GDevelop/Core/GDCore/Project/InitialInstancesContainer.h

/*
 * 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 <list>
#include "GDCore/Project/InitialInstance.h"
#include "GDCore/String.h"
namespace gd {
class InitialInstanceFunctor;
}
namespace gd {
class Project;
}
namespace gd {
class SerializerElement;
}

namespace gd {

/**
 * \brief Defines a container of gd::InitialInstances.
 *
 * The container is notably able to ensure that pointers
 * to the elements of the container are not invalidated when
 * a change occurs (through InsertNewInitialInstance or RemoveInstance
 * for example). <br>
 * Thus, the implementations uses a std::list
 * for holding the instances. In this way, the container is not required
 * to provide a direct access to element based on an index. Instead,
 * the method IterateOverInstances is used to perform operations.
 *
 * \see gd::InitialInstanceFunctor
 */
class GD_CORE_API InitialInstancesContainer {
 public:
  InitialInstancesContainer(){};
  virtual ~InitialInstancesContainer();

  /**
   * \brief Return a pointer to a copy of the container.
   * A such method is needed as the IDE may want to store copies of some
   * containers and so need a way to do polymorphic copies.
   *
   * Typical implementation example:
   * \code
   * return new MyContainer(*this);
   * \endcode
   */
  InitialInstancesContainer *Clone() const {
    return new InitialInstancesContainer(*this);
  };

  /**
   * Must construct the class from the source
   * A such method is needed as the IDE may want to store copies of some
   * containers and so need a way to do polymorphic copies.
   *
   * Typical implementation example:
   * \code
   * try
   * {
   *     const MyContainer & castedSource = dynamic_cast<const
   * MyContainer&>(source); operator=(castedSource);
   * }
   * catch(...) { std::cout << "WARNING: Tried to create a MyContainer object
   * from an object which is not a MyContainer"; } \endcode
   */
  void Create(const InitialInstancesContainer &source);

  /** \name Instances management
   * Members functions related to managing the instances
   */
  ///@{

  /**
   * \brief Return the number of instances
   */
  std::size_t GetInstancesCount() const;

  /**
   * \brief Apply \a func to each instance of the container.
   * \see InitialInstanceFunctor
   */
  void IterateOverInstances(InitialInstanceFunctor &func);

  /**
   * \brief Apply \a func to each instance of the container.
   * \see InitialInstanceFunctor
   */
  void IterateOverInstances(
    const std::function< bool(gd::InitialInstance &) >& func);

  /**
   * Get the instances on the specified layer,
   * sort them regarding their Z order and then apply \a func on them.
   * \param func The functor to be applied.
   * \param layer The layer
   *
   * \see InitialInstanceFunctor
   */
  void IterateOverInstancesWithZOrdering(InitialInstanceFunctor &func,
                                         const gd::String &layer);

  /**
   * \brief Insert the specified \a instance into the list and return a
   * a reference to the newly added instance.
   */
  InitialInstance &InsertInitialInstance(const InitialInstance &instance);

  /**
   * \brief Insert a new blank instance at the end of the list and return a
   * a reference to the newly added instance.
   */
  InitialInstance &InsertNewInitialInstance();

  /**
   * \brief Remove the specified \a instance
   */
  void RemoveInstance(const gd::InitialInstance &instance);

  /**
   * \brief Remove all instances from layer \a layerName.
   */
  void RemoveAllInstancesOnLayer(const gd::String &layerName);

  /**
   * \brief Move the instances on layer \a fromLayer to layer \a toLayer.
   */
  void MoveInstancesToLayer(const gd::String &fromLayer,
                            const gd::String &toLayer);

  /**
   * \brief Remove instances of object named \a objectName
   */
  void RemoveInitialInstancesOfObject(const gd::String &objectName);

  /**
   * \brief Change instances with object's name \a oldName to \a newName
   */
  void RenameInstancesOfObject(const gd::String &oldName,
                               const gd::String &newName);

  /**
   * \brief Return the number of instances on the layer named \a layerName.
   */
  std::size_t GetLayerInstancesCount(const gd::String &layerName) const;

  /**
   * \brief Return true if there is at least one instance on the layer named \a
   * layerName.
   */
  bool SomeInstancesAreOnLayer(const gd::String &layerName) const;

  /**
   * \brief Return true if there is at least one instance of the given object.
   */
  bool HasInstancesOfObject(const gd::String &objectName) const;

  /**
   * \brief Return true if there is at least N instances of the given object.
   */
  bool
  IsInstancesCountOfObjectGreaterThan(const gd::String &objectName,
                                      const std::size_t minInstanceCount) const;

  /**
   * \brief Remove all instances
   */
  void Clear();

  ///@}

  /** \name Saving and loading
   * Members functions related to saving and loading the object.
   */
  ///@{

  /**
   * \brief Serialize instances container.
   */
  virtual void SerializeTo(SerializerElement &element) const;

  /**
   * \brief Unserialize the instances container.
   */
  virtual void UnserializeFrom(const SerializerElement &element);
  ///@}

 private:
  void RemoveInstanceIf(
      std::function<bool(const gd::InitialInstance &)> predicate);

  std::list<gd::InitialInstance> initialInstances;

  static gd::InitialInstance badPosition;
};

/**
 * \brief Tool class to be used with
 * gd::InitialInstancesContainer::IterateOverInstances.
 *
 * \see gd::InitialInstancesContainer
 * \see gd::HighestZOrderFinder
 */
class GD_CORE_API InitialInstanceFunctor {
 public:
  InitialInstanceFunctor(){};
  virtual ~InitialInstanceFunctor();

  virtual void operator()(InitialInstance &instance) = 0;
};

/** \brief Tool class picking returning the highest Z order of instances on a
 * layer.
 *
 * \see gd::InitialInstanceFunctor
 * \see gd::InitialInstancesContainer
 */
class GD_CORE_API HighestZOrderFinder : public gd::InitialInstanceFunctor {
 public:
  HighestZOrderFinder()
      : highestZOrder(0),
        lowestZOrder(0),
        instancesCount(0),
        firstCall(true),
        layerRestricted(false){};
  virtual ~HighestZOrderFinder(){};

  virtual void operator()(gd::InitialInstance &instance);

  /**
   * \brief Restrict to instances on the specified layer.
   */
  void RestrictSearchToLayer(const gd::String &layerName_) {
    layerName = layerName_;
    layerRestricted = true;
  };

  /**
   * \brief After calling the instances container iterate method with this
   * functor, this method will return the highest Z order of the instances.
   */
  int GetHighestZOrder() const { return highestZOrder; }

  /**
   * \brief After calling the instances container iterate method with this
   * functor, this method will return the lowest Z order of the instances.
   */
  int GetLowestZOrder() const { return lowestZOrder; }

  /**
   * \brief After calling the instances container iterate method with this
   * functor, this method will return the number of instances.
   */
  size_t GetInstancesCount() const { return instancesCount; }

  void Reset() {
    highestZOrder = 0;
    lowestZOrder = 0;
    instancesCount = 0;
    firstCall = true;
    layerRestricted = false;
    layerName.clear();
  }

 private:
  int highestZOrder;
  int lowestZOrder;
  size_t instancesCount;
  bool firstCall;

  bool layerRestricted;  ///< If true, the search is restricted to the layer
                         ///< called \a layerName.
  gd::String layerName;
};

}  // namespace gd