @@ class GD_CORE_API ExpressionParser2 {
     ExpressionParserLocation location;
   };
 
-  IdentifierAndLocation ReadIdentifierName() {
+  IdentifierAndLocation ReadIdentifierName(bool allowDeprecatedSpacesInName = true) {
     gd::String name;
     size_t startPosition = currentPosition;
     while (currentPosition < expression.size() &&
            (CheckIfChar(IsAllowedInIdentifier)
             // Allow whitespace in identifier name for compatibility
-            || expression[currentPosition] == ' ')) {
+            || (allowDeprecatedSpacesInName && expression[currentPosition] == ' '))) {
       name += expression[currentPosition];
       currentPosition++;
     }

Core/GDCore/Events/Parsers/ExpressionParser2Node.h

@@ -189,7 +189,7 @@ struct GD_CORE_API IdentifierOrFunctionCallOrObjectFunctionNameOrEmptyNode
  *
  * The name of a function to call on an object or the behavior,
  * for example: "MyObject.Function" or "MyObject.Physics".
- * 
+ *
  * A variable, potentially with accessor to its child,
  * for example: MyVariable or MyVariable.MyChild
  */
@@ -239,13 +239,14 @@ struct GD_CORE_API VariableAccessorOrVariableBracketAccessorNode : public Expres
 };
 
 /**
- * \brief A variable with bracket accessor or at least 2 "dot" accessors.
+ * \brief A variable, or object variable, with bracket accessor or at least 2 "dot" accessors.
+ *
+ * Example: `MyVariable["MyChildren"]` or `MyVariable.MyChildren.MyGrandChildren`.
+ * Example: `MyObject["MyVariable"]` or `MyObject.MyVariable.MyChildren`.
  *
- * Example: MyVariable[MyChildren] or MyVariable.MyChildren.MyGranChildren.
- * 
  * Other cases like "MyVariable" or "MyVariable.MyChildren" are IdentifierNode
  * to allow handling ambiguities.
- * 
+ *
  * \see gd::IdentifierNode
  * \see gd::VariableAccessorNode
  * \see gd::VariableBracketAccessorNode
@@ -267,7 +268,7 @@ struct GD_CORE_API VariableNode : public FunctionCallOrObjectFunctionNameOrEmpty
 };
 
 /**
- * \brief A bracket accessor of a variable. Example: MyChild
+ * \brief A direct accessor to a child variable. Example: MyChild
  * in MyVariable.MyChild
  */
 struct GD_CORE_API VariableAccessorNode
@@ -285,7 +286,7 @@ struct GD_CORE_API VariableAccessorNode
 };
 
 /**
- * \brief A bracket accessor of a variable. Example: ["MyChild"]
+ * \brief A bracket accessor to a child variable. Example: ["MyChild"]
  * (in MyVariable["MyChild"]).
  */
 struct GD_CORE_API VariableBracketAccessorNode
@@ -303,10 +304,10 @@ struct GD_CORE_API VariableBracketAccessorNode
 /**
  * \brief The name of a function to call on an object or the behavior
  * For example: "MyObject.Physics::LinearVelocity".
- * 
+ *
  * Other cases like "MyObject.Function" or "MyObject.Physics" are IdentifierNode
  * to allow handling ambiguities.
- * 
+ *
  * \see gd::IdentifierNode
  */
 struct GD_CORE_API ObjectFunctionNameNode

Core/GDCore/Events/Parsers/GrammarTerminals.h

@@ -75,10 +75,21 @@ inline bool IsZeroDigit(gd::String::value_type character) {
   return character == '0';
 }
 
+inline bool IsAdditionalReservedCharacter(gd::String::value_type character) {
+  // These characters are not part of the grammar - but are often used in programming language
+  // and could become operators or part of the grammar one day.
+  return character == '~' || character == '\'' || character == '%' ||
+         character == '#' || character == '@' || character == '|' ||
+         character == '&' || character == '`' || character == '$' ||
+         character == ';';
+
+}
+
 /**
  * Check if the given character can be used in an identifier. This is
  * any unicode character, except for:
- * `, . " () [] {} + - < > ? ^ = \ : ! / *` and whitespaces (space, line break, carriage return).
+ * `, . " () [] {} + - < > ? ^ = \ : ! / * ~ ' % # @ | & $ ;`
+ * and backtick and whitespaces (space, line break, carriage return).
  *
  * This is loosely based on what is allowed in languages like JavaScript
  * (see https://mathiasbynens.be/notes/javascript-properties), without support
@@ -96,7 +107,7 @@ inline bool IsAllowedInIdentifier(gd::String::value_type character) {
   if (!IsParameterSeparator(character) && !IsDot(character) &&
       !IsQuote(character) && !IsBracket(character) &&
       !IsExpressionOperator(character) && !IsTermOperator(character) &&
-      !IsWhitespace(character)) {
+      !IsWhitespace(character) && !IsAdditionalReservedCharacter(character)) {
     return true;
   }
 

Core/GDCore/Extensions/Builtin/BaseObjectExtension.cpp

@@ -1277,9 +1277,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
 
   // Deprecated
   obj.AddAction("SetEffectDoubleParameter",
-                _("Effect parameter (number)"),
-                _("Change the value of a parameter of an effect.") + "\n" +
-                    _("You can find the parameter names (and change the effect "
+                _("Effect property (number)"),
+                _("Change the value of a property of an effect.") + "\n" +
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Set _PARAM2_ to _PARAM3_ for effect _PARAM1_ of _PARAM0_"),
                 _("Effects"),
@@ -1287,17 +1287,17 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
                 "res/actions/effect.png")
       .AddParameter("object", _("Object"))
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
       .AddParameter("expression", _("New value"))
       .MarkAsSimple()
       .SetHidden();
 
   // Deprecated
   obj.AddAction("SetEffectStringParameter",
-                _("Effect parameter (string)"),
-                _("Change the value (string) of a parameter of an effect.") +
+                _("Effect property (string)"),
+                _("Change the value (string) of a property of an effect.") +
                     "\n" +
-                    _("You can find the parameter names (and change the effect "
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Set _PARAM2_ to _PARAM3_ for effect _PARAM1_ of _PARAM0_"),
                 _("Effects"),
@@ -1305,16 +1305,16 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
                 "res/actions/effect.png")
       .AddParameter("object", _("Object"))
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
       .AddParameter("string", _("New value"))
       .MarkAsSimple()
       .SetHidden();
 
   // Deprecated
   obj.AddAction("SetEffectBooleanParameter",
-                _("Effect parameter (enable or disable)"),
-                _("Enable or disable a parameter of an effect.") + "\n" +
-                    _("You can find the parameter names (and change the effect "
+                _("Effect property (enable or disable)"),
+                _("Enable or disable a property of an effect.") + "\n" +
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Enable _PARAM2_ for effect _PARAM1_ of _PARAM0_: _PARAM3_"),
                 _("Effects"),
@@ -1322,8 +1322,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
                 "res/actions/effect.png")
       .AddParameter("object", _("Object"))
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
-      .AddParameter("yesorno", _("Enable?"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
+      .AddParameter("yesorno", _("Enable this property"))
       .MarkAsSimple()
       .SetHidden();
 

Core/GDCore/Extensions/Builtin/CameraExtension.cpp

@@ -444,9 +444,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsCameraExtension(
   extension
       .AddAction(
           "SetLayerEffectParameter",
-          _("Effect parameter (number)"),
-          _("Change the value of a parameter of an effect.") + "\n" +
-              _("You can find the parameter names (and change the effect "
+          _("Effect property (number)"),
+          _("Change the value of a property of an effect.") + "\n" +
+              _("You can find the property names (and change the effect "
                 "names) in the effects window."),
           _("Set _PARAM3_ to _PARAM4_ for effect _PARAM2_ of layer _PARAM1_"),
           _("Effects"),
@@ -456,16 +456,16 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsCameraExtension(
       .AddParameter("layer", _("Layer"), "", true)
       .SetDefaultValue("\"\"")
       .AddParameter("layerEffectName", _("Effect name"))
-      .AddParameter("layerEffectParameterName", _("Parameter name"))
+      .AddParameter("layerEffectParameterName", _("Property name"))
       .AddParameter("expression", _("New value"))
       .MarkAsAdvanced();
 
   extension
       .AddAction(
           "SetLayerEffectStringParameter",
-          _("Effect parameter (string)"),
-          _("Change the value (string) of a parameter of an effect.") + "\n" +
-              _("You can find the parameter names (and change the effect "
+          _("Effect property (string)"),
+          _("Change the value (string) of a property of an effect.") + "\n" +
+              _("You can find the property names (and change the effect "
                 "names) in the effects window."),
           _("Set _PARAM3_ to _PARAM4_ for effect _PARAM2_ of layer _PARAM1_"),
           _("Effects"),
@@ -475,16 +475,16 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsCameraExtension(
       .AddParameter("layer", _("Layer"), "", true)
       .SetDefaultValue("\"\"")
       .AddParameter("layerEffectName", _("Effect name"))
-      .AddParameter("layerEffectParameterName", _("Parameter name"))
+      .AddParameter("layerEffectParameterName", _("Property name"))
       .AddParameter("string", _("New value"))
       .MarkAsAdvanced();
 
   extension
       .AddAction(
           "SetLayerEffectBooleanParameter",
-          _("Effect parameter (enable or disable)"),
-          _("Enable or disable a parameter of an effect.") + "\n" +
-              _("You can find the parameter names (and change the effect "
+          _("Effect property (enable or disable)"),
+          _("Enable or disable a property of an effect.") + "\n" +
+              _("You can find the property names (and change the effect "
                 "names) in the effects window."),
           _("Enable _PARAM3_ for effect _PARAM2_ of layer _PARAM1_: _PARAM4_"),
           _("Effects"),
@@ -494,8 +494,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsCameraExtension(
       .AddParameter("layer", _("Layer"), "", true)
       .SetDefaultValue("\"\"")
       .AddParameter("layerEffectName", _("Effect name"))
-      .AddParameter("layerEffectParameterName", _("Parameter name"))
-      .AddParameter("yesorno", _("Enable this parameter"))
+      .AddParameter("layerEffectParameterName", _("Property name"))
+      .AddParameter("yesorno", _("Enable this property"))
       .MarkAsAdvanced();
 
   extension

Core/GDCore/Extensions/Builtin/Capabilities/AnimatableExtension.cpp

@@ -59,7 +59,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsAnimatableExtension(
          "Name",
          _("Animation (by name)"),
          _("the animation played by the object using the name of the "
-           "animation."),
+           "animation"),
          _("the animation"),
          _("Animations and images"),
          "res/actions/animation24.png")
@@ -72,7 +72,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsAnimatableExtension(
 
   aut.AddScopedAction("PauseAnimation",
                 _("Pause the animation"),
-                _("Pause the animation of the object"),
+                _("Pause the animation of the object."),
                 _("Pause the animation of _PARAM0_"),
                 _("Animations and images"),
                 "res/actions/animation24.png",
@@ -83,7 +83,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsAnimatableExtension(
 
   aut.AddScopedAction("PlayAnimation",
                 _("Resume the animation"),
-                _("Resume the animation of the object"),
+                _("Resume the animation of the object."),
                 _("Resume the animation of _PARAM0_"),
                 _("Animations and images"),
                 "res/actions/animation24.png",

Core/GDCore/Extensions/Builtin/Capabilities/EffectExtension.cpp

@@ -52,9 +52,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
       .MarkAsSimple();
 
   aut.AddScopedAction("SetEffectDoubleParameter",
-                _("Effect parameter (number)"),
-                _("Change the value of a parameter of an effect.") + "\n" +
-                    _("You can find the parameter names (and change the effect "
+                _("Effect property (number)"),
+                _("Change the value of a property of an effect.") + "\n" +
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Set _PARAM3_ to _PARAM4_ for effect _PARAM2_ of _PARAM0_"),
                 _("Effects"),
@@ -63,15 +63,15 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "EffectBehavior")
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
       .AddParameter("expression", _("New value"))
       .MarkAsSimple();
 
   aut.AddScopedAction("SetEffectStringParameter",
-                _("Effect parameter (string)"),
-                _("Change the value (string) of a parameter of an effect.") +
+                _("Effect property (string)"),
+                _("Change the value (string) of a property of an effect.") +
                     "\n" +
-                    _("You can find the parameter names (and change the effect "
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Set _PARAM3_ to _PARAM4_ for effect _PARAM2_ of _PARAM0_"),
                 _("Effects"),
@@ -80,14 +80,14 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "EffectBehavior")
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
       .AddParameter("string", _("New value"))
       .MarkAsSimple();
 
   aut.AddScopedAction("SetEffectBooleanParameter",
-                _("Effect parameter (enable or disable)"),
-                _("Enable or disable a parameter of an effect.") + "\n" +
-                    _("You can find the parameter names (and change the effect "
+                _("Effect property (enable or disable)"),
+                _("Enable or disable a property of an effect.") + "\n" +
+                    _("You can find the property names (and change the effect "
                       "names) in the effects window."),
                 _("Enable _PARAM3_ for effect _PARAM2_ of _PARAM0_: _PARAM4_"),
                 _("Effects"),
@@ -96,8 +96,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "EffectBehavior")
       .AddParameter("objectEffectName", _("Effect name"))
-      .AddParameter("objectEffectParameterName", _("Parameter name"))
-      .AddParameter("yesorno", _("Enable?"))
+      .AddParameter("objectEffectParameterName", _("Property name"))
+      .AddParameter("yesorno", _("Enable this property"))
       .MarkAsSimple();
 
   aut.AddScopedCondition("IsEffectEnabled",

Core/GDCore/Extensions/Builtin/Capabilities/ResizableExtension.cpp

@@ -14,7 +14,7 @@ using namespace std;
 namespace gd {
 
 void GD_CORE_API BuiltinExtensionsImplementer::ImplementsResizableExtension(
-    gd::PlatformExtension& extension) {
+    gd::PlatformExtension &extension) {
   extension
       .SetExtensionInformation("ResizableCapability",
                                _("Resizable capability"),
@@ -22,84 +22,86 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsResizableExtension(
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Size"))
-      .SetIcon("res/actions/scale24_black.png");
+  extension.AddInstructionOrExpressionGroupMetadata(_("Size")).SetIcon(
+      "res/actions/scale24_black.png");
 
-  gd::BehaviorMetadata& aut = extension.AddBehavior(
-      "ResizableBehavior",
-      _("Resizable capability"),
-      "Resizable",
-      _("Change the object dimensions."),
-      "",
-      "res/actions/scale24_black.png",
-      "ResizableBehavior",
-      std::make_shared<gd::Behavior>(),
-      std::make_shared<gd::BehaviorsSharedData>())
-    .SetHidden();
+  gd::BehaviorMetadata &aut =
+      extension
+          .AddBehavior("ResizableBehavior",
+                       _("Resizable capability"),
+                       "Resizable",
+                       _("Change the object dimensions."),
+                       "",
+                       "res/actions/scale24_black.png",
+                       "ResizableBehavior",
+                       std::make_shared<gd::Behavior>(),
+                       std::make_shared<gd::BehaviorsSharedData>())
+          .SetHidden();
 
   aut.AddScopedAction("SetWidth",
-                _("Width"),
-                _("Change the width of the object."),
-                _("the width"),
-                _("Size"),
-                "res/actions/scaleWidth24_black.png",
-                "res/actions/scaleWidth_black.png")
+                      _("Width"),
+                      _("Change the width of the object."),
+                      _("the width"),
+                      _("Size"),
+                      "res/actions/scaleWidth24_black.png",
+                      "res/actions/scaleWidth_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ResizableBehavior")
-      .UseStandardOperatorParameters("number",
-                                     ParameterOptions::MakeNewOptions().SetDescription(
-                                        _("Width")))
+      .UseStandardOperatorParameters(
+          "number",
+          ParameterOptions::MakeNewOptions().SetDescription(_("Width")))
       .MarkAsAdvanced();
 
   aut.AddScopedCondition("Width",
-                   _("Width"),
-                   _("Compare the width of the object."),
-                   _("the width"),
-                   _("Size"),
-                   "res/conditions/scaleWidth24_black.png",
-                   "res/conditions/scaleWidth_black.png")
+                         _("Width"),
+                         _("Compare the width of the object."),
+                         _("the width"),
+                         _("Size"),
+                         "res/conditions/scaleWidth24_black.png",
+                         "res/conditions/scaleWidth_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ResizableBehavior")
       .UseStandardRelationalOperatorParameters(
-          "number", ParameterOptions::MakeNewOptions().SetDescription(
-                        _("Width")))
+          "number",
+          ParameterOptions::MakeNewOptions().SetDescription(_("Width")))
       .MarkAsAdvanced();
 
   aut.AddScopedAction("SetHeight",
-                _("Height"),
-                _("Change the height of the object."),
-                _("the height"),
-                _("Size"),
-                "res/actions/scaleHeight24_black.png",
-                "res/actions/scaleHeight_black.png")
+                      _("Height"),
+                      _("Change the height of the object."),
+                      _("the height"),
+                      _("Size"),
+                      "res/actions/scaleHeight24_black.png",
+                      "res/actions/scaleHeight_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ResizableBehavior")
-      .UseStandardOperatorParameters("number",
-                                     ParameterOptions::MakeNewOptions().SetDescription(
-                                        _("Height")))
+      .UseStandardOperatorParameters(
+          "number",
+          ParameterOptions::MakeNewOptions().SetDescription(_("Height")))
       .MarkAsAdvanced();
 
   aut.AddScopedCondition("Height",
-                   _("Height"),
-                   _("Compare the height of the object."),
-                   _("the height"),
-                   _("Size"),
-                   "res/conditions/scaleHeight24_black.png",
-                   "res/conditions/scaleHeight_black.png")
+                         _("Height"),
+                         _("Compare the height of the object."),
+                         _("the height"),
+                         _("Size"),
+                         "res/conditions/scaleHeight24_black.png",
+                         "res/conditions/scaleHeight_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ResizableBehavior")
       .UseStandardRelationalOperatorParameters(
-          "number", ParameterOptions::MakeNewOptions().SetDescription(
-                        _("Height")))
+          "number",
+          ParameterOptions::MakeNewOptions().SetDescription(_("Height")))
       .MarkAsAdvanced();
 
-  aut.AddScopedAction("SetSize",
-                _("Size"),
-                _("Change the size of an object."),
-                _("Change the size of _PARAM0_: set to _PARAM1_ x _PARAM2_"),
-                _("Size"),
-                "res/actions/scale24_black.png",
-                "res/actions/scale_black.png")
+  aut.AddScopedAction(
+         "SetSize",
+         _("Size"),
+         _("Change the size of an object."),
+         _("Change the size of _PARAM0_: set to _PARAM2_ x _PARAM3_"),
+         _("Size"),
+         "res/actions/scale24_black.png",
+         "res/actions/scale_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ResizableBehavior")
       .AddParameter("expression", _("Width"))

Core/GDCore/Extensions/Builtin/Capabilities/ScalableExtension.cpp

@@ -61,7 +61,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsScalableExtension(
          _("the scale on X axis of the object (default scale is 1)"),
          _("the scale on X axis"),
          _("Scale"),
-         "res/actions/scale24_black.png")
+         "res/actions/scaleWidth24_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ScalableBehavior")
       .UseStandardParameters(
@@ -77,7 +77,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsScalableExtension(
          _("the scale on Y axis of the object (default scale is 1)"),
          _("the scale on Y axis"),
          _("Scale"),
-         "res/actions/scale24_black.png")
+         "res/actions/scaleHeight24_black.png")
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "ScalableBehavior")
       .UseStandardParameters(

Core/GDCore/Extensions/Builtin/CommonInstructionsExtension.cpp

@@ -35,6 +35,8 @@ BuiltinExtensionsImplementer::ImplementsCommonInstructionsExtension(
       .AddInstructionOrExpressionGroupMetadata(_("Events and control flow"))
       .SetIcon("res/conditions/toujours24_black.png");
 
+  // This condition is deprecated as this does not bring anything new
+  // and can be confusing or misleading for beginners.
   extension
       .AddCondition("Always",
                     _("Always"),
@@ -46,7 +48,8 @@ BuiltinExtensionsImplementer::ImplementsCommonInstructionsExtension(
                     "res/conditions/toujours_black.png")
       .SetHelpPath("/all-features/advanced-conditions")
       .AddCodeOnlyParameter("conditionInverted", "")
-      .MarkAsAdvanced();
+      .MarkAsAdvanced()
+      .SetHidden();
 
   // Compatibility with GD <= 5.0.127
   extension
@@ -114,8 +117,9 @@ BuiltinExtensionsImplementer::ImplementsCommonInstructionsExtension(
 
   // Compatibility with GD <= 5.0.127
   extension
-      .AddDuplicatedCondition(
-          "Egal", "BuiltinCommonInstructions::CompareNumbers", {.unscoped = true})
+      .AddDuplicatedCondition("Egal",
+                              "BuiltinCommonInstructions::CompareNumbers",
+                              {.unscoped = true})
       .SetHidden();
   // end of compatibility code
 
@@ -135,8 +139,9 @@ BuiltinExtensionsImplementer::ImplementsCommonInstructionsExtension(
 
   // Compatibility with GD <= 5.0.127
   extension
-      .AddDuplicatedCondition(
-          "StrEqual", "BuiltinCommonInstructions::CompareStrings", {.unscoped = true})
+      .AddDuplicatedCondition("StrEqual",
+                              "BuiltinCommonInstructions::CompareStrings",
+                              {.unscoped = true})
       .SetHidden();
   // end of compatibility code
 

Core/GDCore/Extensions/Metadata/MetadataProvider.cpp

@@ -14,6 +14,7 @@
 #include "GDCore/Extensions/Platform.h"
 #include "GDCore/Extensions/PlatformExtension.h"
 #include "GDCore/Project/Layout.h"  // For GetTypeOfObject and GetTypeOfBehavior
+#include "GDCore/Project/ObjectsContainersList.h"
 #include "GDCore/String.h"
 #include "GDCore/Events/Parsers/ExpressionParser2.h"
 
@@ -391,20 +392,19 @@ MetadataProvider::GetBehaviorAnyExpressionMetadata(const gd::Platform& platform,
 }
 
 const gd::ExpressionMetadata& MetadataProvider::GetFunctionCallMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& node) {
 
   if (!node.behaviorName.empty()) {
-    gd::String behaviorType = 
-        GetTypeOfBehavior(globalObjectsContainer, objectsContainer, node.behaviorName);
+    gd::String behaviorType =
+        objectsContainersList.GetTypeOfBehavior(node.behaviorName);
     return MetadataProvider::GetBehaviorAnyExpressionMetadata(
             platform, behaviorType, node.functionName);
   }
   else if (!node.objectName.empty()) {
-    gd::String objectType = 
-        GetTypeOfObject(globalObjectsContainer, objectsContainer, node.objectName);
+    gd::String objectType =
+        objectsContainersList.GetTypeOfObject(node.objectName);
     return MetadataProvider::GetObjectAnyExpressionMetadata(
                   platform, objectType, node.functionName);
   }
@@ -412,10 +412,9 @@ const gd::ExpressionMetadata& MetadataProvider::GetFunctionCallMetadata(
   return MetadataProvider::GetAnyExpressionMetadata(platform, node.functionName);
 }
 
-  const gd::ParameterMetadata* MetadataProvider::GetFunctionCallParameterMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+const gd::ParameterMetadata* MetadataProvider::GetFunctionCallParameterMetadata(
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& functionCall,
     ExpressionNode& parameter) {
       int parameterIndex = -1;
@@ -429,17 +428,15 @@ const gd::ExpressionMetadata& MetadataProvider::GetFunctionCallMetadata(
         return nullptr;
       }
       return MetadataProvider::GetFunctionCallParameterMetadata(
-          platform, 
-          globalObjectsContainer,
-          objectsContainer,
+          platform,
+          objectsContainersList,
           functionCall,
           parameterIndex);
 }
 
-  const gd::ParameterMetadata* MetadataProvider::GetFunctionCallParameterMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+const gd::ParameterMetadata* MetadataProvider::GetFunctionCallParameterMetadata(
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& functionCall,
     int parameterIndex) {
       // Search the parameter metadata index skipping invisible ones.
@@ -448,7 +445,7 @@ const gd::ExpressionMetadata& MetadataProvider::GetFunctionCallMetadata(
           ExpressionParser2::WrittenParametersFirstIndex(
               functionCall.objectName, functionCall.behaviorName);
       const gd::ExpressionMetadata &metadata = MetadataProvider::GetFunctionCallMetadata(
-          platform, globalObjectsContainer, objectsContainer, functionCall);
+          platform, objectsContainersList, functionCall);
 
       if (IsBadExpressionMetadata(metadata)) {
         return nullptr;

Core/GDCore/Extensions/Metadata/MetadataProvider.h

@@ -15,6 +15,7 @@ class ExpressionMetadata;
 class ExpressionMetadata;
 class Platform;
 class PlatformExtension;
+class ObjectsContainersList;
 struct FunctionCallNode;
 struct ExpressionNode;
 }  // namespace gd
@@ -237,22 +238,19 @@ class GD_CORE_API MetadataProvider {
       const gd::Platform& platform, gd::String objectType, gd::String exprType);
 
   static const gd::ExpressionMetadata& GetFunctionCallMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& node);
 
   static const gd::ParameterMetadata* GetFunctionCallParameterMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& functionCall,
     ExpressionNode& parameter);
 
   static const gd::ParameterMetadata* GetFunctionCallParameterMetadata(
-    const gd::Platform& platform, 
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer,
+    const gd::Platform& platform,
+    const gd::ObjectsContainersList &objectsContainersList,
     FunctionCallNode& functionCall,
     int parameterIndex);
 

Core/GDCore/Extensions/Metadata/ParameterMetadata.h

@@ -34,6 +34,11 @@ class GD_CORE_API ParameterMetadata {
    */
   gd::ValueTypeMetadata &GetValueTypeMetadata() { return valueTypeMetadata; }
 
+  /**
+   * \brief Return the metadata of the parameter type.
+   */
+  const gd::ValueTypeMetadata &GetValueTypeMetadata() const { return valueTypeMetadata; }
+
   /**
    * \brief Set the metadata of the parameter type.
    */

Core/GDCore/Extensions/Metadata/ParameterMetadataTools.cpp

@@ -8,6 +8,7 @@
 #include "GDCore/Events/Expression.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/ObjectsContainer.h"
+#include "GDCore/Project/ObjectsContainersList.h"
 #include "GDCore/Project/Project.h"
 #include "GDCore/String.h"
 #include "InstructionMetadata.h"
@@ -15,6 +16,8 @@
 #include "GDCore/Events/Parsers/ExpressionParser2NodePrinter.h"
 
 namespace gd {
+const ParameterMetadata ParameterMetadataTools::badParameterMetadata;
+
 void ParameterMetadataTools::ParametersToObjectsContainer(
     const gd::Project& project,
     const std::vector<gd::ParameterMetadata>& parameters,
@@ -57,6 +60,55 @@ void ParameterMetadataTools::ParametersToObjectsContainer(
   }
 }
 
+void ParameterMetadataTools::ForEachParameterWithPrefix(
+    const std::vector<const std::vector<gd::ParameterMetadata>*>&
+        parametersVectorsList,
+    const gd::String& prefix,
+    std::function<void(const gd::ParameterMetadata&)> cb) {
+  for (auto it = parametersVectorsList.rbegin();
+       it != parametersVectorsList.rend();
+       ++it) {
+    const std::vector<gd::ParameterMetadata>* parametersVector = *it;
+
+    for (const auto& parameterMetadata: *parametersVector) {
+      if (parameterMetadata.GetName().find(prefix) == 0) cb(parameterMetadata);
+    }
+  }
+}
+
+bool ParameterMetadataTools::Has(
+      const std::vector<const std::vector<gd::ParameterMetadata>*>& parametersVectorsList,
+      const gd::String& parameterName) {
+  for (auto it = parametersVectorsList.rbegin();
+       it != parametersVectorsList.rend();
+       ++it) {
+    const std::vector<gd::ParameterMetadata>* parametersVector = *it;
+
+    for (const auto& parameterMetadata: *parametersVector) {
+      if (parameterMetadata.GetName() == parameterName) return true;
+    }
+  }
+
+  return false;
+}
+
+const gd::ParameterMetadata& ParameterMetadataTools::Get(
+    const std::vector<const std::vector<gd::ParameterMetadata>*>&
+        parametersVectorsList,
+    const gd::String& parameterName) {
+  for (auto it = parametersVectorsList.rbegin();
+       it != parametersVectorsList.rend();
+       ++it) {
+    const std::vector<gd::ParameterMetadata>* parametersVector = *it;
+
+    for (const auto& parameterMetadata: *parametersVector) {
+      if (parameterMetadata.GetName() == parameterName) return parameterMetadata;
+    }
+  }
+
+  return badParameterMetadata;
+}
+
 void ParameterMetadataTools::IterateOverParameters(
     const std::vector<gd::Expression>& parameters,
     const std::vector<gd::ParameterMetadata>& parametersMetadata,
@@ -105,8 +157,7 @@ void ParameterMetadataTools::IterateOverParametersWithIndex(
 
 void ParameterMetadataTools::IterateOverParametersWithIndex(
     const gd::Platform &platform,
-    const gd::ObjectsContainer &globalObjectsContainer,
-    const gd::ObjectsContainer &objectsContainer, FunctionCallNode &node,
+    const gd::ObjectsContainersList &objectsContainersList, FunctionCallNode &node,
     std::function<void(const gd::ParameterMetadata &parameterMetadata,
                        std::unique_ptr<gd::ExpressionNode> &parameterNode,
                        size_t parameterIndex, const gd::String &lastObjectName)>
@@ -117,8 +168,7 @@ void ParameterMetadataTools::IterateOverParametersWithIndex(
   const gd::ExpressionMetadata &metadata =
       isObjectFunction ? MetadataProvider::GetObjectAnyExpressionMetadata(
                              platform,
-                             GetTypeOfObject(globalObjectsContainer,
-                                             objectsContainer, node.objectName),
+                             objectsContainersList.GetTypeOfObject(node.objectName),
                              node.functionName)
                        : MetadataProvider::GetAnyExpressionMetadata(
                              platform, node.functionName);

Core/GDCore/Extensions/Metadata/ParameterMetadataTools.h

@@ -3,9 +3,8 @@
  * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
  * reserved. This project is released under the MIT License.
  */
-#if defined(GD_IDE_ONLY)
-#ifndef ParameterMetadataTools_H
-#define ParameterMetadataTools_H
+#pragma once
+#include <functional>
 #include <vector>
 #include <memory>
 #include "GDCore/String.h"
@@ -13,6 +12,7 @@ namespace gd {
 class Platform;
 class Project;
 class ObjectsContainer;
+class ObjectsContainersList;
 class ParameterMetadata;
 class Expression;
 struct FunctionCallNode;
@@ -27,6 +27,19 @@ class GD_CORE_API ParameterMetadataTools {
       const std::vector<gd::ParameterMetadata>& parameters,
       gd::ObjectsContainer& outputObjectsContainer);
 
+  static void ForEachParameterWithPrefix(
+      const std::vector<const std::vector<gd::ParameterMetadata>*>& parametersVectorsList,
+      const gd::String& prefix,
+      std::function<void(const gd::ParameterMetadata&)> cb);
+
+  static bool Has(
+      const std::vector<const std::vector<gd::ParameterMetadata>*>& parametersVectorsList,
+      const gd::String& parameterName);
+
+  static const gd::ParameterMetadata& Get(
+      const std::vector<const std::vector<gd::ParameterMetadata>*>& parametersVectorsList,
+      const gd::String& parameterName);
+
   /**
    * Iterate over a list of parameters and their values.
    * Callback function is called with the parameter metadata, its value
@@ -59,8 +72,7 @@ class GD_CORE_API ParameterMetadataTools {
    */
   static void IterateOverParametersWithIndex(
       const gd::Platform &platform,
-      const gd::ObjectsContainer &globalObjectsContainer,
-      const gd::ObjectsContainer &objectsContainer, FunctionCallNode &node,
+      const gd::ObjectsContainersList &objectsContainersList, FunctionCallNode &node,
       std::function<void(const gd::ParameterMetadata &parameterMetadata,
                          std::unique_ptr<gd::ExpressionNode> &parameterNode,
                          size_t parameterIndex,
@@ -74,8 +86,8 @@ class GD_CORE_API ParameterMetadataTools {
   static size_t GetObjectParameterIndexFor(
       const std::vector<gd::ParameterMetadata>& parametersMetadata,
       size_t parameterIndex);
+
+private:
+  static const gd::ParameterMetadata badParameterMetadata;
 };
 }  // namespace gd
-
-#endif  // ParameterMetadataTools_H
-#endif

Core/GDCore/Extensions/Metadata/ValueTypeMetadata.h

@@ -121,6 +121,13 @@ class GD_CORE_API ValueTypeMetadata {
     return gd::ValueTypeMetadata::IsTypeExpression("string", name);
   }
 
+  /**
+   * \brief Return true if the type is a boolean.
+   */
+  bool IsBoolean() const {
+    return gd::ValueTypeMetadata::IsTypeExpression("boolean", name);
+  }
+
   /**
    * \brief Return true if the type of the parameter is a number.
    * \note If you had a new type of parameter, also add it in the IDE (
@@ -131,6 +138,24 @@ class GD_CORE_API ValueTypeMetadata {
     return gd::ValueTypeMetadata::IsTypeExpression("variable", name);
   }
 
+  /**
+   * \brief Return true if the type is a variable but from a specific scope
+   * (scene, project or object). In new code, prefer to use the more generic "variable"
+   * parameter (which accepts any variable coming from an object or from containers in the scope).
+   */
+  bool IsLegacyPreScopedVariable() const {
+    return gd::ValueTypeMetadata::IsTypeLegacyPreScopedVariable(name);
+  }
+
+  /**
+   * \brief Return true if the type is a variable but from a specific scope
+   * (scene, project or object). In new code, prefer to use the more generic "variable"
+   * parameter (which accepts any variable coming from an object or from containers in the scope).
+   */
+  static bool IsTypeLegacyPreScopedVariable(const gd::String &type) {
+    return type == "scenevar" || type == "globalvar" || type == "objectvar";
+  }
+
   /**
    * \brief Return true if the type is representing one object
    * (or more, i.e: an object group).
@@ -175,8 +200,13 @@ class GD_CORE_API ValueTypeMetadata {
              parameterType == "externalLayoutName" ||
              parameterType == "leaderboardId" ||
              parameterType == "identifier";
+    } else if (type == "boolean") {
+      return parameterType == "yesorno" || parameterType == "trueorfalse";
     } else if (type == "variable") {
-      return parameterType == "objectvar" || parameterType == "globalvar" ||
+      return
+             parameterType == "variable" || // Any variable.
+             // Old, "pre-scoped" variables:
+             parameterType == "objectvar" || parameterType == "globalvar" ||
              parameterType == "scenevar";
     } else if (type == "resource") {
       return parameterType == "fontResource" ||
@@ -196,7 +226,7 @@ class GD_CORE_API ValueTypeMetadata {
    * \brief Return the expression type from the parameter type.
    * Declinations of "number" and "string" types (like "forceMultiplier" or
    * "sceneName") are replaced by "number" and "string".
-   * 
+   *
    * \note It only maps string and number types.
    */
   static const gd::String &GetExpressionPrimitiveValueType(const gd::String &parameterType);
@@ -205,7 +235,7 @@ class GD_CORE_API ValueTypeMetadata {
    * \brief Return the primitive type from the parameter type.
    * Declinations of "number" and "string" types (like "forceMultiplier" or
    * "sceneName") are replaced by "number" and "string".
-   * 
+   *
    * \note It also maps variable and boolean types.
    */
   static const gd::String &GetPrimitiveValueType(const gd::String &parameterType);

Core/GDCore/IDE/Events/ArbitraryEventsWorker.cpp

@@ -11,6 +11,8 @@
 #include "GDCore/Events/Event.h"
 #include "GDCore/Events/EventsList.h"
 #include "GDCore/Events/Instruction.h"
+#include "GDCore/Events/Expression.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadata.h"
 #include "GDCore/String.h"
 
 using namespace std;
@@ -47,7 +49,14 @@ bool ArbitraryEventsWorker::VisitEvent(gd::BaseEvent& event) {
   for (std::size_t j = 0; j < actionsVectors.size(); ++j)
     VisitInstructionList(*actionsVectors[j], false);
 
-  return false;
+  auto allExpressionsWithMetadata = event.GetAllExpressionsWithMetadata();
+  for (auto& expressionAndMetadata : allExpressionsWithMetadata) {
+    shouldDelete |= VisitEventExpression(
+      *expressionAndMetadata.first, expressionAndMetadata.second);
+  }
+
+
+  return shouldDelete;
 }
 
 bool ArbitraryEventsWorker::VisitLinkEvent(gd::LinkEvent& linkEvent) {
@@ -75,6 +84,11 @@ bool ArbitraryEventsWorker::VisitInstruction(gd::Instruction& instruction,
   return DoVisitInstruction(instruction, isCondition);
 }
 
+bool ArbitraryEventsWorker::VisitEventExpression(gd::Expression& expression,
+                                                 const gd::ParameterMetadata& metadata) {
+  return DoVisitEventExpression(expression, metadata);
+}
+
 ArbitraryEventsWorkerWithContext::~ArbitraryEventsWorkerWithContext() {}
 
 
@@ -141,6 +155,12 @@ void ReadOnlyArbitraryEventsWorker::VisitInstruction(const gd::Instruction& inst
   DoVisitInstruction(instruction, isCondition);
 }
 
+
+void ReadOnlyArbitraryEventsWorker::VisitEventExpression(const gd::Expression& expression,
+                                                 const gd::ParameterMetadata& metadata) {
+  DoVisitEventExpression(expression, metadata);
+}
+
 void ReadOnlyArbitraryEventsWorker::StopAnyEventIteration() {
   shouldStopIteration = true;
 }

Core/GDCore/IDE/Events/ArbitraryEventsWorker.h

@@ -10,6 +10,7 @@
 #include <vector>
 #include "GDCore/Events/InstructionsList.h"
 #include "GDCore/Events/EventVisitor.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/String.h"
 namespace gd {
 class Instruction;
@@ -17,6 +18,8 @@ class BaseEvent;
 class LinkEvent;
 class EventsList;
 class ObjectsContainer;
+class Expression;
+class ParameterMetadata;
 }  // namespace gd
 
 namespace gd {
@@ -47,6 +50,7 @@ class GD_CORE_API ArbitraryEventsWorker : private EventVisitor {
   void VisitInstructionList(gd::InstructionsList& instructions,
                             bool areConditions);
   bool VisitInstruction(gd::Instruction& instruction, bool isCondition);
+  bool VisitEventExpression(gd::Expression& expression, const gd::ParameterMetadata& metadata);
 
   /**
    * Called to do some work on an event list.
@@ -62,9 +66,9 @@ class GD_CORE_API ArbitraryEventsWorker : private EventVisitor {
 
   /**
    * Called to do some work on a link event.
-   * 
+   *
    * Note that DoVisitEvent is also called with this event.
-   * 
+   *
    * \return true if the event must be deleted from the events list, false
    * otherwise (default).
    */
@@ -85,6 +89,16 @@ class GD_CORE_API ArbitraryEventsWorker : private EventVisitor {
                                   bool isCondition) {
     return false;
   };
+
+  /**
+   * Called to do some work on an expression of an event.
+   * \return true if the event must be deleted from the list, false
+   * otherwise (default).
+   */
+  virtual bool DoVisitEventExpression(gd::Expression& expression,
+                                      const gd::ParameterMetadata& metadata) {
+    return false;
+  }
 };
 
 /**
@@ -99,8 +113,7 @@ class GD_CORE_API ArbitraryEventsWorkerWithContext
     : public ArbitraryEventsWorker {
  public:
   ArbitraryEventsWorkerWithContext()
-      : currentGlobalObjectsContainer(nullptr),
-        currentObjectsContainer(nullptr){};
+      : projectScopedContainers(nullptr){};
   virtual ~ArbitraryEventsWorkerWithContext();
 
