Add a [valid] property of [MouseTrackerAnnotation] indicates the annotation states. (#69866)

packages/flutter/lib/src/rendering/mouse_tracking.dart

@@ -55,10 +55,11 @@ class MouseTrackerAnnotation with Diagnosticable {
     this.onEnter,
     this.onExit,
     this.cursor = MouseCursor.defer,
+    this.validForMouseTracker = true,
   }) : assert(cursor != null);
 
   /// Triggered when a mouse pointer, with or without buttons pressed, has
-  /// entered the region.
+  /// entered the region and [validForMouseTracker] is true.
   ///
   /// This callback is triggered when the pointer has started to be contained by
   /// the region, either due to a pointer event, or due to the movement or
@@ -72,7 +73,7 @@ class MouseTrackerAnnotation with Diagnosticable {
   final PointerEnterEventListener? onEnter;
 
   /// Triggered when a mouse pointer, with or without buttons pressed, has
-  /// exited the region.
+  /// exited the region and [validForMouseTracker] is true.
   ///
   /// This callback is triggered when the pointer has stopped being contained
   /// by the region, either due to a pointer event, or due to the movement or
@@ -100,6 +101,15 @@ class MouseTrackerAnnotation with Diagnosticable {
   ///  * [MouseRegion.cursor], which provide values to this field.
   final MouseCursor cursor;
 
+  /// Whether this is included when [MouseTracker] collects the list of annotations.
+  ///
+  /// If [validForMouseTracker] is false, this object is excluded from the current annotation list
+  /// even if it's included in the hit test, affecting mouse-related behavior such as enter events,
+  /// exit events, and mouse cursors. The [validForMouseTracker] does not affect hit testing.
+  ///
+  /// The [validForMouseTracker] is true for [MouseTrackerAnnotation]s built by the constructor.
+  final bool validForMouseTracker;
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
@@ -487,7 +497,7 @@ mixin _MouseTrackerEventMixin on BaseMouseTracker {
     final PointerExitEvent baseExitEvent = PointerExitEvent.fromMouseEvent(latestEvent);
     lastAnnotations.forEach((MouseTrackerAnnotation annotation, Matrix4 transform) {
       if (!nextAnnotations.containsKey(annotation))
-        if (annotation.onExit != null)
+        if (annotation.validForMouseTracker && annotation.onExit != null)
           annotation.onExit!(baseExitEvent.transformed(lastAnnotations[annotation]));
     });
 
@@ -498,7 +508,7 @@ mixin _MouseTrackerEventMixin on BaseMouseTracker {
     ).toList();
     final PointerEnterEvent baseEnterEvent = PointerEnterEvent.fromMouseEvent(latestEvent);
     for (final MouseTrackerAnnotation annotation in enteringAnnotations.reversed) {
-      if (annotation.onEnter != null)
+      if (annotation.validForMouseTracker && annotation.onEnter != null)
         annotation.onEnter!(baseEnterEvent.transformed(nextAnnotations[annotation]));
     }
   }

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

@@ -732,6 +732,9 @@ mixin _PlatformViewGestureMixin on RenderBox implements MouseTrackerAnnotation {
   @override
   MouseCursor get cursor => MouseCursor.uncontrolled;
 
+  @override
+  bool get validForMouseTracker => true;
+
   @override
   void handleEvent(PointerEvent event, HitTestEntry entry) {
     if (event is PointerDownEvent) {

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -2777,11 +2777,13 @@ class RenderMouseRegion extends RenderProxyBox implements MouseTrackerAnnotation
     this.onHover,
     this.onExit,
     MouseCursor cursor = MouseCursor.defer,
+    bool validForMouseTracker = true,
     bool opaque = true,
     RenderBox? child,
   }) : assert(opaque != null),
        assert(cursor != null),
        _cursor = cursor,
+       _validForMouseTracker = validForMouseTracker,
        _opaque = opaque,
        super(child);
 
@@ -2849,6 +2851,25 @@ class RenderMouseRegion extends RenderProxyBox implements MouseTrackerAnnotation
     }
   }
 
