Don't call PlatformViewCreatedCallbacks after AndroidViewController is disposed (#116854)

* Don't call `PlatformViewCreatedCallback`s after `AndroidViewController` is disposed

Before this change it was possible that, if a `AndroidViewController` was disposed before we got the notification that the platform view was created, `PlatformViewCreatedCallback`s where called even after calling `AndroidViewController.dispose`.

Also makes `_PlatformViewLinkState._onPlatformViewCreated` more carful to only call `setState` when mounted.

Closes #84628
Closes #96384

* Allow all widgets to remove listeners from controller

* Remove assert

* Add expectations to test

packages/flutter/lib/src/services/platform_views.dart

@@ -863,7 +863,7 @@ abstract class AndroidViewController extends PlatformViewController {
   Future<void> setLayoutDirection(TextDirection layoutDirection) async {
     assert(
       _state != _AndroidViewState.disposed,
-      'trying to set a layout direction for a disposed UIView. View id: $viewId',
+      'trying to set a layout direction for a disposed Android view. View id: $viewId',
     );
 
     if (layoutDirection == _layoutDirection) {
@@ -938,12 +938,13 @@ abstract class AndroidViewController extends PlatformViewController {
   /// disposed.
   @override
   Future<void> dispose() async {
-    if (_state == _AndroidViewState.creating || _state == _AndroidViewState.created) {
+    final _AndroidViewState state = _state;
+    _state = _AndroidViewState.disposed;
+    _platformViewCreatedCallbacks.clear();
+    PlatformViewsService._instance._focusCallbacks.remove(viewId);
+    if (state == _AndroidViewState.creating || state == _AndroidViewState.created) {
       await _sendDisposeMessage();
     }
-    _platformViewCreatedCallbacks.clear();
-    _state = _AndroidViewState.disposed;
-    PlatformViewsService._instance._focusCallbacks.remove(viewId);
   }
 }
 

packages/flutter/lib/src/widgets/platform_view.dart

@@ -485,7 +485,7 @@ class _AndroidViewState extends State<AndroidView> {
     _layoutDirection = newLayoutDirection;
 
     if (widget.viewType != oldWidget.viewType) {
-      _controller.dispose();
+      _controller.disposePostFrame();
       _createNewAndroidView();
       return;
     }
@@ -890,7 +890,7 @@ class _PlatformViewLinkState extends State<PlatformViewLink> {
     super.didUpdateWidget(oldWidget);
 
     if (widget.viewType != oldWidget.viewType) {
-      _controller?.dispose();
+      _controller?.disposePostFrame();
       // The _surface has to be recreated as its controller is disposed.
       // Setting _surface to null will trigger its creation in build().
       _surface = null;
@@ -911,10 +911,12 @@ class _PlatformViewLinkState extends State<PlatformViewLink> {
   }
 
   void _onPlatformViewCreated(int id) {
+    if (mounted) {
       setState(() {
         _platformViewCreated = true;
       });
     }
+  }
 
   void _handleFrameworkFocusChanged(bool isFocused) {
     if (!isFocused) {
@@ -1209,3 +1211,13 @@ class _PlatformViewPlaceHolder extends SingleChildRenderObjectWidget {
     renderObject.onLayout = onLayout;
   }
 }
+
+extension on PlatformViewController {
+  /// Disposes the controller in a post-frame callback, to allow other widgets to
+  /// remove their listeners before the controller is disposed.
+  void disposePostFrame() {
+    SchedulerBinding.instance.addPostFrameCallback((_) {
+      dispose();
+    });
+  }
+}

packages/flutter/test/services/platform_views_test.dart

@@ -268,6 +268,19 @@ void main() {
       await controller2.create(size: const Size(100.0, 200.0));
       expect(createdViews, orderedEquals(<int>[0, 5]));
 
+      final AndroidViewController controller3 = PlatformViewsService.initAndroidView(
+        id: 10,
+        viewType: 'webview',
+        layoutDirection: TextDirection.ltr,
+      )..addOnPlatformViewCreatedListener(callback);
+      expect(createdViews, orderedEquals(<int>[0, 5]));
+
+      await Future.wait(<Future<void>>[
+        controller3.create(size: const Size(100.0, 200.0)),
+        controller3.dispose(),
+      ]);
+
+      expect(createdViews, orderedEquals(<int>[0, 5]));
     });
 
     test("change Android view's directionality before creation", () async {

packages/flutter/test/widgets/platform_view_test.dart

@@ -2718,6 +2718,32 @@ void main() {
       expect(disposedController.disposed, true);
     });
 
+    testWidgets('PlatformViewLink handles onPlatformViewCreated when disposed', (WidgetTester tester) async {
+      late PlatformViewCreationParams creationParams;
+      late FakePlatformViewController controller;
+      final PlatformViewLink platformViewLink = PlatformViewLink(
+        viewType: 'webview',
+        onCreatePlatformView: (PlatformViewCreationParams params) {
+          creationParams = params;
+          return controller = FakePlatformViewController(params.id);
+        },
+        surfaceFactory: (BuildContext context, PlatformViewController controller) {
+          return PlatformViewSurface(
+            gestureRecognizers: const <Factory<OneSequenceGestureRecognizer>>{},
+            controller: controller,
+            hitTestBehavior: PlatformViewHitTestBehavior.opaque,
+          );
+        },
+      );
+
+      await tester.pumpWidget(platformViewLink);
+
+      await tester.pumpWidget(Container());
+
+      expect(controller.disposed, true);
+      expect(() => creationParams.onPlatformViewCreated(creationParams.id), returnsNormally);
+    });
+
     testWidgets('PlatformViewLink widget survives widget tree change', (WidgetTester tester) async {
       final GlobalKey key = GlobalKey();
       final int currentViewId = platformViewsRegistry.getNextPlatformViewId();