   /**
@@ -108,30 +121,27 @@ class GD_CORE_API ArbitraryEventsWorkerWithContext
    * giving the objects container on which the events are applying to.
    */
   void Launch(gd::EventsList& events,
-              const gd::ObjectsContainer& globalObjectsContainer_,
-              const gd::ObjectsContainer& objectsContainer_) {
-    currentGlobalObjectsContainer = &globalObjectsContainer_;
-    currentObjectsContainer = &objectsContainer_;
+              const gd::ProjectScopedContainers& projectScopedContainers_) {
+    projectScopedContainers = &projectScopedContainers_;
     ArbitraryEventsWorker::Launch(events);
   };
 
   void Launch(gd::EventsList& events) = delete;
 
  protected:
-  const gd::ObjectsContainer& GetGlobalObjectsContainer() {
+  const gd::ProjectScopedContainers& GetProjectScopedContainers() {
     // Pointers are guaranteed to be not nullptr after
     // Launch was called.
-    return *currentGlobalObjectsContainer;
+    return *projectScopedContainers;
   };
-  const gd::ObjectsContainer& GetObjectsContainer() {
+  const gd::ObjectsContainersList& GetObjectsContainersList() {
     // Pointers are guaranteed to be not nullptr after
     // Launch was called.
-    return *currentObjectsContainer;
+    return projectScopedContainers->GetObjectsContainersList();
   };
 
  private:
-  const gd::ObjectsContainer* currentGlobalObjectsContainer;
-  const gd::ObjectsContainer* currentObjectsContainer;
+  const gd::ProjectScopedContainers* projectScopedContainers;
 };
 
 /**
@@ -162,6 +172,7 @@ protected:
   void VisitInstructionList(const gd::InstructionsList& instructions,
                             bool areConditions);
   void VisitInstruction(const gd::Instruction& instruction, bool isCondition);
+  void VisitEventExpression(const gd::Expression& expression, const gd::ParameterMetadata& metadata);
 
   /**
    * Called to do some work on an event list.
@@ -175,7 +186,7 @@ protected:
 
   /**
    * Called to do some work on a link event.
-   * 
+   *
    * Note that DoVisitEvent is also called with this event.
    */
   virtual void DoVisitLinkEvent(const gd::LinkEvent& linkEvent) {};
@@ -192,6 +203,13 @@ protected:
   virtual void DoVisitInstruction(const gd::Instruction& instruction,
                                   bool isCondition) {};
 
+  /**
+   * Called to do some work on an expression of an event.
+   */
+  virtual void DoVisitEventExpression(const gd::Expression& expression,
+                                      const gd::ParameterMetadata& metadata) {
+  }
+
   bool shouldStopIteration;
 };
 
@@ -207,8 +225,7 @@ class GD_CORE_API ReadOnlyArbitraryEventsWorkerWithContext
     : public ReadOnlyArbitraryEventsWorker {
  public:
   ReadOnlyArbitraryEventsWorkerWithContext()
-      : currentGlobalObjectsContainer(nullptr),
-        currentObjectsContainer(nullptr){};
+      : projectScopedContainers(nullptr){};
   virtual ~ReadOnlyArbitraryEventsWorkerWithContext();
 
   /**
@@ -216,30 +233,22 @@ class GD_CORE_API ReadOnlyArbitraryEventsWorkerWithContext
    * giving the objects container on which the events are applying to.
    */
   void Launch(const gd::EventsList& events,
-              const gd::ObjectsContainer& globalObjectsContainer_,
-              const gd::ObjectsContainer& objectsContainer_) {
-    currentGlobalObjectsContainer = &globalObjectsContainer_;
-    currentObjectsContainer = &objectsContainer_;
+              const gd::ProjectScopedContainers& projectScopedContainers_) {
+    projectScopedContainers = &projectScopedContainers_;
     ReadOnlyArbitraryEventsWorker::Launch(events);
   };
 
   void Launch(gd::EventsList& events) = delete;
 
  protected:
-  const gd::ObjectsContainer& GetGlobalObjectsContainer() {
+  const gd::ProjectScopedContainers& GetProjectScopedContainers() {
     // Pointers are guaranteed to be not nullptr after
     // Launch was called.
-    return *currentGlobalObjectsContainer;
-  };
-  const gd::ObjectsContainer& GetObjectsContainer() {
-    // Pointers are guaranteed to be not nullptr after
-    // Launch was called.
-    return *currentObjectsContainer;
+    return *projectScopedContainers;
   };
 
  private:
-  const gd::ObjectsContainer* currentGlobalObjectsContainer;
-  const gd::ObjectsContainer* currentObjectsContainer;
+  const gd::ProjectScopedContainers* projectScopedContainers;
 };
 
 }  // namespace gd

Core/GDCore/IDE/Events/BehaviorTypeRenamer.cpp

@@ -4,7 +4,6 @@
 #include "GDCore/Extensions/Metadata/MetadataProvider.h"
 #include "GDCore/Extensions/PlatformExtension.h"
 #include "GDCore/IDE/WholeProjectRefactorer.h"
-#include "GDCore/IDE/Events/ExpressionTypeFinder.h"
 #include "GDCore/Project/Behavior.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/Project.h"

Core/GDCore/IDE/Events/CustomObjectTypeRenamer.cpp

@@ -4,7 +4,6 @@
 #include "GDCore/Extensions/Metadata/MetadataProvider.h"
 #include "GDCore/Extensions/PlatformExtension.h"
 #include "GDCore/IDE/WholeProjectRefactorer.h"
-#include "GDCore/IDE/Events/ExpressionTypeFinder.h"
 #include "GDCore/Project/Behavior.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/Project.h"

Core/GDCore/IDE/Events/EventsBehaviorRenamer.cpp

@@ -31,14 +31,10 @@ namespace gd {
 class GD_CORE_API ExpressionBehaviorRenamer
     : public ExpressionParser2NodeWorker {
  public:
-  ExpressionBehaviorRenamer(const gd::ObjectsContainer& globalObjectsContainer_,
-                            const gd::ObjectsContainer& objectsContainer_,
-                            const gd::String& objectName_,
+  ExpressionBehaviorRenamer(const gd::String& objectName_,
                             const gd::String& oldBehaviorName_,
                             const gd::String& newBehaviorName_)
       : hasDoneRenaming(false),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
         objectName(objectName_),
         oldBehaviorName(oldBehaviorName_),
         newBehaviorName(newBehaviorName_){};
@@ -97,8 +93,6 @@ class GD_CORE_API ExpressionBehaviorRenamer
 
  private:
   bool hasDoneRenaming;
-  const gd::ObjectsContainer& globalObjectsContainer;
-  const gd::ObjectsContainer& objectsContainer;
   const gd::String& objectName;  // The object name for which the behavior
                                  // must be replaced.
   const gd::String& oldBehaviorName;
@@ -132,9 +126,7 @@ bool EventsBehaviorRenamer::DoVisitInstruction(gd::Instruction& instruction,
         } else {
           auto node = parameterValue.GetRootNode();
           if (node) {
-            ExpressionBehaviorRenamer renamer(GetGlobalObjectsContainer(),
-                                              GetObjectsContainer(),
-                                              objectName,
+            ExpressionBehaviorRenamer renamer(objectName,
                                               oldBehaviorName,
                                               newBehaviorName);
             node->Visit(renamer);

Core/GDCore/IDE/Events/EventsContextAnalyzer.cpp

@@ -19,6 +19,8 @@
 #include "GDCore/IDE/Events/ExpressionTypeFinder.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ObjectsContainersList.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/String.h"
 
 namespace gd {
@@ -33,13 +35,11 @@ class GD_CORE_API ExpressionObjectsAnalyzer
  public:
   ExpressionObjectsAnalyzer(
         const gd::Platform &platform_,
-        const gd::ObjectsContainer &globalObjectsContainer_,
-        const gd::ObjectsContainer &objectsContainer_,
+        const gd::ProjectScopedContainers &projectScopedContainers_,
         const gd::String &rootType_,
         EventsContext& context_) :
         platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         rootType(rootType_),
         context(context_){};
   virtual ~ExpressionObjectsAnalyzer(){};
@@ -58,6 +58,25 @@ class GD_CORE_API ExpressionObjectsAnalyzer
   void OnVisitNumberNode(NumberNode& node) override {}
   void OnVisitTextNode(TextNode& node) override {}
   void OnVisitVariableNode(VariableNode& node) override {
+    auto type = gd::ExpressionTypeFinder::GetType(platform, projectScopedContainers.GetObjectsContainersList(), rootType, node);
+
+    if (gd::ParameterMetadata::IsExpression("variable", type)) {
+      // Nothing to do (this can't reference an object)
+    } else {
+      projectScopedContainers.MatchIdentifierWithName<void>(node.name, [&]() {
+          // This is an object variable.
+          context.AddObjectName(projectScopedContainers, node.name);
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
+    }
+
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
@@ -69,26 +88,41 @@ class GD_CORE_API ExpressionObjectsAnalyzer
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitIdentifierNode(IdentifierNode& node) override {
-    auto type = gd::ExpressionTypeFinder::GetType(platform, globalObjectsContainer, objectsContainer, rootType, node);
+    auto type = gd::ExpressionTypeFinder::GetType(platform, projectScopedContainers.GetObjectsContainersList(), rootType, node);
     if (gd::ParameterMetadata::IsObject(type)) {
-      context.AddObjectName(node.identifierName);
+      context.AddObjectName(projectScopedContainers, node.identifierName);
+    } else if (gd::ParameterMetadata::IsExpression("variable", type)) {
+      // Nothing to do (identifier is a variable but not an object).
+    } else {
+      projectScopedContainers.MatchIdentifierWithName<void>(node.identifierName, [&]() {
+          // This is an object variable.
+          context.AddObjectName(projectScopedContainers, node.identifierName);
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
     }
   }
   void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {
     if (!node.objectName.empty()) {
-      context.AddObjectName(node.objectName);
+      context.AddObjectName(projectScopedContainers, node.objectName);
 
       if (!node.behaviorFunctionName.empty()) {
-        context.AddBehaviorName(node.objectName, node.objectFunctionOrBehaviorName);
+        context.AddBehaviorName(projectScopedContainers, node.objectName, node.objectFunctionOrBehaviorName);
       }
     }
   }
   void OnVisitFunctionCallNode(FunctionCallNode& node) override {
     if (!node.objectName.empty()) {
-      context.AddObjectName(node.objectName);
+      context.AddObjectName(projectScopedContainers, node.objectName);
 
       if (!node.behaviorName.empty()) {
-        context.AddBehaviorName(node.objectName, node.behaviorName);
+        context.AddBehaviorName(projectScopedContainers, node.objectName, node.behaviorName);
       }
     }
     for (auto& parameter : node.parameters) {
@@ -99,8 +133,7 @@ class GD_CORE_API ExpressionObjectsAnalyzer
 
  private:
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
   const gd::String rootType;
 
   EventsContext& context;
@@ -121,8 +154,7 @@ bool EventsContextAnalyzer::DoVisitInstruction(gd::Instruction& instruction,
              const gd::Expression& parameterValue,
              const gd::String& lastObjectName) {
         AnalyzeParameter(platform,
-                         project,
-                         layout,
+                         GetProjectScopedContainers(),
                          parameterMetadata,
                          parameterValue,
                          context,
@@ -134,8 +166,7 @@ bool EventsContextAnalyzer::DoVisitInstruction(gd::Instruction& instruction,
 
 void EventsContextAnalyzer::AnalyzeParameter(
     const gd::Platform& platform,
-    const gd::ObjectsContainer& project,
-    const gd::ObjectsContainer& layout,
+    const gd::ProjectScopedContainers& projectScopedContainers,
     const gd::ParameterMetadata& metadata,
     const gd::Expression& parameter,
     EventsContext& context,
@@ -143,59 +174,39 @@ void EventsContextAnalyzer::AnalyzeParameter(
   const auto& value = parameter.GetPlainString();
   const auto& type = metadata.GetType();
   if (ParameterMetadata::IsObject(type)) {
-    context.AddObjectName(value);
+    context.AddObjectName(projectScopedContainers, value);
   } else if (ParameterMetadata::IsExpression("number", type)) {
     auto node = parameter.GetRootNode();
 
-    ExpressionObjectsAnalyzer analyzer(platform, project, layout, "number", context);
+    ExpressionObjectsAnalyzer analyzer(platform, projectScopedContainers, "number", context);
     node->Visit(analyzer);
   } else if (ParameterMetadata::IsExpression("string", type)) {
     auto node = parameter.GetRootNode();
 
-    ExpressionObjectsAnalyzer analyzer(platform, project, layout, "string", context);
+    ExpressionObjectsAnalyzer analyzer(platform, projectScopedContainers, "string", context);
     node->Visit(analyzer);
   } else if (ParameterMetadata::IsBehavior(type)) {
-    context.AddBehaviorName(lastObjectName, value);
+    context.AddBehaviorName(projectScopedContainers, lastObjectName, value);
   }
 }
 
-void EventsContext::AddObjectName(const gd::String& objectOrGroupName) {
-  for (auto& realObjectName : ExpandObjectsName(objectOrGroupName)) {
+void EventsContext::AddObjectName(const gd::ProjectScopedContainers& projectScopedContainers,
+                                  const gd::String& objectOrGroupName) {
+  auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+  for (auto& realObjectName : objectsContainersList.ExpandObjectName(objectOrGroupName)) {
     objectNames.insert(realObjectName);
   }
   referencedObjectOrGroupNames.insert(objectOrGroupName);
 }
 
-void EventsContext::AddBehaviorName(const gd::String& objectOrGroupName,
+void EventsContext::AddBehaviorName(const gd::ProjectScopedContainers& projectScopedContainers,
+                                    const gd::String& objectOrGroupName,
                                     const gd::String& behaviorName) {
-  for (auto& realObjectName : ExpandObjectsName(objectOrGroupName)) {
+                                      auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+  for (auto& realObjectName : objectsContainersList.ExpandObjectName(objectOrGroupName)) {
     objectOrGroupBehaviorNames[realObjectName].insert(behaviorName);
   }
   objectOrGroupBehaviorNames[objectOrGroupName].insert(behaviorName);
 }
 
-std::vector<gd::String> EventsContext::ExpandObjectsName(
-    const gd::String& objectName) {
-  // Note: this logic is duplicated in EventsCodeGenerator::ExpandObjectsName
-  std::vector<gd::String> realObjects;
-  if (project.GetObjectGroups().Has(objectName))
-    realObjects =
-        project.GetObjectGroups().Get(objectName).GetAllObjectsNames();
-  else if (layout.GetObjectGroups().Has(objectName))
-    realObjects = layout.GetObjectGroups().Get(objectName).GetAllObjectsNames();
-  else
-    realObjects.push_back(objectName);
-
-  // Ensure that all returned objects actually exists.
-  for (std::size_t i = 0; i < realObjects.size();) {
-    if (!layout.HasObjectNamed(realObjects[i]) &&
-        !project.HasObjectNamed(realObjects[i]))
-      realObjects.erase(realObjects.begin() + i);
-    else
-      ++i;
-  }
-
-  return realObjects;
-}
-
 }  // namespace gd

Core/GDCore/IDE/Events/EventsContextAnalyzer.h

@@ -15,6 +15,7 @@ namespace gd {
 class BaseEvent;
 class Platform;
 class ObjectsContainer;
+class ObjectsContainersList;
 class Project;
 class Layout;
 class EventsList;
@@ -29,12 +30,13 @@ namespace gd {
  */
 class GD_CORE_API EventsContext {
  public:
-  EventsContext(gd::ObjectsContainer& project_, gd::ObjectsContainer& layout_)
-      : project(project_), layout(layout_){};
+  EventsContext(){};
   virtual ~EventsContext(){};
 
-  void AddObjectName(const gd::String& objectOrGroupName);
-  void AddBehaviorName(const gd::String& objectOrGroupName,
+  void AddObjectName(const gd::ProjectScopedContainers& projectScopedContainers,
+                     const gd::String& objectOrGroupName);
+  void AddBehaviorName(const gd::ProjectScopedContainers& projectScopedContainers,
+                       const gd::String& objectOrGroupName,
                        const gd::String& behaviorName);
 
   /**
@@ -59,13 +61,9 @@ class GD_CORE_API EventsContext {
   }
 
  private:
-  std::vector<gd::String> ExpandObjectsName(const gd::String& objectOrGroupName);
-
   std::set<gd::String> referencedObjectOrGroupNames;
   std::set<gd::String> objectNames;
   std::map<gd::String, std::set<gd::String>> objectOrGroupBehaviorNames;
-  gd::ObjectsContainer& project;
-  gd::ObjectsContainer& layout;
 };
 
 /**
@@ -73,15 +71,10 @@ class GD_CORE_API EventsContext {
  *
  * \ingroup IDE
  */
-class GD_CORE_API EventsContextAnalyzer : public ArbitraryEventsWorker {
+class GD_CORE_API EventsContextAnalyzer : public ArbitraryEventsWorkerWithContext {
  public:
-  EventsContextAnalyzer(const gd::Platform& platform_,
-                        gd::ObjectsContainer& project_,
-                        gd::ObjectsContainer& layout_)
-      : platform(platform_),
-        project(project_),
-        layout(layout_),
-        context(project, layout){};
+  EventsContextAnalyzer(const gd::Platform& platform_)
+      : platform(platform_) {};
   virtual ~EventsContextAnalyzer(){};
 
   /**
@@ -90,8 +83,7 @@ class GD_CORE_API EventsContextAnalyzer : public ArbitraryEventsWorker {
   const EventsContext& GetEventsContext() { return context; }
 
   static void AnalyzeParameter(const gd::Platform& platform,
-                               const gd::ObjectsContainer& project,
-                               const gd::ObjectsContainer& layout,
+                               const gd::ProjectScopedContainers& projectScopedContainers,
                                const gd::ParameterMetadata& metadata,
                                const gd::Expression& parameter,
                                EventsContext& context,
@@ -102,8 +94,6 @@ class GD_CORE_API EventsContextAnalyzer : public ArbitraryEventsWorker {
                                   bool isCondition);
 
   const gd::Platform& platform;
-  gd::ObjectsContainer& project;
-  gd::ObjectsContainer& layout;
   EventsContext context;
 };
 

Core/GDCore/IDE/Events/EventsIdentifiersFinder.cpp

@@ -34,14 +34,12 @@ class GD_CORE_API IdentifierFinderExpressionNodeWorker
  public:
   IdentifierFinderExpressionNodeWorker(std::set<gd::String>& results_,
                               const gd::Platform &platform_,
-                              const gd::ObjectsContainer &globalObjectsContainer_,
-                              const gd::ObjectsContainer &objectsContainer_,
+                              const gd::ProjectScopedContainers &projectScopedContainers_,
                               const gd::String& identifierType_,
                               const gd::String& objectName_ = "")
       : results(results_),
         platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         identifierType(identifierType_),
         objectName(objectName_){};
   virtual ~IdentifierFinderExpressionNodeWorker(){};
@@ -79,14 +77,14 @@ class GD_CORE_API IdentifierFinderExpressionNodeWorker
     const gd::ExpressionMetadata &metadata = isObjectFunction ?
             MetadataProvider::GetObjectAnyExpressionMetadata(
                 platform,
-                GetTypeOfObject(globalObjectsContainer, objectsContainer, objectName),
+                projectScopedContainers.GetObjectsContainersList().GetTypeOfObject(objectName),
                 node.functionName):
           MetadataProvider::GetAnyExpressionMetadata(platform, node.functionName);
 
     if (gd::MetadataProvider::IsBadExpressionMetadata(metadata)) {
       return;
     }
-    
+
     size_t parameterIndex = 0;
     for (size_t metadataIndex = (isObjectFunction ? 1 : 0); metadataIndex < metadata.parameters.size()
       && parameterIndex < node.parameters.size(); ++metadataIndex) {
@@ -111,8 +109,7 @@ class GD_CORE_API IdentifierFinderExpressionNodeWorker
 
  private:
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
 
   std::set<gd::String>& results;  ///< Reference to the std::set where argument
                                   ///< values must be stored.
@@ -166,8 +163,7 @@ class GD_CORE_API IdentifierFinderEventWorker
           IdentifierFinderExpressionNodeWorker searcher(
               results,
               platform,
-              GetGlobalObjectsContainer(),
-              GetObjectsContainer(),
+              GetProjectScopedContainers(),
               identifierType,
               objectName);
           node->Visit(searcher);
@@ -227,7 +223,8 @@ void EventsIdentifiersFinder::FindArgumentsInEventsAndDependencies(
                                         platform,
                                         identifierType,
                                         objectName);
-  eventWorker.Launch(layout.GetEvents(), project, layout);
+  eventWorker.Launch(layout.GetEvents(),
+      gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout));
 
   DependenciesAnalyzer dependenciesAnalyzer = DependenciesAnalyzer(project, layout);
   dependenciesAnalyzer.Analyze();
@@ -238,7 +235,8 @@ void EventsIdentifiersFinder::FindArgumentsInEventsAndDependencies(
                                           platform,
                                           identifierType,
                                           objectName);
-    eventWorker.Launch(externalEvents.GetEvents(), project, layout);
+    eventWorker.Launch(externalEvents.GetEvents(),
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout));
   }
   for (const gd::String& sceneName : dependenciesAnalyzer.GetScenesDependencies()) {
     const gd::Layout& dependencyLayout = project.GetLayout(sceneName);
@@ -247,7 +245,8 @@ void EventsIdentifiersFinder::FindArgumentsInEventsAndDependencies(
                                           platform,
                                           identifierType,
                                           objectName);
-    eventWorker.Launch(dependencyLayout.GetEvents(), project, dependencyLayout);
+    eventWorker.Launch(dependencyLayout.GetEvents(),
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, dependencyLayout));
   }
 }
 

Core/GDCore/IDE/Events/EventsPropertyReplacer.cpp

@@ -0,0 +1,277 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#include "GDCore/IDE/Events/EventsPropertyReplacer.h"
+
+#include <map>
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "GDCore/Events/Event.h"
+#include "GDCore/Events/EventsList.h"
+#include "GDCore/Events/Parsers/ExpressionParser2NodePrinter.h"
+#include "GDCore/Events/Parsers/ExpressionParser2NodeWorker.h"
+#include "GDCore/Extensions/Metadata/MetadataProvider.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadata.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadataTools.h"
+#include "GDCore/IDE/Events/ExpressionValidator.h"
+#include "GDCore/Project/Layout.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Project/PropertiesContainer.h"
+#include "GDCore/String.h"
+#include "GDCore/Tools/Log.h"
+
+namespace gd {
+
+/**
+ * \brief Go through the nodes and rename properties,
+ * or signal if the instruction must be renamed if a removed property is used.
+ *
+ * \see gd::ExpressionParser2
+ */
+class GD_CORE_API ExpressionPropertyReplacer
+    : public ExpressionParser2NodeWorker {
+ public:
+  ExpressionPropertyReplacer(
+      const gd::Platform& platform_,
+      const gd::ProjectScopedContainers& projectScopedContainers_,
+      const gd::PropertiesContainer& targetPropertiesContainer_,
+      const std::unordered_map<gd::String, gd::String>& oldToNewPropertyNames_,
+      const std::unordered_set<gd::String>& removedPropertyNames_)
+      : hasDoneRenaming(false),
+        removedPropertyUsed(false),
+        platform(platform_),
+        projectScopedContainers(projectScopedContainers_),
+        targetPropertiesContainer(targetPropertiesContainer_),
+        oldToNewPropertyNames(oldToNewPropertyNames_),
+        removedPropertyNames(removedPropertyNames_){};
+  virtual ~ExpressionPropertyReplacer(){};
+
+  bool HasDoneRenaming() const { return hasDoneRenaming; }
+  bool IsRemovedPropertyUsed() const { return removedPropertyUsed; }
+
+ protected:
+  void OnVisitSubExpressionNode(SubExpressionNode& node) override {
+    node.expression->Visit(*this);
+  }
+  void OnVisitOperatorNode(OperatorNode& node) override {
+    node.leftHandSide->Visit(*this);
+    node.rightHandSide->Visit(*this);
+  }
+  void OnVisitUnaryOperatorNode(UnaryOperatorNode& node) override {
+    node.factor->Visit(*this);
+  }
+  void OnVisitNumberNode(NumberNode& node) override {}
+  void OnVisitTextNode(TextNode& node) override {}
+  void OnVisitVariableNode(VariableNode& node) override {
+    auto& propertiesContainersList =
+        projectScopedContainers.GetPropertiesContainersList();
+
+    // The node represents a variable or an object name on which a variable
+    // will be accessed, or a property with a child.
+
+    // Match the potential *new* name of the property, because refactorings are
+    // done after changes in the variables container.
+    projectScopedContainers.MatchIdentifierWithName<void>(
+      GetPotentialNewName(node.name),
+      [&]() {
+        // Do nothing, it's an object variable.
+        if (node.child) node.child->Visit(*this);
+      }, [&]() {
+        // Do nothing, it's a variable.
+        if (node.child) node.child->Visit(*this);
+      }, [&]() {
+        // This is a property, check if it's coming from the target container with
+        // properties to replace.
+        if (propertiesContainersList.HasPropertiesContainer(
+                targetPropertiesContainer)) {
+          // The node represents a property, that can come from the target
+          // (because the target is in the scope), replace or remove it:
+          RenameOrRemovePropertyOfTargetPropertyContainer(node.name);
+        }
+
+        if (node.child) node.child->Visit(*this);
+      }, [&]() {
+        // Do nothing, it's a parameter.
+        if (node.child) node.child->Visit(*this);
+      }, [&]() {
+        // This is something else - potentially a deleted property.
+        // Check if it's coming from the target container with
+        // properties to replace.
+        if (propertiesContainersList.HasPropertiesContainer(
+                targetPropertiesContainer)) {
+          // The node represents a property, that can come from the target
+          // (because the target is in the scope), replace or remove it:
+          RenameOrRemovePropertyOfTargetPropertyContainer(node.name);
+        }
+
+        if (node.child) node.child->Visit(*this);
+      });
+  }
+  void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
+    if (node.child) node.child->Visit(*this);
+  }
+  void OnVisitVariableBracketAccessorNode(
+      VariableBracketAccessorNode& node) override {
+    node.expression->Visit(*this);
+    if (node.child) node.child->Visit(*this);
+  }
+  void OnVisitIdentifierNode(IdentifierNode& node) override {
+    auto& propertiesContainersList =
+        projectScopedContainers.GetPropertiesContainersList();
+
+    // Match the potential *new* name of the property, because refactorings are
+    // done after changes in the variables container.
+    projectScopedContainers.MatchIdentifierWithName<void>(
+      GetPotentialNewName(node.identifierName),
+      [&]() {
+        // Do nothing, it's an object variable.
+      }, [&]() {
+        // Do nothing, it's a variable.
+      }, [&]() {
+        // This is a property, check if it's coming from the target container with
+        // properties to replace.
+        if (propertiesContainersList.HasPropertiesContainer(
+                targetPropertiesContainer)) {
+          // The node represents a property, that can come from the target
+          // (because the target is in the scope), replace or remove it:
+          RenameOrRemovePropertyOfTargetPropertyContainer(node.identifierName);
+        }
+      }, [&]() {
+        // Do nothing, it's a parameter.
+      }, [&]() {
+        // This is something else - potentially a deleted property.
+        // Check if it's coming from the target container with
+        // properties to replace.
+        if (propertiesContainersList.HasPropertiesContainer(
+                targetPropertiesContainer)) {
+          // The node represents a property, that can come from the target
+          // (because the target is in the scope), replace or remove it:
+          RenameOrRemovePropertyOfTargetPropertyContainer(node.identifierName);
+        }
+      });
+  }
+  void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {}
+  void OnVisitFunctionCallNode(FunctionCallNode& node) override {
+    for (auto& parameter : node.parameters) {
+      parameter->Visit(*this);
+    }
+  }
+  void OnVisitEmptyNode(EmptyNode& node) override {}
+
+ private:
+  bool hasDoneRenaming;
+  bool removedPropertyUsed;
+
+  const gd::String& GetPotentialNewName(const gd::String& oldName) {
+    return oldToNewPropertyNames.count(oldName) >= 1
+            ? oldToNewPropertyNames.find(oldName)->second
+            : oldName;
+  }
+
+  bool RenameOrRemovePropertyOfTargetPropertyContainer(
+      gd::String& propertyName) {
+    if (oldToNewPropertyNames.count(propertyName) >= 1) {
+      propertyName = oldToNewPropertyNames.find(propertyName)->second;
+      hasDoneRenaming = true;
+      return true;
+    } else if (removedPropertyNames.count(propertyName) >= 1) {
+      removedPropertyUsed = true;
+      return true;
+    }
+
+    return false;  // Nothing was changed or done.
+  }
+
+  // Scope:
+  const gd::Platform& platform;
+  const gd::ProjectScopedContainers& projectScopedContainers;
+
+  // Renaming or removing to do:
+  const gd::PropertiesContainer& targetPropertiesContainer;
+  const std::unordered_map<gd::String, gd::String>& oldToNewPropertyNames;
+  const std::unordered_set<gd::String>& removedPropertyNames;
+
+  gd::String objectNameToUseForVariableAccessor;
+};
+
+bool EventsPropertyReplacer::DoVisitInstruction(gd::Instruction& instruction,
+                                                bool isCondition) {
+  const auto& metadata = isCondition
+                             ? gd::MetadataProvider::GetConditionMetadata(
+                                   platform, instruction.GetType())
+                             : gd::MetadataProvider::GetActionMetadata(
+                                   platform, instruction.GetType());
+  bool shouldDeleteInstruction = false;
+
+  gd::ParameterMetadataTools::IterateOverParametersWithIndex(
+      instruction.GetParameters(),
+      metadata.GetParameters(),
+      [&](const gd::ParameterMetadata& parameterMetadata,
+          const gd::Expression& parameterValue,
+          size_t parameterIndex,
+          const gd::String& lastObjectName) {
+        const gd::String& type = parameterMetadata.GetType();
+
+        if (!gd::ParameterMetadata::IsExpression("variable", type) &&
+            !gd::ParameterMetadata::IsExpression("number", type) &&
+            !gd::ParameterMetadata::IsExpression("string", type))
+          return;  // Not an expression that can contain properties.
+
+        auto node = parameterValue.GetRootNode();
+        if (node) {
+          ExpressionPropertyReplacer renamer(platform,
+                                             GetProjectScopedContainers(),
+                                             targetPropertiesContainer,
+                                             oldToNewPropertyNames,
+                                             removedPropertyNames);
+          node->Visit(renamer);
+
+          if (renamer.IsRemovedPropertyUsed()) {
+            shouldDeleteInstruction = true;
+          } else if (renamer.HasDoneRenaming()) {
+            instruction.SetParameter(
+                parameterIndex, ExpressionParser2NodePrinter::PrintNode(*node));
+          }
+        }
+      });
+
+  return shouldDeleteInstruction;
+}
+
+bool EventsPropertyReplacer::DoVisitEventExpression(
+    gd::Expression& expression, const gd::ParameterMetadata& metadata) {
+  const gd::String& type = metadata.GetType();
+
+  if (!gd::ParameterMetadata::IsExpression("variable", type) &&
+      !gd::ParameterMetadata::IsExpression("number", type) &&
+      !gd::ParameterMetadata::IsExpression("string", type))
+    return false;  // Not an expression that can contain properties.
+
+  auto node = expression.GetRootNode();
+  if (node) {
+    ExpressionPropertyReplacer renamer(platform,
+                                       GetProjectScopedContainers(),
+                                       targetPropertiesContainer,
+                                       oldToNewPropertyNames,
+                                       removedPropertyNames);
+    node->Visit(renamer);
+
+    if (renamer.IsRemovedPropertyUsed()) {
+      return true;
+    } else if (renamer.HasDoneRenaming()) {
+      expression = ExpressionParser2NodePrinter::PrintNode(*node);
+    }
+  }
+
+  return false;
+}
+
+EventsPropertyReplacer::~EventsPropertyReplacer() {}
+
+}  // namespace gd

Core/GDCore/IDE/Events/EventsPropertyReplacer.h

@@ -0,0 +1,56 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+#include <map>
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "GDCore/IDE/Events/ArbitraryEventsWorker.h"
+#include "GDCore/String.h"
+namespace gd {
+class BaseEvent;
+class PropertiesContainer;
+class EventsList;
+class Platform;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief Replace in expressions and in parameters of actions or conditions,
+ * references to the name of a property by another.
+ *
+ * \ingroup IDE
+ */
+class GD_CORE_API EventsPropertyReplacer
+    : public ArbitraryEventsWorkerWithContext {
+ public:
+  EventsPropertyReplacer(
+      const gd::Platform &platform_,
+      const gd::PropertiesContainer &targetPropertiesContainer_,
+      const std::unordered_map<gd::String, gd::String> &oldToNewPropertyNames_,
+      const std::unordered_set<gd::String> &removedPropertyNames_)
+      : platform(platform_),
+        targetPropertiesContainer(targetPropertiesContainer_),
+        oldToNewPropertyNames(oldToNewPropertyNames_),
+        removedPropertyNames(removedPropertyNames_){};
+  virtual ~EventsPropertyReplacer();
+
+ private:
+  bool DoVisitInstruction(gd::Instruction &instruction,
+                          bool isCondition) override;
+  bool DoVisitEventExpression(gd::Expression &expression,
+                              const gd::ParameterMetadata &metadata) override;
+
+  const gd::Platform &platform;
+  const gd::PropertiesContainer &targetPropertiesContainer;
+  const std::unordered_map<gd::String, gd::String> &oldToNewPropertyNames;
+  const std::unordered_set<gd::String> &removedPropertyNames;
+};
+
+}  // namespace gd

Core/GDCore/IDE/Events/EventsRefactorer.cpp

@@ -20,6 +20,7 @@
 #include "GDCore/IDE/Events/InstructionSentenceFormatter.h"
 #include "GDCore/Project/ObjectsContainer.h"
 #include "GDCore/Project/EventsBasedObject.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/IDE/Events/ExpressionTypeFinder.h"
 
 using namespace std;
@@ -36,14 +37,12 @@ const gd::String EventsRefactorer::searchIgnoredCharacters = ";:,#()";
 class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
  public:
   ExpressionObjectRenamer(const gd::Platform &platform_,
-                          const gd::ObjectsContainer &globalObjectsContainer_,
-                          const gd::ObjectsContainer &objectsContainer_,
+                          const gd::ProjectScopedContainers& projectScopedContainers_,
                           const gd::String &rootType_,
                           const gd::String& objectName_,
                           const gd::String& objectNewName_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         rootType(rootType_),
         hasDoneRenaming(false),
         objectName(objectName_),
@@ -51,14 +50,13 @@ class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
   virtual ~ExpressionObjectRenamer(){};
 
   static bool Rename(const gd::Platform &platform,
-                     const gd::ObjectsContainer &globalObjectsContainer,
-                     const gd::ObjectsContainer &objectsContainer,
+                     const gd::ProjectScopedContainers &projectScopedContainers,
                      const gd::String &rootType,
                      gd::ExpressionNode& node,
                      const gd::String& objectName,
                      const gd::String& objectNewName) {
-    if (gd::ExpressionValidator::HasNoErrors(platform, globalObjectsContainer, objectsContainer, rootType, node)) {
-      ExpressionObjectRenamer renamer(platform, globalObjectsContainer, objectsContainer, rootType, objectName, objectNewName);
+    if (gd::ExpressionValidator::HasNoErrors(platform, projectScopedContainers, rootType, node)) {
+      ExpressionObjectRenamer renamer(platform, projectScopedContainers, rootType, objectName, objectNewName);
       node.Visit(renamer);
 
       return renamer.HasDoneRenaming();
@@ -83,6 +81,29 @@ class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
   void OnVisitNumberNode(NumberNode& node) override {}
   void OnVisitTextNode(TextNode& node) override {}
   void OnVisitVariableNode(VariableNode& node) override {
+    const auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+    auto type = gd::ExpressionTypeFinder::GetType(platform, objectsContainersList, rootType, node);
+
+    if (gd::ValueTypeMetadata::IsTypeLegacyPreScopedVariable(type)) {
+      // Nothing to do (this can't reference an object)
+    } else {
+      if (node.name == objectName) {
+        projectScopedContainers.MatchIdentifierWithName<void>(node.name, [&]() {
+          // This is an object variable.
+          hasDoneRenaming = true;
+          node.name = objectNewName;
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
+      }
+    }
+
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
@@ -94,11 +115,29 @@ class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitIdentifierNode(IdentifierNode& node) override {
-    auto type = gd::ExpressionTypeFinder::GetType(platform, globalObjectsContainer, objectsContainer, rootType, node);
+    auto type = gd::ExpressionTypeFinder::GetType(platform, projectScopedContainers.GetObjectsContainersList(), rootType, node);
     if (gd::ParameterMetadata::IsObject(type) &&
         node.identifierName == objectName) {
       hasDoneRenaming = true;
       node.identifierName = objectNewName;
+    } else if (gd::ValueTypeMetadata::IsTypeLegacyPreScopedVariable(type)) {
+      // Nothing to do (this can't reference an object)
+    } else {
+      if (node.identifierName == objectName) {
+        projectScopedContainers.MatchIdentifierWithName<void>(node.identifierName, [&]() {
+          // This is an object variable.
+          hasDoneRenaming = true;
+          node.identifierName = objectNewName;
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
+      }
     }
   }
   void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {
@@ -124,8 +163,7 @@ class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
   const gd::String& objectNewName;
 
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
   const gd::String rootType;
 };
 
@@ -138,26 +176,23 @@ class GD_CORE_API ExpressionObjectRenamer : public ExpressionParser2NodeWorker {
 class GD_CORE_API ExpressionObjectFinder : public ExpressionParser2NodeWorker {
  public:
   ExpressionObjectFinder(const gd::Platform &platform_,
-                         const gd::ObjectsContainer &globalObjectsContainer_,
-                         const gd::ObjectsContainer &objectsContainer_,
+                         const gd::ProjectScopedContainers &projectScopedContainers_,
                          const gd::String &rootType_,
-                         const gd::String& objectName_)
+                         const gd::String& searchedObjectName_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         rootType(rootType_),
         hasObject(false),
-        objectName(objectName_){};
+        searchedObjectName(searchedObjectName_){};
   virtual ~ExpressionObjectFinder(){};
 
   static bool CheckIfHasObject(const gd::Platform &platform,
-                               const gd::ObjectsContainer &globalObjectsContainer,
-                               const gd::ObjectsContainer &objectsContainer,
+                               const gd::ProjectScopedContainers &projectScopedContainers,
                                const gd::String &rootType,
                                gd::ExpressionNode& node,
                                const gd::String& objectName) {
-    if (gd::ExpressionValidator::HasNoErrors(platform, globalObjectsContainer, objectsContainer, rootType, node)) {
-      ExpressionObjectFinder finder(platform, globalObjectsContainer, objectsContainer, rootType, objectName);
+    if (gd::ExpressionValidator::HasNoErrors(platform, projectScopedContainers, rootType, node)) {
+      ExpressionObjectFinder finder(platform, projectScopedContainers, rootType, objectName);
       node.Visit(finder);
 
       return finder.HasFoundObject();
@@ -182,6 +217,28 @@ class GD_CORE_API ExpressionObjectFinder : public ExpressionParser2NodeWorker {
   void OnVisitNumberNode(NumberNode& node) override {}
   void OnVisitTextNode(TextNode& node) override {}
   void OnVisitVariableNode(VariableNode& node) override {
+    const auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+    auto type = gd::ExpressionTypeFinder::GetType(platform, objectsContainersList, rootType, node);
+
+    if (gd::ValueTypeMetadata::IsTypeLegacyPreScopedVariable(type)) {
+      // Nothing to do (this can't reference an object)
+    } else {
+      if (node.name == searchedObjectName) {
+        projectScopedContainers.MatchIdentifierWithName<void>(node.name, [&]() {
+          // This is an object variable.
+          hasObject = true;
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
+      }
+    }
+
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
@@ -193,19 +250,36 @@ class GD_CORE_API ExpressionObjectFinder : public ExpressionParser2NodeWorker {
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitIdentifierNode(IdentifierNode& node) override {
-    auto type = gd::ExpressionTypeFinder::GetType(platform, globalObjectsContainer, objectsContainer, rootType, node);
+    auto type = gd::ExpressionTypeFinder::GetType(platform, projectScopedContainers.GetObjectsContainersList(), rootType, node);
     if (gd::ParameterMetadata::IsObject(type) &&
-        node.identifierName == objectName) {
+        node.identifierName == searchedObjectName) {
       hasObject = true;
+    } else if (gd::ValueTypeMetadata::IsTypeLegacyPreScopedVariable(type)) {
+      // Nothing to do (this can't reference an object)
+    } else {
+      if (node.identifierName == searchedObjectName) {
+        projectScopedContainers.MatchIdentifierWithName<void>(node.identifierName, [&]() {
+          // This is an object variable.
+          hasObject = true;
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+        }, [&]() {
+          // This is a parameter.
+        }, [&]() {
+          // This is something else.
+        });
+      }
     }
   }
   void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {
-    if (node.objectName == objectName) {
+    if (node.objectName == searchedObjectName) {
       hasObject = true;
     }
   }
   void OnVisitFunctionCallNode(FunctionCallNode& node) override {
-    if (node.objectName == objectName) {
+    if (node.objectName == searchedObjectName) {
       hasObject = true;
     }
     for (auto& parameter : node.parameters) {
@@ -216,17 +290,15 @@ class GD_CORE_API ExpressionObjectFinder : public ExpressionParser2NodeWorker {
 
  private:
   bool hasObject;
-  const gd::String& objectName;
+  const gd::String& searchedObjectName;
 