+  @override
+  bool get validForMouseTracker => _validForMouseTracker;
+  bool _validForMouseTracker;
+
+  @override
+  void attach(PipelineOwner owner) {
+    super.attach(owner);
+    _validForMouseTracker = true;
+  }
+
+  @override
+  void detach() {
+    // It's possible that the renderObject be detached during mouse events
+    // dispatching, set the [MouseTrackerAnnotation.validForMouseTracker] false to prevent
+    // the callbacks from being called.
+    _validForMouseTracker = false;
+    super.detach();
+  }
+
   @override
   void performResize() {
     size = constraints.biggest;
@@ -2868,6 +2889,7 @@ class RenderMouseRegion extends RenderProxyBox implements MouseTrackerAnnotation
     ));
     properties.add(DiagnosticsProperty<MouseCursor>('cursor', cursor, defaultValue: MouseCursor.defer));
     properties.add(DiagnosticsProperty<bool>('opaque', opaque, defaultValue: true));
+    properties.add(FlagProperty('validForMouseTracker', value: validForMouseTracker, defaultValue: true, ifFalse: 'invalid for MouseTracker'));
   }
 }
 

packages/flutter/test/rendering/mouse_tracking_test_utils.dart

@@ -72,7 +72,7 @@ class TestMouseTrackerFlutterBinding extends BindingBase
 
 // An object that mocks the behavior of a render object with [MouseTrackerAnnotation].
 class TestAnnotationTarget with Diagnosticable implements MouseTrackerAnnotation, HitTestTarget  {
-  const TestAnnotationTarget({this.onEnter, this.onHover, this.onExit, this.cursor = MouseCursor.defer});
+  const TestAnnotationTarget({this.onEnter, this.onHover, this.onExit, this.cursor = MouseCursor.defer, this.validForMouseTracker = true});
 
   @override
   final PointerEnterEventListener? onEnter;
@@ -85,6 +85,9 @@ class TestAnnotationTarget with Diagnosticable implements MouseTrackerAnnotation
   @override
   final MouseCursor cursor;
 
+  @override
+  final bool validForMouseTracker;
+
   @override
   void handleEvent(PointerEvent event, HitTestEntry entry) {
     if (event is PointerHoverEvent)

packages/flutter/test/widgets/mouse_region_test.dart

@@ -1695,6 +1695,7 @@ void main() {
       onExit: (PointerExitEvent event) {},
       onHover: (PointerHoverEvent event) {},
       cursor: SystemMouseCursors.click,
+      validForMouseTracker: false,
       child: RenderErrorBox(),
     ).debugFillProperties(builder);
 
@@ -1706,6 +1707,7 @@ void main() {
       'size: MISSING',
       'listeners: enter, hover, exit',
       'cursor: SystemMouseCursor(click)',
+      'invalid for MouseTracker',
     ]);
   });
 
@@ -1728,6 +1730,37 @@ void main() {
     await gesture.moveBy(const Offset(10.0, 10.0));
     expect(tester.binding.hasScheduledFrame, isFalse);
   });
+
+  // Regression test for https://github.com/flutter/flutter/issues/67044
+  testWidgets('Handle mouse events should ignore the detached MouseTrackerAnnotation', (WidgetTester tester) async {
+    await tester.pumpWidget(MaterialApp(
+      home: Center(
+        child: Draggable<int>(
+          feedback: Container(width: 20, height: 20, color: Colors.blue),
+          childWhenDragging: Container(width: 20, height: 20, color: Colors.yellow),
+          child: RaisedButton(child: const Text('Drag me'), onPressed: (){}),
+        ),
+      ),
+    ));
+
+    // Long press the button with mouse.
+    final Offset textFieldPos = tester.getCenter(find.byType(Text));
+    final TestGesture gesture = await tester.startGesture(
+      textFieldPos,
+      kind: PointerDeviceKind.mouse,
+    );
+    addTearDown(gesture.removePointer);
+    await tester.pump(const Duration(seconds: 2));
+    await tester.pumpAndSettle();
+
+    // Drag the Draggable Widget will replace the child with [childWhenDragging].
+    await gesture.moveBy(const Offset(10.0, 10.0));
+    await tester.pump(); // Trigger detach the button.
+
+    // Continue drag mouse should not trigger any assert.
+    await gesture.moveBy(const Offset(10.0, 10.0));
+    expect(tester.takeException(), isNull);
+  });
 }
 
 // Render widget `topLeft` at the top-left corner, stacking on top of the widget