Add confirm before close dialog to newIDE

newIDE/app/src/MainFrame/index.js

@@ -19,6 +19,7 @@ import ProjectManager from '../ProjectManager';
 import PlatformSpecificAssetsDialog from '../PlatformSpecificAssetsEditor/PlatformSpecificAssetsDialog';
 import LoaderModal from '../UI/LoaderModal';
 import EditorBar from '../UI/EditorBar';
+import CloseConfirmDialog from '../UI/CloseConfirmDialog';
 import ProfileDialog from '../Profile/ProfileDialog';
 import Window from '../Utils/Window';
 import { showErrorBox } from '../UI/Messages/MessageBox';
@@ -996,6 +997,7 @@ export default class MainFrame extends Component<*, State> {
             onClose={() => this.openAboutDialog(false)}
             updateStatus={updateStatus}
           />
+          <CloseConfirmDialog shouldPrompt={!!this.state.currentProject} />
         </div>
       </Providers>
     );

newIDE/app/src/UI/CloseConfirmDialog.js

@@ -0,0 +1,61 @@
+// @flow
+import * as React from 'react';
+import optionalRequire from '../Utils/OptionalRequire';
+import Window from '../Utils/Window';
+const electron = optionalRequire('electron');
+
+type Props = {|
+  shouldPrompt: boolean,
+|};
+
+export default class CloseConfirmDialog extends React.Component<Props, *> {
+  _delayElectronClose = true;
+
+  componentDidMount() {
+    this._setup(this.props);
+  }
+
+  componentWillReceiveProps(newProps: Props) {
+    if (newProps.shouldPrompt !== this.props.shouldPrompt)
+      this._setup(newProps);
+  }
+
+  _setup(props: Props) {
+    if (Window.isDev()) return; // Don't prevent live-reload in development
+
+    const { shouldPrompt } = props;
+    const message =
+      'Are you sure you want to quit GDevelop? Any unsaved changes will be lost.';
+
+    if (electron) {
+      window.onbeforeunload = e => {
+        if (this._delayElectronClose && shouldPrompt) {
+          //eslint-disable-next-line
+          const answer = confirm(message);
+          setTimeout(() => {
+            if (answer) {
+              // If answer is positive, re-trigger the close
+              this._delayElectronClose = false;
+              electron.remote.getCurrentWindow().close();
+            }
+          });
+
+          // First, prevents closing the window immediately
+          e.returnValue = true;
+        } else {
+          // Returning undefined will let the window close
+        }
+      };
+    } else if (window) {
+      if (shouldPrompt) {
+        window.onbeforeunload = () => message;
+      } else {
+        window.onbeforeunload = null;
+      }
+    }
+  }
+
+  render() {
+    return null;
+  }
+}