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
   const gd::String rootType;
 };
 
 bool EventsRefactorer::RenameObjectInActions(const gd::Platform& platform,
-                                             gd::ObjectsContainer& project,
-                                             gd::ObjectsContainer& layout,
+                                             gd::ProjectScopedContainers& projectScopedContainers,
                                              gd::InstructionsList& actions,
                                              gd::String oldName,
                                              gd::String newName) {
@@ -245,7 +317,7 @@ bool EventsRefactorer::RenameObjectInActions(const gd::Platform& platform,
                    "number", instrInfos.parameters[pNb].GetType())) {
         auto node = actions[aId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectRenamer::Rename(platform, project, layout, "number", *node, oldName, newName)) {
+        if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "number", *node, oldName, newName)) {
           actions[aId].SetParameter(
               pNb, ExpressionParser2NodePrinter::PrintNode(*node));
         }
@@ -255,7 +327,7 @@ bool EventsRefactorer::RenameObjectInActions(const gd::Platform& platform,
                    "string", instrInfos.parameters[pNb].GetType())) {
         auto node = actions[aId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectRenamer::Rename(platform, project, layout, "string", *node, oldName, newName)) {
+        if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "string", *node, oldName, newName)) {
           actions[aId].SetParameter(
               pNb, ExpressionParser2NodePrinter::PrintNode(*node));
         }
@@ -265,8 +337,7 @@ bool EventsRefactorer::RenameObjectInActions(const gd::Platform& platform,
     if (!actions[aId].GetSubInstructions().empty())
       somethingModified =
           RenameObjectInActions(platform,
-                                project,
-                                layout,
+                                projectScopedContainers,
                                 actions[aId].GetSubInstructions(),
                                 oldName,
                                 newName) ||
@@ -278,8 +349,7 @@ bool EventsRefactorer::RenameObjectInActions(const gd::Platform& platform,
 
 bool EventsRefactorer::RenameObjectInConditions(
     const gd::Platform& platform,
-    gd::ObjectsContainer& project,
-    gd::ObjectsContainer& layout,
+    gd::ProjectScopedContainers& projectScopedContainers,
     gd::InstructionsList& conditions,
     gd::String oldName,
     gd::String newName) {
@@ -299,7 +369,7 @@ bool EventsRefactorer::RenameObjectInConditions(
                    "number", instrInfos.parameters[pNb].GetType())) {
         auto node = conditions[cId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectRenamer::Rename(platform, project, layout, "number", *node, oldName, newName)) {
+        if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "number", *node, oldName, newName)) {
           conditions[cId].SetParameter(
               pNb, ExpressionParser2NodePrinter::PrintNode(*node));
         }
@@ -309,7 +379,7 @@ bool EventsRefactorer::RenameObjectInConditions(
                    "string", instrInfos.parameters[pNb].GetType())) {
         auto node = conditions[cId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectRenamer::Rename(platform, project, layout, "string", *node, oldName, newName)) {
+        if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "string", *node, oldName, newName)) {
           conditions[cId].SetParameter(
               pNb, ExpressionParser2NodePrinter::PrintNode(*node));
         }
@@ -319,8 +389,7 @@ bool EventsRefactorer::RenameObjectInConditions(
     if (!conditions[cId].GetSubInstructions().empty())
       somethingModified =
           RenameObjectInConditions(platform,
-                                   project,
-                                   layout,
+                                   projectScopedContainers,
                                    conditions[cId].GetSubInstructions(),
                                    oldName,
                                    newName) ||
@@ -332,8 +401,7 @@ bool EventsRefactorer::RenameObjectInConditions(
 
 bool EventsRefactorer::RenameObjectInEventParameters(
     const gd::Platform& platform,
-    gd::ObjectsContainer& project,
-    gd::ObjectsContainer& layout,
+    gd::ProjectScopedContainers& projectScopedContainers,
     gd::Expression& expression,
     gd::ParameterMetadata parameterMetadata,
     gd::String oldName,
@@ -348,7 +416,7 @@ bool EventsRefactorer::RenameObjectInEventParameters(
                                            parameterMetadata.GetType())) {
     auto node = expression.GetRootNode();
 
-    if (ExpressionObjectRenamer::Rename(platform, project, layout, "number", *node, oldName, newName)) {
+    if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "number", *node, oldName, newName)) {
       expression = ExpressionParser2NodePrinter::PrintNode(*node);
     }
   }
@@ -357,7 +425,7 @@ bool EventsRefactorer::RenameObjectInEventParameters(
                                            parameterMetadata.GetType())) {
     auto node = expression.GetRootNode();
 
-    if (ExpressionObjectRenamer::Rename(platform, project, layout, "string", *node, oldName, newName)) {
+    if (ExpressionObjectRenamer::Rename(platform, projectScopedContainers, "string", *node, oldName, newName)) {
       expression = ExpressionParser2NodePrinter::PrintNode(*node);
     }
   }
@@ -366,8 +434,7 @@ bool EventsRefactorer::RenameObjectInEventParameters(
 }
 
 void EventsRefactorer::RenameObjectInEvents(const gd::Platform& platform,
-                                            gd::ObjectsContainer& project,
-                                            gd::ObjectsContainer& layout,
+                                            gd::ProjectScopedContainers& projectScopedContainers,
                                             gd::EventsList& events,
                                             gd::String oldName,
                                             gd::String newName) {
@@ -376,14 +443,14 @@ void EventsRefactorer::RenameObjectInEvents(const gd::Platform& platform,
         events[i].GetAllConditionsVectors();
     for (std::size_t j = 0; j < conditionsVectors.size(); ++j) {
       bool somethingModified = RenameObjectInConditions(
-          platform, project, layout, *conditionsVectors[j], oldName, newName);
+          platform, projectScopedContainers, *conditionsVectors[j], oldName, newName);
     }
 
     vector<gd::InstructionsList*> actionsVectors =
         events[i].GetAllActionsVectors();
     for (std::size_t j = 0; j < actionsVectors.size(); ++j) {
       bool somethingModified = RenameObjectInActions(
-          platform, project, layout, *actionsVectors[j], oldName, newName);
+          platform, projectScopedContainers, *actionsVectors[j], oldName, newName);
     }
 
     vector<pair<gd::Expression*, gd::ParameterMetadata>>
@@ -393,8 +460,7 @@ void EventsRefactorer::RenameObjectInEvents(const gd::Platform& platform,
       gd::ParameterMetadata parameterMetadata =
           expressionsWithMetadata[j].second;
       bool somethingModified = RenameObjectInEventParameters(platform,
-                                                             project,
-                                                             layout,
+                                                             projectScopedContainers,
                                                              *expression,
                                                              parameterMetadata,
                                                              oldName,
@@ -403,8 +469,7 @@ void EventsRefactorer::RenameObjectInEvents(const gd::Platform& platform,
 
     if (events[i].CanHaveSubEvents())
       RenameObjectInEvents(platform,
-                           project,
-                           layout,
+                           projectScopedContainers,
                            events[i].GetSubEvents(),
                            oldName,
                            newName);
@@ -412,8 +477,7 @@ void EventsRefactorer::RenameObjectInEvents(const gd::Platform& platform,
 }
 
 bool EventsRefactorer::RemoveObjectInActions(const gd::Platform& platform,
-                                             gd::ObjectsContainer& globalObjectsContainer,
-                                             gd::ObjectsContainer& objectsContainer,
+                                             gd::ProjectScopedContainers& projectScopedContainers,
                                              gd::InstructionsList& actions,
                                              gd::String name) {
   bool somethingModified = false;
@@ -435,7 +499,7 @@ bool EventsRefactorer::RemoveObjectInActions(const gd::Platform& platform,
                    "number", instrInfos.parameters[pNb].GetType())) {
         auto node = actions[aId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectFinder::CheckIfHasObject(platform, globalObjectsContainer, objectsContainer, "number", *node, name)) {
+        if (ExpressionObjectFinder::CheckIfHasObject(platform, projectScopedContainers, "number", *node, name)) {
           deleteMe = true;
           break;
         }
@@ -445,7 +509,7 @@ bool EventsRefactorer::RemoveObjectInActions(const gd::Platform& platform,
                    "string", instrInfos.parameters[pNb].GetType())) {
         auto node = actions[aId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectFinder::CheckIfHasObject(platform, globalObjectsContainer, objectsContainer, "string", *node, name)) {
+        if (ExpressionObjectFinder::CheckIfHasObject(platform, projectScopedContainers, "string", *node, name)) {
           deleteMe = true;
           break;
         }
@@ -459,8 +523,7 @@ bool EventsRefactorer::RemoveObjectInActions(const gd::Platform& platform,
     } else if (!actions[aId].GetSubInstructions().empty())
       somethingModified =
           RemoveObjectInActions(platform,
-                                globalObjectsContainer,
-                                objectsContainer,
+                                projectScopedContainers,
                                 actions[aId].GetSubInstructions(),
                                 name) ||
           somethingModified;
@@ -471,8 +534,7 @@ bool EventsRefactorer::RemoveObjectInActions(const gd::Platform& platform,
 
 bool EventsRefactorer::RemoveObjectInConditions(
     const gd::Platform& platform,
-    gd::ObjectsContainer& globalObjectsContainer,
-    gd::ObjectsContainer& objectsContainer,
+    gd::ProjectScopedContainers& projectScopedContainers,
     gd::InstructionsList& conditions,
     gd::String name) {
   bool somethingModified = false;
@@ -495,7 +557,7 @@ bool EventsRefactorer::RemoveObjectInConditions(
                    "number", instrInfos.parameters[pNb].GetType())) {
         auto node = conditions[cId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectFinder::CheckIfHasObject(platform, globalObjectsContainer, objectsContainer, "number", *node, name)) {
+        if (ExpressionObjectFinder::CheckIfHasObject(platform, projectScopedContainers, "number", *node, name)) {
           deleteMe = true;
           break;
         }
@@ -505,7 +567,7 @@ bool EventsRefactorer::RemoveObjectInConditions(
                    "string", instrInfos.parameters[pNb].GetType())) {
         auto node = conditions[cId].GetParameter(pNb).GetRootNode();
 
-        if (ExpressionObjectFinder::CheckIfHasObject(platform, globalObjectsContainer, objectsContainer, "string", *node, name)) {
+        if (ExpressionObjectFinder::CheckIfHasObject(platform, projectScopedContainers, "string", *node, name)) {
           deleteMe = true;
           break;
         }
@@ -519,8 +581,7 @@ bool EventsRefactorer::RemoveObjectInConditions(
     } else if (!conditions[cId].GetSubInstructions().empty())
       somethingModified =
           RemoveObjectInConditions(platform,
-                                   globalObjectsContainer,
-                                   objectsContainer,
+                                   projectScopedContainers,
                                    conditions[cId].GetSubInstructions(),
                                    name) ||
           somethingModified;
@@ -530,8 +591,7 @@ bool EventsRefactorer::RemoveObjectInConditions(
 }
 
 void EventsRefactorer::RemoveObjectInEvents(const gd::Platform& platform,
-                                            gd::ObjectsContainer& globalObjectsContainer,
-                                            gd::ObjectsContainer& objectsContainer,
+                                            gd::ProjectScopedContainers& projectScopedContainers,
                                             gd::EventsList& events,
                                             gd::String name) {
   for (std::size_t i = 0; i < events.size(); ++i) {
@@ -539,19 +599,19 @@ void EventsRefactorer::RemoveObjectInEvents(const gd::Platform& platform,
         events[i].GetAllConditionsVectors();
     for (std::size_t j = 0; j < conditionsVectors.size(); ++j) {
       bool conditionsModified = RemoveObjectInConditions(
-          platform, globalObjectsContainer, objectsContainer, *conditionsVectors[j], name);
+          platform, projectScopedContainers, *conditionsVectors[j], name);
     }
 
     vector<gd::InstructionsList*> actionsVectors =
         events[i].GetAllActionsVectors();
     for (std::size_t j = 0; j < actionsVectors.size(); ++j) {
       bool actionsModified = RemoveObjectInActions(
-          platform, globalObjectsContainer, objectsContainer, *actionsVectors[j], name);
+          platform, projectScopedContainers, *actionsVectors[j], name);
     }
 
     if (events[i].CanHaveSubEvents())
       RemoveObjectInEvents(
-          platform, globalObjectsContainer, objectsContainer, events[i].GetSubEvents(), name);
+          platform, projectScopedContainers, events[i].GetSubEvents(), name);
   }
 }
 
@@ -587,20 +647,20 @@ std::vector<EventsSearchResult> EventsRefactorer::ReplaceStringInEvents(
   for (std::size_t i = 0; i < events.size(); ++i) {
     bool eventModified = false;
 
-    std::vector<gd::Expression*> allObjectExpressions =
-        events[i].GetAllObjectExpressions();
-    for (std::size_t j = 0; j < allObjectExpressions.size(); ++j) {
+    auto allExpressionsWithMetadata = events[i].GetAllExpressionsWithMetadata();
+    for (auto& expressionAndMetadata : allExpressionsWithMetadata) {
+      gd::Expression* expression = expressionAndMetadata.first;
+
       gd::String newExpressionPlainString =
-          matchCase ? allObjectExpressions[j]->GetPlainString().FindAndReplace(
+          matchCase ? expression->GetPlainString().FindAndReplace(
                           toReplace, newString, true)
                     : ReplaceAllOccurrencesCaseInsensitive(
-                          allObjectExpressions[j]->GetPlainString(),
+                          expression->GetPlainString(),
                           toReplace,
                           newString);
 
-      if (newExpressionPlainString !=
-          allObjectExpressions[j]->GetPlainString()) {
-        *allObjectExpressions[j] = gd::Expression(newExpressionPlainString);
+      if (newExpressionPlainString != expression->GetPlainString()) {
+        *expression = gd::Expression(newExpressionPlainString);
 
         if (!eventModified) {
           modifiedEvents.push_back(EventsSearchResult(
@@ -815,14 +875,14 @@ vector<EventsSearchResult> EventsRefactorer::SearchInEvents(
   for (std::size_t i = 0; i < events.size(); ++i) {
     bool eventAddedInResults = false;
 
-    std::vector<gd::Expression*> allObjectExpressions =
-        events[i].GetAllObjectExpressions();
-    for (std::size_t j = 0; j < allObjectExpressions.size(); ++j) {
+    auto allExpressionsWithMetadata = events[i].GetAllExpressionsWithMetadata();
+    for (auto& expressionAndMetadata : allExpressionsWithMetadata) {
+      gd::Expression* expression = expressionAndMetadata.first;
+
       size_t foundPosition =
           matchCase
-              ? allObjectExpressions[j]->GetPlainString().find(search)
-              : allObjectExpressions[j]->GetPlainString().FindCaseInsensitive(
-                    search);
+              ? expression->GetPlainString().find(search)
+              : expression->GetPlainString().FindCaseInsensitive(search);
 
       if (foundPosition != gd::String::npos && !eventAddedInResults) {
         results.push_back(EventsSearchResult(

Core/GDCore/IDE/Events/EventsRefactorer.h

@@ -14,6 +14,8 @@
 namespace gd {
 class EventsList;
 class ObjectsContainer;
+class ObjectsContainersList;
+class ProjectScopedContainers;
 class Platform;
 class ExternalEvents;
 class BaseEvent;
@@ -79,8 +81,7 @@ class GD_CORE_API EventsRefactorer {
    * events ).
    */
   static void RenameObjectInEvents(const gd::Platform& platform,
-                                   gd::ObjectsContainer& project,
-                                   gd::ObjectsContainer& layout,
+                                   gd::ProjectScopedContainers& projectScopedContainers,
                                    gd::EventsList& events,
                                    gd::String oldName,
                                    gd::String newName);
@@ -89,8 +90,7 @@ class GD_CORE_API EventsRefactorer {
    * Remove all actions or conditions using an object
    */
   static void RemoveObjectInEvents(const gd::Platform& platform,
-                                   gd::ObjectsContainer& project,
-                                   gd::ObjectsContainer& layout,
+                                   gd::ProjectScopedContainers& projectScopedContainers,
                                    gd::EventsList& events,
                                    gd::String name);
 
@@ -136,8 +136,7 @@ class GD_CORE_API EventsRefactorer {
    * \return true if something was modified.
    */
   static bool RenameObjectInActions(const gd::Platform& platform,
-                                    gd::ObjectsContainer& project,
-                                    gd::ObjectsContainer& layout,
+                                    gd::ProjectScopedContainers& projectScopedContainers,
                                     gd::InstructionsList& instructions,
                                     gd::String oldName,
                                     gd::String newName);
@@ -149,8 +148,7 @@ class GD_CORE_API EventsRefactorer {
    * \return true if something was modified.
    */
   static bool RenameObjectInConditions(const gd::Platform& platform,
-                                       gd::ObjectsContainer& project,
-                                       gd::ObjectsContainer& layout,
+                                       gd::ProjectScopedContainers& projectScopedContainers,
                                        gd::InstructionsList& instructions,
                                        gd::String oldName,
                                        gd::String newName);
@@ -163,8 +161,7 @@ class GD_CORE_API EventsRefactorer {
    */
   static bool RenameObjectInEventParameters(
       const gd::Platform& platform,
-      gd::ObjectsContainer& project,
-      gd::ObjectsContainer& layout,
+      gd::ProjectScopedContainers& projectScopedContainers,
       gd::Expression& expression,
       gd::ParameterMetadata parameterMetadata,
       gd::String oldName,
@@ -176,8 +173,7 @@ class GD_CORE_API EventsRefactorer {
    * \return true if something was modified.
    */
   static bool RemoveObjectInConditions(const gd::Platform& platform,
-                                       gd::ObjectsContainer& project,
-                                       gd::ObjectsContainer& layout,
+                                       gd::ProjectScopedContainers& projectScopedContainers,
                                        gd::InstructionsList& conditions,
                                        gd::String name);
 
@@ -187,8 +183,7 @@ class GD_CORE_API EventsRefactorer {
    * \return true if something was modified.
    */
   static bool RemoveObjectInActions(const gd::Platform& platform,
-                                    gd::ObjectsContainer& project,
-                                    gd::ObjectsContainer& layout,
+                                    gd::ProjectScopedContainers& projectScopedContainers,
                                     gd::InstructionsList& conditions,
                                     gd::String name);
 

Core/GDCore/IDE/Events/EventsVariableReplacer.cpp

@@ -0,0 +1,404 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#include "GDCore/IDE/Events/EventsVariableReplacer.h"
+
+#include <map>
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "GDCore/Events/Event.h"
+#include "GDCore/Events/EventsList.h"
+#include "GDCore/Events/Parsers/ExpressionParser2NodePrinter.h"
+#include "GDCore/Events/Parsers/ExpressionParser2NodeWorker.h"
+#include "GDCore/Extensions/Metadata/MetadataProvider.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadata.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadataTools.h"
+#include "GDCore/IDE/Events/ExpressionValidator.h"
+#include "GDCore/IDE/Events/ExpressionVariableOwnerFinder.h"
+#include "GDCore/Project/Layout.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Project/VariablesContainer.h"
+#include "GDCore/String.h"
+#include "GDCore/Tools/Log.h"
+
+namespace gd {
+
+/**
+ * \brief Go through the nodes and rename variables,
+ * or signal if the instruction must be renamed if a removed variable is used.
+ *
+ * \see gd::ExpressionParser2
+ */
+class GD_CORE_API ExpressionVariableReplacer
+    : public ExpressionParser2NodeWorker {
+ public:
+  ExpressionVariableReplacer(
+      const gd::Platform& platform_,
+      const gd::ProjectScopedContainers& projectScopedContainers_,
+      const gd::VariablesContainer& targetVariablesContainer_,
+      const std::unordered_map<gd::String, gd::String>& oldToNewVariableNames_,
+      const std::unordered_set<gd::String>& removedVariableNames_)
+      : hasDoneRenaming(false),
+        removedVariableUsed(false),
+        platform(platform_),
+        projectScopedContainers(projectScopedContainers_),
+        forcedInitialVariablesContainer(nullptr),
+        targetVariablesContainer(targetVariablesContainer_),
+        oldToNewVariableNames(oldToNewVariableNames_),
+        removedVariableNames(removedVariableNames_){};
+  virtual ~ExpressionVariableReplacer(){};
+
+  void SetForcedInitialVariablesContainer(
+      const gd::VariablesContainer* forcedInitialVariablesContainer_) {
+    forcedInitialVariablesContainer = forcedInitialVariablesContainer_;
+  }
+
+  bool HasDoneRenaming() const { return hasDoneRenaming; }
+  bool IsRemovedVariableUsed() const { return removedVariableUsed; }
+
+ protected:
+  void OnVisitSubExpressionNode(SubExpressionNode& node) override {
+    node.expression->Visit(*this);
+  }
+  void OnVisitOperatorNode(OperatorNode& node) override {
+    node.leftHandSide->Visit(*this);
+    node.rightHandSide->Visit(*this);
+  }
+  void OnVisitUnaryOperatorNode(UnaryOperatorNode& node) override {
+    node.factor->Visit(*this);
+  }
+  void OnVisitNumberNode(NumberNode& node) override {}
+  void OnVisitTextNode(TextNode& node) override {}
+  void OnVisitVariableNode(VariableNode& node) override {
+    // The node represents a variable or an object name on which a variable
+    // will be accessed.
+
+    if (forcedInitialVariablesContainer) {
+      // A scope was forced. Honor it: it means this node represents a variable
+      // of the forced variables container.
+      if (forcedInitialVariablesContainer == &targetVariablesContainer) {
+        RenameOrRemoveVariableOfTargetVariableContainer(node.name);
+      }
+
+      if (node.child) node.child->Visit(*this);
+      return;
+    }
+
+    // Match the potential *new* name of the variable, because refactorings are
+    // done after changes in the variables container.
+    projectScopedContainers.MatchIdentifierWithName<void>(
+        GetPotentialNewName(node.name),
+        [&]() {
+          // This represents an object.
+          // Remember the object name.
+          objectNameToUseForVariableAccessor = node.name;
+          if (node.child) node.child->Visit(*this);
+          objectNameToUseForVariableAccessor = "";
+        },
+        [&]() {
+          // This is a variable.
+          if (projectScopedContainers.GetVariablesContainersList()
+                  .HasVariablesContainer(targetVariablesContainer)) {
+            // The node represents a variable, that can come from the target
+            // (because the target is in the scope), replace or remove it:
+            RenameOrRemoveVariableOfTargetVariableContainer(node.name);
+          }
+
+          if (node.child) node.child->Visit(*this);
+        },
+        [&]() {
+          // This is a property.
+          if (node.child) node.child->Visit(*this);
+        },
+        [&]() {
+          // This is a parameter.
+          if (node.child) node.child->Visit(*this);
+        },
+        [&]() {
+          // This is something else - potentially a deleted variable.
+          if (projectScopedContainers.GetVariablesContainersList()
+                  .HasVariablesContainer(targetVariablesContainer)) {
+            // The node represents a variable, that can come from the target
+            // (because the target is in the scope), replace or remove it:
+            RenameOrRemoveVariableOfTargetVariableContainer(node.name);
+          }
+
+          if (node.child) node.child->Visit(*this);
+        });
+  }
+  void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
+    auto& objectsContainersList =
+        projectScopedContainers.GetObjectsContainersList();
+    if (!objectNameToUseForVariableAccessor.empty()) {
+      if (objectsContainersList.HasVariablesContainer(
+              objectNameToUseForVariableAccessor, targetVariablesContainer)) {
+        // The node represents an object variable, and this object variables are
+        // the target. Do the replacement or removals:
+        RenameOrRemoveVariableOfTargetVariableContainer(node.name);
+      }
+    }
+    objectNameToUseForVariableAccessor = "";
+
+    if (node.child) node.child->Visit(*this);
+  }
+  void OnVisitVariableBracketAccessorNode(
+      VariableBracketAccessorNode& node) override {
+    objectNameToUseForVariableAccessor = "";
+
+    node.expression->Visit(*this);
+    if (node.child) node.child->Visit(*this);
+  }
+  void OnVisitIdentifierNode(IdentifierNode& node) override {
+    auto& objectsContainersList =
+        projectScopedContainers.GetObjectsContainersList();
+
+    // The node represents a variable or an object variable in an expression
+    // (and if it's a variable reference or a value does not have any importance
+    // here).
+
+    if (forcedInitialVariablesContainer) {
+      // A scope was forced. Honor it: it means this node represents a variable
+      // of the forced variables container.
+      if (forcedInitialVariablesContainer == &targetVariablesContainer) {
+        RenameOrRemoveVariableOfTargetVariableContainer(node.identifierName);
+      }
+      return;
+    }
+
+    // Match the potential *new* name of the variable, because refactorings are
+    // done after changes in the variables container.
+    projectScopedContainers.MatchIdentifierWithName<void>(
+        GetPotentialNewName(node.identifierName),
+        [&]() {
+          // This represents an object.
+          if (objectsContainersList.HasVariablesContainer(
+                  node.identifierName, targetVariablesContainer)) {
+            // The node represents an object variable, and this object variables
+            // are the target. Do the replacement or removals:
+            RenameOrRemoveVariableOfTargetVariableContainer(
+                node.childIdentifierName);
+          }
+        },
+        [&]() {
+          // This is a variable.
+          if (projectScopedContainers.GetVariablesContainersList()
+                  .HasVariablesContainer(targetVariablesContainer)) {
+            // The node represents a variable, that can come from the target
+            // (because the target is in the scope), replace or remove it:
+            RenameOrRemoveVariableOfTargetVariableContainer(
+                node.identifierName);
+          }
+        },
+        [&]() {
+          // This is a property.
+        },
+        [&]() {
+          // This is a parameter.
+        },
+        [&]() {
+          // This is something else - potentially a deleted variable.
+          if (projectScopedContainers.GetVariablesContainersList()
+                  .HasVariablesContainer(targetVariablesContainer)) {
+            // The node represents a variable, that can come from the target
+            // (because the target is in the scope), replace or remove it:
+            RenameOrRemoveVariableOfTargetVariableContainer(
+                node.identifierName);
+          }
+        });
+  }
+  void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {}
+  void OnVisitFunctionCallNode(FunctionCallNode& node) override {
+    const gd::ExpressionMetadata& metadata =
+        MetadataProvider::GetFunctionCallMetadata(
+            platform, projectScopedContainers.GetObjectsContainersList(), node);
+
+    for (size_t parameterIndex = 0; parameterIndex < node.parameters.size();
+         ++parameterIndex) {
+      const gd::ParameterMetadata* parameterMetadata =
+          MetadataProvider::GetFunctionCallParameterMetadata(
+              platform,
+              projectScopedContainers.GetObjectsContainersList(),
+              node,
+              parameterIndex);
+
+      // Handle legacy pre-scoped variable parameters: in this case, we
+      // force the "scope" at which starts the evalution of variables.
+      if (parameterMetadata && parameterMetadata->GetValueTypeMetadata()
+                                   .IsLegacyPreScopedVariable()) {
+        const gd::VariablesContainer* oldForcedInitialVariablesContainer =
+            forcedInitialVariablesContainer;
+
+        forcedInitialVariablesContainer = nullptr;
+        if (parameterMetadata->GetType() == "globalvar") {
+          forcedInitialVariablesContainer =
+              projectScopedContainers.GetVariablesContainersList()
+                  .GetTopMostVariablesContainer();
+        } else if (parameterMetadata->GetType() == "scenevar") {
+          forcedInitialVariablesContainer =
+              projectScopedContainers.GetVariablesContainersList()
+                  .GetBottomMostVariablesContainer();
+        } else if (parameterMetadata->GetType() == "objectvar") {
+          auto objectName = gd::ExpressionVariableOwnerFinder::GetObjectName(
+              platform,
+              projectScopedContainers.GetObjectsContainersList(),
+              node.objectName,
+              *node.parameters[parameterIndex].get());
+          forcedInitialVariablesContainer =
+              projectScopedContainers.GetObjectsContainersList()
+                  .GetObjectOrGroupVariablesContainer(objectName);
+        }
+
+        node.parameters[parameterIndex]->Visit(*this);
+        forcedInitialVariablesContainer = oldForcedInitialVariablesContainer;
+      } else {
+        // For any other parameter, there is no special treatment being needed.
+        node.parameters[parameterIndex]->Visit(*this);
+      }
+    }
+  }
+  void OnVisitEmptyNode(EmptyNode& node) override {}
+
+ private:
+  bool hasDoneRenaming;
+  bool removedVariableUsed;
+
+  const gd::String& GetPotentialNewName(const gd::String& oldName) {
+    return oldToNewVariableNames.count(oldName) >= 1
+            ? oldToNewVariableNames.find(oldName)->second
+            : oldName;
+  }
+
+  bool RenameOrRemoveVariableOfTargetVariableContainer(
+      gd::String& variableName) {
+    if (oldToNewVariableNames.count(variableName) >= 1) {
+      variableName = oldToNewVariableNames.find(variableName)->second;
+      hasDoneRenaming = true;
+      return true;
+    } else if (removedVariableNames.count(variableName) >= 1) {
+      removedVariableUsed = true;
+      return true;
+    }
+
+    return false;  // Nothing was changed or done.
+  }
+
+  // Scope:
+  const gd::Platform& platform;
+  const gd::ProjectScopedContainers& projectScopedContainers;
+  const gd::VariablesContainer* forcedInitialVariablesContainer;
+
+  // Renaming or removing to do:
+  const gd::VariablesContainer& targetVariablesContainer;
+  const std::unordered_map<gd::String, gd::String>& oldToNewVariableNames;
+  const std::unordered_set<gd::String>& removedVariableNames;
+
+  gd::String objectNameToUseForVariableAccessor;
+};
+
+const gd::VariablesContainer*
+EventsVariableReplacer::FindForcedVariablesContainerIfAny(
+    const gd::String& type, const gd::String& lastObjectName) {
+  // Handle legacy pre-scoped variable parameters: in this case, we
+  // force the "scope" at which starts the evalution of variables.
+  if (type == "objectvar") {
+    return GetProjectScopedContainers()
+        .GetObjectsContainersList()
+        .GetObjectOrGroupVariablesContainer(lastObjectName);
+  } else if (type == "globalvar") {
+    return GetProjectScopedContainers()
+        .GetVariablesContainersList()
+        .GetTopMostVariablesContainer();
+  } else if (type == "scenevar") {
+    return GetProjectScopedContainers()
+        .GetVariablesContainersList()
+        .GetBottomMostVariablesContainer();
+  }
+
+  return nullptr;
+}
+
+bool EventsVariableReplacer::DoVisitInstruction(gd::Instruction& instruction,
+                                                bool isCondition) {
+  const auto& metadata = isCondition
+                             ? gd::MetadataProvider::GetConditionMetadata(
+                                   platform, instruction.GetType())
+                             : gd::MetadataProvider::GetActionMetadata(
+                                   platform, instruction.GetType());
+  bool shouldDeleteInstruction = false;
+
+  gd::ParameterMetadataTools::IterateOverParametersWithIndex(
+      instruction.GetParameters(),
+      metadata.GetParameters(),
+      [&](const gd::ParameterMetadata& parameterMetadata,
+          const gd::Expression& parameterValue,
+          size_t parameterIndex,
+          const gd::String& lastObjectName) {
+        const gd::String& type = parameterMetadata.GetType();
+
+        if (!gd::ParameterMetadata::IsExpression("variable", type) &&
+            !gd::ParameterMetadata::IsExpression("number", type) &&
+            !gd::ParameterMetadata::IsExpression("string", type))
+          return;  // Not an expression that can contain variables.
+
+        auto node = parameterValue.GetRootNode();
+        if (node) {
+          ExpressionVariableReplacer renamer(platform,
+                                             GetProjectScopedContainers(),
+                                             targetVariablesContainer,
+                                             oldToNewVariableNames,
+                                             removedVariableNames);
+          renamer.SetForcedInitialVariablesContainer(
+              FindForcedVariablesContainerIfAny(type, lastObjectName));
+          node->Visit(renamer);
+
+          if (renamer.IsRemovedVariableUsed()) {
+            shouldDeleteInstruction = true;
+          } else if (renamer.HasDoneRenaming()) {
+            instruction.SetParameter(
+                parameterIndex, ExpressionParser2NodePrinter::PrintNode(*node));
+          }
+        }
+      });
+
+  return shouldDeleteInstruction;
+}
+
+bool EventsVariableReplacer::DoVisitEventExpression(
+    gd::Expression& expression, const gd::ParameterMetadata& metadata) {
+  const gd::String& type = metadata.GetType();
+
+  if (!gd::ParameterMetadata::IsExpression("variable", type) &&
+      !gd::ParameterMetadata::IsExpression("number", type) &&
+      !gd::ParameterMetadata::IsExpression("string", type))
+    return false;  // Not an expression that can contain variables.
+
+  auto node = expression.GetRootNode();
+  if (node) {
+    ExpressionVariableReplacer renamer(platform,
+                                       GetProjectScopedContainers(),
+                                       targetVariablesContainer,
+                                       oldToNewVariableNames,
+                                       removedVariableNames);
+    renamer.SetForcedInitialVariablesContainer(
+        FindForcedVariablesContainerIfAny(type, ""));
+    node->Visit(renamer);
+
+    if (renamer.IsRemovedVariableUsed()) {
+      return true;
+    } else if (renamer.HasDoneRenaming()) {
+      expression = ExpressionParser2NodePrinter::PrintNode(*node);
+    }
+  }
+
+  return false;
+}
+
+EventsVariableReplacer::~EventsVariableReplacer() {}
+
+}  // namespace gd

Core/GDCore/IDE/Events/EventsVariableReplacer.h

@@ -0,0 +1,60 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+#include <map>
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "GDCore/IDE/Events/ArbitraryEventsWorker.h"
+#include "GDCore/String.h"
+namespace gd {
+class BaseEvent;
+class VariablesContainer;
+class EventsList;
+class Platform;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief Replace in expressions and in parameters of actions or conditions,
+ * references to the name of a variable by another.
+ *
+ * \ingroup IDE
+ */
+class GD_CORE_API EventsVariableReplacer
+    : public ArbitraryEventsWorkerWithContext {
+ public:
+  EventsVariableReplacer(
+      const gd::Platform &platform_,
+      const gd::VariablesContainer &targetVariablesContainer_,
+      const std::unordered_map<gd::String, gd::String> &oldToNewVariableNames_,
+      const std::unordered_set<gd::String> &removedVariableNames_)
+      : platform(platform_),
+        targetVariablesContainer(targetVariablesContainer_),
+        oldToNewVariableNames(oldToNewVariableNames_),
+        removedVariableNames(removedVariableNames_){};
+  virtual ~EventsVariableReplacer();
+
+ private:
+  bool DoVisitInstruction(gd::Instruction &instruction,
+                          bool isCondition) override;
+  bool DoVisitEventExpression(gd::Expression &expression,
+                              const gd::ParameterMetadata &metadata) override;
+
+  const gd::VariablesContainer *FindForcedVariablesContainerIfAny(
+      const gd::String &type, const gd::String &lastObjectName);
+
+  const gd::Platform &platform;
+  const gd::VariablesContainer &targetVariablesContainer;
+  gd::String objectName;
+  const std::unordered_map<gd::String, gd::String> &oldToNewVariableNames;
+  const std::unordered_set<gd::String> &removedVariableNames;
+};
+
+}  // namespace gd

Core/GDCore/IDE/Events/EventsVariablesFinder.cpp

@@ -17,6 +17,7 @@
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/Project/ExternalEvents.h"
 #include "GDCore/IDE/DependenciesAnalyzer.h"
 
@@ -34,14 +35,12 @@ class GD_CORE_API VariableFinderExpressionNodeWorker
  public:
   VariableFinderExpressionNodeWorker(std::set<gd::String>& results_,
                               const gd::Platform &platform_,
-                              const gd::ObjectsContainer &globalObjectsContainer_,
-                              const gd::ObjectsContainer &objectsContainer_,
+                              const gd::ProjectScopedContainers &projectScopedContainers_,
                               const gd::String& parameterType_,
                               const gd::String& objectName_ = "")
       : results(results_),
         platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         parameterType(parameterType_),
         objectName(objectName_){};
   virtual ~VariableFinderExpressionNodeWorker(){};
@@ -60,6 +59,9 @@ class GD_CORE_API VariableFinderExpressionNodeWorker
   void OnVisitNumberNode(NumberNode& node) override {}
   void OnVisitTextNode(TextNode& node) override {}
   void OnVisitVariableNode(VariableNode& node) override {
+    // We don't check variables or object variables here, because object variables only work
+    // if the variable is already declared.
+
     if (node.child) node.child->Visit(*this);
   }
   void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
@@ -70,7 +72,10 @@ class GD_CORE_API VariableFinderExpressionNodeWorker
     node.expression->Visit(*this);
     if (node.child) node.child->Visit(*this);
   }
-  void OnVisitIdentifierNode(IdentifierNode& node) override {}
+  void OnVisitIdentifierNode(IdentifierNode& node) override {
+    // We don't check object variables here, because object variables only work
+    // if the variable is already declared.
+  }
   void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {}
   void OnVisitFunctionCallNode(FunctionCallNode& node) override {
     bool considerFunction = objectName.empty() || node.objectName == objectName;
@@ -79,7 +84,7 @@ class GD_CORE_API VariableFinderExpressionNodeWorker
     const gd::ExpressionMetadata &metadata = isObjectFunction ?
             MetadataProvider::GetObjectAnyExpressionMetadata(
                 platform,
-                GetTypeOfObject(globalObjectsContainer, objectsContainer, objectName),
+                projectScopedContainers.GetObjectsContainersList().GetTypeOfObject(objectName),
                 node.functionName):
             MetadataProvider::GetAnyExpressionMetadata(platform, node.functionName);
 
@@ -110,8 +115,7 @@ class GD_CORE_API VariableFinderExpressionNodeWorker
 
  private:
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
 
   std::set<gd::String>& results;  ///< Reference to the std::set where argument
                                   ///< values must be stored.
@@ -163,8 +167,7 @@ class GD_CORE_API VariableFinderEventWorker
           VariableFinderExpressionNodeWorker searcher(
               results,
               platform,
-              GetGlobalObjectsContainer(),
-              GetObjectsContainer(),
+              GetProjectScopedContainers(),
               parameterType,
               objectName);
           node->Visit(searcher);
@@ -252,7 +255,8 @@ void EventsVariablesFinder::FindArgumentsInEventsAndDependencies(
                                         platform,
                                         parameterType,
                                         objectName);
-  eventWorker.Launch(layout.GetEvents(), project, layout);
+  eventWorker.Launch(layout.GetEvents(),
+      gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout));
 
   DependenciesAnalyzer dependenciesAnalyzer = DependenciesAnalyzer(project, layout);
   dependenciesAnalyzer.Analyze();
@@ -263,7 +267,8 @@ void EventsVariablesFinder::FindArgumentsInEventsAndDependencies(
                                           platform,
                                           parameterType,
                                           objectName);
-    eventWorker.Launch(externalEvents.GetEvents(), project, layout);
+    eventWorker.Launch(externalEvents.GetEvents(),
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout));
   }
   for (const gd::String& sceneName : dependenciesAnalyzer.GetScenesDependencies()) {
     const gd::Layout& dependencyLayout = project.GetLayout(sceneName);
@@ -272,7 +277,8 @@ void EventsVariablesFinder::FindArgumentsInEventsAndDependencies(
                                           platform,
                                           parameterType,
                                           objectName);
-    eventWorker.Launch(dependencyLayout.GetEvents(), project, dependencyLayout);
+    eventWorker.Launch(dependencyLayout.GetEvents(),
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, dependencyLayout));
   }
 }
 

Core/GDCore/IDE/Events/ExpressionCompletionFinder.cpp

@@ -10,21 +10,15 @@ namespace gd {
 const gd::ParameterMetadata
     ExpressionCompletionDescription::badParameterMetadata;
 
+const gd::ObjectConfiguration
+    ExpressionCompletionDescription::badObjectConfiguration;
+
 /**
  * \brief Turn an ExpressionCompletionDescription to a string.
  */
 std::ostream& operator<<(std::ostream& os,
                          ExpressionCompletionDescription const& value) {
-  os << "{ " << value.GetCompletionKind() << ", " << value.GetType() << ", "
-     << value.GetPrefix() << ", " << value.GetObjectName() << ", "
-     << value.GetBehaviorName() << ", "
-     << (value.IsExact() ? "exact" : "non-exact") << ", "
-     << (value.IsLastParameter() ? "last parameter" : "not last parameter")
-     << ", "
-     << (value.HasParameterMetadata()
-             ? gd::String::From(&value.GetParameterMetadata())
-             : "no parameter metadata")
-     << " }";
+  os << value.ToString();
   return os;
 }
 

Core/GDCore/IDE/Events/ExpressionLeftSideTypeFinder.h

@@ -20,6 +20,7 @@
 namespace gd {
 class Expression;
 class ObjectsContainer;
+class ObjectsContainersList;
 class Platform;
 class ParameterMetadata;
 class ExpressionMetadata;
@@ -40,11 +41,10 @@ class GD_CORE_API ExpressionLeftSideTypeFinder : public ExpressionParser2NodeWor
    * operations.
    */
   static const gd::String GetType(const gd::Platform &platform,
-                      const gd::ObjectsContainer &globalObjectsContainer,
-                      const gd::ObjectsContainer &objectsContainer,
+                      const gd::ObjectsContainersList &objectsContainersList,
                       gd::ExpressionNode& node) {
     gd::ExpressionLeftSideTypeFinder typeFinder(
-        platform, globalObjectsContainer, objectsContainer);
+        platform, objectsContainersList);
     node.Visit(typeFinder);
     return typeFinder.GetType();
   }
@@ -53,11 +53,9 @@ class GD_CORE_API ExpressionLeftSideTypeFinder : public ExpressionParser2NodeWor
 
  protected:
   ExpressionLeftSideTypeFinder(const gd::Platform &platform_,
-                       const gd::ObjectsContainer &globalObjectsContainer_,
-                       const gd::ObjectsContainer &objectsContainer_)
+                       const gd::ObjectsContainersList &objectsContainersList_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        objectsContainersList(objectsContainersList_),
         type("unknown") {};
 
   const gd::String &GetType() {
@@ -85,7 +83,7 @@ class GD_CORE_API ExpressionLeftSideTypeFinder : public ExpressionParser2NodeWor
   }
   void OnVisitFunctionCallNode(FunctionCallNode& node) override {
     const gd::ExpressionMetadata &metadata = MetadataProvider::GetFunctionCallMetadata(
-        platform, globalObjectsContainer, objectsContainer, node);
+        platform, objectsContainersList, node);
     if (gd::MetadataProvider::IsBadExpressionMetadata(metadata)) {
       type = "unknown";
     }
@@ -113,8 +111,7 @@ class GD_CORE_API ExpressionLeftSideTypeFinder : public ExpressionParser2NodeWor
   gd::String type;
 
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ObjectsContainersList &objectsContainersList;
   const gd::String rootType;
 };
 

Core/GDCore/IDE/Events/ExpressionTypeFinder.h

@@ -21,6 +21,7 @@
 namespace gd {
 class Expression;
 class ObjectsContainer;
+class ObjectsContainersList;
 class Platform;
 class ParameterMetadata;
 class ExpressionMetadata;
@@ -31,7 +32,7 @@ namespace gd {
 /**
  * \brief Find the type of the expression or sub-expression that a given node
  * represents.
- * 
+ *
  * The type returned by this worker is a mix of:
  * - an expected type looking up like a parameter declaration
  * - an actual type looking down, but only looking at the most left branch
@@ -50,12 +51,11 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
    * sub-expression that a given node represents.
    */
   static const gd::String GetType(const gd::Platform &platform,
-                      const gd::ObjectsContainer &globalObjectsContainer,
-                      const gd::ObjectsContainer &objectsContainer,
+                      const gd::ObjectsContainersList &objectsContainersList,
                       const gd::String &rootType,
                       gd::ExpressionNode& node) {
     gd::ExpressionTypeFinder typeFinder(
-        platform, globalObjectsContainer, objectsContainer, rootType);
+        platform, objectsContainersList, rootType);
     node.Visit(typeFinder);
     return typeFinder.GetType();
   }
@@ -64,12 +64,10 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
 
  protected:
   ExpressionTypeFinder(const gd::Platform &platform_,
-                       const gd::ObjectsContainer &globalObjectsContainer_,
-                       const gd::ObjectsContainer &objectsContainer_,
+                       const gd::ObjectsContainersList &objectsContainersList_,
                        const gd::String &rootType_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        objectsContainersList(objectsContainersList_),
         rootType(rootType_),
         type(ExpressionTypeFinder::unknownType),
         child(nullptr) {};
@@ -114,9 +112,8 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
       type = ExpressionTypeFinder::unknownType;
     }
     auto leftSideType = gd::ExpressionLeftSideTypeFinder::GetType(
-        platform, 
-        globalObjectsContainer,
-        objectsContainer,
+        platform,
+        objectsContainersList,
         node);
     if (leftSideType == ExpressionTypeFinder::numberType
      || leftSideType == ExpressionTypeFinder::stringType) {
@@ -129,7 +126,7 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
   void OnVisitFunctionCallNode(FunctionCallNode& node) override {
     if (child == nullptr) {
       const gd::ExpressionMetadata &metadata = MetadataProvider::GetFunctionCallMetadata(
-          platform, globalObjectsContainer, objectsContainer, node);
+          platform, objectsContainersList, node);
       if (gd::MetadataProvider::IsBadExpressionMetadata(metadata)) {
         VisitParent(node);
       }
@@ -141,8 +138,7 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
       const gd::ParameterMetadata* parameterMetadata =
           gd::MetadataProvider::GetFunctionCallParameterMetadata(
               platform,
-              globalObjectsContainer,
-              objectsContainer,
+              objectsContainersList,
               node,
               *child);
       if (parameterMetadata == nullptr || parameterMetadata->GetType().empty()) {
@@ -162,9 +158,8 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
     }
     else if (rootType == ExpressionTypeFinder::numberOrStringType) {
       auto leftSideType = gd::ExpressionLeftSideTypeFinder::GetType(
-          platform, 
-          globalObjectsContainer,
-          objectsContainer,
+          platform,
+          objectsContainersList,
           node);
       if (leftSideType == ExpressionTypeFinder::numberType
        || leftSideType == ExpressionTypeFinder::stringType) {
@@ -188,8 +183,7 @@ class GD_CORE_API ExpressionTypeFinder : public ExpressionParser2NodeWorker {
   ExpressionNode *child;
 
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ObjectsContainersList &objectsContainersList;
   const gd::String rootType;
 };
 

Core/GDCore/IDE/Events/ExpressionValidator.cpp

@@ -11,16 +11,20 @@
 
 #include "GDCore/CommonTools.h"
 #include "GDCore/Events/Expression.h"
+#include "GDCore/Events/Parsers/ExpressionParser2.h"
 #include "GDCore/Extensions/Metadata/ExpressionMetadata.h"
 #include "GDCore/Extensions/Metadata/InstructionMetadata.h"
 #include "GDCore/Extensions/Metadata/MetadataProvider.h"
 #include "GDCore/Extensions/Metadata/ObjectMetadata.h"
 #include "GDCore/Extensions/Platform.h"
 #include "GDCore/Project/Layout.h"
+#include "GDCore/Project/ObjectsContainersList.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Project/Variable.h"
+#include "GDCore/Project/VariablesContainersList.h"
 #include "GDCore/Tools/Localization.h"
 #include "GDCore/Tools/MakeUnique.h"
-#include "GDCore/Events/Parsers/ExpressionParser2.h"
 
 using namespace std;
 
@@ -59,61 +63,167 @@ size_t GetMaximumParametersNumber(
 
 }  // namespace
 
-ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::FunctionCallNode& function) {
+bool ExpressionValidator::ValidateObjectVariableOrVariableOrProperty(
+    const gd::IdentifierNode& identifier) {
+  auto validateVariableTypeForExpression =
+      [this, &identifier](gd::Variable::Type type) {
+        // Collections type can't be used directly in expressions, a child
+        // must be accessed.
+        if (type == Variable::Structure) {
+          RaiseTypeError(_("You need to specify the name of the child variable "
+                           "to access. For example: `MyVariable.child`."),
+                         identifier.identifierNameLocation);
+        } else if (type == Variable::Array) {
+          RaiseTypeError(_("You need to specify the name of the child variable "
+                           "to access. For example: `MyVariable[0]`."),
+                         identifier.identifierNameLocation);
 
+        } else {
+          // Number, string or boolean variables can be used in expressions.
+          return;
+        }
+      };
+
+  const auto& variablesContainersList = projectScopedContainers.GetVariablesContainersList();
+  const auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+  const auto& propertiesContainersList = projectScopedContainers.GetPropertiesContainersList();
+  const auto& parametersVectorsList = projectScopedContainers.GetParametersVectorsList();
+
+  return projectScopedContainers.MatchIdentifierWithName<bool>(identifier.identifierName,
+    [&]() {
+      // This represents an object.
+      if (identifier.childIdentifierName.empty()) {
+        RaiseTypeError(_("An object variable or expression should be entered."),
+                        identifier.identifierNameLocation);
+        return true; // We should have found a variable.
+      }
+
+      if (!objectsContainersList.HasObjectOrGroupWithVariableNamed(identifier.identifierName, identifier.childIdentifierName)) {
+        RaiseTypeError(_("This variable does not exist on this object or group."),
+                        identifier.identifierNameLocation);
+        return true; // We should have found a variable.
+      }
+
+      return true; // We found a variable.
+    }, [&]() {
+      // This is a variable.
+
+      // Try to identify a declared variable with the name (and maybe the child
+      // variable).
+
+      const gd::Variable& variable =
+          variablesContainersList.Get(identifier.identifierName);
+
+      if (identifier.childIdentifierName.empty()) {
+        // Just the root variable is accessed, check it can be used in an
+        // expression.
+        validateVariableTypeForExpression(variable.GetType());
+
+        return true; // We found a variable.
+      } else {
+        // A child variable is accessed, check it can be used in an expression.
+        if (!variable.HasChild(identifier.childIdentifierName)) {
+          RaiseTypeError(_("No child variable with this name found."),
+                        identifier.childIdentifierNameLocation);
+
+          return true; // We should have found a variable.
+        }
+
+        const gd::Variable& childVariable =
+            variable.GetChild(identifier.childIdentifierName);
+        return true; // We found a variable.
+      }
+    }, [&]() {
+      // This is a property.
+      if (!identifier.childIdentifierName.empty()) {
+        RaiseTypeError(_("Accessing a child variable of a property is not possible - just write the property name."),
+            identifier.childIdentifierNameLocation);
+        return true; // We found a property, even if the child is not allowed.
+      }
+
+      return true; // We found a property.
+    }, [&]() {
+      // This is a parameter.
+      if (!identifier.childIdentifierName.empty()) {
+        RaiseTypeError(_("Accessing a child variable of a parameter is not possible - just write the parameter name."),
+            identifier.childIdentifierNameLocation);
+        return true; // We found a parameter, even if the child is not allowed.
+      }
+
+      const auto& parameter = gd::ParameterMetadataTools::Get(parametersVectorsList, identifier.identifierName);
+      const auto& valueTypeMetadata = parameter.GetValueTypeMetadata();
+      if (!valueTypeMetadata.IsNumber() && !valueTypeMetadata.IsString() && !valueTypeMetadata.IsBoolean()) {
+        RaiseTypeError(_("This parameter is not a string, number or boolean - it can't be used in an expression."),
+            identifier.identifierNameLocation);
+        return true; // We found a parameter, even though the type is incompatible.
+      }
+
+      return true; // We found a parameter.
+    }, [&]() {
+      // This is something else.
+      return false;
+    });
+}
+
+ExpressionValidator::Type ExpressionValidator::ValidateFunction(
+    const gd::FunctionCallNode& function) {
   ReportAnyError(function);
-  
-  gd::String objectType = function.objectName.empty() ? "" :
-      GetTypeOfObject(globalObjectsContainer, objectsContainer, function.objectName);
-      
-  gd::String behaviorType = function.behaviorName.empty() ? "" :
-      GetTypeOfBehavior(globalObjectsContainer, objectsContainer, function.behaviorName);
 
-  const gd::ExpressionMetadata &metadata = function.behaviorName.empty() ?
-      function.objectName.empty() ?
-          MetadataProvider::GetAnyExpressionMetadata(platform, function.functionName) :
-          MetadataProvider::GetObjectAnyExpressionMetadata(
-              platform, objectType, function.functionName) : 
-      MetadataProvider::GetBehaviorAnyExpressionMetadata(
-            platform, behaviorType, function.functionName);
+  auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+
+  gd::String objectType =
+      function.objectName.empty()
+          ? ""
+          : objectsContainersList.GetTypeOfObject(function.objectName);
+
+  gd::String behaviorType = function.behaviorName.empty()
+                                ? ""
+                                : objectsContainersList.GetTypeOfBehavior(function.behaviorName);
+
+  const gd::ExpressionMetadata& metadata =
+      function.behaviorName.empty()
+          ? function.objectName.empty()
+                ? MetadataProvider::GetAnyExpressionMetadata(
+                      platform, function.functionName)
+                : MetadataProvider::GetObjectAnyExpressionMetadata(
+                      platform, objectType, function.functionName)
+          : MetadataProvider::GetBehaviorAnyExpressionMetadata(
+                platform, behaviorType, function.functionName);
 
   Type returnType = StringToType(metadata.GetReturnType());
 
   if (!function.objectName.empty() &&
-      !globalObjectsContainer.HasObjectNamed(function.objectName) &&
-      !globalObjectsContainer.GetObjectGroups().Has(function.objectName) &&
-      !objectsContainer.HasObjectNamed(function.objectName) &&
-      !objectsContainer.GetObjectGroups().Has(function.objectName)) {
+      !objectsContainersList.HasObjectOrGroupNamed(function.objectName)) {
     RaiseTypeError(_("This object doesn't exist."),
-                   function.objectNameLocation, /*isFatal=*/false);
+                   function.objectNameLocation,
+                   /*isFatal=*/false);
     return returnType;
   }
 
   if (!function.behaviorName.empty() &&
-      !gd::HasBehaviorInObjectOrGroup(globalObjectsContainer, objectsContainer,
-                                     function.objectName,
-                                     function.behaviorName)) {
+      !objectsContainersList.HasBehaviorInObjectOrGroup(function.objectName,
+                                      function.behaviorName)) {
     RaiseTypeError(_("This behavior is not attached to this object."),
-                   function.behaviorNameLocation, /*isFatal=*/false);
+                   function.behaviorNameLocation,
+                   /*isFatal=*/false);
     return returnType;
   }
 
   if (!function.objectName.empty() &&
-    // If the function needs a capability on the object that may not be covered
-    // by all objects, check it now.
-  !metadata.GetRequiredBaseObjectCapability().empty()) {
-    const gd::ObjectMetadata &objectMetadata =
+      // If the function needs a capability on the object that may not be
+      // covered by all objects, check it now.
+      !metadata.GetRequiredBaseObjectCapability().empty()) {
+    const gd::ObjectMetadata& objectMetadata =
         MetadataProvider::GetObjectMetadata(platform, objectType);
   }
 
   if (gd::MetadataProvider::IsBadExpressionMetadata(metadata)) {
-    RaiseError(
-        "invalid_function_name",
-        _("Cannot find an expression with this name: ") +
-            function.functionName + "\n" +
-            _("Double check that you've not made any typo in the name."),
-        function.location);
-      return returnType;
+    RaiseError("invalid_function_name",
+               _("Cannot find an expression with this name: ") +
+                   function.functionName + "\n" +
+                   _("Double check that you've not made any typo in the name."),
+               function.location);
+    return returnType;
   }
 
   // Validate the type of the function
@@ -128,9 +238,9 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
     } else if (parentType != Type::Number &&
                parentType != Type::NumberOrString) {
       RaiseTypeError(_("You tried to use an expression that returns a "
-                              "number, but another type is expected:") +
-                              " " + TypeToString(parentType),
-                            function.location);
+                       "number, but another type is expected:") +
+                         " " + TypeToString(parentType),
+                     function.location);
       return returnType;
     }
   } else if (returnType == Type::String) {
@@ -144,16 +254,16 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
     } else if (parentType != Type::String &&
                parentType != Type::NumberOrString) {
       RaiseTypeError(_("You tried to use an expression that returns a "
-                              "string, but another type is expected:") +
-                              " " + TypeToString(parentType),
-                            function.location);
+                       "string, but another type is expected:") +
+                         " " + TypeToString(parentType),
+                     function.location);
       return returnType;
     }
   } else {
     if (parentType != returnType) {
       RaiseTypeError(
-          _("You tried to use an expression with the wrong return type:") + " " +
-            TypeToString(returnType),
+          _("You tried to use an expression with the wrong return type:") +
+              " " + TypeToString(returnType),
           function.location);
       return returnType;
     }
@@ -162,10 +272,12 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
   // Validate parameters count
   size_t minParametersCount = GetMinimumParametersNumber(
       metadata.parameters,
-      ExpressionParser2::WrittenParametersFirstIndex(function.objectName, function.behaviorName));
+      ExpressionParser2::WrittenParametersFirstIndex(function.objectName,
+                                                     function.behaviorName));
   size_t maxParametersCount = GetMaximumParametersNumber(
       metadata.parameters,
-      ExpressionParser2::WrittenParametersFirstIndex(function.objectName, function.behaviorName));
+      ExpressionParser2::WrittenParametersFirstIndex(function.objectName,
+                                                     function.behaviorName));
   if (function.parameters.size() < minParametersCount ||
       function.parameters.size() > maxParametersCount) {
     gd::String expectedCountMessage =
@@ -179,28 +291,29 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
     if (function.parameters.size() < minParametersCount) {
       RaiseError(
           "too_few_parameters",
-          _("You have not entered enough parameters for the expression.") + " " +
-              expectedCountMessage,
+          _("You have not entered enough parameters for the expression.") +
+              " " + expectedCountMessage,
           function.location);
     } else {
       RaiseError(
           "extra_parameter",
           _("This parameter was not expected by this expression. Remove it "
-          "or verify that you've entered the proper expression name.") + " " +
-              expectedCountMessage,
-          ExpressionParserLocation(
-              function.parameters[maxParametersCount]->location.GetStartPosition(),
-              function.location.GetEndPosition() - 1));
+            "or verify that you've entered the proper expression name.") +
+              " " + expectedCountMessage,
+          ExpressionParserLocation(function.parameters[maxParametersCount]
+                                       ->location.GetStartPosition(),
+                                   function.location.GetEndPosition() - 1));
     }
     return returnType;
   }
 
   // TODO: reverse the order of diagnostic?
   size_t writtenParametersFirstIndex =
-      ExpressionParser2::WrittenParametersFirstIndex(
-          function.objectName, function.behaviorName);
+      ExpressionParser2::WrittenParametersFirstIndex(function.objectName,
+                                                     function.behaviorName);
   int metadataIndex = writtenParametersFirstIndex;
-  for (int parameterIndex = 0; parameterIndex < function.parameters.size(); parameterIndex++) {
+  for (int parameterIndex = 0; parameterIndex < function.parameters.size();
+       parameterIndex++) {
     auto& parameter = function.parameters[parameterIndex];
     while (metadata.GetParameters()[metadataIndex].IsCodeOnly()) {
       // The sizes are already checked above.
@@ -208,45 +321,45 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
     }
     auto& parameterMetadata = metadata.GetParameters()[metadataIndex];
 
-    if (!parameterMetadata.IsOptional() || dynamic_cast<EmptyNode*>(parameter.get()) == nullptr) {
+    if (!parameterMetadata.IsOptional() ||
+        dynamic_cast<EmptyNode*>(parameter.get()) == nullptr) {
       auto currentParentType = parentType;
       parentType = StringToType(parameterMetadata.GetType());
       parameter->Visit(*this);
       parentType = currentParentType;
-      
-      const gd::String &expectedParameterType = parameterMetadata.GetType();
+
+      const gd::String& expectedParameterType = parameterMetadata.GetType();
       if (gd::ParameterMetadata::IsExpression(
-          ExpressionValidator::variableTypeString, expectedParameterType)) {
-        if (dynamic_cast<IdentifierNode *>(parameter.get()) == nullptr
-         && dynamic_cast<VariableNode *>(parameter.get()) == nullptr) {
-          RaiseError(
-                  "malformed_variable_parameter",
-                  _("A variable name was expected but something else was "
-                    "written. Enter just the name of the variable for this "
-                    "parameter."),
-                parameter->location);
+              ExpressionValidator::variableTypeString, expectedParameterType)) {
+        if (dynamic_cast<IdentifierNode*>(parameter.get()) == nullptr &&
+            dynamic_cast<VariableNode*>(parameter.get()) == nullptr) {
+          RaiseError("malformed_variable_parameter",
+                     _("A variable name was expected but something else was "
+                       "written. Enter just the name of the variable for this "
+                       "parameter."),
+                     parameter->location);
         }
       } else if (gd::ParameterMetadata::IsObject(expectedParameterType)) {
-        if (dynamic_cast<IdentifierNode *>(parameter.get()) == nullptr) {
-          RaiseError(
-                  "malformed_object_parameter",
-                  _("An object name was expected but something else was "
-                    "written. Enter just the name of the object for this "
-                    "parameter."),
-                parameter->location);
+        if (dynamic_cast<IdentifierNode*>(parameter.get()) == nullptr) {
+          RaiseError("malformed_object_parameter",
+                     _("An object name was expected but something else was "
+                       "written. Enter just the name of the object for this "
+                       "parameter."),
+                     parameter->location);
         }
       }
       // String and number are already checked in children.
       else if (!gd::ParameterMetadata::IsExpression(
-               ExpressionValidator::numberTypeString, expectedParameterType)
-            && !gd::ParameterMetadata::IsExpression(
-              ExpressionValidator::stringTypeString, expectedParameterType)) {
-        RaiseError(
-                "unknown_parameter_type",
-                _("This function is improperly set up. Reach out to the "
-                  "extension developer or a GDevelop maintainer to fix "
-                  "this issue"),
-                parameter->location);
+                   ExpressionValidator::numberTypeString,
+                   expectedParameterType) &&
+               !gd::ParameterMetadata::IsExpression(
+                   ExpressionValidator::stringTypeString,
+                   expectedParameterType)) {
+        RaiseError("unknown_parameter_type",
+                   _("This function is improperly set up. Reach out to the "
+                     "extension developer or a GDevelop maintainer to fix "
+                     "this issue"),
+                   parameter->location);
       }
     }
     metadataIndex++;
@@ -254,55 +367,60 @@ ExpressionValidator::Type ExpressionValidator::ValidateFunction(const gd::Functi
   return returnType;
 }
 
-  // TODO factorize in a file with an enum and helpers?
-  const gd::String ExpressionValidator::unknownTypeString = "unknown";
-  const gd::String ExpressionValidator::numberTypeString = "number";
-  const gd::String ExpressionValidator::stringTypeString = "string";
-  const gd::String ExpressionValidator::numberOrStringTypeString = "number|string";
-  const gd::String ExpressionValidator::variableTypeString = "variable";
-  const gd::String ExpressionValidator::objectTypeString = "object";
-  const gd::String ExpressionValidator::emptyTypeString = "empty";
+// TODO factorize in a file with an enum and helpers?
+const gd::String ExpressionValidator::unknownTypeString = "unknown";
+const gd::String ExpressionValidator::numberTypeString = "number";
+const gd::String ExpressionValidator::stringTypeString = "string";
+const gd::String ExpressionValidator::numberOrStringTypeString =
+    "number|string";
+const gd::String ExpressionValidator::variableTypeString = "variable";
+const gd::String ExpressionValidator::objectTypeString = "object";
+const gd::String ExpressionValidator::emptyTypeString = "empty";
 
-  const gd::String &ExpressionValidator::TypeToString(Type type) {
-    switch (type) {
-      case Type::Unknown:
+const gd::String& ExpressionValidator::TypeToString(Type type) {
+  switch (type) {
+    case Type::Unknown:
       return unknownTypeString;
-      case Type::Number:
+    case Type::Number:
       return numberTypeString;
-      case Type::String:
+    case Type::String:
       return stringTypeString;
-      case Type::NumberOrString:
+    case Type::NumberOrString:
       return numberOrStringTypeString;
-      case Type::Variable:
+    case Type::Variable:
       return variableTypeString;
-      case Type::Object:
+    case Type::Object:
       return objectTypeString;
-      case Type::Empty:
+    case Type::Empty:
       return emptyTypeString;
-    }
-    return unknownTypeString;
   }
+  return unknownTypeString;
+}
 
-  ExpressionValidator::Type ExpressionValidator::StringToType(const gd::String &type) {
-    if (type == ExpressionValidator::numberTypeString
-     || gd::ParameterMetadata::IsExpression(ExpressionValidator::numberTypeString, type)) {
-      return Type::Number;
-    }
-    if (type == ExpressionValidator::stringTypeString
-     || gd::ParameterMetadata::IsExpression(ExpressionValidator::stringTypeString, type)) {
-      return Type::String;
-    }
-    if (type == ExpressionValidator::numberOrStringTypeString) {
-      return Type::NumberOrString;
-    }
-    if (type == ExpressionValidator::variableTypeString
-     || gd::ParameterMetadata::IsExpression(ExpressionValidator::variableTypeString, type)) {
-      return Type::Variable;
-    }
-    if (type == ExpressionValidator::objectTypeString
-     || gd::ParameterMetadata::IsObject(type)) {
-      return Type::Object;
-    }
-    return Type::Unknown;
+ExpressionValidator::Type ExpressionValidator::StringToType(
+    const gd::String& type) {
+  if (type == ExpressionValidator::numberTypeString ||
+      gd::ParameterMetadata::IsExpression(ExpressionValidator::numberTypeString,
+                                          type)) {
+    return Type::Number;
   }
+  if (type == ExpressionValidator::stringTypeString ||
+      gd::ParameterMetadata::IsExpression(ExpressionValidator::stringTypeString,
+                                          type)) {
+    return Type::String;
+  }
+  if (type == ExpressionValidator::numberOrStringTypeString) {
+    return Type::NumberOrString;
+  }
+  if (type == ExpressionValidator::variableTypeString ||
+      gd::ParameterMetadata::IsExpression(
+          ExpressionValidator::variableTypeString, type)) {
+    return Type::Variable;
+  }
+  if (type == ExpressionValidator::objectTypeString ||
+      gd::ParameterMetadata::IsObject(type)) {
+    return Type::Object;
+  }
+  return Type::Unknown;
+}
 }  // namespace gd

Core/GDCore/IDE/Events/ExpressionValidator.h

@@ -13,13 +13,18 @@
 #include "GDCore/Tools/MakeUnique.h"
 #include "GDCore/Tools/Localization.h"
 #include "GDCore/Extensions/Metadata/ExpressionMetadata.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Project/VariablesContainersList.h"
 
 namespace gd {
 class Expression;
 class ObjectsContainer;
+class VariablesContainer;
 class Platform;
 class ParameterMetadata;
 class ExpressionMetadata;
+class VariablesContainersList;
+class ProjectScopedContainers;
 }  // namespace gd
 
 namespace gd {
@@ -33,14 +38,13 @@ namespace gd {
 class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
  public:
   ExpressionValidator(const gd::Platform &platform_,
-                      const gd::ObjectsContainer &globalObjectsContainer_,
-                      const gd::ObjectsContainer &objectsContainer_,
+                      const gd::ProjectScopedContainers & projectScopedContainers_,
                       const gd::String &rootType_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         parentType(StringToType(gd::ParameterMetadata::GetExpressionValueType(rootType_))),
-        childType(Type::Unknown) {};
+        childType(Type::Unknown),
+        forbidsUsageOfBracketsBecauseParentIsObject(false) {};
   virtual ~ExpressionValidator(){};
 
   /**
@@ -48,11 +52,10 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
    * any error including non-fatal ones.
    */
   static bool HasNoErrors(const gd::Platform &platform,
-                      const gd::ObjectsContainer &globalObjectsContainer,
-                      const gd::ObjectsContainer &objectsContainer,
+                      const gd::ProjectScopedContainers & projectScopedContainers,
                       const gd::String &rootType,
                       gd::ExpressionNode& node) {
-    gd::ExpressionValidator validator(platform, globalObjectsContainer, objectsContainer, rootType);
+    gd::ExpressionValidator validator(platform, projectScopedContainers, rootType);
     node.Visit(validator);
     return validator.GetAllErrors().empty();
   }
@@ -82,7 +85,7 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
   }
   void OnVisitOperatorNode(OperatorNode& node) override {
     ReportAnyError(node);
-    
+
     node.leftHandSide->Visit(*this);
     const Type leftType = childType;
 
@@ -185,28 +188,69 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
   }
   void OnVisitVariableNode(VariableNode& node) override {
     ReportAnyError(node);
-    if (node.child) {
-      node.child->Visit(*this);
-    }
-    childType = Type::Variable;
-    if (parentType == Type::String) {
-      RaiseTypeError(_("Variables must be surrounded by VariableString()."),
-                     node.location);
-    } else if (parentType == Type::Number) {
-      RaiseTypeError(_("Variables must be surrounded by Variable()."),
-                     node.location);
-    } else if (parentType == Type::NumberOrString) {
-      RaiseTypeError(
-          _("Variables must be surrounded by Variable() or VariableString()."),
-          node.location);
-    } else if (parentType != Type::Variable) {
+
+    if (parentType == Type::Variable) {
+      childType = Type::Variable;
+
+      if (node.child) {
+        node.child->Visit(*this);
+      }
+    } else if (parentType == Type::String || parentType == Type::Number || parentType == Type::NumberOrString) {
+      // The node represents a variable or an object variable in an expression waiting for its *value* to be returned.
+      childType = parentType;
+
+      const auto& variablesContainersList = projectScopedContainers.GetVariablesContainersList();
+      const auto& objectsContainersList = projectScopedContainers.GetObjectsContainersList();
+      const auto& propertiesContainerList = projectScopedContainers.GetPropertiesContainersList();
+
+      forbidsUsageOfBracketsBecauseParentIsObject = false;
+      projectScopedContainers.MatchIdentifierWithName<void>(node.name,
+        [&]() {
+          // This represents an object.
+
+          // While understood by the parser, it's forbidden to use the bracket notation just after
+          // an object name (`MyObject["MyVariable"]`).
+          forbidsUsageOfBracketsBecauseParentIsObject = true;
+        }, [&]() {
+          // This is a variable.
+        }, [&]() {
+          // This is a property.
+          // Being in this node implies that there is at least a child - which is not supported for properties.
+          RaiseTypeError(_("Accessing a child variable of a property is not possible - just write the property name."),
+              node.location);
+        }, [&]() {
+          // This is a parameter.
+          // Being in this node implies that there is at least a child - which is not supported for parameters.
+          RaiseTypeError(_("Accessing a child variable of a parameter is not possible - just write the parameter name."),
+              node.location);
+        }, [&]() {
+          // This is something else.
+          RaiseTypeError(_("No object, variable or property with this name found."),
+              node.location);
+        });
+
+      if (node.child) {
+        node.child->Visit(*this);
+      }
+
+      forbidsUsageOfBracketsBecauseParentIsObject = false;
+    } else {
       RaiseTypeError(_("You entered a variable, but this type was expected:") +
                          " " + TypeToString(parentType),
                      node.location);
+
+      if (node.child) {
+        node.child->Visit(*this);
+      }
     }
   }
   void OnVisitVariableAccessorNode(VariableAccessorNode& node) override {
     ReportAnyError(node);
+
+    // In the case we accessed an object variable (`MyObject.MyVariable`),
+    // brackets can now be used (`MyObject.MyVariable["MyChildVariable"]` is now valid).
+    forbidsUsageOfBracketsBecauseParentIsObject = false;
+
     if (node.child) {
       node.child->Visit(*this);
     }
@@ -215,6 +259,15 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
       VariableBracketAccessorNode& node) override {
     ReportAnyError(node);
 
+    if (forbidsUsageOfBracketsBecauseParentIsObject) {
+      RaiseError("brackets_not_allowed_for_objects",
+                 _("You can't use the brackets to access an object variable. "
+                   "Use a dot followed by the variable name, like this: "
+                   "`MyObject.MyVariable`."),
+                 node.location);
+    }
+    forbidsUsageOfBracketsBecauseParentIsObject = false;
+
     Type currentParentType = parentType;
     parentType = Type::NumberOrString;
     node.expression->Visit(*this);
@@ -227,19 +280,29 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
   void OnVisitIdentifierNode(IdentifierNode& node) override {
     ReportAnyError(node);
     if (parentType == Type::String) {
-      RaiseTypeError(_("You must wrap your text inside double quotes "
-                            "(example: \"Hello world\")."),
-                          node.location);
+      if (!ValidateObjectVariableOrVariableOrProperty(node)) {
+        // The identifier is not a variable, so either the variable is not properly declared
+        // or it's a text without quotes.
+        RaiseTypeError(_("You must wrap your text inside double quotes "
+                              "(example: \"Hello world\")."),
+                            node.location);
+      }
     }
     else if (parentType == Type::Number) {
-      RaiseTypeError(
-          _("You must enter a number."), node.location);
+      if (!ValidateObjectVariableOrVariableOrProperty(node)) {
+        // The identifier is not a variable, so the variable is not properly declared.
+        RaiseTypeError(
+            _("You must enter a number."), node.location);
+      }
     }
     else if (parentType == Type::NumberOrString) {
-      RaiseTypeError(
-          _("You must enter a number or a text, wrapped inside double quotes "
-            "(example: \"Hello world\")."),
-          node.location);
+      if (!ValidateObjectVariableOrVariableOrProperty(node)) {
+        // The identifier is not a variable, so either the variable is not properly declared
+        // or it's a text without quotes.
+        RaiseTypeError(
+            _("You must enter a number or a text, wrapped inside double quotes (example: \"Hello world\"), or a variable name."),
+            node.location);
+      }
     }
     else if (parentType != Type::Object && parentType != Type::Variable) {
       // It can't happen.
@@ -278,6 +341,7 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
  private:
   enum Type {Unknown = 0, Number, String, NumberOrString, Variable, Object, Empty};
   Type ValidateFunction(const gd::FunctionCallNode& function);
+  bool ValidateObjectVariableOrVariableOrProperty(const gd::IdentifierNode& identifier);
 
   void ReportAnyError(const ExpressionNode& node, bool isFatal = true) {
     if (node.diagnostic && node.diagnostic->IsError()) {
@@ -291,7 +355,7 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
     }
   }
 
-  void RaiseError(const gd::String &type, 
+  void RaiseError(const gd::String &type,
       const gd::String &message, const ExpressionParserLocation &location, bool isFatal = true) {
     auto diagnostic = gd::make_unique<ExpressionParserError>(
         type, message, location);
@@ -329,11 +393,11 @@ class GD_CORE_API ExpressionValidator : public ExpressionParser2NodeWorker {
   std::vector<ExpressionParserDiagnostic*> fatalErrors;
   std::vector<ExpressionParserDiagnostic*> allErrors;
   std::vector<std::unique_ptr<ExpressionParserDiagnostic>> supplementalErrors;
-  Type childType;
-  Type parentType;
+  Type childType; ///< The type "discovered" down the tree and passed up.
+  Type parentType; ///< The type "required" by the top of the tree.
+  bool forbidsUsageOfBracketsBecauseParentIsObject;
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
 };
 
 }  // namespace gd

Core/GDCore/IDE/Events/ExpressionVariableOwnerFinder.h

@@ -15,6 +15,7 @@
 #include "GDCore/Extensions/Metadata/ObjectMetadata.h"
 #include "GDCore/Extensions/Metadata/ParameterMetadata.h"
 #include "GDCore/Project/Layout.h"  // For GetTypeOfObject and GetTypeOfBehavior
+#include "GDCore/Project/ObjectsContainersList.h"
 #include "GDCore/Tools/Localization.h"
 
 namespace gd {
@@ -31,6 +32,10 @@ namespace gd {
  * \brief Find the object name that should be used as a context of the
  * expression or sub-expression that a given node represents.
  *
+ * This is needed because of the legacy convention where a "objectvar"
+ * parameter represents a variable of the object represented by the previous "object"
+ * parameter.
+ *
  * \see gd::ExpressionParser2
  */
 class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWorker {
@@ -41,12 +46,11 @@ class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWo
    * context of the expression or sub-expression that a given node represents.
    */
   static const gd::String GetObjectName(const gd::Platform &platform,
-                      const gd::ObjectsContainer &globalObjectsContainer,
-                      const gd::ObjectsContainer &objectsContainer,
+                      const gd::ObjectsContainersList &objectsContainersList,
                       const gd::String& rootObjectName,
                       gd::ExpressionNode& node) {
     gd::ExpressionVariableOwnerFinder typeFinder(
-        platform, globalObjectsContainer, objectsContainer, rootObjectName);
+        platform, objectsContainersList, rootObjectName);
     node.Visit(typeFinder);
     return typeFinder.GetObjectName();
   }
@@ -55,12 +59,10 @@ class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWo
 
  protected:
   ExpressionVariableOwnerFinder(const gd::Platform &platform_,
-                       const gd::ObjectsContainer &globalObjectsContainer_,
-                       const gd::ObjectsContainer &objectsContainer_,
+                       const gd::ObjectsContainersList &objectsContainersList_,
                        const gd::String& rootObjectName_)
       : platform(platform_),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        objectsContainersList(objectsContainersList_),
         rootObjectName(rootObjectName_),
         objectName(""),
         variableNode(nullptr) {};
@@ -126,9 +128,8 @@ class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWo
     }
     const gd::ParameterMetadata* parameterMetadata =
         MetadataProvider::GetFunctionCallParameterMetadata(
-            platform, 
-            globalObjectsContainer,
-            objectsContainer,
+            platform,
+            objectsContainersList,
             functionCall,
             parameterIndex);
     if (parameterMetadata == nullptr
@@ -142,9 +143,8 @@ class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWo
     for (int previousIndex = parameterIndex - 1; previousIndex >= 0; previousIndex--) {
       const gd::ParameterMetadata* previousParameterMetadata =
           MetadataProvider::GetFunctionCallParameterMetadata(
-              platform, 
-              globalObjectsContainer,
-              objectsContainer,
+              platform,
+              objectsContainersList,
               functionCall,
               previousIndex);
       if (previousParameterMetadata != nullptr
@@ -162,8 +162,7 @@ class GD_CORE_API ExpressionVariableOwnerFinder : public ExpressionParser2NodeWo
   gd::ExpressionNode *variableNode;
 
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ObjectsContainersList &objectsContainersList;
   const gd::String &rootObjectName;
 };
 

Core/GDCore/IDE/Events/ExpressionsParameterMover.cpp

@@ -31,16 +31,14 @@ namespace gd {
 class GD_CORE_API ExpressionParameterMover
     : public ExpressionParser2NodeWorker {
  public:
-  ExpressionParameterMover(const gd::ObjectsContainer& globalObjectsContainer_,
-                           const gd::ObjectsContainer& objectsContainer_,
+  ExpressionParameterMover(const gd::ProjectScopedContainers& projectScopedContainers_,
                            const gd::String& behaviorType_,
                            const gd::String& objectType_,
                            const gd::String& functionName_,
                            std::size_t oldIndex_,
                            std::size_t newIndex_)
       : hasDoneMoving(false),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         behaviorType(behaviorType_),
         objectType(objectType_),
         functionName(functionName_),
@@ -98,16 +96,16 @@ class GD_CORE_API ExpressionParameterMover
         // This refactor only applies on events object functions
         // and events object functions doesn't exist yet.
         // This is a dead code.
-        const gd::String& thisObjectType = gd::GetTypeOfObject(
-            globalObjectsContainer, objectsContainer, node.objectName);
+        const gd::String& thisObjectType = projectScopedContainers
+            .GetObjectsContainersList().GetTypeOfObject(node.objectName);
         if (thisObjectType == objectType) {
           moveParameter(node.parameters, 1);
           hasDoneMoving = true;
         }
       } else if (!behaviorType.empty() && !node.behaviorName.empty()) {
         // Move parameter of a behavior function
-        const gd::String& thisBehaviorType = gd::GetTypeOfBehavior(
-            globalObjectsContainer, objectsContainer, node.behaviorName);
+        const gd::String& thisBehaviorType = projectScopedContainers
+            .GetObjectsContainersList().GetTypeOfBehavior(node.behaviorName);
         if (thisBehaviorType == behaviorType) {
           moveParameter(node.parameters, 2);
           hasDoneMoving = true;
@@ -126,8 +124,7 @@ class GD_CORE_API ExpressionParameterMover
 
  private:
   bool hasDoneMoving;
-  const gd::ObjectsContainer& globalObjectsContainer;
-  const gd::ObjectsContainer& objectsContainer;
+  const gd::ProjectScopedContainers& projectScopedContainers;
   const gd::String& behaviorType;  // The behavior type of the function which
                                    // must have a parameter moved (optional).
   const gd::String& objectType;    // The object type of the function which
@@ -155,8 +152,7 @@ bool ExpressionsParameterMover::DoVisitInstruction(gd::Instruction& instruction,
 
     auto node = expression.GetRootNode();
     if (node) {
-      ExpressionParameterMover mover(GetGlobalObjectsContainer(),
-                                     GetObjectsContainer(),
+      ExpressionParameterMover mover(GetProjectScopedContainers(),
                                      behaviorType,
                                      objectType,
                                      functionName,

Core/GDCore/IDE/Events/ExpressionsRenamer.cpp

@@ -23,22 +23,20 @@
 namespace gd {
 
 /**
- * \brief Go through the nodes and change the given object name to a new one.
+ * \brief Go through the nodes and change the given function name to a new name.
  *
  * \see gd::ExpressionParser2
  */
 class GD_CORE_API ExpressionFunctionRenamer
     : public ExpressionParser2NodeWorker {
  public:
-  ExpressionFunctionRenamer(const gd::ObjectsContainer& globalObjectsContainer_,
-                            const gd::ObjectsContainer& objectsContainer_,
+  ExpressionFunctionRenamer(const gd::ProjectScopedContainers& projectScopedContainers_,
                             const gd::String& behaviorType_,
                             const gd::String& objectType_,
                             const gd::String& oldFunctionName_,
                             const gd::String& newFunctionName_)
       : hasDoneRenaming(false),
-        globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+        projectScopedContainers(projectScopedContainers_),
         behaviorType(behaviorType_),
         objectType(objectType_),
         oldFunctionName(oldFunctionName_),
@@ -71,16 +69,18 @@ class GD_CORE_API ExpressionFunctionRenamer
     node.expression->Visit(*this);
     if (node.child) node.child->Visit(*this);
   }
-  void OnVisitIdentifierNode(IdentifierNode& node) override {}
+  void OnVisitIdentifierNode(IdentifierNode& node) override {
+    // Nothing to do as this is either a variable, an object variable a property or something else
+    // but not an expression.
+  }
   void OnVisitObjectFunctionNameNode(ObjectFunctionNameNode& node) override {
     if (!node.behaviorFunctionName.empty()) {
       // Behavior function name
       if (!behaviorType.empty() &&
           node.behaviorFunctionName == oldFunctionName) {
-        const gd::String& thisBehaviorType =
-            gd::GetTypeOfBehavior(globalObjectsContainer,
-                                  objectsContainer,
-                                  node.objectFunctionOrBehaviorName);
+        const gd::String& thisBehaviorType = projectScopedContainers
+          .GetObjectsContainersList().GetTypeOfBehavior(
+            node.objectFunctionOrBehaviorName);
         if (thisBehaviorType == behaviorType) {
           node.behaviorFunctionName = newFunctionName;
           hasDoneRenaming = true;
@@ -90,8 +90,8 @@ class GD_CORE_API ExpressionFunctionRenamer
       // Object function name
       if (behaviorType.empty() && !objectType.empty() &&
           node.objectFunctionOrBehaviorName == oldFunctionName) {
-        const gd::String& thisObjectType = gd::GetTypeOfObject(
-            globalObjectsContainer, objectsContainer, node.objectName);
+        const gd::String& thisObjectType = projectScopedContainers
+            .GetObjectsContainersList().GetTypeOfObject(node.objectName);
         if (thisObjectType == objectType) {
           node.objectFunctionOrBehaviorName = newFunctionName;
           hasDoneRenaming = true;
@@ -104,16 +104,16 @@ class GD_CORE_API ExpressionFunctionRenamer
       if (behaviorType.empty() && !objectType.empty() &&
           !node.objectName.empty()) {
         // Replace an object function
-        const gd::String& thisObjectType = gd::GetTypeOfObject(
-            globalObjectsContainer, objectsContainer, node.objectName);
+        const gd::String& thisObjectType = projectScopedContainers
+            .GetObjectsContainersList().GetTypeOfObject(node.objectName);
         if (thisObjectType == objectType) {
           node.functionName = newFunctionName;
           hasDoneRenaming = true;
         }
       } else if (!behaviorType.empty() && !node.behaviorName.empty()) {
         // Replace a behavior function
-        const gd::String& thisBehaviorType = gd::GetTypeOfBehavior(
-            globalObjectsContainer, objectsContainer, node.behaviorName);
+        const gd::String& thisBehaviorType = projectScopedContainers
+            .GetObjectsContainersList().GetTypeOfBehavior(node.behaviorName);
         if (thisBehaviorType == behaviorType) {
           node.functionName = newFunctionName;
           hasDoneRenaming = true;
@@ -132,8 +132,7 @@ class GD_CORE_API ExpressionFunctionRenamer
 
  private:
   bool hasDoneRenaming;
-  const gd::ObjectsContainer& globalObjectsContainer;
-  const gd::ObjectsContainer& objectsContainer;
+  const gd::ProjectScopedContainers& projectScopedContainers;
   const gd::String& behaviorType;  // The behavior type for which the expression
                                    // must be replaced (optional).
   const gd::String& objectType;    // The object type for which the expression
@@ -159,8 +158,7 @@ bool ExpressionsRenamer::DoVisitInstruction(gd::Instruction& instruction,
 
     auto node = expression.GetRootNode();
     if (node) {
-      ExpressionFunctionRenamer renamer(GetGlobalObjectsContainer(),
-                                        GetObjectsContainer(),
+      ExpressionFunctionRenamer renamer(GetProjectScopedContainers(),
                                         behaviorType,
                                         objectType,
                                         oldFunctionName,

Core/GDCore/IDE/Events/ProjectElementRenamer.cpp

@@ -34,13 +34,12 @@ class GD_CORE_API ExpressionIdentifierStringFinder
 public:
   ExpressionIdentifierStringFinder(
       const gd::Platform &platform_,
-      const gd::ObjectsContainer &globalObjectsContainer_,
-      const gd::ObjectsContainer &objectsContainer_,
+      const gd::ProjectScopedContainers& projectScopedContainers_,
       const gd::String &expressionPlainString_,
       const gd::String &parameterType_, const gd::String &objectName_,
       const gd::String &layerName_, const gd::String &oldName_)
-      : platform(platform_), globalObjectsContainer(globalObjectsContainer_),
-        objectsContainer(objectsContainer_),
+      : platform(platform_),
+        projectScopedContainers(projectScopedContainers_),
         expressionPlainString(expressionPlainString_),
         parameterType(parameterType_), objectName(objectName_),
         layerName(layerName_), oldName(oldName_){};
@@ -82,7 +81,7 @@ protected:
   void OnVisitFunctionCallNode(FunctionCallNode &node) override {
     gd::String lastLayerName;
     gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-        platform, globalObjectsContainer, objectsContainer, node,
+        platform, projectScopedContainers.GetObjectsContainersList(), node,
         [&](const gd::ParameterMetadata &parameterMetadata,
             std::unique_ptr<gd::ExpressionNode> &parameterNode,
             size_t parameterIndex, const gd::String &lastObjectName) {
@@ -123,8 +122,7 @@ protected:
 
 private:
   const gd::Platform &platform;
-  const gd::ObjectsContainer &globalObjectsContainer;
-  const gd::ObjectsContainer &objectsContainer;
+  const gd::ProjectScopedContainers &projectScopedContainers;
   /// It's used to extract parameter content.
   const gd::String &expressionPlainString;
   const gd::String &oldName;
@@ -176,7 +174,7 @@ bool ProjectElementRenamer::DoVisitInstruction(gd::Instruction &instruction,
         auto node = parameterValue.GetRootNode();
         if (node) {
           ExpressionIdentifierStringFinder finder(
-              platform, GetGlobalObjectsContainer(), GetObjectsContainer(),
+              platform, GetProjectScopedContainers(),
               parameterValue.GetPlainString(), parameterType, objectName,
               layerName, oldName);
           node->Visit(finder);

Core/GDCore/IDE/Events/UsedExtensionsFinder.cpp

@@ -108,6 +108,33 @@ void UsedExtensionsFinder::OnVisitUnaryOperatorNode(UnaryOperatorNode& node) {
 // Add variable extension and visit sub-expressions on variable nodes
 void UsedExtensionsFinder::OnVisitVariableNode(VariableNode& node) {
   result.GetUsedExtensions().insert("BuiltinVariables");
+
+  auto type = gd::ExpressionTypeFinder::GetType(
+      project.GetCurrentPlatform(), GetObjectsContainersList(), rootType, node);
+
+  if (gd::ParameterMetadata::IsExpression("variable", type)) {
+    // Nothing to do (this can't reference an object)
+  } else {
+    GetProjectScopedContainers().MatchIdentifierWithName<void>(node.name,
+      [&]() {
+        // This represents an object.
+        auto metadata = gd::MetadataProvider::GetExtensionAndObjectMetadata(
+          project.GetCurrentPlatform(), node.name);
+        result.GetUsedExtensions().insert(metadata.GetExtension().GetName());
+        for (auto &&includeFile : metadata.GetMetadata().includeFiles) {
+          result.GetUsedIncludeFiles().insert(includeFile);
+        }
+      }, [&]() {
+        // This is a variable.
+      }, [&]() {
+        // This is a property.
+      }, [&]() {
+        // This is a parameter.
+      }, [&]() {
+        // This is something else.
+      });
+  }
+
   if (node.child) node.child->Visit(*this);
 };
 
@@ -127,9 +154,10 @@ void UsedExtensionsFinder::OnVisitVariableBracketAccessorNode(
 // Add extensions bound to Objects/Behaviors/Functions
 void UsedExtensionsFinder::OnVisitIdentifierNode(IdentifierNode &node) {
   auto type = gd::ExpressionTypeFinder::GetType(
-      project.GetCurrentPlatform(), GetGlobalObjectsContainer(),
-      GetObjectsContainer(), rootType, node);
-  if (gd::ParameterMetadata::IsObject(type)) {
+      project.GetCurrentPlatform(), GetObjectsContainersList(), rootType, node);
+  if (gd::ParameterMetadata::IsObject(type) ||
+      GetObjectsContainersList().HasObjectOrGroupNamed(node.identifierName)) {
+    // An object or object variable is used.
     auto metadata = gd::MetadataProvider::GetExtensionAndObjectMetadata(
         project.GetCurrentPlatform(), node.identifierName);
     result.GetUsedExtensions().insert(metadata.GetExtension().GetName());

Core/GDCore/IDE/ProjectBrowserHelper.cpp

@@ -16,7 +16,9 @@
 #include "GDCore/Project/EventsFunctionsExtension.h"
 #include "GDCore/Project/ExternalEvents.h"
 #include "GDCore/Project/Layout.h"
+#include "GDCore/Project/PropertiesContainer.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "GDCore/String.h"
 
 namespace gd {
@@ -86,15 +88,17 @@ void ProjectBrowserHelper::ExposeLayoutEvents(
 void ProjectBrowserHelper::ExposeLayoutEvents(
     gd::Project &project, gd::Layout &layout,
     gd::ArbitraryEventsWorkerWithContext &worker) {
+  auto projectScopedContainers =
+    gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout);
 
   // Add layouts events
-  worker.Launch(layout.GetEvents(), project, layout);
+  worker.Launch(layout.GetEvents(), projectScopedContainers);
 
   // Add external events events
   for (std::size_t s = 0; s < project.GetExternalEventsCount(); s++) {
     auto &externalEvents = project.GetExternalEvents(s);
     if (externalEvents.GetAssociatedLayout() == layout.GetName()) {
-      worker.Launch(externalEvents.GetEvents(), project, layout);
+      worker.Launch(externalEvents.GetEvents(), projectScopedContainers);
     }
   }
 }
@@ -108,15 +112,19 @@ void ProjectBrowserHelper::ExposeProjectEvents(
   // Add layouts events
   for (std::size_t s = 0; s < project.GetLayoutsCount(); s++) {
     auto &layout = project.GetLayout(s);
-    worker.Launch(layout.GetEvents(), project, layout);
+    auto projectScopedContainers =
+      gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout);
+    worker.Launch(layout.GetEvents(), projectScopedContainers);
   }
   // Add external events events
   for (std::size_t s = 0; s < project.GetExternalEventsCount(); s++) {
     const auto &externalEvents = project.GetExternalEvents(s);
     const gd::String &associatedLayout = externalEvents.GetAssociatedLayout();
     if (project.HasLayoutNamed(associatedLayout)) {
-      worker.Launch(project.GetExternalEvents(s).GetEvents(), project,
-                    project.GetLayout(associatedLayout));
+      auto &layout = project.GetLayout(associatedLayout);
+      auto projectScopedContainers =
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout);
+      worker.Launch(project.GetExternalEvents(s).GetEvents(), projectScopedContainers);
     }
   }
   // Add events based extensions
@@ -130,9 +138,11 @@ void ProjectBrowserHelper::ExposeProjectEvents(
       gd::EventsFunctionTools::FreeEventsFunctionToObjectsContainer(
           project, eventsFunctionsExtension, *eventsFunction,
           globalObjectsAndGroups, objectsAndGroups);
+      auto projectScopedContainers =
+        gd::ProjectScopedContainers::MakeNewProjectScopedContainersFor(globalObjectsAndGroups, objectsAndGroups);
+      projectScopedContainers.AddParameters(eventsFunction->GetParameters());
 
-      worker.Launch(eventsFunction->GetEvents(), globalObjectsAndGroups,
-                    objectsAndGroups);
+      worker.Launch(eventsFunction->GetEvents(), projectScopedContainers);
     }
 
     // Add (behavior) events functions
@@ -169,9 +179,13 @@ void ProjectBrowserHelper::ExposeEventsBasedBehaviorEvents(
     gd::EventsFunctionTools::BehaviorEventsFunctionToObjectsContainer(
         project, eventsBasedBehavior, *eventsFunction, globalObjectsAndGroups,
         objectsAndGroups);
+    auto projectScopedContainers =
+      gd::ProjectScopedContainers::MakeNewProjectScopedContainersFor(globalObjectsAndGroups, objectsAndGroups);
+    projectScopedContainers.AddPropertiesContainer(eventsBasedBehavior.GetSharedPropertyDescriptors());
+    projectScopedContainers.AddPropertiesContainer(eventsBasedBehavior.GetPropertyDescriptors());
+    projectScopedContainers.AddParameters(eventsFunction->GetParameters());
 
-    worker.Launch(eventsFunction->GetEvents(), globalObjectsAndGroups,
-                  objectsAndGroups);
+    worker.Launch(eventsFunction->GetEvents(), projectScopedContainers);
   }
 }
 
@@ -185,9 +199,12 @@ void ProjectBrowserHelper::ExposeEventsBasedObjectEvents(
     gd::EventsFunctionTools::ObjectEventsFunctionToObjectsContainer(
         project, eventsBasedObject, *eventsFunction, globalObjectsAndGroups,
         objectsAndGroups);
+    auto projectScopedContainers =
+      gd::ProjectScopedContainers::MakeNewProjectScopedContainersFor(globalObjectsAndGroups, objectsAndGroups);
+    projectScopedContainers.AddPropertiesContainer(eventsBasedObject.GetPropertyDescriptors());
+    projectScopedContainers.AddParameters(eventsFunction->GetParameters());
 
-    worker.Launch(eventsFunction->GetEvents(), globalObjectsAndGroups,
-                  objectsAndGroups);
+    worker.Launch(eventsFunction->GetEvents(), projectScopedContainers);
   }
 }
 

Core/GDCore/IDE/WholeProjectRefactorer.cpp

@@ -5,6 +5,8 @@
  */
 #include "WholeProjectRefactorer.h"
 
+#include <unordered_map>
+
 #include "GDCore/Extensions/Metadata/BehaviorMetadata.h"
 #include "GDCore/Extensions/Metadata/MetadataProvider.h"
 #include "GDCore/Extensions/PlatformExtension.h"
@@ -15,6 +17,8 @@
 #include "GDCore/IDE/Events/CustomObjectTypeRenamer.h"
 #include "GDCore/IDE/Events/EventsBehaviorRenamer.h"
 #include "GDCore/IDE/Events/EventsRefactorer.h"
+#include "GDCore/IDE/Events/EventsPropertyReplacer.h"
+#include "GDCore/IDE/Events/EventsVariableReplacer.h"
 #include "GDCore/IDE/Events/ExpressionsParameterMover.h"
 #include "GDCore/IDE/Events/ExpressionsRenamer.h"
 #include "GDCore/IDE/Events/InstructionsParameterMover.h"
@@ -46,6 +50,8 @@
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/ObjectGroup.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Serialization/SerializerElement.h"
 #include "GDCore/String.h"
 #include "GDCore/Tools/Log.h"
 
@@ -132,6 +138,72 @@ void WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
   }
 }
 
+VariablesChangeset WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+    gd::Project &project,
+    const gd::SerializerElement &oldSerializedVariablesContainer,
+    const gd::VariablesContainer &newVariablesContainer) {
+  gd::VariablesChangeset changeset;
+
+  gd::VariablesContainer oldVariablesContainer;
+  oldVariablesContainer.UnserializeFrom(oldSerializedVariablesContainer);
+
+  if (oldVariablesContainer.GetPersistentUuid() !=
+      newVariablesContainer.GetPersistentUuid()) {
+    gd::LogWarning(
+        _("Called ComputeChangesetForVariablesContainer on variables containers "
+          "that are different - they can't be compared."));
+    return changeset;
+  }
+
+  std::unordered_map<gd::String, gd::String> removedUuidAndNames;
+  for (std::size_t i = 0; i < oldVariablesContainer.Count(); ++i) {
+    const auto &variable = oldVariablesContainer.Get(i);
+    const auto &variableName = oldVariablesContainer.GetNameAt(i);
+
+    // All variables are candidate to be removed.
+    removedUuidAndNames[variable.GetPersistentUuid()] = variableName;
+  }
+  for (std::size_t i = 0; i < newVariablesContainer.Count(); ++i) {
+    const auto &variable = newVariablesContainer.Get(i);
+    const auto &variableName = newVariablesContainer.GetNameAt(i);
+
+    auto existingOldVariableUuidAndName =
+        removedUuidAndNames.find(variable.GetPersistentUuid());
+    if (existingOldVariableUuidAndName == removedUuidAndNames.end()) {
+      // This is a new variable.
+    } else {
+      const gd::String &oldName = existingOldVariableUuidAndName->second;
+
+      if (oldName != variableName) {
+        // This is a renamed variable.
+        changeset.oldToNewVariableNames[oldName] = variableName;
+      }
+
+      // Renamed or not, this is not a removed variable.
+      removedUuidAndNames.erase(variable.GetPersistentUuid());
+    }
+  }
+
+  for (const auto &removedUuidAndName : removedUuidAndNames) {
+    changeset.removedVariableNames.insert(removedUuidAndName.second);
+  }
+
+  return changeset;
+}
+
+void WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+    gd::Project &project,
+    const gd::VariablesContainer &newVariablesContainer,
+    const gd::VariablesChangeset& changeset) {
+  gd::EventsVariableReplacer eventsVariableReplacer(
+      project.GetCurrentPlatform(),
+      newVariablesContainer,
+      changeset.oldToNewVariableNames,
+      changeset.removedVariableNames);
+  gd::ProjectBrowserHelper::ExposeProjectEvents(project,
+                                                eventsVariableReplacer);
+}
+
 void WholeProjectRefactorer::UpdateExtensionNameInEventsBasedBehavior(
     gd::Project &project,
     const gd::EventsFunctionsExtension &eventsFunctionsExtension,
@@ -671,6 +743,15 @@ void WholeProjectRefactorer::RenameEventsBasedBehaviorProperty(
         EventsBasedBehavior::GetPropertyExpressionName(newPropertyName));
     gd::ProjectBrowserHelper::ExposeProjectEvents(project, expressionRenamer);
 
+    std::unordered_map<gd::String, gd::String> oldToNewPropertyNames = {{oldPropertyName, newPropertyName}};
+    std::unordered_set<gd::String> removedPropertyNames;
+    gd::EventsPropertyReplacer eventsPropertyReplacer(
+      project.GetCurrentPlatform(),
+      properties,
+      oldToNewPropertyNames,
+      removedPropertyNames);
+    gd::ProjectBrowserHelper::ExposeProjectEvents(project, eventsPropertyReplacer);
+
     gd::InstructionsTypeRenamer actionRenamer = gd::InstructionsTypeRenamer(
         project,
         gd::PlatformExtension::GetBehaviorEventsFunctionFullType(
@@ -698,7 +779,7 @@ void WholeProjectRefactorer::RenameEventsBasedBehaviorSharedProperty(
     const gd::EventsFunctionsExtension &eventsFunctionsExtension,
     const gd::EventsBasedBehavior &eventsBasedBehavior,
     const gd::String &oldPropertyName, const gd::String &newPropertyName) {
-  auto &properties = eventsBasedBehavior.GetPropertyDescriptors();
+  auto &properties = eventsBasedBehavior.GetSharedPropertyDescriptors();
   if (!properties.Has(oldPropertyName))
     return;
 
@@ -732,6 +813,15 @@ void WholeProjectRefactorer::RenameEventsBasedBehaviorSharedProperty(
         EventsBasedBehavior::GetSharedPropertyExpressionName(newPropertyName));
     gd::ProjectBrowserHelper::ExposeProjectEvents(project, expressionRenamer);
 
+    std::unordered_map<gd::String, gd::String> oldToNewPropertyNames = {{oldPropertyName, newPropertyName}};
+    std::unordered_set<gd::String> removedPropertyNames;
+    gd::EventsPropertyReplacer eventsPropertyReplacer(
+      project.GetCurrentPlatform(),
+      properties,
+      oldToNewPropertyNames,
+      removedPropertyNames);
+    gd::ProjectBrowserHelper::ExposeProjectEvents(project, eventsPropertyReplacer);
+
     gd::InstructionsTypeRenamer actionRenamer = gd::InstructionsTypeRenamer(
         project,
         gd::PlatformExtension::GetBehaviorEventsFunctionFullType(
@@ -780,6 +870,15 @@ void WholeProjectRefactorer::RenameEventsBasedObjectProperty(
       EventsBasedObject::GetPropertyExpressionName(newPropertyName));
   gd::ProjectBrowserHelper::ExposeProjectEvents(project, expressionRenamer);
 
+  std::unordered_map<gd::String, gd::String> oldToNewPropertyNames = {{oldPropertyName, newPropertyName}};
+  std::unordered_set<gd::String> removedPropertyNames;
+  gd::EventsPropertyReplacer eventsPropertyReplacer(
+    project.GetCurrentPlatform(),
+    properties,
+    oldToNewPropertyNames,
+    removedPropertyNames);
+  gd::ProjectBrowserHelper::ExposeProjectEvents(project, eventsPropertyReplacer);
+
   gd::InstructionsTypeRenamer actionRenamer = gd::InstructionsTypeRenamer(
       project,
       gd::PlatformExtension::GetObjectEventsFunctionFullType(
@@ -1299,10 +1398,12 @@ void WholeProjectRefactorer::DoRenameObject(
 void WholeProjectRefactorer::ObjectOrGroupRemovedInLayout(
     gd::Project &project, gd::Layout &layout, const gd::String &objectName,
     bool isObjectGroup, bool removeEventsAndGroups) {
+  auto projectScopedContainers = gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout);
+
   // Remove object in the current layout
   if (removeEventsAndGroups) {
     gd::EventsRefactorer::RemoveObjectInEvents(project.GetCurrentPlatform(),
-                                               project, layout,
+                                               projectScopedContainers,
                                                layout.GetEvents(), objectName);
   }
   if (!isObjectGroup) { // Object groups can't have instances or be in other
@@ -1321,8 +1422,9 @@ void WholeProjectRefactorer::ObjectOrGroupRemovedInLayout(
     for (auto &externalEventsName :
          GetAssociatedExternalEvents(project, layout.GetName())) {
       auto &externalEvents = project.GetExternalEvents(externalEventsName);
+
       gd::EventsRefactorer::RemoveObjectInEvents(
-          project.GetCurrentPlatform(), project, layout,
+          project.GetCurrentPlatform(), projectScopedContainers,
           externalEvents.GetEvents(), objectName);
     }
   }
@@ -1344,9 +1446,12 @@ void WholeProjectRefactorer::ObjectOrGroupRenamedInLayout(
     const gd::String &newName, bool isObjectGroup) {
   if (oldName == newName || newName.empty() || oldName.empty())
     return;
+
+  auto projectScopedContainers = gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout);
+
   // Rename object in the current layout
   gd::EventsRefactorer::RenameObjectInEvents(
-      project.GetCurrentPlatform(), project, layout, layout.GetEvents(),
+      project.GetCurrentPlatform(), projectScopedContainers, layout.GetEvents(),
       oldName, newName);
 
   if (!isObjectGroup) { // Object groups can't have instances or be in other
@@ -1362,7 +1467,7 @@ void WholeProjectRefactorer::ObjectOrGroupRenamedInLayout(
        GetAssociatedExternalEvents(project, layout.GetName())) {
     auto &externalEvents = project.GetExternalEvents(externalEventsName);
     gd::EventsRefactorer::RenameObjectInEvents(
-        project.GetCurrentPlatform(), project, layout,
+        project.GetCurrentPlatform(), projectScopedContainers,
         externalEvents.GetEvents(), oldName, newName);
   }
 
@@ -1512,10 +1617,13 @@ void WholeProjectRefactorer::ObjectOrGroupRemovedInEventsFunction(
     gd::ObjectsContainer &globalObjectsContainer,
     gd::ObjectsContainer &objectsContainer, const gd::String &objectName,
     bool isObjectGroup, bool removeEventsAndGroups) {
-  // Remove object in the current layout
+  // In theory we should pass a ProjectScopedContainers to this function so it does not have to construct one.
+  // In practice, this is ok because we only deal with objects.
+  auto projectScopedContainers = gd::ProjectScopedContainers::MakeNewProjectScopedContainersFor(globalObjectsContainer, objectsContainer);
+
   if (removeEventsAndGroups) {
     gd::EventsRefactorer::RemoveObjectInEvents(
-        project.GetCurrentPlatform(), globalObjectsContainer, objectsContainer,
+        project.GetCurrentPlatform(), projectScopedContainers,
         eventsFunction.GetEvents(), objectName);
   }
   if (!isObjectGroup) { // Object groups can't be in other groups
@@ -1547,9 +1655,12 @@ void WholeProjectRefactorer::ObjectOrGroupRenamedInEventsFunction(
     gd::ObjectsContainer &globalObjectsContainer,
     gd::ObjectsContainer &objectsContainer, const gd::String &oldName,
     const gd::String &newName, bool isObjectGroup) {
-  // Rename object in the current layout
+  // In theory we should pass a ProjectScopedContainers to this function so it does not have to construct one.
+  // In practice, this is ok because we only deal with objects.
+  auto projectScopedContainers = gd::ProjectScopedContainers::MakeNewProjectScopedContainersFor(globalObjectsContainer, objectsContainer);
+
   gd::EventsRefactorer::RenameObjectInEvents(
-      project.GetCurrentPlatform(), globalObjectsContainer, objectsContainer,
+      project.GetCurrentPlatform(), projectScopedContainers,
       eventsFunction.GetEvents(), oldName, newName);
 
   if (!isObjectGroup) { // Object groups can't be in other groups
@@ -1594,7 +1705,7 @@ void WholeProjectRefactorer::GlobalObjectOrGroupRemoved(
     if (layout.HasObjectNamed(objectName))
       continue;
 
-    ObjectOrGroupRemovedInLayout(project, layout, objectName, isObjectGroup,
+        ObjectOrGroupRemovedInLayout(project, layout, objectName, isObjectGroup,
                                  removeEventsAndGroups);
   }
 }

Core/GDCore/IDE/WholeProjectRefactorer.h

@@ -7,7 +7,9 @@
 
 #include <set>
 #include <unordered_set>
+#include <unordered_map>
 #include <vector>
+#include "GDCore/String.h"
 namespace gd {
 class Platform;
 class Project;
@@ -18,6 +20,7 @@ class String;
 class EventsFunctionsExtension;
 class EventsFunction;
 class ObjectsContainer;
+class VariablesContainer;
 class EventsBasedBehavior;
 class EventsBasedObject;
 class ArbitraryEventsWorker;
@@ -30,10 +33,20 @@ class Behavior;
 class BehaviorMetadata;
 class UnfilledRequiredBehaviorPropertyProblem;
 class ProjectBrowser;
+class SerializerElement;
 }  // namespace gd
 
 namespace gd {
 
+struct VariablesChangeset {
+  std::unordered_set<gd::String> removedVariableNames;
+  std::unordered_map<gd::String, gd::String> oldToNewVariableNames;
+
+  bool HasRemovedVariables() { return !removedVariableNames.empty(); }
+
+  VariablesChangeset& ClearRemovedVariables() { removedVariableNames.clear(); return *this; }
+};
+
 /**
  * \brief Tool functions to do refactoring on the whole project after
  * changes like deletion or renaming of an object.
@@ -45,6 +58,23 @@ namespace gd {
 class GD_CORE_API WholeProjectRefactorer {
  public:
 
+  /**
+   * \brief Compute the changes made on the variables of a variable container.
+   */
+  static VariablesChangeset ComputeChangesetForVariablesContainer(
+    gd::Project &project,
+    const gd::SerializerElement &oldSerializedVariablesContainer,
+    const gd::VariablesContainer &newVariablesContainer);
+
+  /**
+   * \brief Refactor the project according to the changes (renaming or deletion)
+   * made to variables.
+   */
+  static void ApplyRefactoringForVariablesContainer(
+    gd::Project &project,
+    const gd::VariablesContainer &newVariablesContainer,
+    const gd::VariablesChangeset& changeset);
+
   /**
    * \brief Refactor the project **before** an events function extension is
    * renamed.

Core/GDCore/Project/AbstractEventsBasedEntity.cpp

@@ -4,6 +4,7 @@
  * reserved. This project is released under the MIT License.
  */
 #include "AbstractEventsBasedEntity.h"
+
 #include "EventsFunctionsContainer.h"
 #include "GDCore/Serialization/SerializerElement.h"
 #include "GDCore/Tools/MakeUnique.h"
@@ -13,7 +14,10 @@ namespace gd {
 AbstractEventsBasedEntity::AbstractEventsBasedEntity(
     const gd::String& _name,
     gd::EventsFunctionsContainer::FunctionOwner functionContainerSource)
-    : name(_name), fullName(""), eventsFunctionsContainer(functionContainerSource) {}
+    : name(_name),
+      fullName(""),
+      eventsFunctionsContainer(functionContainerSource),
+      propertyDescriptors(functionContainerSource) {}
 
 void AbstractEventsBasedEntity::SerializeTo(SerializerElement& element) const {
   element.SetAttribute("description", description);
@@ -27,8 +31,8 @@ void AbstractEventsBasedEntity::SerializeTo(SerializerElement& element) const {
       "propertyDescriptor", element.AddChild("propertyDescriptors"));
 }
 
-void AbstractEventsBasedEntity::UnserializeFrom(gd::Project& project,
-                                          const SerializerElement& element) {
+void AbstractEventsBasedEntity::UnserializeFrom(
+    gd::Project& project, const SerializerElement& element) {
   description = element.GetStringAttribute("description");
   name = element.GetStringAttribute("name");
   fullName = element.GetStringAttribute("fullName");

Core/GDCore/Project/AbstractEventsBasedEntity.h

@@ -8,7 +8,7 @@
 
 #include <vector>
 #include "GDCore/Project/NamedPropertyDescriptor.h"
-#include "GDCore/Tools/SerializableWithNameList.h"
+#include "GDCore/Project/PropertiesContainer.h"
 #include "GDCore/Project/EventsFunctionsContainer.h"
 #include "GDCore/String.h"
 namespace gd {
@@ -98,15 +98,14 @@ class GD_CORE_API AbstractEventsBasedEntity {
   /**
    * \brief Return a reference to the list of the properties.
    */
-  SerializableWithNameList<NamedPropertyDescriptor>& GetPropertyDescriptors() {
+  gd::PropertiesContainer& GetPropertyDescriptors() {
     return propertyDescriptors;
   }
 
   /**
    * \brief Return a const reference to the list of the properties.
    */
-  const SerializableWithNameList<NamedPropertyDescriptor>& GetPropertyDescriptors()
-      const {
+  const gd::PropertiesContainer& GetPropertyDescriptors() const {
     return propertyDescriptors;
   }
 
@@ -150,7 +149,7 @@ class GD_CORE_API AbstractEventsBasedEntity {
   gd::String fullName;
   gd::String description;
   gd::EventsFunctionsContainer eventsFunctionsContainer;
-  SerializableWithNameList<NamedPropertyDescriptor> propertyDescriptors;
+  gd::PropertiesContainer propertyDescriptors;
   gd::String extensionName;
 };
 

Core/GDCore/Project/BehaviorConfigurationContainer.h

@@ -31,10 +31,10 @@ namespace gd {
  */
 class GD_CORE_API BehaviorConfigurationContainer {
  public:
-
-  BehaviorConfigurationContainer(){};
-  BehaviorConfigurationContainer(const gd::String& name_, const gd::String& type_)
-      : name(name_), type(type_){};
+  BehaviorConfigurationContainer() : folded(false){};
+  BehaviorConfigurationContainer(const gd::String& name_,
+                                 const gd::String& type_)
+      : name(name_), type(type_), folded(false){};
   virtual ~BehaviorConfigurationContainer();
   virtual BehaviorConfigurationContainer* Clone() const { return new BehaviorConfigurationContainer(*this); }
 
@@ -61,7 +61,7 @@ class GD_CORE_API BehaviorConfigurationContainer {
   /**
    * \brief Called when the IDE wants to know about the custom properties of the
    * behavior.
-   * 
+   *
    * \return a std::map with properties names as key.
    * \see gd::PropertyDescriptor
    */
@@ -104,6 +104,17 @@ class GD_CORE_API BehaviorConfigurationContainer {
   const gd::SerializerElement& GetContent() const { return content; };
   gd::SerializerElement& GetContent() { return content; };
 
+  /**
+   * \brief Set if the behavior configuration panel should be folded in the UI.
+   */
+  void SetFolded(bool fold = true) { folded = fold; }
+
+  /**
+   * \brief True if the behavior configuration panel should be folded in the UI.
+   */
+  bool IsFolded() const { return folded; }
+
+
 protected:
   /**
    * \brief Called when the IDE wants to know about the custom properties of the
@@ -148,6 +159,7 @@ protected:
                     ///< in the form "ExtensionName::BehaviorTypeName"
 
   gd::SerializerElement content;  // Storage for the behavior properties
+  bool folded;
 };
 
 }  // namespace gd

Core/GDCore/Project/CustomConfigurationHelper.cpp

@@ -8,6 +8,7 @@
 #include "GDCore/IDE/Project/ArbitraryResourceWorker.h"
 #include "GDCore/Project/Behavior.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/PropertiesContainer.h"
 #include "GDCore/Project/PropertyDescriptor.h"
 #include "GDCore/Serialization/Serializer.h"
 #include "GDCore/Serialization/SerializerElement.h"
@@ -17,7 +18,7 @@
 using namespace gd;
 
 void CustomConfigurationHelper::InitializeContent(
-    const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+    const gd::PropertiesContainer &properties,
     gd::SerializerElement &configurationContent) {
   for (auto &&property : properties.GetInternalVector()) {
     auto &element = configurationContent.AddChild(property->GetName());
@@ -35,7 +36,7 @@ void CustomConfigurationHelper::InitializeContent(
 }
 
 std::map<gd::String, gd::PropertyDescriptor> CustomConfigurationHelper::GetProperties(
-    const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+    const gd::PropertiesContainer &properties,
     const gd::SerializerElement &configurationContent) {
   auto behaviorProperties = std::map<gd::String, gd::PropertyDescriptor>();
 
@@ -71,7 +72,7 @@ std::map<gd::String, gd::PropertyDescriptor> CustomConfigurationHelper::GetPrope
 }
 
 bool CustomConfigurationHelper::UpdateProperty(
-    const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+    const gd::PropertiesContainer &properties,
     gd::SerializerElement &configurationContent,
     const gd::String &propertyName,
     const gd::String &newValue) {

Core/GDCore/Project/CustomConfigurationHelper.h

@@ -9,6 +9,7 @@
 #include "GDCore/Project/Behavior.h"
 #include "GDCore/Project/EventsBasedBehavior.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/PropertiesContainer.h"
 #include "GDCore/Project/PropertyDescriptor.h"
 #include "GDCore/Serialization/Serializer.h"
 #include "GDCore/Serialization/SerializerElement.h"
@@ -25,15 +26,15 @@ public:
   CustomConfigurationHelper() {}
 
   static void InitializeContent(
-      const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+      const gd::PropertiesContainer &properties,
       gd::SerializerElement &behaviorContent);
 
   static std::map<gd::String, gd::PropertyDescriptor> GetProperties(
-      const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+      const gd::PropertiesContainer &properties,
       const gd::SerializerElement &behaviorContent);
 
   static bool UpdateProperty(
-      const gd::SerializableWithNameList<gd::NamedPropertyDescriptor> &properties,
+      const gd::PropertiesContainer &properties,
       gd::SerializerElement &behaviorContent,
       const gd::String &name,
       const gd::String &value);

Core/GDCore/Project/EventsBasedBehavior.cpp

@@ -13,7 +13,8 @@ namespace gd {
 EventsBasedBehavior::EventsBasedBehavior()
     : AbstractEventsBasedEntity(
         "MyBehavior",
-        gd::EventsFunctionsContainer::FunctionOwner::Behavior) {}
+        gd::EventsFunctionsContainer::FunctionOwner::Behavior),
+        sharedPropertyDescriptors(gd::EventsFunctionsContainer::FunctionOwner::Behavior) {}
 
 void EventsBasedBehavior::SerializeTo(SerializerElement& element) const {
   AbstractEventsBasedEntity::SerializeTo(element);

Core/GDCore/Project/EventsBasedBehavior.h

@@ -9,7 +9,7 @@
 #include <vector>
 #include "GDCore/Project/AbstractEventsBasedEntity.h"
 #include "GDCore/Project/NamedPropertyDescriptor.h"
-#include "GDCore/Tools/SerializableWithNameList.h"
+#include "GDCore/Project/PropertiesContainer.h"
 #include "GDCore/Project/EventsFunctionsContainer.h"
 #include "GDCore/String.h"
 namespace gd {
@@ -91,14 +91,14 @@ class GD_CORE_API EventsBasedBehavior: public AbstractEventsBasedEntity {
   /**
    * \brief Return a reference to the list of shared properties.
    */
-  SerializableWithNameList<NamedPropertyDescriptor>& GetSharedPropertyDescriptors() {
+  gd::PropertiesContainer& GetSharedPropertyDescriptors() {
     return sharedPropertyDescriptors;
   }
 
   /**
    * \brief Return a const reference to the list of shared properties.
    */
-  const SerializableWithNameList<NamedPropertyDescriptor>& GetSharedPropertyDescriptors()
+  const gd::PropertiesContainer& GetSharedPropertyDescriptors()
       const {
     return sharedPropertyDescriptors;
   }
@@ -140,7 +140,7 @@ class GD_CORE_API EventsBasedBehavior: public AbstractEventsBasedEntity {
  private:
   gd::String objectType;
   bool isPrivate = false;
-  SerializableWithNameList<NamedPropertyDescriptor> sharedPropertyDescriptors;
+  gd::PropertiesContainer sharedPropertyDescriptors;
 };
 
 }  // namespace gd

Core/GDCore/Project/Layer.h

@@ -13,19 +13,75 @@
 
 namespace gd {
 class Effect;
-}
-namespace gd {
 class Camera;
-}
-namespace gd {
 class SerializerElement;
-}
-namespace gd {
 class EffectsContainer;
 }
 
 namespace gd {
 
+/**
+ * \brief A camera is used to render a specific area of a layout.
+ *
+ * \see gd::Layout
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API Camera {
+ public:
+  Camera();
+  ~Camera(){};
+
+  /**
+   * \brief Change the viewport, i.e the area of the window where the camera
+   * will be displayed. \note The coordinates must be between 0 and 1.
+   */
+  void SetViewport(float x1_, float y1_, float x2_, float y2_) {
+    x1 = x1_;
+    x2 = x2_;
+    y1 = y1_;
+    y2 = y2_;
+  };
+  void SetViewportX1(float x1_) { x1 = x1_; };
+  void SetViewportY1(float y1_) { y1 = y1_; };
+  void SetViewportX2(float x2_) { x2 = x2_; };
+  void SetViewportY2(float y2_) { y2 = y2_; };
+  float GetViewportX1() const { return x1; };
+  float GetViewportY1() const { return y1; };
+  float GetViewportX2() const { return x2; };
+  float GetViewportY2() const { return y2; };
+
+  /**
+   * \brief Change the size of the rendered area of the scene, in pixels.
+   */
+  void SetSize(float width_, float height_) {
+    width = width_;
+    height = height_;
+  };
+  float GetWidth() const { return width; };
+  float GetHeight() const { return height; };
+
+  void SetUseDefaultSize(bool useDefaultSize = true) {
+    defaultSize = useDefaultSize;
+  };
+  bool UseDefaultSize() const { return defaultSize; }
+
+  void SetUseDefaultViewport(bool useDefaultViewport = true) {
+    defaultViewport = useDefaultViewport;
+  };
+  bool UseDefaultViewport() const { return defaultViewport; }
+
+ private:
+  bool defaultSize;      ///< True if the camera use the default window size
+  bool defaultViewport;  ///< True if the camera use the default viewport size
+
+  float x1;
+  float y1;
+  float x2;
+  float y2;
+  float width;   ///< The width of the rendered area
+  float height;  ///< The height of the rendered area
+};
+
 /**
  * \brief Represents a layer of a layout.
  *
@@ -241,68 +297,6 @@ struct LayerHasName : public std::binary_function<gd::Layer, gd::String, bool> {
   }
 };
 
-/**
- * \brief A camera is used to render a specific area of a layout.
- *
- * \see gd::Layout
- * \ingroup PlatformDefinition
- */
-class GD_CORE_API Camera {
- public:
-  Camera();
-  ~Camera(){};
-
-  /**
-   * \brief Change the viewport, i.e the area of the window where the camera
-   * will be displayed. \note The coordinates must be between 0 and 1.
-   */
-  void SetViewport(float x1_, float y1_, float x2_, float y2_) {
-    x1 = x1_;
-    x2 = x2_;
-    y1 = y1_;
-    y2 = y2_;
-  };
-  void SetViewportX1(float x1_) { x1 = x1_; };
-  void SetViewportY1(float y1_) { y1 = y1_; };
-  void SetViewportX2(float x2_) { x2 = x2_; };
-  void SetViewportY2(float y2_) { y2 = y2_; };
-  float GetViewportX1() const { return x1; };
-  float GetViewportY1() const { return y1; };
-  float GetViewportX2() const { return x2; };
-  float GetViewportY2() const { return y2; };
-
-  /**
-   * \brief Change the size of the rendered area of the scene, in pixels.
-   */
-  void SetSize(float width_, float height_) {
-    width = width_;
-    height = height_;
-  };
-  float GetWidth() const { return width; };
-  float GetHeight() const { return height; };
-
-  void SetUseDefaultSize(bool useDefaultSize = true) {
-    defaultSize = useDefaultSize;
-  };
-  bool UseDefaultSize() const { return defaultSize; }
-
-  void SetUseDefaultViewport(bool useDefaultViewport = true) {
-    defaultViewport = useDefaultViewport;
-  };
-  bool UseDefaultViewport() const { return defaultViewport; }
-
- private:
-  bool defaultSize;      ///< True if the camera use the default window size
-  bool defaultViewport;  ///< True if the camera use the default viewport size
-
-  float x1;
-  float y1;
-  float x2;
-  float y2;
-  float width;   ///< The width of the rendered area
-  float height;  ///< The height of the rendered area
-};
-
 }  // namespace gd
 
 #endif  // GDCORE_LAYER_H

Core/GDCore/Project/Layout.cpp

@@ -742,7 +742,7 @@ gd::String GD_CORE_API GetTypeOfBehavior(const gd::ObjectsContainer& project,
 vector<gd::String> GD_CORE_API
 GetBehaviorsOfObject(const gd::ObjectsContainer& project,
                      const gd::ObjectsContainer& layout,
-                     gd::String name,
+                     const gd::String& name,
                      bool searchInGroups) {
   bool behaviorsAlreadyInserted = false;
   vector<gd::String> behaviors;

Core/GDCore/Project/Layout.h

@@ -435,6 +435,7 @@ std::vector<gd::String> GetHiddenLayers(const Layout& layout);
  * \note If a group contains only objects of a same type, then the group has
  * this type. Otherwise, it is considered as an object without any specific
  * type.
+ * \deprecated Use gd::ObjectsContainersList::GetTypeOfObject instead.
  *
  * @return Type of the object/group.
  */
@@ -444,6 +445,7 @@ gd::String GD_CORE_API GetTypeOfObject(const ObjectsContainer& game,
                                        bool searchInGroups = true);
 /**
  * \brief Check if an object or all objects of a group has a behavior.
+ * \deprecated Use gd::ObjectsContainersList::HasBehaviorInObjectOrGroup instead.
  */
 bool GD_CORE_API HasBehaviorInObjectOrGroup(const gd::ObjectsContainer &project,
                                             const gd::ObjectsContainer &layout,
@@ -479,6 +481,7 @@ gd::String GD_CORE_API GetTypeOfBehaviorInObjectOrGroup(const gd::ObjectsContain
 /**
  * \brief Get a type from a behavior name
  * @return Type of the behavior.
+ * @deprecated - Use GetTypeOfBehaviorInObjectOrGroup instead.
  */
 gd::String GD_CORE_API GetTypeOfBehavior(const ObjectsContainer& game,
                                          const ObjectsContainer& layout,
@@ -495,7 +498,7 @@ gd::String GD_CORE_API GetTypeOfBehavior(const ObjectsContainer& game,
 std::vector<gd::String> GD_CORE_API
 GetBehaviorsOfObject(const ObjectsContainer& game,
                      const ObjectsContainer& layout,
-                     gd::String objectName,
+                     const gd::String& objectName,
                      bool searchInGroups = true);
 
 }  // namespace gd

Core/GDCore/Project/LoadingScreen.cpp

@@ -5,7 +5,6 @@
  */
 
 #include "LoadingScreen.h"
-
 #include "GDCore/Serialization/SerializerElement.h"
 
 namespace gd {

Core/GDCore/Project/Object.cpp

@@ -15,6 +15,7 @@
 #include "GDCore/Serialization/SerializerElement.h"
 #include "GDCore/Project/PropertyDescriptor.h"
 #include "GDCore/Tools/Log.h"
+#include "GDCore/Tools/UUID/UUID.h"
 
 namespace gd {
 
@@ -35,6 +36,7 @@ Object::Object(const gd::String& name_,
     }
 
 void Object::Init(const gd::Object& object) {
+  persistentUuid = object.persistentUuid;
   name = object.name;
   assetStoreId = object.assetStoreId;
   objectVariables = object.objectVariables;
@@ -127,6 +129,8 @@ gd::Behavior* Object::AddNewBehavior(const gd::Project& project,
 
 void Object::UnserializeFrom(gd::Project& project,
                              const SerializerElement& element) {
+  persistentUuid = element.GetStringAttribute("persistentUuid");
+
   SetType(element.GetStringAttribute("type"));
   assetStoreId = element.GetStringAttribute("assetStoreId");
   name = element.GetStringAttribute("name", name, "nom");
@@ -197,6 +201,9 @@ void Object::UnserializeFrom(gd::Project& project,
 }
 
 void Object::SerializeTo(SerializerElement& element) const {
+  if (!persistentUuid.empty())
+    element.SetStringAttribute("persistentUuid", persistentUuid);
+
   element.SetAttribute("name", GetName());
   element.SetAttribute("assetStoreId", GetAssetStoreId());
   element.SetAttribute("type", GetType());
@@ -227,4 +234,18 @@ void Object::SerializeTo(SerializerElement& element) const {
   configuration->SerializeTo(element);
 }
 
+Object& Object::ResetPersistentUuid() {
+  persistentUuid = UUID::MakeUuid4();
+  objectVariables.ResetPersistentUuid();
+
+  return *this;
+}
+
+Object& Object::ClearPersistentUuid() {
+  persistentUuid = "";
+  objectVariables.ClearPersistentUuid();
+
+  return *this;
+}
+
 }  // namespace gd

Core/GDCore/Project/Object.h

@@ -243,6 +243,18 @@ class GD_CORE_API Object {
    * \see DoUnserializeFrom
    */
   void UnserializeFrom(gd::Project& project, const SerializerElement& element);
+
+  /**
+   * \brief Reset the persistent UUID, used to recognize
+   * the same object between serialization.
+   */
+  Object& ResetPersistentUuid();
+
+  /**
+   * \brief Remove the persistent UUID - when the object no
+   * longer need to be recognized between serializations.
+   */
+  Object& ClearPersistentUuid();
   ///@}
 
  protected:
@@ -259,6 +271,8 @@ class GD_CORE_API Object {
   gd::String tags;      ///< Comma-separated list of tags
   gd::EffectsContainer
       effectsContainer;  ///< The effects container for the object.
+  mutable gd::String persistentUuid;  ///< A persistent random version 4 UUID,
+                                      ///< useful for computing changesets.
 
   /**
    * Initialize object using another object. Used by copy-ctor and assign-op.

Core/GDCore/Project/ObjectGroupsContainer.cpp

@@ -162,4 +162,11 @@ void ObjectGroupsContainer::Move(std::size_t oldIndex, std::size_t newIndex) {
   objectGroups.insert(objectGroups.begin() + newIndex, std::move(objectGroup));
 }
 
+void ObjectGroupsContainer::ForEachNameWithPrefix(const gd::String& prefix,
+                                                std::function<void(const gd::String& name)> fn) const {
+  for (const auto& objectGroup: objectGroups) {
+    if (objectGroup->GetName().find(prefix) == 0) fn(objectGroup->GetName());
+  }
+}
+
 }  // namespace gd

Core/GDCore/Project/ObjectGroupsContainer.h

@@ -116,6 +116,11 @@ class GD_CORE_API ObjectGroupsContainer {
    * \brief Clear all groups of the container.
    */
   inline void Clear() { objectGroups.clear(); }
+
+  /**
+   * \brief Call the callback for each group name starting with the prefix passed in parameter.
+   */
+  void ForEachNameWithPrefix(const gd::String& prefix, std::function<void(const gd::String& name)> fn) const;
   ///@}
 
   /** \name Saving and loading

Core/GDCore/Project/ObjectsContainersList.cpp

@@ -0,0 +1,250 @@
+#include "ObjectsContainersList.h"
+
+#include <vector>
+
+#include "GDCore/Project/Layout.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Project/ObjectsContainer.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/VariablesContainer.h"
+#include "GDCore/String.h"
+#include "GDCore/Tools/Log.h"
+
+namespace gd {
+
+ObjectsContainersList
+ObjectsContainersList::MakeNewObjectsContainersListForProjectAndLayout(
+    const gd::Project& project, const gd::Layout& layout) {
+  ObjectsContainersList objectsContainersList;
+  objectsContainersList.Add(project);
+  objectsContainersList.Add(layout);
+  return objectsContainersList;
+}
+
+ObjectsContainersList
+ObjectsContainersList::MakeNewObjectsContainersListForContainers(
+    const gd::ObjectsContainer& globalObjectsContainer,
+    const gd::ObjectsContainer& objectsContainer) {
+  ObjectsContainersList objectsContainersList;
+  objectsContainersList.Add(globalObjectsContainer);
+  objectsContainersList.Add(objectsContainer);
+  return objectsContainersList;
+}
+
+bool ObjectsContainersList::HasObjectOrGroupNamed(
+    const gd::String& name) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(name) || (*it)->GetObjectGroups().Has(name))
+      return true;
+  }
+
+  return false;
+}
+
+bool ObjectsContainersList::HasObjectNamed(const gd::String& name) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(name)) return true;
+  }
+
+  return false;
+}
+
+bool ObjectsContainersList::HasObjectOrGroupWithVariableNamed(
+    const gd::String& objectOrGroupName, const gd::String& variableName) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(objectOrGroupName)) {
+      const auto& variables =
+          (*it)->GetObject(objectOrGroupName).GetVariables();
+      return variables.Has(variableName);
+    }
+    if ((*it)->GetObjectGroups().Has(objectOrGroupName)) {
+      // Could be adapted if objects groups have variables in the future.
+    }
+  }
+
+  return false;
+}
+
+bool ObjectsContainersList::HasVariablesContainer(
+    const gd::String& objectOrGroupName,
+    const gd::VariablesContainer& variablesContainer) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(objectOrGroupName)) {
+      return &variablesContainer ==
+             &(*it)->GetObject(objectOrGroupName).GetVariables();
+    }
+    if ((*it)->GetObjectGroups().Has(objectOrGroupName)) {
+      // Could be adapted if objects groups have variables in the future.
+    }
+  }
+
+  return false;
+}
+
+const gd::VariablesContainer*
+ObjectsContainersList::GetObjectOrGroupVariablesContainer(
+    const gd::String& objectOrGroupName) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(objectOrGroupName)) {
+      return &(*it)->GetObject(objectOrGroupName).GetVariables();
+    }
+    if ((*it)->GetObjectGroups().Has(objectOrGroupName)) {
+      // Could be adapted if objects groups have variables in the future.
+    }
+  }
+
+  return nullptr;
+}
+
+void ObjectsContainersList::ForEachNameWithPrefix(
+    const gd::String& prefix,
+    std::function<void(const gd::String& name,
+                       const gd::ObjectConfiguration* objectConfiguration)> fn)
+    const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    for (const auto& object : (*it)->GetObjects()) {
+      if (object->GetName().find(prefix) == 0)
+        fn(object->GetName(), &object->GetConfiguration());
+    }
+    (*it)->GetObjectGroups().ForEachNameWithPrefix(
+        prefix, [&](const gd::String& name) { fn(name, nullptr); });
+  }
+}
+
+std::vector<gd::String> ObjectsContainersList::ExpandObjectName(
+    const gd::String& objectOrGroupName,
+    const gd::String& onlyObjectToSelectIfPresent) const {
+  std::vector<gd::String> realObjects;
+
+  // Check progressively each object container to find the object or the group
+  // with the specified name.
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    if ((*it)->HasObjectNamed(objectOrGroupName)) {
+      // We found the object, it's a single object with this name.
+      realObjects.push_back(objectOrGroupName);
+      break;
+    }
+    if ((*it)->GetObjectGroups().Has(objectOrGroupName)) {
+      // We found a group with this name, expand the object names inside of it.
+      realObjects =
+          (*it)->GetObjectGroups().Get(objectOrGroupName).GetAllObjectsNames();
+      break;
+    }
+  }
+
+  // If the "current object" is present, use it and only it.
+  if (!onlyObjectToSelectIfPresent.empty() &&
+      find(realObjects.begin(),
+           realObjects.end(),
+           onlyObjectToSelectIfPresent) != realObjects.end()) {
+    realObjects.clear();
+    realObjects.push_back(onlyObjectToSelectIfPresent);
+  }
+
+  // Ensure that all returned objects actually exists (i.e: if some groups have
+  // names refering to non existing objects, don't return them).
+  for (std::size_t i = 0; i < realObjects.size();) {
+    if (!HasObjectNamed(realObjects[i]))
+      realObjects.erase(realObjects.begin() + i);
+    else
+      ++i;
+  }
+
+  return realObjects;
+}
+
+void ObjectsContainersList::ForEachObject(
+    std::function<void(const gd::Object& object)> fn) const {
+  for (auto it = objectsContainers.rbegin(); it != objectsContainers.rend();
+       ++it) {
+    const auto& objectsContainer = **it;
+    for (const auto& object : objectsContainer.GetObjects()) {
+      fn(*object);
+    }
+  }
+}
+
+gd::String ObjectsContainersList::GetTypeOfObject(
+    const gd::String& objectName) const {
+  if (objectsContainers.size() != 2) {
+    std::cout << this << std::endl;
+    std::cout << objectsContainers.size() << std::endl;
+    // TODO: rework forwarded methods so they can work with any number of
+    // containers.
+    gd::LogFatalError(
+        "ObjectsContainersList::GetTypeOfObject called with objectsContainers "
+        "not being exactly 2. This is a logical error and will crash.");
+  }
+  return gd::GetTypeOfObject(
+      *objectsContainers[0], *objectsContainers[1], objectName, true);
+}
+
+bool ObjectsContainersList::HasBehaviorInObjectOrGroup(
+    const gd::String& objectOrGroupName, const gd::String& behaviorName) const {
+  if (objectsContainers.size() != 2) {
+    // TODO: rework forwarded methods so they can work with any number of
+    // containers.
+    gd::LogFatalError(
+        "ObjectsContainersList::GetTypeOfObject called with objectsContainers "
+        "not being exactly 2. This is a logical error and will crash.");
+  }
+  return gd::HasBehaviorInObjectOrGroup(*objectsContainers[0],
+                                        *objectsContainers[1],
+                                        objectOrGroupName,
+                                        behaviorName,
+                                        true);
+}
+
+gd::String ObjectsContainersList::GetTypeOfBehaviorInObjectOrGroup(
+    const gd::String& objectOrGroupName,
+    const gd::String& behaviorName,
+    bool searchInGroups) const {
+  if (objectsContainers.size() != 2) {
+    // TODO: rework forwarded methods so they can work with any number of
+    // containers.
+    gd::LogFatalError(
+        "ObjectsContainersList::GetTypeOfObject called with objectsContainers "
+        "not being exactly 2. This is a logical error and will crash.");
+  }
+  return gd::GetTypeOfBehaviorInObjectOrGroup(*objectsContainers[0],
+                                              *objectsContainers[1],
+                                              objectOrGroupName,
+                                              behaviorName,
+                                              searchInGroups);
+}
+
+gd::String ObjectsContainersList::GetTypeOfBehavior(
+    const gd::String& behaviorName, bool searchInGroups) const {
+  if (objectsContainers.size() != 2) {
+    // TODO: rework forwarded methods so they can work with any number of
+    // containers.
+    gd::LogFatalError(
+        "ObjectsContainersList::GetTypeOfObject called with objectsContainers "
+        "not being exactly 2. This is a logical error and will crash.");
+  }
+  return gd::GetTypeOfBehavior(
+      *objectsContainers[0], *objectsContainers[1], behaviorName, searchInGroups);
+}
+
+std::vector<gd::String> ObjectsContainersList::GetBehaviorsOfObject(
+    const gd::String& objectName, bool searchInGroups) const {
+  if (objectsContainers.size() != 2) {
+    // TODO: rework forwarded methods so they can work with any number of
+    // containers.
+    gd::LogFatalError(
+        "ObjectsContainersList::GetTypeOfObject called with objectsContainers "
+        "not being exactly 2. This is a logical error and will crash.");
+  }
+
+  return gd::GetBehaviorsOfObject(
+      *objectsContainers[0], *objectsContainers[1], objectName, searchInGroups);
+}
+
+}  // namespace gd

Core/GDCore/Project/ObjectsContainersList.h

@@ -0,0 +1,142 @@
+#pragma once
+#include <vector>
+
+#include "Variable.h"
+
+namespace gd {
+class String;
+class Project;
+class Layout;
+class ObjectsContainer;
+class VariablesContainer;
+class Object;
+class ObjectConfiguration;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief A list of objects containers, useful for accessing objects in a
+ * scoped way, along with methods to access them.
+ *
+ * \see gd::Object
+ * \see gd::ObjectsContainer
+ * \see gd::Project
+ * \see gd::Layout
+ *
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API ObjectsContainersList {
+ public:
+  virtual ~ObjectsContainersList(){};
+
+  static ObjectsContainersList MakeNewObjectsContainersListForProjectAndLayout(
+      const gd::Project& project, const gd::Layout& layout);
+
+  static ObjectsContainersList MakeNewObjectsContainersListForContainers(
+      const gd::ObjectsContainer& globalObjectsContainer,
+      const gd::ObjectsContainer& objectsContainer);
+
+  /**
+   * \brief Check if the specified object or group exists.
+   */
+  bool HasObjectOrGroupNamed(const gd::String& name) const;
+
+  /**
+   * \brief Check if the specified object or group has the specified variable in
+   * its declared variables.
+   */
+  bool HasObjectOrGroupWithVariableNamed(const gd::String& objectOrGroupName,
+                                         const gd::String& variableName) const;
+
+  /**
+   * \brief Check if the specified object or group has the specified variables
+   * container.
+   */
+  bool HasVariablesContainer(
+      const gd::String& objectOrGroupName,
+      const gd::VariablesContainer& variablesContainer) const;
+
+  /**
+   * \brief Return the container of the variables for the specified object or
+   * group of objects.
+   */
+  const gd::VariablesContainer* GetObjectOrGroupVariablesContainer(
+      const gd::String& objectOrGroupName) const;
+
+  /**
+   * \brief Get a type from an object/group name.
+   * \note If a group contains only objects of a same type, then the group has
+   * this type. Otherwise, it is considered as an object without any specific
+   * type.
+   *
+   * @return Type of the object/group.
+   */
+  gd::String GetTypeOfObject(const gd::String& objectName) const;
+
+  /**
+   * \brief Check if an object or all object of a group has a behavior.
+   */
+  bool HasBehaviorInObjectOrGroup(const gd::String& objectOrGroupName,
+                                  const gd::String& behaviorName) const;
+
+  /**
+    * \brief Get the type of a behavior if an object or all objects of a group has it.
+    */
+  gd::String GetTypeOfBehaviorInObjectOrGroup(const gd::String &objectOrGroupName,
+                                              const gd::String &behaviorName,
+                                              bool searchInGroups = true) const;
+
+  /**
+   * \brief Get a type from a behavior name
+   * @return Type of the behavior.
+   * @deprecated - Use GetTypeOfBehaviorInObjectOrGroup instead.
+   */
+  gd::String GetTypeOfBehavior(const gd::String& behaviorName, bool searchInGroups = true) const;
+
+  /**
+   * \brief Get behaviors of an object/group
+   * \note The behaviors of a group are the behaviors which are found in common
+   * when looking all the objects of the group.
+   *
+   * @return Vector containing names of behaviors
+   */
+  std::vector<gd::String>
+  GetBehaviorsOfObject(const gd::String& objectName,
+                       bool searchInGroups = true) const;
+
+  /**
+   * \brief Return a list containing all objects refered to by the group.
+   * If an object name is passed, then only this object name is returned.
+   *
+   * If \a onlyObjectToSelectIfPresent is set and present in the group(s),
+   * only this object will be returned. This is useful for considering this
+   * object as the "currently selected" object, when generating a condition or
+   * an action.
+   */
+  std::vector<gd::String> ExpandObjectName(
+      const gd::String& objectOrGroupName,
+      const gd::String& onlyObjectToSelectIfPresent = "") const;
+
+  void ForEachObject(std::function<void(const gd::Object& object)> fn) const;
+
+  /**
+   * \brief Call the callback for each object or group name starting with the prefix passed in parameter.
+   */
+  void ForEachNameWithPrefix(const gd::String& prefix, std::function<void(const gd::String& name, const gd::ObjectConfiguration* objectConfiguration)> fn) const;
+
+  /** Do not use - should be private but accessible to let Emscripten create a
+   * temporary. */
+  ObjectsContainersList(){};
+
+ private:
+  bool HasObjectNamed(const gd::String& name) const;
+
+  void Add(const gd::ObjectsContainer& objectsContainer) {
+    objectsContainers.push_back(&objectsContainer);
+  };
+
+  std::vector<const gd::ObjectsContainer*> objectsContainers;
+};
+
+}  // namespace gd

Core/GDCore/Project/ProjectScopedContainers.h

@@ -0,0 +1,174 @@
+#pragma once
+#include <set>
+
+#include "GDCore/Extensions/Metadata/ParameterMetadataTools.h"
+#include "ObjectsContainersList.h"
+#include "PropertiesContainersList.h"
+#include "VariablesContainersList.h"
+
+namespace gd {
+class Project;
+class ObjectsContainer;
+class ObjectsContainersList;
+class VariablesContainersList;
+class PropertiesContainersList;
+class NamedPropertyDescriptor;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief Holds references to variables, objects, properties and other
+ * containers.
+ *
+ * This is useful to access elements of a project from a specific location,
+ * honoring the scope of each element.
+ *
+ * For example, in an expression, when an identifier is written, this class is
+ * used to know what this identifier refers too.
+ */
+class ProjectScopedContainers {
+ public:
+  ProjectScopedContainers(
+      const gd::ObjectsContainersList &objectsContainersList_,
+      const gd::VariablesContainersList &variablesContainersList_,
+      const gd::PropertiesContainersList &propertiesContainersList_)
+      : objectsContainersList(objectsContainersList_),
+        variablesContainersList(variablesContainersList_),
+        propertiesContainersList(propertiesContainersList_){};
+  virtual ~ProjectScopedContainers(){};
+
+  static ProjectScopedContainers
+  MakeNewProjectScopedContainersForProjectAndLayout(const gd::Project &project,
+                                                    const gd::Layout &layout) {
+    ProjectScopedContainers projectScopedContainers(
+        ObjectsContainersList::MakeNewObjectsContainersListForProjectAndLayout(
+            project, layout),
+        VariablesContainersList::
+            MakeNewVariablesContainersListForProjectAndLayout(project, layout),
+        PropertiesContainersList::MakeNewEmptyPropertiesContainersList());
+
+    return projectScopedContainers;
+  }
+
+  static ProjectScopedContainers MakeNewProjectScopedContainersFor(
+      const gd::ObjectsContainer &globalObjectsContainers,
+      const gd::ObjectsContainer &objectsContainers) {
+    ProjectScopedContainers projectScopedContainers(
+        ObjectsContainersList::MakeNewObjectsContainersListForContainers(
+            globalObjectsContainers, objectsContainers),
+        VariablesContainersList::MakeNewEmptyVariablesContainersList(),
+        PropertiesContainersList::MakeNewEmptyPropertiesContainersList());
+
+    return projectScopedContainers;
+  }
+
+  ProjectScopedContainers &AddPropertiesContainer(
+      const gd::PropertiesContainer &container) {
+    propertiesContainersList.Add(container);
+
+    return *this;
+  }
+
+  ProjectScopedContainers &AddParameters(
+      const std::vector<gd::ParameterMetadata> &parameters) {
+    parametersVectorsList.push_back(&parameters);
+
+    return *this;
+  }
+
+  template <class ReturnType>
+  ReturnType MatchIdentifierWithName(
+      const gd::String &name,
+      std::function<ReturnType()> objectCallback,
+      std::function<ReturnType()> variableCallback,
+      std::function<ReturnType()> propertyCallback,
+      std::function<ReturnType()> parameterCallback,
+      std::function<ReturnType()> notFoundCallback) const {
+    if (objectsContainersList.HasObjectOrGroupNamed(name))
+      return objectCallback();
+    else if (variablesContainersList.Has(name))
+      return variableCallback();
+    else if (ParameterMetadataTools::Has(parametersVectorsList, name))
+      return parameterCallback();
+    else if (propertiesContainersList.Has(name))
+      return propertyCallback();
+
+    return notFoundCallback();
+  };
+
+  void ForEachIdentifierWithPrefix(
+      const gd::String &prefix,
+      std::function<void(const gd::String &name,
+                         const ObjectConfiguration *objectConfiguration)>
+          objectCallback,
+      std::function<void(const gd::String &name, const gd::Variable &variable)>
+          variableCallback,
+      std::function<void(const gd::NamedPropertyDescriptor &property)>
+          propertyCallback,
+      std::function<void(const gd::ParameterMetadata &parameter)>
+          parameterCallback) const {
+    std::set<gd::String> namesAlreadySeen;
+
+    objectsContainersList.ForEachNameWithPrefix(
+        prefix,
+        [&](const gd::String &name,
+            const ObjectConfiguration *objectConfiguration) {
+          if (namesAlreadySeen.count(name) == 0) {
+            namesAlreadySeen.insert(name);
+            objectCallback(name, objectConfiguration);
+          }
+        });
+    variablesContainersList.ForEachVariableWithPrefix(
+        prefix, [&](const gd::String &name, const gd::Variable &variable) {
+          if (namesAlreadySeen.count(name) == 0) {
+            namesAlreadySeen.insert(name);
+            variableCallback(name, variable);
+          }
+        });
+    gd::ParameterMetadataTools::ForEachParameterWithPrefix(
+        parametersVectorsList,
+        prefix,
+        [&](const gd::ParameterMetadata &parameter) {
+          if (namesAlreadySeen.count(parameter.GetName()) == 0) {
+            namesAlreadySeen.insert(parameter.GetName());
+            parameterCallback(parameter);
+          }
+        });
+    propertiesContainersList.ForEachPropertyWithPrefix(
+        prefix, [&](const gd::NamedPropertyDescriptor &property) {
+          if (namesAlreadySeen.count(property.GetName()) == 0) {
+            namesAlreadySeen.insert(property.GetName());
+            propertyCallback(property);
+          }
+        });
+  };
+
+  const gd::ObjectsContainersList &GetObjectsContainersList() const {
+    return objectsContainersList;
+  };
+
+  const gd::VariablesContainersList &GetVariablesContainersList() const {
+    return variablesContainersList;
+  };
+
+  const gd::PropertiesContainersList &GetPropertiesContainersList() const {
+    return propertiesContainersList;
+  };
+
+  const std::vector<const std::vector<gd::ParameterMetadata> *> &GetParametersVectorsList() const {
+    return parametersVectorsList;
+  };
+
+  /** Do not use - should be private but accessible to let Emscripten create a
+   * temporary. */
+  ProjectScopedContainers(){};
+
+ private:
+  gd::ObjectsContainersList objectsContainersList;
+  gd::VariablesContainersList variablesContainersList;
+  gd::PropertiesContainersList propertiesContainersList;
+  std::vector<const std::vector<gd::ParameterMetadata> *> parametersVectorsList;
+};
+
+}  // namespace gd

Core/GDCore/Project/PropertiesContainer.h

@@ -0,0 +1,46 @@
+#pragma once
+#include "EventsFunctionsContainer.h"
+#include "GDCore/Tools/SerializableWithNameList.h"
+#include "NamedPropertyDescriptor.h"
+
+namespace gd {
+
+/**
+ * \brief A container of properties, used for custom behaviors, custom objects,
+ * extensions...
+ *
+ * \see gd::NamedPropertyDescriptor
+ *
+ * \ingroup PlatformDefinition
+ */
+class PropertiesContainer
+    : public SerializableWithNameList<NamedPropertyDescriptor> {
+ public:
+  PropertiesContainer(EventsFunctionsContainer::FunctionOwner owner)
+      : SerializableWithNameList<NamedPropertyDescriptor>(), owner(owner) {}
+
+  PropertiesContainer(const PropertiesContainer& other)
+      : SerializableWithNameList<NamedPropertyDescriptor>(other),
+        owner(other.owner) {}
+
+  PropertiesContainer& operator=(const PropertiesContainer& other) {
+    if (this != &other) {
+      SerializableWithNameList<NamedPropertyDescriptor>::operator=(other);
+      owner = other.owner;
+    }
+    return *this;
+  }
+
+  void ForEachPropertyWithPrefix(const gd::String& prefix, std::function<void(const gd::NamedPropertyDescriptor& property)> fn) const {
+    for (const auto& property: elements) {
+      if (property->GetName().find(prefix) == 0) fn(*property);
+    }
+  }
+
+  EventsFunctionsContainer::FunctionOwner GetOwner() const { return owner; }
+
+ private:
+  EventsFunctionsContainer::FunctionOwner owner;
+};
+
+}  // namespace gd

Core/GDCore/Project/PropertiesContainersList.cpp

@@ -0,0 +1,67 @@
+#include "PropertiesContainersList.h"
+
+#include <functional>
+#include <vector>
+
+#include "PropertiesContainer.h"
+
+namespace gd {
+
+NamedPropertyDescriptor PropertiesContainersList::badNamedPropertyDescriptor;
+PropertiesContainer PropertiesContainersList::badPropertiesContainer(gd::EventsFunctionsContainer::FunctionOwner::Extension);
+
+PropertiesContainersList
+PropertiesContainersList::MakeNewPropertiesContainersListFor(
+    const gd::PropertiesContainer& propertiesContainer) {
+  PropertiesContainersList propertiesContainersList;
+  propertiesContainersList.Add(propertiesContainer);
+  return propertiesContainersList;
+}
+
+PropertiesContainersList
+PropertiesContainersList::MakeNewEmptyPropertiesContainersList() {
+  PropertiesContainersList propertiesContainersList;
+  return propertiesContainersList;
+}
+
+bool PropertiesContainersList::Has(const gd::String& name) const {
+  for (auto it = propertiesContainers.rbegin();
+       it != propertiesContainers.rend();
+       ++it) {
+    if ((*it)->Has(name)) return true;
+  }
+
+  return false;
+}
+
+std::pair<std::reference_wrapper<const gd::PropertiesContainer>,
+          std::reference_wrapper<const NamedPropertyDescriptor>>
+PropertiesContainersList::Get(const gd::String& name) const {
+  for (auto it = propertiesContainers.rbegin();
+       it != propertiesContainers.rend();
+       ++it) {
+    if ((*it)->Has(name)) return {**it, (*it)->Get(name)};
+  }
+
+  return {badPropertiesContainer, badNamedPropertyDescriptor};
+}
+
+bool PropertiesContainersList::HasPropertiesContainer(const gd::PropertiesContainer& propertiesContainer) const {
+  for (auto it = propertiesContainers.rbegin(); it != propertiesContainers.rend();
+       ++it) {
+    if (*it == &propertiesContainer) return true;
+  }
+
+  return false;
+}
+
+void PropertiesContainersList::ForEachPropertyWithPrefix(
+    const gd::String& prefix,
+    std::function<void(const gd::NamedPropertyDescriptor& property)> fn) const {
+  for (auto it = propertiesContainers.rbegin(); it != propertiesContainers.rend();
+       ++it) {
+    (*it)->ForEachPropertyWithPrefix(prefix, fn);
+  }
+}
+
+}  // namespace gd

Core/GDCore/Project/PropertiesContainersList.h

@@ -0,0 +1,84 @@
+#pragma once
+#include <functional>
+#include <vector>
+
+#include "PropertiesContainer.h"
+
+namespace gd {
+class String;
+class Project;
+class Layout;
+class NamedPropertyDescriptor;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief A list of property containers, useful for accessing properties in a
+ * scoped way.
+ *
+ * \see gd::NamedPropertyDescriptor
+ * \see gd::Project
+ * \see gd::Layout
+ *
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API PropertiesContainersList {
+ public:
+  virtual ~PropertiesContainersList(){};
+
+  static PropertiesContainersList MakeNewPropertiesContainersListFor(
+      const gd::PropertiesContainer& propertiesContainer);
+  static PropertiesContainersList MakeNewEmptyPropertiesContainersList();
+
+  /**
+   * \brief Add a new container of properties in the list.
+   * Add containers in order from the most global one to the most local one.
+   */
+  void Add(const gd::PropertiesContainer& propertiesContainer) {
+    propertiesContainers.push_back(&propertiesContainer);
+  };
+
+  /**
+   * \brief Return true if the specified property is in one of the containers.
+   */
+  bool Has(const gd::String& name) const;
+
+  /**
+   * \brief Return a reference to the property called \a name, and the
+   * properties container holding it.
+   */
+  std::pair<std::reference_wrapper<const gd::PropertiesContainer>,
+            std::reference_wrapper<const NamedPropertyDescriptor>>
+  Get(const gd::String& name) const;
+
+  /**
+   * \brief Return true if the specified properties container is present.
+   */
+  bool HasPropertiesContainer(const gd::PropertiesContainer& propertiesContainer) const;
+
+  /**
+   * Get the properties container at the bottom of the scope (so the most
+   * "local" one).
+   */
+  const PropertiesContainer* GetBottomMostPropertiesContainer() const {
+    if (propertiesContainers.empty()) return nullptr;
+    return propertiesContainers.back();
+  }
+
+  /**
+   * \brief Call the callback for each property having a name starting with the specified prefix.
+   */
+  void ForEachPropertyWithPrefix(const gd::String& prefix, std::function<void(const gd::NamedPropertyDescriptor& property)> fn) const;
+
+  /** Do not use - should be private but accessible to let Emscripten create a
+   * temporary. */
+  PropertiesContainersList(){};
+
+ private:
+  std::vector<const gd::PropertiesContainer*> propertiesContainers;
+  static NamedPropertyDescriptor badNamedPropertyDescriptor;
+  static PropertiesContainer badPropertiesContainer;
+};
+
+}  // namespace gd

Core/GDCore/Project/Variable.cpp

@@ -10,6 +10,7 @@
 
 #include "GDCore/Serialization/SerializerElement.h"
 #include "GDCore/String.h"
+#include "GDCore/Tools/UUID/UUID.h"
 
 using namespace std;
 
@@ -228,6 +229,9 @@ void Variable::SerializeTo(SerializerElement& element) const {
   element.SetStringAttribute("type", TypeAsString(GetType()));
   if (IsFolded()) element.SetBoolAttribute("folded", true);
 
+  if (!persistentUuid.empty())
+    element.SetStringAttribute("persistentUuid", persistentUuid);
+
   if (type == Type::String) {
     element.SetStringAttribute("value", GetString());
   } else if (type == Type::Number) {
@@ -254,6 +258,8 @@ void Variable::SerializeTo(SerializerElement& element) const {
 void Variable::UnserializeFrom(const SerializerElement& element) {
   type = StringAsType(element.GetStringAttribute("type", "string"));
 
+  persistentUuid = element.GetStringAttribute("persistentUuid");
+
   // Compatibility with GD <= 5.0.0-beta102
   // Before, everything was stored as strings.
   // We can unserialize primitives as string as they can be converted from/to
@@ -290,7 +296,12 @@ void Variable::UnserializeFrom(const SerializerElement& element) {
         PushNew().UnserializeFrom(childElement);
     }
   }
-}  // namespace gd
+}
+
+Variable& Variable::ResetPersistentUuid() {
+  persistentUuid = UUID::MakeUuid4();
+  return *this;
+}
 
 std::vector<gd::String> Variable::GetAllChildrenNames() const {
   std::vector<gd::String> names;
@@ -338,7 +349,8 @@ Variable::Variable(const Variable& other)
       str(other.str),
       folded(other.folded),
       boolVal(other.boolVal),
-      type(other.type) {
+      type(other.type),
+      persistentUuid(other.persistentUuid) {
   CopyChildren(other);
 }
 
@@ -349,6 +361,7 @@ Variable& Variable::operator=(const Variable& other) {
     folded = other.folded;
     boolVal = other.boolVal;
     type = other.type;
+    persistentUuid = other.persistentUuid;
     CopyChildren(other);
   }
 

Core/GDCore/Project/Variable.h

@@ -338,6 +338,24 @@ class GD_CORE_API Variable {
    * \brief Unserialize the variable.
    */
   void UnserializeFrom(const SerializerElement& element);
+
+  /**
+   * \brief Reset the persistent UUID used to recognize
+   * the same variable between serialization.
+   */
+  Variable& ResetPersistentUuid();
+
+  /**
+   * \brief Remove the persistent UUID - when the variable no
+   * longer needs to be recognized between serializations.
+   */
+  Variable& ClearPersistentUuid() { persistentUuid = ""; return *this; };
+
+  /**
+   * \brief Get the persistent UUID used to recognize
+   * the same variable between serialization.
+   */
+  const gd::String& GetPersistentUuid() const { return persistentUuid; };
   ///@}
 
  private:
@@ -361,6 +379,8 @@ class GD_CORE_API Variable {
   mutable std::vector<std::shared_ptr<Variable>>
       childrenArray;  ///< Children, when the variable is considered as an
                       ///< array.
+  mutable gd::String persistentUuid;  ///< A persistent random version 4 UUID,
+                                      ///< useful for computing changesets.
 
   /**
    * Initialize children by copying them from another variable.  Used by

Core/GDCore/Project/VariablesContainer.cpp

@@ -12,6 +12,7 @@
 #include "GDCore/Serialization/SerializerElement.h"
 #include "GDCore/String.h"
 #include "GDCore/TinyXml/tinyxml.h"
+#include "GDCore/Tools/UUID/UUID.h"
 
 namespace gd {
 
@@ -161,7 +162,18 @@ void VariablesContainer::Move(std::size_t oldIndex, std::size_t newIndex) {
   variables.insert(variables.begin() + newIndex, nameAndVariable);
 }
 
+void VariablesContainer::ForEachVariableWithPrefix(
+    const gd::String& prefix,
+    std::function<void(const gd::String& name, const gd::Variable& variable)> fn) const {
+  for (const auto& nameAndVariable: variables) {
+    if (nameAndVariable.first.find(prefix) == 0) fn(nameAndVariable.first, *nameAndVariable.second);
+  }
+}
+
 void VariablesContainer::SerializeTo(SerializerElement& element) const {
+  if (!persistentUuid.empty())
+    element.SetStringAttribute("persistentUuid", persistentUuid);
+
   element.ConsiderAsArrayOf("variable");
   for (std::size_t j = 0; j < variables.size(); j++) {
     SerializerElement& variableElement = element.AddChild("variable");
@@ -171,6 +183,8 @@ void VariablesContainer::SerializeTo(SerializerElement& element) const {
 }
 
 void VariablesContainer::UnserializeFrom(const SerializerElement& element) {
+  persistentUuid = element.GetStringAttribute("persistentUuid");
+
   Clear();
   element.ConsiderAsArrayOf("variable", "Variable");
   for (std::size_t j = 0; j < element.GetChildrenCount(); j++) {
@@ -183,6 +197,24 @@ void VariablesContainer::UnserializeFrom(const SerializerElement& element) {
   }
 }
 
+VariablesContainer& VariablesContainer::ResetPersistentUuid() {
+  persistentUuid = UUID::MakeUuid4();
+  for(auto& variable: variables) {
+    variable.second->ResetPersistentUuid();
+  }
+
+  return *this;
+}
+
+VariablesContainer& VariablesContainer::ClearPersistentUuid() {
+  persistentUuid = "";
+  for(auto& variable: variables) {
+    variable.second->ClearPersistentUuid();
+  }
+
+  return *this;
+}
+
 VariablesContainer::VariablesContainer(const VariablesContainer& other) {
   Init(other);
 }
@@ -195,6 +227,7 @@ VariablesContainer& VariablesContainer::operator=(
 }
 
 void VariablesContainer::Init(const gd::VariablesContainer& other) {
+  persistentUuid = other.persistentUuid;
   variables.clear();
   for (auto& it : other.variables) {
     variables.push_back(

Core/GDCore/Project/VariablesContainer.h

@@ -137,6 +137,11 @@ class GD_CORE_API VariablesContainer {
    * \brief Clear all variables of the container.
    */
   inline void Clear() { variables.clear(); }
+
+  /**
+   * \brief Call the callback for each variable with a name starting with the specified prefix.
+   */
+  void ForEachVariableWithPrefix(const gd::String& prefix, std::function<void(const gd::String& name, const gd::Variable& variable)> fn) const;
   ///@}
 
   /** \name Saving and loading
@@ -152,10 +157,30 @@ class GD_CORE_API VariablesContainer {
    * \brief Unserialize the variable container.
    */
   void UnserializeFrom(const SerializerElement& element);
+
+  /**
+   * \brief Reset the persistent UUID, used to recognize
+   * the same variables between serialization.
+   */
+  VariablesContainer& ResetPersistentUuid();
+
+  /**
+   * \brief Remove the persistent UUID - when the variables no
+   * longer need to be recognized between serializations.
+   */
+  VariablesContainer& ClearPersistentUuid();
+
+  /**
+   * \brief Get the persistent UUID used to recognize
+   * the same variables between serialization.
+   */
+  const gd::String& GetPersistentUuid() const { return persistentUuid; };
   ///@}
 
  private:
   std::vector<std::pair<gd::String, std::shared_ptr<gd::Variable>>> variables;
+  mutable gd::String persistentUuid;  ///< A persistent random version 4 UUID,
+                                      ///< useful for computing changesets.
   static gd::Variable badVariable;
   static gd::String badName;
 

Core/GDCore/Project/VariablesContainersList.cpp

@@ -0,0 +1,64 @@
+#include "VariablesContainersList.h"
+
+#include <vector>
+
+#include "GDCore/Project/Layout.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/Variable.h"
+
+namespace gd {
+
+Variable VariablesContainersList::badVariable;
+
+VariablesContainersList
+VariablesContainersList::MakeNewVariablesContainersListForProjectAndLayout(
+    const gd::Project& project, const gd::Layout& layout) {
+  VariablesContainersList variablesContainersList;
+  variablesContainersList.Add(project.GetVariables());
+  variablesContainersList.Add(layout.GetVariables());
+  return variablesContainersList;
+}
+
+VariablesContainersList
+VariablesContainersList::MakeNewEmptyVariablesContainersList() {
+  VariablesContainersList variablesContainersList;
+  return variablesContainersList;
+}
+
+bool VariablesContainersList::Has(const gd::String& name) const {
+  for (auto it = variablesContainers.rbegin(); it != variablesContainers.rend();
+       ++it) {
+    if ((*it)->Has(name)) return true;
+  }
+
+  return false;
+}
+
+const Variable& VariablesContainersList::Get(const gd::String& name) const {
+  for (auto it = variablesContainers.rbegin(); it != variablesContainers.rend();
+       ++it) {
+    if ((*it)->Has(name)) return (*it)->Get(name);
+  }
+
+  return badVariable;
+}
+
+bool VariablesContainersList::HasVariablesContainer(const gd::VariablesContainer& variablesContainer) const {
+  for (auto it = variablesContainers.rbegin(); it != variablesContainers.rend();
+       ++it) {
+    if (*it == &variablesContainer) return true;
+  }
+
+  return false;
+}
+
+void VariablesContainersList::ForEachVariableWithPrefix(
+    const gd::String& prefix,
+    std::function<void(const gd::String& name, const gd::Variable& variable)> fn) const {
+  for (auto it = variablesContainers.rbegin(); it != variablesContainers.rend();
+       ++it) {
+    (*it)->ForEachVariableWithPrefix(prefix, fn);
+  }
+}
+
+}  // namespace gd

Core/GDCore/Project/VariablesContainersList.h

@@ -0,0 +1,85 @@
+#pragma once
+#include <vector>
+#include <functional>
+
+namespace gd {
+class String;
+class Project;
+class Layout;
+class VariablesContainer;
+class Variable;
+}  // namespace gd
+
+namespace gd {
+
+/**
+ * \brief A list of variables containers, useful for accessing variables in a
+ * scoped way.
+ *
+ * \see gd::Variable
+ * \see gd::Project
+ * \see gd::Layout
+ *
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API VariablesContainersList {
+ public:
+  virtual ~VariablesContainersList(){};
+
+  static VariablesContainersList
+  MakeNewVariablesContainersListForProjectAndLayout(const gd::Project& project,
+                                                    const gd::Layout& layout);
+
+  static VariablesContainersList MakeNewEmptyVariablesContainersList();
+
+  /**
+   * \brief Return true if the specified variable is in one of the containers.
+   */
+  bool Has(const gd::String& name) const;
+
+  /**
+   * \brief Return a reference to the variable called \a name.
+   */
+  const Variable& Get(const gd::String& name) const;
+
+  /**
+   * \brief Return true if the specified variable container is present.
+   */
+  bool HasVariablesContainer(const gd::VariablesContainer& variablesContainer) const;
+
+  /**
+   * Get the variables container at the top of the scope (so the most "global" one).
+   * \brief Avoid using apart when a scope must be forced.
+   */
+  const VariablesContainer* GetTopMostVariablesContainer() const {
+    if (variablesContainers.empty()) return nullptr;
+    return variablesContainers.front();
+  };
+
+  /**
+   * Get the variables container at the bottom of the scope (so the most "local" one).
+   * \brief Avoid using apart when a scope must be forced.
+   */
+  const VariablesContainer* GetBottomMostVariablesContainer() const {
+    if (variablesContainers.empty()) return nullptr;
+    return variablesContainers.back();
+  }
+
+  /**
+   * \brief Call the callback for each variable having a name starting with the specified prefix.
+   */
+  void ForEachVariableWithPrefix(const gd::String& prefix, std::function<void(const gd::String& name, const gd::Variable& variable)> fn) const;
+
+  /** Do not use - should be private but accessible to let Emscripten create a temporary. */
+  VariablesContainersList() {};
+ private:
+
+  void Add(const gd::VariablesContainer& variablesContainer) {
+    variablesContainers.push_back(&variablesContainer);
+  };
+
+  std::vector<const gd::VariablesContainer*> variablesContainers;
+  static Variable badVariable;
+};
+
+}  // namespace gd

Core/GDCore/String.cpp

@@ -251,26 +251,26 @@ String& String::replace_if(iterator i1, iterator i2, std::function<bool(char32_t
     return *this;
 }
 
-String& String::RemoveConsecutiveOccurrences(iterator i1, iterator i2, const char c)
-{
-    std::vector<std::pair<size_type, size_type>> ranges_to_remove;
-    for(iterator current_index = i1.base(); current_index < i2.base(); current_index++)
-    {
-        if (*current_index == c){
-            iterator current_subindex = current_index;
-            std::advance(current_subindex, 1);
-            if (*current_subindex == c) {
-                while(current_subindex < end() && *current_subindex == c)
-                {
-                    current_subindex++;
-                }
-                replace(std::distance(begin(), current_index),
-                        std::distance(current_index, current_subindex),
-                        c);
-
-                std::advance(current_index, 1);
-            }
+String &String::RemoveConsecutiveOccurrences(iterator i1,
+                                             iterator i2,
+                                             const char c) {
+    iterator end = i2;
+    for (iterator current_index = i1.base(); current_index < end.base();
+         current_index++) {
+      if (*current_index == c) {
+        iterator current_subindex = current_index;
+        current_subindex++;
+        while (current_subindex < end.base() && *current_subindex == c) {
+          current_subindex++;
         }
+        difference_type difference_to_replace =
+            std::distance(current_index, current_subindex);
+        if (difference_to_replace > 1) {
+          replace(
+              std::distance(begin(), current_index), difference_to_replace, c);
+          std::advance(end, -(difference_to_replace - 1));
+        }
+      }
     }
     return *this;
 }

Core/tests/DummyPlatform.cpp

@@ -13,6 +13,8 @@
 #include "GDCore/Project/Project.h"
 #include "GDCore/Tools/Localization.h"
 #include "GDCore/Events/Builtin/StandardEvent.h"
+#include "GDCore/Events/Builtin/ForEachChildVariableEvent.h"
+#include "GDCore/Events/Builtin/RepeatEvent.h"
 #include "GDCore/Extensions/Metadata/MultipleInstructionMetadata.h"
 #include "GDCore/Extensions/Metadata/ParameterOptions.h"
 #include "catch.hpp"
@@ -103,6 +105,8 @@ void SetupProjectWithDummyPlatform(gd::Project& project,
   commonInstructionsExtension->SetExtensionInformation(
       "BuiltinCommonInstructions", "instruction extension", "", "", "");
   commonInstructionsExtension->AddEvent("Standard", "Standard event", "", "", "", std::make_shared<gd::StandardEvent>());
+  commonInstructionsExtension->AddEvent("ForEachChildVariable", "For each child variable event", "", "", "", std::make_shared<gd::ForEachChildVariableEvent>());
+  commonInstructionsExtension->AddEvent("Repeat", "Repeat event", "", "", "", std::make_shared<gd::RepeatEvent>());
 
   std::shared_ptr<gd::PlatformExtension> baseObjectExtension =
       std::shared_ptr<gd::PlatformExtension>(new gd::PlatformExtension);
@@ -243,6 +247,20 @@ void SetupProjectWithDummyPlatform(gd::Project& project,
       .AddParameter("soundfile", "Parameter 3 (an audio resource)")
       .SetFunctionName("doSomethingWithResources");
 
+  extension
+      ->AddAction("DoSomethingWithLegacyPreScopedVariables",
+                  "Do something with variables",
+                  "This does something with variables",
+                  "Do something with variables please",
+                  "",
+                  "",
+                  "")
+      .AddParameter("scenevar", "Scene variable")
+      .AddParameter("globalvar", "Global variable")
+      .AddParameter("object", "Some object")
+      .AddParameter("objectvar", "Some variable of the object")
+      .SetFunctionName("doSomethingWithVariables");
+
   extension->AddExpression("GetNumber", "Get me a number", "", "", "")
       .SetFunctionName("getNumber");
   extension
@@ -345,7 +363,7 @@ void SetupProjectWithDummyPlatform(gd::Project& project,
       .AddParameter("object", _("Object"), "Sprite")
       .AddParameter("expression", _("Number parameter"))
       .AddParameter("string", _("String parameter"))
-      .AddParameter("", _("Identifier parameter"))
+      .AddParameter("expression", _("Identifier parameter"))
       .SetFunctionName("getObjectStringWith3Param");
   object
       .AddStrExpression("GetObjectStringWith2ObjectParam",
@@ -560,15 +578,15 @@ void SetupProjectWithDummyPlatform(gd::Project& project,
   extension
       ->AddExpression(
           "LayerEffectParameter",
-          _("Effect parameter (number)"),
-          _("Return the value of a parameter of an effect."),
+          _("Effect property (number)"),
+          _("Return the value of a property of an effect."),
           _("Effects"),
           "")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("layer", _("Layer (base layer if empty)"), "", true)
       .SetDefaultValue("\"\"")
       .AddParameter("layerEffectName", _("Effect name"))
-      .AddParameter("layerEffectParameterName", _("Parameter name"));
+      .AddParameter("layerEffectParameterName", _("Property name"));
   }
 
   {

Core/tests/EventsBehaviorRenamer.cpp

@@ -15,6 +15,7 @@
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "catch.hpp"
 
 namespace {
@@ -35,6 +36,8 @@ TEST_CASE("EventsBehaviorRenamer (expressions)", "[common]") {
   gd::Platform platform;
   SetupProjectWithDummyPlatform(project, platform);
   auto &layout1 = project.InsertNewLayout("Layout1", 0);
+  auto projectScopedContainers =
+    gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
 
   auto &object1 =
       layout1.InsertNewObject(project, "MyExtension::Sprite", "Object1", 0);
@@ -57,7 +60,7 @@ TEST_CASE("EventsBehaviorRenamer (expressions)", "[common]") {
   // Rename the first behavior.
   gd::EventsBehaviorRenamer behaviorRenamer(
       platform, "Object1", "MyBehavior", "MyRenamedBehavior");
-  behaviorRenamer.Launch(layout1.GetEvents(), project, layout1);
+  behaviorRenamer.Launch(layout1.GetEvents(), projectScopedContainers);
 
   // Verify the expression were updated.
   REQUIRE(EnsureStandardEvent(layout1.GetEvents().GetEvent(0))
@@ -74,6 +77,8 @@ TEST_CASE("EventsBehaviorRenamer (instructions)", "[common]") {
   gd::Platform platform;
   SetupProjectWithDummyPlatform(project, platform);
   auto &layout1 = project.InsertNewLayout("Layout1", 0);
+  auto projectScopedContainers =
+    gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
 
   auto &object1 =
       layout1.InsertNewObject(project, "MyExtension::Sprite", "Object1", 0);
@@ -109,7 +114,7 @@ TEST_CASE("EventsBehaviorRenamer (instructions)", "[common]") {
   // Rename MyBehavior.
   gd::EventsBehaviorRenamer behaviorRenamer(
       platform, "Object1", "MyBehavior", "MyRenamedBehavior");
-  behaviorRenamer.Launch(layout1.GetEvents(), project, layout1);
+  behaviorRenamer.Launch(layout1.GetEvents(), projectScopedContainers);
 
   // Ensure the action using MyBehavior has its parameter renamed.
   REQUIRE(EnsureStandardEvent(layout1.GetEvents().GetEvent(0))

Core/tests/ExpressionCodeGenerator.cpp

@@ -20,6 +20,13 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
   gd::Platform platform;
   SetupProjectWithDummyPlatform(project, platform);
   auto &layout1 = project.InsertNewLayout("Layout1", 0);
+
+  // Add some variables and objects:
+  layout1.GetVariables().InsertNew("MySceneVariable", 0);
+  layout1.GetVariables().InsertNew("MySceneVariable2", 1);
+  layout1.GetVariables().InsertNew("MySceneStructureVariable", 2).GetChild("MyChild");
+  layout1.GetVariables().InsertNew("MySceneStructureVariable2", 2).GetChild("MyChild");
+
   layout1.InsertNewObject(project, "MyExtension::Sprite", "MySpriteObject", 0);
   layout1.InsertNewObject(
       project, "MyExtension::Sprite", "MyOtherSpriteObject", 1);
@@ -27,6 +34,15 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
                           "MyExtension::FakeObjectWithDefaultBehavior",
                           "FakeObjectWithDefaultBehavior",
                           2);
+
+  // Also insert a variable having the same name as an object:
+  layout1.InsertNewObject(project, "MyExtension::Sprite", "ObjectWithNameReused", 3);
+  layout1.GetVariables().InsertNew("ObjectWithNameReused", 3).GetChild("MyChild");
+
+  // Also insert a global variable having the same name as a scene variable:
+  layout1.GetVariables().InsertNew("SceneVariableWithNameReused", 4);
+  project.GetVariables().InsertNew("SceneVariableWithNameReused", 0);
+
   auto &group = layout1.GetObjectGroups().InsertNew("AllObjects");
   group.AddObject("MySpriteObject");
   group.AddObject("MyOtherSpriteObject");
@@ -269,7 +285,7 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
           parser.ParseExpression("MySpriteObject.GetObjectStringWith3Param("
                                  "MySpriteObject.GetObjectNumber() / 2.3, "
                                  "MySpriteObject.GetObjectStringWith1Param("
-                                 "MyExtension::GetNumber()), test)");
+                                 "MyExtension::GetNumber()), UnknownObject.Unknown)");
       gd::ExpressionCodeGenerator expressionCodeGenerator("string",
                                                           "",
                                                           codeGenerator,
@@ -281,8 +297,7 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
               "MySpriteObject.getObjectStringWith3Param(MySpriteObject."
               "getObjectNumber() ?? 0 / 2.3, "
               "MySpriteObject.getObjectStringWith1Param(getNumber()) ?? \"\", "
-              "/* Error during generation, unrecognized identifier type: "
-              "unknown with value test */ \"test\") ?? \"\"");
+              "0) ?? \"\"");
     }
     SECTION("missing parameter") {
       {
@@ -392,9 +407,178 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
               "123) ?? \"\"");
     }
   }
-  SECTION("Function name") {
+  SECTION("Properties (1 level)") {
+    gd::PropertiesContainer propertiesContainer(gd::EventsFunctionsContainer::Extension);
+
+    auto projectScopedContainersWithProperties = gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
+    projectScopedContainersWithProperties.AddPropertiesContainer(propertiesContainer);
+
+    propertiesContainer.InsertNew("MyProperty");
+    propertiesContainer.InsertNew("MyProperty2");
+
+    gd::EventsCodeGenerator codeGeneratorWithProperties(platform, projectScopedContainersWithProperties);
+
+    {
+      auto node =
+        parser.ParseExpression("MyProperty + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGeneratorWithProperties,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getPropertyMyProperty() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MyProperty + MyProperty2");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGeneratorWithProperties,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getPropertyMyProperty() + getPropertyMyProperty2()");
+    }
+  }
+  SECTION("Parameters (1 level)") {
+    std::vector<gd::ParameterMetadata> parameters;
+    gd::ParameterMetadata param1;
+    param1.SetName("MyParameter1");
+    param1.SetType("number");
+    gd::ParameterMetadata param2;
+    param2.SetName("MyParameter2");
+    param2.SetType("string");
+    parameters.push_back(param1);
+    parameters.push_back(param2);
+
+    auto projectScopedContainersWithParameters = gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
+    projectScopedContainersWithParameters.AddParameters(parameters);
+
+    gd::EventsCodeGenerator codeGeneratorWithProperties(platform, projectScopedContainersWithParameters);
+
+    {
+      auto node =
+        parser.ParseExpression("MyParameter1 + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGeneratorWithProperties,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getParameterMyParameter1() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MyParameter1 + MyParameter2");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGeneratorWithProperties,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getParameterMyParameter1() + getParameterMyParameter2()");
+    }
+  }
+  SECTION("Scene variables (1 level)") {
+    {
+      auto node =
+        parser.ParseExpression("MySceneVariable + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneVariable).getAsNumber() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MySceneVariable + MySceneVariable2");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneVariable).getAsNumber() + getLayoutVariable(MySceneVariable2).getAsNumber()");
+    }
+  }
+  SECTION("Scene variables (conflict with a global variable)") {
+    {
+      auto node =
+        parser.ParseExpression("SceneVariableWithNameReused + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(SceneVariableWithNameReused).getAsNumber() + 1");
+    }
+  }
+  SECTION("Scene variables (2 levels)") {
+    {
+      auto node =
+        parser.ParseExpression("MySceneStructureVariable.MyChild + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneStructureVariable).getChild(\"MyChild\").getAsNumber() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MySceneStructureVariable.MyChild + MySceneStructureVariable2.MyChild");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneStructureVariable).getChild(\"MyChild\").getAsNumber() + getLayoutVariable(MySceneStructureVariable2).getChild(\"MyChild\").getAsNumber()");
+    }
+  }
+  SECTION("Scene variables (2 levels with bracket accessor)") {
+    {
+      auto node =
+        parser.ParseExpression("MySceneStructureVariable[\"MyChild\"] + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneStructureVariable).getChild(\"MyChild\").getAsNumber() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MySceneStructureVariable[\"MyChild\"] + MySceneStructureVariable2[\"MyChild\"]");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getLayoutVariable(MySceneStructureVariable).getChild(\"MyChild\").getAsNumber() + getLayoutVariable(MySceneStructureVariable2).getChild(\"MyChild\").getAsNumber()");
+    }
+  }
+  SECTION("Object variable with non existing object (invalid)") {
     auto node =
-        parser.ParseExpression("MySpriteObject.GetObjectNumber");
+        parser.ParseExpression("MyNonExistingSpriteObject.MyVariable");
     gd::ExpressionCodeGenerator expressionCodeGenerator("number",
                                                         "",
                                                         codeGenerator,
@@ -404,6 +588,124 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
     node->Visit(expressionCodeGenerator);
     REQUIRE(expressionCodeGenerator.GetOutput() == "0");
   }
+  SECTION("Object variables (1 level)") {
+    {
+      auto node =
+        parser.ParseExpression("MySpriteObject.MyVariable + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getAsNumber() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MySpriteObject.MyVariable + MySpriteObject.MyVariable2");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getAsNumber() + getVariableForObject(MySpriteObject, MyVariable2).getAsNumber()");
+    }
+  }
+  SECTION("Object variables (conflict with a scene variable)") {
+    {
+      auto node =
+        parser.ParseExpression("ObjectWithNameReused.MyVariable + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(ObjectWithNameReused, MyVariable).getAsNumber() + 1");
+    }
+  }
+  SECTION("Object variables (1 level with bracket accessor) (invalid)") {
+    {
+      auto node =
+        parser.ParseExpression("MySpriteObject[\"BracketNotationCantBeUsedHere\"] + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "fakeBadVariable.getAsNumber() + 1");
+    }
+    {
+      auto node =
+        parser.ParseExpression("MySpriteObject.MyVariable + MySpriteObject.MyVariable2");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getAsNumber() + getVariableForObject(MySpriteObject, MyVariable2).getAsNumber()");
+    }
+  }
+  SECTION("Object variables (2 levels)") {
+    {
+      auto node =
+          parser.ParseExpression("MySpriteObject.MyVariable.MyChildVariable + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getChild(\"MyChildVariable\").getAsNumber() + 1");
+    }
+    {
+      auto node =
+          parser.ParseExpression("MySpriteObject.MyVariable.MyChildVariable + MySpriteObject.MyVariable2.MyChildVariable");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getChild(\"MyChildVariable\").getAsNumber() + getVariableForObject(MySpriteObject, MyVariable2).getChild(\"MyChildVariable\").getAsNumber()");
+    }
+  }
+  SECTION("Object variables (2 levels with bracket accessor)") {
+    {
+      auto node =
+          parser.ParseExpression("MySpriteObject.MyVariable[\"MyChildVariable\"] + 1");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getChild(\"MyChildVariable\").getAsNumber() + 1");
+    }
+    {
+      auto node =
+          parser.ParseExpression("MySpriteObject.MyVariable[\"MyChildVariable\"] + MySpriteObject.MyVariable2[\"MyChildVariable\"]");
+      gd::ExpressionCodeGenerator expressionCodeGenerator("number",
+                                                          "",
+                                                          codeGenerator,
+                                                          context);
+
+      REQUIRE(node);
+      node->Visit(expressionCodeGenerator);
+      REQUIRE(expressionCodeGenerator.GetOutput() == "getVariableForObject(MySpriteObject, MyVariable).getChild(\"MyChildVariable\").getAsNumber() + getVariableForObject(MySpriteObject, MyVariable2).getChild(\"MyChildVariable\").getAsNumber()");
+    }
+  }
   SECTION("Invalid variables") {
     SECTION("empty variable") {
       REQUIRE(gd::ExpressionCodeGenerator::GenerateExpressionCode(
@@ -459,7 +761,7 @@ TEST_CASE("ExpressionCodeGenerator", "[common][events]") {
             "\"world\" ]", "")
               == "getLayoutVariable(myVariable).getChild(\"hello\" + \"world\")");
     }
-    SECTION("object variable") {
+    SECTION("object variable (legacy)") {
       REQUIRE(gd::ExpressionCodeGenerator::GenerateExpressionCode(
                   codeGenerator, context, "objectvar", "myVariable", "MySpriteObject")
               == "getVariableForObject(MySpriteObject, myVariable)");

Core/tests/ExpressionCompletionFinder.cpp

@@ -5,6 +5,8 @@
  */
 #include "GDCore/IDE/Events/ExpressionCompletionFinder.h"
 
+#include <vector>
+
 #include "DummyPlatform.h"
 #include "GDCore/Events/Parsers/ExpressionParser2.h"
 #include "GDCore/Extensions/Metadata/MetadataProvider.h"
@@ -12,6 +14,7 @@
 #include "GDCore/Extensions/PlatformExtension.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "catch.hpp"
 
 TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
@@ -19,7 +22,14 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
   gd::Platform platform;
   SetupProjectWithDummyPlatform(project, platform);
   auto& layout1 = project.InsertNewLayout("Layout1", 0);
-  layout1.InsertNewObject(project, "MyExtension::Sprite", "MyObject", 0);
+  layout1.GetVariables().InsertNew("myVariable");
+  auto& object1 =
+      layout1.InsertNewObject(project, "MyExtension::Sprite", "MyObject", 0);
+  object1.GetVariables().InsertNew("myObjectVariable");
+
+  gd::ProjectScopedContainers projectScopedContainers =
+      gd::ProjectScopedContainers::
+          MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
 
   gd::ExpressionParser2 parser;
 
@@ -28,38 +38,49 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
                                size_t location) {
     auto node = parser.ParseExpression(expression);
     REQUIRE(node != nullptr);
-    return gd::ExpressionCompletionFinder::GetCompletionDescriptionsFor(
-        platform, project, layout1, type, *node, location);
+    auto completions =
+        gd::ExpressionCompletionFinder::GetCompletionDescriptionsFor(
+            platform, projectScopedContainers, type, *node, location);
+
+    std::vector<gd::String> completionsAsString;
+    for (const auto& completion : completions) {
+      completionsAsString.push_back(completion.ToString());
+    }
+    return completionsAsString;
   };
 
-  const std::vector<gd::ExpressionCompletionDescription>
-      expectedEmptyCompletions;
+  const std::vector<gd::String> expectedEmptyCompletions;
 
   SECTION("Identifier") {
     SECTION("Object or expression completions when type is string") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("string", "My", 0, 2),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "string", "My", 0, 2)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "My", 0, 2).ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "My", 0) == expectedCompletions);
       REQUIRE(getCompletionsFor("string", "My", 1) == expectedCompletions);
       REQUIRE(getCompletionsFor("string", "My", 2) == expectedEmptyCompletions);
     }
     SECTION("Object or expression completions when type is number") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("number", "My", 0, 2),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "number", "My", 0, 2)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, number, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("number", "My", 0, 2).ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number", "My", 0) == expectedCompletions);
       REQUIRE(getCompletionsFor("number", "My", 1) == expectedCompletions);
       REQUIRE(getCompletionsFor("number", "My", 2) == expectedEmptyCompletions);
     }
     SECTION("Object or expression completions when type is number|string") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject(
-              "number|string", "My", 0, 2),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "number|string", "My", 0, 2)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, number|string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("number|string", "My", 0, 2).ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number|string", "My", 0) ==
               expectedCompletions);
       REQUIRE(getCompletionsFor("number|string", "My", 1) ==
@@ -68,26 +89,51 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
               expectedEmptyCompletions);
     }
     SECTION("Object or expression completions in a variable name") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("string", "My", 0, 2),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "string", "My", 0, 2)};
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My", 52) == expectedCompletions);
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My", 53) == expectedCompletions);
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My", 54) == expectedEmptyCompletions);
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "My", 0, 2).ToString()
+      };
+      // clang-format on
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My",
+                  52) == expectedCompletions);
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My",
+                  53) == expectedCompletions);
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[\"abc\" + My",
+                  54) == expectedEmptyCompletions);
     }
     SECTION("Object or expression completions in a variable index") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("number", "My", 0, 2),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "number", "My", 0, 2)};
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[12345 + My", 52) == expectedCompletions);
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[12345 + My", 53) == expectedCompletions);
-      REQUIRE(getCompletionsFor("number", "MyExtension::GetVariableAsNumber(MyVariable[12345 + My", 54) == expectedEmptyCompletions);
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, number, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("number", "My", 0, 2).ToString()
+      };
+      // clang-format on
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[12345 + My",
+                  52) == expectedCompletions);
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[12345 + My",
+                  53) == expectedCompletions);
+      REQUIRE(getCompletionsFor(
+                  "number",
+                  "MyExtension::GetVariableAsNumber(MyVariable[12345 + My",
+                  54) == expectedEmptyCompletions);
     }
     SECTION("Object when type is an object") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("object", "My", 0, 2)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, object, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("object", "My", 0) == expectedCompletions);
       REQUIRE(getCompletionsFor("object", "My", 1) == expectedCompletions);
       REQUIRE(getCompletionsFor("object", "My", 2) == expectedEmptyCompletions);
@@ -96,9 +142,11 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
     SECTION("Object when type is an object (alternate type)") {
       // Also test alternate types also considered as objects (but that can
       // result in different code generation):
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject(
-              "objectPtr", "My", 0, 2)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, objectPtr, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("objectPtr", "My", 0) == expectedCompletions);
       REQUIRE(getCompletionsFor("objectPtr", "My", 1) == expectedCompletions);
       REQUIRE(getCompletionsFor("objectPtr", "My", 2) ==
@@ -121,13 +169,15 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
 
   SECTION("Free function") {
     SECTION("Test 1") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForExpression(
-              "string", "Function", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription> expectedExactCompletions{
-          gd::ExpressionCompletionDescription::ForExpression(
+      std::vector<gd::String> expectedCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix(
               "string", "Function", 0, 8)
-              .SetIsExact(true)};
+              .ToString()};
+      std::vector<gd::String> expectedExactCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix(
+              "string", "Function", 0, 8)
+              .SetIsExact(true)
+              .ToString()};
       REQUIRE(getCompletionsFor("string", "Function(", 0) ==
               expectedCompletions);
       REQUIRE(getCompletionsFor("string", "Function(", 1) ==
@@ -147,43 +197,48 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
       REQUIRE(getCompletionsFor("string", "Function(\"", 9) ==
               expectedEmptyCompletions);
 
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForObject("unknown", "a", 9, 10),
-          gd::ExpressionCompletionDescription::ForExpression(
-              "unknown", "a", 9, 10)};
-      REQUIRE(getCompletionsFor("string", "Function(a", 9) ==
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 0, unknown, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }",
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("unknown", "My", 9, 10).ToString()
+      };
+      // clang-format on
+      REQUIRE(getCompletionsFor("string", "Function(My", 10) ==
               expectedCompletions);
     }
     SECTION("Function with a Variable as argument") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForVariable(
-              "scenevar", "myVar", 33, 38)};
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 3, no type, 1, no prefix, myVariable, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, no object configuration }",
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number",
                                 "MyExtension::GetVariableAsNumber(myVar",
                                 33) == expectedCompletions);
     }
     SECTION("Object function with a Variable as argument") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForVariable(
-              "objectvar", "myVar", 35, 40, "MyObject")};
-        getCompletionsFor("number",
-                                "MyObject.GetObjectVariableAsNumber(myVar",
-                                35);
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          "{ 3, no type, 1, no prefix, myObjectVariable, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, no object configuration }",
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number",
-                                "MyObject.GetObjectVariableAsNumber(myVar",
+                                "MyObject.GetObjectVariableAsNumber(myObj",
                                 35) == expectedCompletions);
     }
     SECTION("Function with a Layer as argument") {
-      std::vector<gd::ExpressionCompletionDescription> expectedCompletions{
-          gd::ExpressionCompletionDescription::ForText(
+      // clang-format off
+      std::vector<gd::String> expectedCompletions{
+          gd::ExpressionCompletionDescription::ForTextWithPrefix(
               "layer",
-              gd::MetadataProvider::GetExpressionMetadata(platform,
-                                                          "MyExtension::MouseX")
-                  .GetParameter(0),
+              gd::MetadataProvider::GetExpressionMetadata(platform, "MyExtension::MouseX").GetParameter(0),
               "",
               20,
               21,
-              false)};
+              false)
+              .ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number", "MyExtension::MouseX(\"", 20) ==
               expectedCompletions);
     }
@@ -191,16 +246,15 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
 
   SECTION("Partial object or behavior function") {
     SECTION("Test with string type") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorOrFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "Func", 9, 13, "MyObject"),
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 9, 13, "MyObject")};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorOrFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("Func", 9, 13, "MyObject").ToString(),
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 9, 13, "MyObject").ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "MyObject.Func", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("string", "MyObject.Func", 7) ==
@@ -215,16 +269,15 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
               expectedEmptyCompletions);
     }
     SECTION("Test with 'number|string' type") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "number|string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorOrFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "Func", 9, 13, "MyObject"),
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "number|string", "Func", 9, 13, "MyObject")};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, number|string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorOrFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("Func", 9, 13, "MyObject").ToString(),
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("number|string", "Func", 9, 13, "MyObject").ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("number|string", "MyObject.Func", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("number|string", "MyObject.Func", 7) ==
@@ -242,21 +295,18 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
 
   SECTION("Object function") {
     SECTION("Test 1") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorOrFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "Func", 9, 13, "MyObject"),
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 9, 13, "MyObject")};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedExactFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 9, 13, "MyObject")
-                  .SetIsExact(true)};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorOrFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("Func", 9, 13, "MyObject").ToString(),
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 9, 13, "MyObject").ToString()
+      };
+      std::vector<gd::String> expectedExactFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 9, 13, "MyObject").SetIsExact(true).ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "MyObject.Func(", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("string", "MyObject.Func(", 7) ==
@@ -278,18 +328,16 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
 
   SECTION("Partial behavior function") {
     SECTION("Test 1") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "MyBehavior", 9, 19, "MyObject")};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 21, 25, "MyObject", "MyBehavior")};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("MyBehavior", 9, 19, "MyObject").ToString()};
+      std::vector<gd::String> expectedFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 21, 25, "MyObject", "MyBehavior").ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::Func", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::Func", 7) ==
@@ -310,18 +358,17 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
               expectedFunctionCompletions);
     }
     SECTION("Test 2") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "MyBehavior", 9, 19, "MyObject")};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "", 21, 21, "MyObject", "MyBehavior")};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("MyBehavior", 9, 19, "MyObject").ToString()
+      };
+      std::vector<gd::String> expectedFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "", 21, 21, "MyObject", "MyBehavior").ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::", 7) ==
@@ -341,23 +388,20 @@ TEST_CASE("ExpressionCompletionFinder", "[common][events]") {
 
   SECTION("Behavior function") {
     SECTION("Test 1") {
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedObjectCompletions{
-              gd::ExpressionCompletionDescription::ForObject(
-                  "string", "MyObject", 0, 8)};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedBehaviorCompletions{
-              gd::ExpressionCompletionDescription::ForBehavior(
-                  "MyBehavior", 9, 19, "MyObject")};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 21, 25, "MyObject", "MyBehavior")};
-      std::vector<gd::ExpressionCompletionDescription>
-          expectedExactFunctionCompletions{
-              gd::ExpressionCompletionDescription::ForExpression(
-                  "string", "Func", 21, 25, "MyObject", "MyBehavior")
-                  .SetIsExact(true)};
+      // clang-format off
+      std::vector<gd::String> expectedObjectCompletions{
+          "{ 0, string, 1, no prefix, MyObject, no object name, no behavior name, non-exact, not last parameter, no parameter metadata, with object configuration }"
+      };
+      std::vector<gd::String> expectedBehaviorCompletions{
+          gd::ExpressionCompletionDescription::ForBehaviorWithPrefix("MyBehavior", 9, 19, "MyObject").ToString()
+      };
+      std::vector<gd::String> expectedFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 21, 25, "MyObject", "MyBehavior").ToString()
+      };
+      std::vector<gd::String> expectedExactFunctionCompletions{
+          gd::ExpressionCompletionDescription::ForExpressionWithPrefix("string", "Func", 21, 25, "MyObject", "MyBehavior").SetIsExact(true).ToString()
+      };
+      // clang-format on
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::Func(", 0) ==
               expectedObjectCompletions);
       REQUIRE(getCompletionsFor("string", "MyObject.MyBehavior::Func(", 7) ==

Core/tests/ExpressionParser2Benchmarks.cpp

@@ -12,6 +12,7 @@
 #include "GDCore/IDE/Events/ExpressionValidator.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
 #include "catch.hpp"
 
 TEST_CASE("ExpressionParser2 - Benchmarks", "[common][events]") {
@@ -21,14 +22,16 @@ TEST_CASE("ExpressionParser2 - Benchmarks", "[common][events]") {
   auto &layout1 = project.InsertNewLayout("Layout1", 0);
   layout1.InsertNewObject(project, "MyExtension::Sprite", "MySpriteObject", 0);
 
+  auto projectScopedContainers = gd::ProjectScopedContainers::MakeNewProjectScopedContainersForProjectAndLayout(project, layout1);
+
   gd::ExpressionParser2 parser;
 
-  auto parseExpression = [&parser, &project, &platform, &layout1](const gd::String &expression) {
-    auto parseExpressionWithType = [&parser, &project, &platform, &layout1,
+  auto parseExpression = [&parser, &platform, &projectScopedContainers](const gd::String &expression) {
+    auto parseExpressionWithType = [&parser, &platform, &projectScopedContainers,
                                     &expression](const gd::String &type) {
       auto node = parser.ParseExpression(expression);
       REQUIRE(node != nullptr);
-      gd::ExpressionValidator validator(platform, project, layout1, type);
+      gd::ExpressionValidator validator(platform, projectScopedContainers, type);
       node->Visit(validator);
     };
 

Core/tests/Layout.cpp

@@ -17,13 +17,6 @@
 
 using namespace gd;
 
-namespace {
-
-void SetupProject(gd::Project &project, gd::Platform &platform){
-
-};
-} // namespace
-
 TEST_CASE("Layout", "[common]") {
 
   SECTION("Find the type of a behavior in a object") {

Core/tests/String.cpp

@@ -0,0 +1,39 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+/**
+ * @file Tests covering String class of GDevelop Core.
+ */
+#include "GDCore/String.h"
+
+#include <algorithm>
+#include <initializer_list>
+#include <map>
+
+#include "GDCore/CommonTools.h"
+#include "catch.hpp"
+
+TEST_CASE("String", "[common]") {
+  SECTION("ReplaceConsecutiveOccurrences") {
+    gd::String str = "        ";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), ' ') ==
+            " ");
+    str = "L'opacité de NewSprite = \"    \"";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), ' ') ==
+            "L'opacité de NewSprite = \" \"");
+    str = "ccccccccc";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), 'c') ==
+            "c");
+    str = "c";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), 'c') ==
+            "c");
+    str = "";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), ' ') ==
+            "");
+    str = "Set animation of     NewSprite to    ";
+    REQUIRE(str.RemoveConsecutiveOccurrences(str.begin(), str.end(), ' ') ==
+            "Set animation of NewSprite to ");
+  }
+}

Core/tests/WholeProjectRefactorer-ApplyRefactoringForVariablesContainer.cpp

@@ -0,0 +1,569 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+/**
+ * @file Tests covering project refactoring
+ */
+#include <algorithm>
+#include <stdexcept>
+
+#include "DummyPlatform.h"
+#include "GDCore/Events/Builtin/ForEachChildVariableEvent.h"
+#include "GDCore/Events/Builtin/LinkEvent.h"
+#include "GDCore/Events/Builtin/RepeatEvent.h"
+#include "GDCore/Events/Builtin/StandardEvent.h"
+#include "GDCore/Events/Event.h"
+#include "GDCore/Extensions/Metadata/MetadataProvider.h"
+#include "GDCore/Extensions/Metadata/ParameterMetadataTools.h"
+#include "GDCore/Extensions/Platform.h"
+#include "GDCore/Extensions/PlatformExtension.h"
+#include "GDCore/IDE/WholeProjectRefactorer.h"
+#include "GDCore/Project/Behavior.h"
+#include "GDCore/Project/EventsFunctionsExtension.h"
+#include "GDCore/Project/ExternalEvents.h"
+#include "GDCore/Project/ExternalLayout.h"
+#include "GDCore/Project/Layout.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/Variable.h"
+#include "GDCore/Serialization/Serializer.h"
+#include "catch.hpp"
+
+TEST_CASE("WholeProjectRefactorer::ApplyRefactoringForVariablesContainer",
+          "[common]") {
+  SECTION("Variable renamed (project, layout, object)") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &layout1 = project.InsertNewLayout("Layout1", 0);
+    gd::StandardEvent &event =
+        dynamic_cast<gd::StandardEvent &>(layout1.GetEvents().InsertNewEvent(
+            project, "BuiltinCommonInstructions::Standard"));
+    gd::ForEachChildVariableEvent &forEachChildVariableEvent =
+        dynamic_cast<gd::ForEachChildVariableEvent &>(
+            layout1.GetEvents().InsertNewEvent(
+                project, "BuiltinCommonInstructions::ForEachChildVariable"));
+    gd::RepeatEvent &repeatEvent =
+        dynamic_cast<gd::RepeatEvent &>(layout1.GetEvents().InsertNewEvent(
+            project, "BuiltinCommonInstructions::Repeat"));
+
+    // Declare global variables.
+    project.GetVariables().InsertNew("MyGlobalVariable", 0).SetValue(123);
+    project.GetVariables().InsertNew("MyGlobalVariable2", 0).SetValue(123);
+    project.GetVariables().InsertNew("SharedVariableName", 0).SetValue(123);
+    project.GetVariables()
+        .InsertNew("MyGlobalStructureVariable", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+    project.GetVariables()
+        .InsertNew("MyGlobalStructureVariable2", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    // Declare variables in the scene.
+    layout1.GetVariables().InsertNew("MySceneVariable", 0).SetValue(123);
+    layout1.GetVariables().InsertNew("MySceneVariable2", 0).SetValue(123);
+    layout1.GetVariables().InsertNew("SharedVariableName", 0).SetValue(123);
+    layout1.GetVariables()
+        .InsertNew("MySceneStructureVariable", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+    layout1.GetVariables()
+        .InsertNew("MySceneStructureVariable2", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    // Declare variables in objects.
+    auto &object1 =
+        layout1.InsertNewObject(project, "MyExtension::Sprite", "Object1", 0);
+    object1.GetVariables().InsertNew("MyObjectVariable");
+    object1.GetVariables()
+        .InsertNew("MyObjectStructureVariable")
+        .GetChild("MyChild")
+        .SetValue(123);
+    auto &object2 =
+        layout1.InsertNewObject(project, "MyExtension::Sprite", "Object2", 0);
+    object2.GetVariables().InsertNew("MyObjectVariable");
+    object2.GetVariables()
+        .InsertNew("MyObjectStructureVariable")
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    // Create an event using the variables.
+    // clang-format off
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomething");
+      action.SetParametersCount(1);
+      action.SetParameter(
+          0,
+          gd::Expression(
+              "1 + "
+              "MySceneVariable + "
+              "MySceneVariable2 + "
+              "Object1.MyObjectVariable + "
+              "Object2.MyObjectVariable + "
+              "Object1.MyObjectStructureVariable.MyChild + "
+              "Object2.MyObjectStructureVariable.MyChild + "
+              "MySceneStructureVariable.MyChild + "
+              "MySceneStructureVariable2.MyChild + "
+              "MyGlobalVariable + "
+              "MyGlobalVariable2 + "
+              "MyGlobalStructureVariable.MyChild + "
+              "MyGlobalStructureVariable2.MyChild"));
+      event.GetActions().Insert(action);
+    }
+    // Expressions with "old" "scenevar", "globalvar", "objectvar":
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomething");
+      action.SetParametersCount(1);
+      action.SetParameter(
+          0,
+          gd::Expression(
+              // "objectvar" (in a free expression):
+              "1 + "
+              "MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyObjectVariable, Object2, MyObjectVariable) + "
+              "MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyObjectStructureVariable.MyChild, Object2, MyObjectStructureVariable.MyChild) + "
+              // "objectvar" (using the name of the object being called):
+              "Object1.GetObjectVariableAsNumber(MyObjectVariable) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectVariable) + "
+              "Object1.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild) + "
+              "Object1.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild) + "
+              // "globalvar" and "scenevar":
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable2) + "
+              "MyExtension::GetGlobalVariableAsNumber(SharedVariableName) + "
+              "MyExtension::GetVariableAsNumber(MySceneVariable) + "
+              "MyExtension::GetVariableAsNumber(MySceneVariable2) + "
+              "MyExtension::GetVariableAsNumber(SharedVariableName) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable.MyChild) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable.MyChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable.MyChild.GrandChild) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild.GrandChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable.MyChild.GrandChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild.GrandChild)"));
+      event.GetActions().Insert(action);
+    }
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MySceneVariable"));
+      action.SetParameter(1, gd::Expression("MyGlobalVariable"));
+      action.SetParameter(2, gd::Expression("Object1"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable"));
+      event.GetActions().Insert(action);
+    }
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("SharedVariableName"));
+      action.SetParameter(1, gd::Expression("SharedVariableName"));
+      action.SetParameter(2, gd::Expression("Object2"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable"));
+      event.GetActions().Insert(action);
+    }
+
+    forEachChildVariableEvent.SetIterableVariableName("MySceneStructureVariable");
+    repeatEvent.SetRepeatExpression("1 + MySceneVariable + Object1.MyObjectVariable + Object2.MyObjectVariable");
+    // clang-format on
+
+    // Do a copy of layout1 to ensure other scene is unchanged after the
+    // refactoring.
+    gd::Layout layout2 = layout1;
+    layout2.SetName("Layout2");
+    project.InsertLayout(layout2, 1);
+    gd::SerializerElement originalSerializedLayout2;
+    layout2.SerializeTo(originalSerializedLayout2);
+
+    // Do the changes and launch the refactoring.
+    project.GetVariables().ResetPersistentUuid();
+    layout1.GetVariables().ResetPersistentUuid();
+    object1.ResetPersistentUuid();
+    gd::SerializerElement originalSerializedProjectVariables;
+    project.GetVariables().SerializeTo(originalSerializedProjectVariables);
+    gd::SerializerElement originalSerializedLayoutVariables;
+    layout1.GetVariables().SerializeTo(originalSerializedLayoutVariables);
+    gd::SerializerElement originalSerializedObject1Variables;
+    object1.GetVariables().SerializeTo(originalSerializedObject1Variables);
+
+    project.GetVariables().Rename("MyGlobalVariable",
+                                  "MyRenamedGlobalVariable");
+    project.GetVariables().Rename("MyGlobalStructureVariable",
+                                  "MyRenamedGlobalStructureVariable");
+    project.GetVariables().Rename("SharedVariableName",
+                                  "RenamedGlobalVariableFromASharedName");
+    auto changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedProjectVariables,
+        project.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        project.GetVariables(),
+        changeset);
+
+    layout1.GetVariables().Rename("MySceneVariable", "MyRenamedSceneVariable");
+    layout1.GetVariables().Rename("MySceneStructureVariable",
+                                  "MyRenamedSceneStructureVariable");
+    changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedLayoutVariables,
+        layout1.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        layout1.GetVariables(),
+        changeset);
+
+    object1.GetVariables().Rename("MyObjectVariable",
+                                  "MyRenamedObjectVariable");
+    object1.GetVariables().Rename("MyObjectStructureVariable",
+                                  "MyRenamedObjectStructureVariable");
+    changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedObject1Variables,
+        object1.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        object1.GetVariables(),
+        changeset);
+
+    // Check the first layout is updated.
+    // clang-format off
+    {
+      // Updated direct access to variables:
+      REQUIRE(event.GetActions()[0].GetParameter(0).GetPlainString() ==
+              "1 + "
+              "MyRenamedSceneVariable + "
+              "MySceneVariable2 + "
+              "Object1.MyRenamedObjectVariable + "
+              "Object2.MyObjectVariable + "
+              "Object1.MyRenamedObjectStructureVariable.MyChild + "
+              "Object2.MyObjectStructureVariable.MyChild + "
+              "MyRenamedSceneStructureVariable.MyChild + "
+              "MySceneStructureVariable2.MyChild + "
+              "MyRenamedGlobalVariable + "
+              "MyGlobalVariable2 + "
+              "MyRenamedGlobalStructureVariable.MyChild + "
+              "MyGlobalStructureVariable2.MyChild"
+      );
+
+      // Updated access to variables using the legacy "pre-scoped" "scenevar",
+      // "globalvar" and "objectvar" parameters in expressions:
+      REQUIRE(event.GetActions()[1].GetParameter(0).GetPlainString() ==
+              "1 + "
+              // Multiple "objectvar" parameters in a free function:
+              "MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyRenamedObjectVariable, Object2, MyObjectVariable) + "
+              // Multiple "objectvar" parameters in a free function, with child
+              // variable:
+              "MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyRenamedObjectStructureVariable.MyChild, Object2, MyObjectStructureVariable.MyChild) + "
+              // Single "objectvar" from the object being accessed:
+              "Object1.GetObjectVariableAsNumber(MyRenamedObjectVariable) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectVariable) + "
+              // Single "objectvar" from the object being accessed, with child
+              // variales:
+              "Object1.GetObjectVariableAsNumber(MyRenamedObjectStructureVariable.MyChild) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild) + "
+              "Object1.GetObjectVariableAsNumber(MyRenamedObjectStructureVariable.MyChild.GrandChild) + "
+              "Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild) + "
+              // "globalvar" and "scenevar" in a free function:
+              "MyExtension::GetGlobalVariableAsNumber(MyRenamedGlobalVariable) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable2) + "
+              "MyExtension::GetGlobalVariableAsNumber(RenamedGlobalVariableFromASharedName) + "
+              "MyExtension::GetVariableAsNumber(MyRenamedSceneVariable) + "
+              "MyExtension::GetVariableAsNumber(MySceneVariable2) + "
+              "MyExtension::GetVariableAsNumber(SharedVariableName) + "
+              // "globalvar" and "scenevar" in a free function, with child
+              // variables:
+              "MyExtension::GetGlobalVariableAsNumber(MyRenamedGlobalStructureVariable.MyChild) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild) + "
+              "MyExtension::GetVariableAsNumber(MyRenamedSceneStructureVariable.MyChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild) + "
+              // "globalvar" and "scenevar" in a free function, with grand child
+              // variables:
+              "MyExtension::GetGlobalVariableAsNumber(MyRenamedGlobalStructureVariable.MyChild.GrandChild) + "
+              "MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild.GrandChild) + "
+              "MyExtension::GetVariableAsNumber(MyRenamedSceneStructureVariable.MyChild.GrandChild) + "
+              "MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild.GrandChild)");
+
+      // Updated "scenevar", "globalvar" and "object" parameters of an
+      // instruction:
+      REQUIRE(event.GetActions()[2].GetParameter(0).GetPlainString() ==
+              "MyRenamedSceneVariable");
+      REQUIRE(event.GetActions()[2].GetParameter(1).GetPlainString() ==
+              "MyRenamedGlobalVariable");
+      REQUIRE(event.GetActions()[2].GetParameter(2).GetPlainString() ==
+              "Object1");
+      REQUIRE(event.GetActions()[2].GetParameter(3).GetPlainString() ==
+              "MyRenamedObjectVariable");
+
+      // Updated "scenevar" and "globalvar" parameters of an instruction:
+      REQUIRE(event.GetActions()[3].GetParameter(0).GetPlainString() ==
+              "SharedVariableName");
+      REQUIRE(event.GetActions()[3].GetParameter(1).GetPlainString() ==
+              "RenamedGlobalVariableFromASharedName");
+
+      // Unchanged "object" and "objectvar" parameters:
+      REQUIRE(event.GetActions()[3].GetParameter(2).GetPlainString() ==
+              "Object2");
+      REQUIRE(event.GetActions()[3].GetParameter(3).GetPlainString() ==
+              "MyObjectVariable");
+    }
+
+    REQUIRE(forEachChildVariableEvent.GetIterableVariableName() == "MyRenamedSceneStructureVariable");
+    REQUIRE(repeatEvent.GetRepeatExpression() == "1 + MyRenamedSceneVariable + Object1.MyRenamedObjectVariable + Object2.MyObjectVariable");
+    // clang-format on
+
+    // Check the other layout is untouched.
+    {
+      gd::SerializerElement serializedLayout2;
+      layout2.SerializeTo(serializedLayout2);
+      REQUIRE(gd::Serializer::ToJSON(serializedLayout2) ==
+              gd::Serializer::ToJSON(originalSerializedLayout2));
+    }
+  }
+  SECTION("Variable removed (project, layout, object)") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &layout1 = project.InsertNewLayout("Layout1", 0);
+    gd::StandardEvent &event =
+        dynamic_cast<gd::StandardEvent &>(layout1.GetEvents().InsertNewEvent(
+            project, "BuiltinCommonInstructions::Standard"));
+
+    // Declare global variables.
+    project.GetVariables().InsertNew("MyGlobalVariable", 0).SetValue(123);
+    project.GetVariables().InsertNew("MyGlobalVariable2", 0).SetValue(123);
+    project.GetVariables().InsertNew("SharedVariableName", 0).SetValue(123);
+    project.GetVariables()
+        .InsertNew("MyGlobalStructureVariable", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+    project.GetVariables()
+        .InsertNew("MyGlobalStructureVariable2", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    // Declare variables in the scene.
+    layout1.GetVariables().InsertNew("MySceneVariable", 0).SetValue(123);
+    layout1.GetVariables().InsertNew("MySceneVariable2", 0).SetValue(123);
+    layout1.GetVariables().InsertNew("SharedVariableName", 0).SetValue(123);
+    layout1.GetVariables()
+        .InsertNew("MySceneStructureVariable", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+    layout1.GetVariables()
+        .InsertNew("MySceneStructureVariable2", 0)
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    // Declare variables in objects.
+    auto &object1 =
+        layout1.InsertNewObject(project, "MyExtension::Sprite", "Object1", 0);
+    object1.GetVariables().InsertNew("MyObjectVariable");
+    object1.GetVariables()
+        .InsertNew("MyObjectStructureVariable")
+        .GetChild("MyChild")
+        .SetValue(123);
+    auto &object2 =
+        layout1.InsertNewObject(project, "MyExtension::Sprite", "Object2", 0);
+    object2.GetVariables().InsertNew("MyObjectVariable");
+    object2.GetVariables()
+        .InsertNew("MyObjectStructureVariable")
+        .GetChild("MyChild")
+        .SetValue(123);
+
+    auto makeTestAction = [](const gd::String &expression) {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomething");
+      action.SetParametersCount(1);
+      action.SetParameter(0, expression);
+      return action;
+    };
+
+    // Create an event using the variables.
+    // clang-format off
+    event.GetActions().Insert(makeTestAction("1 + MySceneVariable"));
+    event.GetActions().Insert(makeTestAction("1 + MySceneVariable2"));
+    event.GetActions().Insert(makeTestAction("1 + Object1.MyObjectVariable"));
+    event.GetActions().Insert(makeTestAction("1 + Object2.MyObjectVariable"));
+    event.GetActions().Insert(makeTestAction("1 + Object1.MyObjectStructureVariable.MyChild"));
+    event.GetActions().Insert(makeTestAction("1 + Object2.MyObjectStructureVariable.MyChild"));
+    event.GetActions().Insert(makeTestAction("1 + MySceneStructureVariable.MyChild"));
+    event.GetActions().Insert(makeTestAction("1 + MySceneStructureVariable2.MyChild"));
+    event.GetActions().Insert(makeTestAction("1 + MyGlobalVariable"));
+    event.GetActions().Insert(makeTestAction("1 + MyGlobalVariable2"));
+    event.GetActions().Insert(makeTestAction("1 + MyGlobalStructureVariable.MyChild"));
+    event.GetActions().Insert(makeTestAction("1 + MyGlobalStructureVariable2.MyChild"));
+
+    // Expressions with "old" "scenevar", "globalvar", "objectvar":
+    // "objectvar" (in a free expression):
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyObjectVariable, Object2, MyObjectVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object2, MyObjectVariable, Object2, MyObjectVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object1, MyObjectStructureVariable.MyChild, Object2, MyObjectStructureVariable.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object2, MyObjectStructureVariable.MyChild, Object2, MyObjectStructureVariable.MyChild)"));
+    // "objectvar" (using the name of the object being called):
+    event.GetActions().Insert(makeTestAction("1 + Object1.GetObjectVariableAsNumber(MyObjectVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + Object2.GetObjectVariableAsNumber(MyObjectVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + Object1.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + Object1.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild)"));
+    event.GetActions().Insert(makeTestAction("1 + Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable2)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(SharedVariableName)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneVariable)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneVariable2)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(SharedVariableName)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable.MyChild.GrandChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild.GrandChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable.MyChild.GrandChild)"));
+    event.GetActions().Insert(makeTestAction("1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild.GrandChild)"));
+
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MySceneVariable")); // To remove
+      action.SetParameter(1, gd::Expression("MyGlobalVariable2"));
+      action.SetParameter(2, gd::Expression("Object2"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable"));
+      event.GetActions().Insert(action);
+    }
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MySceneVariable2"));
+      action.SetParameter(1, gd::Expression("MyGlobalVariable")); // To remove
+      action.SetParameter(2, gd::Expression("Object2"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable"));
+      event.GetActions().Insert(action);
+    }
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MySceneVariable2"));
+      action.SetParameter(1, gd::Expression("MyGlobalVariable2"));
+      action.SetParameter(2, gd::Expression("Object1"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable")); // To remove
+      event.GetActions().Insert(action);
+    }
+    {
+      gd::Instruction action;
+      action.SetType("MyExtension::DoSomethingWithLegacyPreScopedVariables");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MySceneVariable2"));
+      action.SetParameter(1, gd::Expression("MyGlobalVariable2"));
+      action.SetParameter(2, gd::Expression("Object2"));
+      action.SetParameter(3, gd::Expression("MyObjectVariable"));
+      event.GetActions().Insert(action);
+    }
+    // clang-format on
+
+    // Do a copy of layout1 to ensure other scene is unchanged after the
+    // refactoring.
+    gd::Layout layout2 = layout1;
+    layout2.SetName("Layout2");
+    project.InsertLayout(layout2, 1);
+    gd::SerializerElement originalSerializedLayout2;
+    layout2.SerializeTo(originalSerializedLayout2);
+
+    // Do the changes and launch the refactoring.
+    project.GetVariables().ResetPersistentUuid();
+    layout1.GetVariables().ResetPersistentUuid();
+    object1.ResetPersistentUuid();
+    gd::SerializerElement originalSerializedProjectVariables;
+    project.GetVariables().SerializeTo(originalSerializedProjectVariables);
+    gd::SerializerElement originalSerializedLayoutVariables;
+    layout1.GetVariables().SerializeTo(originalSerializedLayoutVariables);
+    gd::SerializerElement originalSerializedObject1Variables;
+    object1.GetVariables().SerializeTo(originalSerializedObject1Variables);
+
+    project.GetVariables().Remove("MyGlobalVariable");
+    project.GetVariables().Remove("MyGlobalStructureVariable");
+    project.GetVariables().Remove("SharedVariableName");
+    auto changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedProjectVariables,
+        project.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        project.GetVariables(),
+        changeset);
+
+    layout1.GetVariables().Remove("MySceneVariable");
+    layout1.GetVariables().Remove("MySceneStructureVariable");
+    changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedLayoutVariables,
+        layout1.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        layout1.GetVariables(),
+        changeset);
+
+    object1.GetVariables().Remove("MyObjectVariable");
+    object1.GetVariables().Remove("MyObjectStructureVariable");
+    changeset = gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+        project,
+        originalSerializedObject1Variables,
+        object1.GetVariables());
+    gd::WholeProjectRefactorer::ApplyRefactoringForVariablesContainer(
+        project,
+        object1.GetVariables(),
+        changeset);
+
+    // Check the first layout is updated.
+    {
+      REQUIRE(event.GetActions().GetCount() == 19);
+
+      // clang-format off
+      // All the actions using the removed variables are gone.
+      REQUIRE(event.GetActions()[0].GetParameter(0).GetPlainString() == "1 + MySceneVariable2");
+      REQUIRE(event.GetActions()[1].GetParameter(0).GetPlainString() == "1 + Object2.MyObjectVariable");
+      REQUIRE(event.GetActions()[2].GetParameter(0).GetPlainString() == "1 + Object2.MyObjectStructureVariable.MyChild");
+      REQUIRE(event.GetActions()[3].GetParameter(0).GetPlainString() == "1 + MySceneStructureVariable2.MyChild");
+      REQUIRE(event.GetActions()[4].GetParameter(0).GetPlainString() == "1 + MyGlobalVariable2");
+      REQUIRE(event.GetActions()[5].GetParameter(0).GetPlainString() == "1 + MyGlobalStructureVariable2.MyChild");
+      REQUIRE(event.GetActions()[6].GetParameter(0).GetPlainString() == "1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object2, MyObjectVariable, Object2, MyObjectVariable)");
+      REQUIRE(event.GetActions()[7].GetParameter(0).GetPlainString() == "1 + MyExtension::GetStringWith2ObjectParamAnd2ObjectVarParam(Object2, MyObjectStructureVariable.MyChild, Object2, MyObjectStructureVariable.MyChild)");
+      REQUIRE(event.GetActions()[8].GetParameter(0).GetPlainString() == "1 + Object2.GetObjectVariableAsNumber(MyObjectVariable)");
+      REQUIRE(event.GetActions()[9].GetParameter(0).GetPlainString() == "1 + Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild)");
+      REQUIRE(event.GetActions()[10].GetParameter(0).GetPlainString() == "1 + Object2.GetObjectVariableAsNumber(MyObjectStructureVariable.MyChild.GrandChild)");
+      REQUIRE(event.GetActions()[11].GetParameter(0).GetPlainString() == "1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalVariable2)");
+      REQUIRE(event.GetActions()[12].GetParameter(0).GetPlainString() == "1 + MyExtension::GetVariableAsNumber(MySceneVariable2)");
+      REQUIRE(event.GetActions()[13].GetParameter(0).GetPlainString() == "1 + MyExtension::GetVariableAsNumber(SharedVariableName)");
+      REQUIRE(event.GetActions()[14].GetParameter(0).GetPlainString() == "1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild)");
+      REQUIRE(event.GetActions()[15].GetParameter(0).GetPlainString() == "1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild)");
+      REQUIRE(event.GetActions()[16].GetParameter(0).GetPlainString() == "1 + MyExtension::GetGlobalVariableAsNumber(MyGlobalStructureVariable2.MyChild.GrandChild)");
+      REQUIRE(event.GetActions()[17].GetParameter(0).GetPlainString() == "1 + MyExtension::GetVariableAsNumber(MySceneStructureVariable2.MyChild.GrandChild)");
+
+      REQUIRE(event.GetActions()[18].GetParameter(0).GetPlainString() == "MySceneVariable2");
+      REQUIRE(event.GetActions()[18].GetParameter(1).GetPlainString() == "MyGlobalVariable2");
+      REQUIRE(event.GetActions()[18].GetParameter(2).GetPlainString() == "Object2");
+      REQUIRE(event.GetActions()[18].GetParameter(3).GetPlainString() == "MyObjectVariable");
+      // clang-format on
+    }
+
+    // Check the other layout is untouched.
+    {
+      gd::SerializerElement serializedLayout2;
+      layout2.SerializeTo(serializedLayout2);
+      REQUIRE(gd::Serializer::ToJSON(serializedLayout2) ==
+              gd::Serializer::ToJSON(originalSerializedLayout2));
+    }
+  }
+}

Core/tests/WholeProjectRefactorer.cpp

@@ -306,7 +306,7 @@ const void SetupEvents(gd::EventsList &eventList) {
       action.SetParameter(
           0,
           gd::Expression(
-              "ObjectWithMyBehavior.GetObjectNumber()"));
+              "ObjectWithMyBehavior.GetObjectNumber() + ObjectWithMyBehavior.MyVariable + ObjectWithMyBehavior.MyStructureVariable.Child"));
       event.GetActions().Insert(action);
       eventList.InsertEvent(event);
     }
@@ -415,13 +415,13 @@ const void SetupEvents(gd::EventsList &eventList) {
     if (eventList.GetEventsCount() != BehaviorSharedPropertyAction) {
       throw std::logic_error("Invalid events setup: " + std::to_string(eventList.GetEventsCount()));
     }
-    // Create an event in the layout using "MyProperty" action
+    // Create an event in the layout using "MySharedProperty" action
     {
       gd::StandardEvent event;
       gd::Instruction instruction;
       instruction.SetType(
           "MyEventsExtension::MyEventsBasedBehavior::" +
-          gd::EventsBasedBehavior::GetSharedPropertyActionName("MyProperty"));
+          gd::EventsBasedBehavior::GetSharedPropertyActionName("MySharedProperty"));
       event.GetActions().Insert(instruction);
       eventList.InsertEvent(event);
     }
@@ -429,13 +429,13 @@ const void SetupEvents(gd::EventsList &eventList) {
     if (eventList.GetEventsCount() != BehaviorSharedPropertyCondition) {
       throw std::logic_error("Invalid events setup: " + std::to_string(eventList.GetEventsCount()));
     }
-    // Create an event in the layout using "MyProperty" condition
+    // Create an event in the layout using "MySharedProperty" condition
     {
       gd::StandardEvent event;
       gd::Instruction instruction;
       instruction.SetType(
           "MyEventsExtension::MyEventsBasedBehavior::" +
-          gd::EventsBasedBehavior::GetSharedPropertyConditionName("MyProperty"));
+          gd::EventsBasedBehavior::GetSharedPropertyConditionName("MySharedProperty"));
       event.GetConditions().Insert(instruction);
       eventList.InsertEvent(event);
     }
@@ -443,7 +443,7 @@ const void SetupEvents(gd::EventsList &eventList) {
     if (eventList.GetEventsCount() != BehaviorSharedPropertyExpression) {
       throw std::logic_error("Invalid events setup: " + std::to_string(eventList.GetEventsCount()));
     }
-    // Create an event in the layout using "MyProperty" expression
+    // Create an event in the layout using "MySharedProperty" expression
     {
       gd::StandardEvent event;
       gd::Instruction instruction;
@@ -452,7 +452,7 @@ const void SetupEvents(gd::EventsList &eventList) {
       instruction.SetParameter(
           0, gd::Expression("ObjectWithMyBehavior.MyBehavior::" +
                             gd::EventsBasedBehavior::GetSharedPropertyExpressionName(
-                                "MyProperty") +
+                                "MySharedProperty") +
                             "()"));
       event.GetActions().Insert(instruction);
       eventList.InsertEvent(event);
@@ -929,11 +929,15 @@ SetupProjectWithEventsFunctionExtension(gd::Project &project) {
         .SetFunctionType(gd::EventsFunction::ActionWithOperator)
         .SetGetterName("MyBehaviorEventsFunctionExpressionAndCondition");
 
-    // Add property
+    // Add a property:
     eventsBasedBehavior.GetPropertyDescriptors()
         .InsertNew("MyProperty", 0)
         .SetType("Number");
-    // The same name is used for the shared property to ensure there is no name
+    // Add a shared property:
+    eventsBasedBehavior.GetSharedPropertyDescriptors()
+        .InsertNew("MySharedProperty", 0)
+        .SetType("Number");
+    // The same name is used for another shared property to ensure there is no name
     // collision.
     eventsBasedBehavior.GetSharedPropertyDescriptors()
         .InsertNew("MyProperty", 0)
@@ -1068,6 +1072,8 @@ SetupProjectWithEventsFunctionExtension(gd::Project &project) {
     auto &childObject = eventsBasedObject.InsertNewObject(
         project, "MyExtension::Sprite", "ObjectWithMyBehavior", 0);
     childObject.AddNewBehavior(project, "MyEventsExtension::MyEventsBasedBehavior", "MyBehavior");
+    childObject.GetVariables().InsertNew("MyVariable");
+    childObject.GetVariables().InsertNew("MyStructureVariable").CastTo(gd::Variable::Structure);
     auto &group = eventsBasedObject.GetObjectGroups().InsertNew("GroupWithMyBehavior");
     group.AddObject(childObject.GetName());
 
@@ -1154,6 +1160,8 @@ SetupProjectWithEventsFunctionExtension(gd::Project &project) {
     auto &object = layout.InsertNewObject(project, "MyExtension::Sprite",
                                           "ObjectWithMyBehavior", 0);
     object.AddNewBehavior(project, "MyEventsExtension::MyEventsBasedBehavior", "MyBehavior");
+    object.GetVariables().InsertNew("MyVariable");
+    object.GetVariables().InsertNew("MyStructureVariable").CastTo(gd::Variable::Structure);
     auto &group = layout.GetObjectGroups().InsertNew("GroupWithMyBehavior", 0);
     group.AddObject("ObjectWithMyBehavior");
 
@@ -1455,10 +1463,10 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
         REQUIRE(GetEventFirstActionFirstParameterString(eventsList->GetEvent(
                     FreeFunctionWithObjects)) == "RenamedObjectWithMyBehavior");
 
-        // Check object name has been renamed in expressions.
+        // Check object name has been renamed in expressions and in object variables.
         REQUIRE(GetEventFirstActionFirstParameterString(
                     eventsList->GetEvent(FreeFunctionWithObjectExpression)) ==
-                "RenamedObjectWithMyBehavior.GetObjectNumber()");
+                "RenamedObjectWithMyBehavior.GetObjectNumber() + RenamedObjectWithMyBehavior.MyVariable + RenamedObjectWithMyBehavior.MyStructureVariable.Child");
       }
     }
   }
@@ -1567,6 +1575,12 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       gd::ParameterMetadataTools::ParametersToObjectsContainer(
           project, eventsFunction.GetParameters(), objectsContainer);
 
+      // Simulate a variable in ObjectWithMyBehavior, even if this is not
+      // supported by the editor.
+      auto& objectWithMyBehavior = objectsContainer.GetObject("ObjectWithMyBehavior");
+      objectWithMyBehavior.GetVariables().InsertNew("MyVariable");
+      objectWithMyBehavior.GetVariables().InsertNew("MyStructureVariable").CastTo(gd::Variable::Structure);
+
       // Trigger the refactoring after the renaming of an object
       gd::WholeProjectRefactorer::ObjectOrGroupRenamedInEventsFunction(
           project, eventsFunction, globalObjectsContainer, objectsContainer,
@@ -1579,11 +1593,11 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
               eventsFunction.GetEvents().GetEvent(FreeFunctionWithObjects)) ==
           "RenamedObjectWithMyBehavior");
 
-      // Check object name has been renamed in expressions.
+      // Check object name has been renamed in expressions and object variables.
       REQUIRE(GetEventFirstActionFirstParameterString(
                   eventsFunction.GetEvents().GetEvent(
                       FreeFunctionWithObjectExpression)) ==
-              "RenamedObjectWithMyBehavior.GetObjectNumber()");
+              "RenamedObjectWithMyBehavior.GetObjectNumber() + RenamedObjectWithMyBehavior.MyVariable + RenamedObjectWithMyBehavior.MyStructureVariable.Child");
     }
   }
 
@@ -1618,10 +1632,10 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
                 objectFunctionEvents.GetEvent(FreeFunctionWithObjects)) ==
             "RenamedObjectWithMyBehavior");
 
-    // Check object name has been renamed in expressions.
+    // Check object name has been renamed in expressions and object variables.
     REQUIRE(GetEventFirstActionFirstParameterString(
                 objectFunctionEvents.GetEvent(FreeFunctionWithObjectExpression)) ==
-              "RenamedObjectWithMyBehavior.GetObjectNumber()");
+              "RenamedObjectWithMyBehavior.GetObjectNumber() + RenamedObjectWithMyBehavior.MyVariable + RenamedObjectWithMyBehavior.MyStructureVariable.Child");
   }
 
   SECTION("Object deleted (in events function)") {
@@ -1742,7 +1756,7 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
                     eventsList->GetEvent(BehaviorActionWithOperator)) ==
           "MyRenamedExtension::MyEventsBasedBehavior::"
           "MyBehaviorEventsFunctionActionWithOperator");
-      
+
       // Check if events-based behaviors properties have been renamed in
       // instructions
       REQUIRE(GetEventFirstActionType(
@@ -1752,7 +1766,7 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       REQUIRE(GetEventFirstActionType(
                   eventsList->GetEvent(BehaviorSharedPropertyAction)) ==
               "MyRenamedExtension::MyEventsBasedBehavior::"
-              "SetSharedPropertyMyProperty");
+              "SetSharedPropertyMySharedProperty");
 
       // Check events-based behavior methods have *not* been renamed in
       // expressions
@@ -2114,7 +2128,7 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       REQUIRE(GetEventFirstActionType(
                   eventsList->GetEvent(BehaviorSharedPropertyAction)) ==
               "MyEventsExtension::MyRenamedEventsBasedBehavior::"
-              "SetSharedPropertyMyProperty");
+              "SetSharedPropertyMySharedProperty");
 
       // Check events-based behavior methods have *not* been renamed in
       // expressions
@@ -2729,16 +2743,16 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       REQUIRE(GetEventFirstActionType(
                   eventsList->GetEvent(BehaviorSharedPropertyAction)) ==
               "MyEventsExtension::MyEventsBasedBehavior::"
-              "SetSharedPropertyMyProperty");
+              "SetSharedPropertyMySharedProperty");
 
       REQUIRE(GetEventFirstConditionType(
                   eventsList->GetEvent(BehaviorSharedPropertyCondition)) ==
               "MyEventsExtension::MyEventsBasedBehavior::"
-              "SharedPropertyMyProperty");
+              "SharedPropertyMySharedProperty");
 
       REQUIRE(GetEventFirstActionFirstParameterString(
                   eventsList->GetEvent(BehaviorSharedPropertyExpression)) ==
-              "ObjectWithMyBehavior.MyBehavior::SharedPropertyMyProperty()");
+              "ObjectWithMyBehavior.MyBehavior::SharedPropertyMySharedProperty()");
     }
   }
 
@@ -2750,6 +2764,11 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
     auto &eventsBasedBehavior =
         eventsExtension.GetEventsBasedBehaviors().Get("MyEventsBasedBehavior");
 
+    gd::WholeProjectRefactorer::RenameEventsBasedBehaviorSharedProperty(
+        project, eventsExtension, eventsBasedBehavior, "MySharedProperty",
+        "MyRenamedSharedProperty");
+
+    // Also wrongly try to rename a property that is not a shared property.
     gd::WholeProjectRefactorer::RenameEventsBasedBehaviorSharedProperty(
         project, eventsExtension, eventsBasedBehavior, "MyProperty",
         "MyRenamedProperty");
@@ -2760,16 +2779,16 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       REQUIRE(GetEventFirstActionType(
                   eventsList->GetEvent(BehaviorSharedPropertyAction)) ==
               "MyEventsExtension::MyEventsBasedBehavior::"
-              "SetSharedPropertyMyRenamedProperty");
+              "SetSharedPropertyMyRenamedSharedProperty");
 
       REQUIRE(GetEventFirstConditionType(
                   eventsList->GetEvent(BehaviorSharedPropertyCondition)) ==
               "MyEventsExtension::MyEventsBasedBehavior::"
-              "SharedPropertyMyRenamedProperty");
+              "SharedPropertyMyRenamedSharedProperty");
 
       REQUIRE(GetEventFirstActionFirstParameterString(
                   eventsList->GetEvent(BehaviorSharedPropertyExpression)) ==
-              "ObjectWithMyBehavior.MyBehavior::SharedPropertyMyRenamedProperty()");
+              "ObjectWithMyBehavior.MyBehavior::SharedPropertyMyRenamedSharedProperty()");
 
       // Ensure that the property was NOT renamed.
       REQUIRE(GetEventFirstActionType(
@@ -2951,7 +2970,7 @@ TEST_CASE("WholeProjectRefactorer (FixInvalidRequiredBehaviorProperties)",
   // - add the behavior "A" to an object
   // Check that no behavior is added on the object for it and that there is no
   // crash.
-  
+
   SECTION("Fix nothing if there are no missing required behavior") {
     gd::Project project;
     gd::Platform platform;
@@ -3732,7 +3751,7 @@ TEST_CASE("RemoveLayer", "[common]") {
 
     layout.InsertNewLayer("My layer", 0);
     otherLayout.InsertNewLayer("My layer", 0);
-    
+
     auto &externalLayout =
         project.InsertNewExternalLayout("My external layout", 0);
     auto &otherExternalLayout =
@@ -3746,7 +3765,7 @@ TEST_CASE("RemoveLayer", "[common]") {
     initialInstances.InsertNewInitialInstance().SetLayer("My layer");
     initialInstances.InsertNewInitialInstance().SetLayer("");
     initialInstances.InsertNewInitialInstance().SetLayer("");
-    
+
     auto &externalInitialInstances = externalLayout.GetInitialInstances();
     externalInitialInstances.InsertNewInitialInstance().SetLayer("My layer");
     externalInitialInstances.InsertNewInitialInstance().SetLayer("My layer");
@@ -3789,7 +3808,7 @@ TEST_CASE("MergeLayers", "[common]") {
 
     layout.InsertNewLayer("My layer", 0);
     otherLayout.InsertNewLayer("My layer", 0);
-    
+
     auto &externalLayout =
         project.InsertNewExternalLayout("My external layout", 0);
     auto &otherExternalLayout =
@@ -3804,7 +3823,7 @@ TEST_CASE("MergeLayers", "[common]") {
     initialInstances.InsertNewInitialInstance().SetLayer("");
     initialInstances.InsertNewInitialInstance().SetLayer("");
     initialInstances.InsertNewInitialInstance().SetLayer("My other layer");
-    
+
     auto &externalInitialInstances = externalLayout.GetInitialInstances();
     externalInitialInstances.InsertNewInitialInstance().SetLayer("My layer");
     externalInitialInstances.InsertNewInitialInstance().SetLayer("My layer");

Extensions/3D/A_RuntimeObject3D.ts

@@ -144,6 +144,40 @@ namespace gdjs {
       return this._z;
     }
 
+    /**
+     * Get the Z position of the rendered object.
+     *
+     * For most objects, this will returns the same value as getZ(). But if the
+     * object has an origin that is not the same as the point (0,0,0) of the
+     * object displayed, getDrawableZ will differ.
+     *
+     * @return The Z position of the rendered object.
+     */
+    getDrawableZ(): float {
+      return this.getZ();
+    }
+
+    /**
+     * Return the Z position of the object center, **relative to the object Z
+     * position** (`getDrawableX`).
+     *
+     * Use `getCenterZInScene` to get the position of the center in the scene.
+     *
+     * @return the Z position of the object center, relative to
+     * `getDrawableZ()`.
+     */
+    getCenterZ(): float {
+      return this.getDepth() / 2;
+    }
+
+    getCenterZInScene(): float {
+      return this.getDrawableZ() + this.getCenterZ();
+    }
+
+    setCenterZInScene(z: float): void {
+      this.setZ(z + this._z - (this.getDrawableZ() + this.getCenterZ()));
+    }
+
     setAngle(angle: float): void {
       super.setAngle(angle);
       this.getRenderer().updateRotation();

Extensions/3D/Base3DBehavior.ts

@@ -15,6 +15,17 @@ namespace gdjs {
      */
     getZ(): float;
 
+    /**
+     * Return the Z position of the object center, **relative to the scene origin**.
+     */
+    getCenterZInScene(): float;
+
+    /**
+     * Change the object center Z position in the scene.
+     * @param z The new Z position of the center in the scene.
+     */
+    setCenterZInScene(z: float): void;
+
     /**
      * Set the object rotation on the X axis.
      *
@@ -132,6 +143,14 @@ namespace gdjs {
       return this.object.getZ();
     }
 
+    getCenterZInScene(): number {
+      return this.object.getCenterZInScene();
+    }
+
+    setCenterZInScene(z: number): void {
+      this.object.setCenterZInScene(z);
+    }
+
     setRotationX(angle: float): void {
       this.object.setRotationX(angle);
     }

Extensions/3D/JsExtension.js

@@ -67,6 +67,22 @@ module.exports = {
         .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
         .setFunctionName('setZ')
         .setGetter('getZ');
+    
+      base3D
+        .addExpressionAndConditionAndAction(
+          'number',
+          'CenterZ',
+          _('Center Z position'),
+          _('the Z position of the center of rotation'),
+          _('the Z position of the center'),
+          _('Position/Center'),
+          'res/conditions/3d_box.svg'
+        )
+        .addParameter('object', _('3D object'))
+        .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
+        .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+        .setFunctionName('setCenterZInScene')
+        .setGetter('getCenterZInScene');
 
       base3D
         .addExpressionAndConditionAndAction(

Extensions/3D/Model3DRuntimeObject.ts

@@ -298,6 +298,11 @@ namespace gdjs {
       return this.getHeight() * centerPoint[1];
     }
 
+    getCenterZ(): float {
+      const centerPoint = this._renderer.getCenterPoint();
+      return this.getDepth() * centerPoint[2];
+    }
+
     getDrawableX(): float {
       const originPoint = this._renderer.getOriginPoint();
       return this.getX() - this.getWidth() * originPoint[0];
@@ -307,6 +312,11 @@ namespace gdjs {
       const originPoint = this._renderer.getOriginPoint();
       return this.getY() - this.getHeight() * originPoint[1];
     }
+
+    getDrawableZ(): float {
+      const originPoint = this._renderer.getOriginPoint();
+      return this.getZ() - this.getDepth() * originPoint[2];
+    }
   }
 
   export namespace Model3DRuntimeObject {