Let InkWell/Ink/ancestor support GlobalKey so that splash does not stop when...

Let InkWell/Ink/ancestor support GlobalKey so that splash does not stop when changing position. (#71138)

packages/flutter/lib/src/material/ink_decoration.dart

@@ -251,9 +251,21 @@ class _InkState extends State<Ink> {
 
   @override
   void deactivate() {
+    _ink?.visible = false;
+    super.deactivate();
+  }
+
+  @override
+  void reactivate() {
+    _ink?.visible = true;
+    super.reactivate();
+  }
+
+  @override
+  void dispose() {
     _ink?.dispose();
     assert(_ink == null);
-    super.deactivate();
+    super.dispose();
   }
 
   Widget _build(BuildContext context) {

packages/flutter/lib/src/material/ink_well.dart

@@ -733,6 +733,7 @@ class _InkResponseState extends State<_InkResponseStateWidget>
     implements _ParentInkResponseState {
   Set<InteractiveInkFeature>? _splashes;
   InteractiveInkFeature? _currentSplash;
+  bool _active = true;
   bool _hovering = false;
   final Map<_HighlightType, InkHighlight?> _highlights = <_HighlightType, InkHighlight?>{};
   late final Map<Type, Action<Intent>> _actionMap = <Type, Action<Intent>>{
@@ -779,7 +780,16 @@ class _InkResponseState extends State<_InkResponseStateWidget>
   @override
   void didUpdateWidget(_InkResponseStateWidget oldWidget) {
     super.didUpdateWidget(oldWidget);
-    if (_isWidgetEnabled(widget) != _isWidgetEnabled(oldWidget)) {
+    final InkFeature? validInkFeature = _getSingleInkFeature();
+    if (validInkFeature != null && !identical(validInkFeature.controller, Material.of(context)!)) {
+      _removeAllFeatures();
+      if (_hovering && enabled)
+        updateHighlight(_HighlightType.hover, value: _hovering, callOnHover: false);
+      _updateFocusHighlights();
+      return;
+    }
+
+    if (enabled != _isWidgetEnabled(oldWidget)) {
       if (enabled) {
         // Don't call wigdet.onHover because many wigets, including the button
         // widgets, apply setState to an ancestor context from onHover.
@@ -789,12 +799,47 @@ class _InkResponseState extends State<_InkResponseStateWidget>
     }
   }
 
+  InkFeature? _getSingleInkFeature() {
+    final List<InkFeature?> inkFeatures = <InkFeature?>[...?_splashes, ..._highlights.values];
+    assert(() {
+      MaterialInkController? lastController;
+      for (final InkFeature? inkFeature in inkFeatures) {
+        if (inkFeature == null)
+          continue;
+        final MaterialInkController controller = inkFeature.controller;
+        if (lastController != null && !identical(controller, lastController))
+          return false;
+        lastController = controller;
+      }
+      return true;
+    }());
+    final InkFeature? validInkFeature = inkFeatures.firstWhere((InkFeature? inkFeature) => inkFeature != null, orElse: () => null);
+    return validInkFeature;
+  }
+
   @override
   void dispose() {
+    _removeAllFeatures();
     FocusManager.instance.removeHighlightModeListener(_handleFocusHighlightModeChange);
     super.dispose();
   }
 
+  void _removeAllFeatures() {
+    if (_splashes != null) {
+      final Set<InteractiveInkFeature> splashes = _splashes!;
+      _splashes = null;
+      for (final InteractiveInkFeature splash in splashes)
+        splash.dispose();
+      _currentSplash = null;
+    }
+    assert(_currentSplash == null);
+    for (final _HighlightType highlight in _highlights.keys) {
+      _highlights[highlight]?.dispose();
+      _highlights[highlight] = null;
+    }
+    widget.parentState?.markChildInkResponsePressed(this, false);
+  }
+
   @override
   bool get wantKeepAlive => highlightsExist || (_splashes != null && _splashes!.isNotEmpty);
 
@@ -830,7 +875,8 @@ class _InkResponseState extends State<_InkResponseStateWidget>
     void handleInkRemoval() {
       assert(_highlights[type] != null);
       _highlights[type] = null;
-      updateKeepAlive();
+      if (_active)
+        updateKeepAlive();
     }
 
     if (type == _HighlightType.pressed) {
@@ -1013,24 +1059,26 @@ class _InkResponseState extends State<_InkResponseStateWidget>
     }
   }
 
+  void _setAllFeaturesVisible(bool visible) {
+    for (final InkFeature? splash in <InkFeature?>[...?_splashes, ..._highlights.values])
+      splash?.visible = visible;
+  }
+
   @override
   void deactivate() {
-    if (_splashes != null) {
-      final Set<InteractiveInkFeature> splashes = _splashes!;
-      _splashes = null;
-      for (final InteractiveInkFeature splash in splashes)
-        splash.dispose();
-      _currentSplash = null;
-    }
-    assert(_currentSplash == null);
-    for (final _HighlightType highlight in _highlights.keys) {
-      _highlights[highlight]?.dispose();
-      _highlights[highlight] = null;
-    }
-    widget.parentState?.markChildInkResponsePressed(this, false);
+    _active = !_active;
+    _setAllFeaturesVisible(false);
     super.deactivate();
   }
 
+  @override
+  void reactivate() {
+    _active = !_active;
+    _setAllFeaturesVisible(true);
+    updateKeepAlive();
+    super.reactivate();
+  }
+
   bool _isWidgetEnabled(_InkResponseStateWidget widget) {
     return widget.onTap != null || widget.onDoubleTap != null || widget.onLongPress != null;
   }
@@ -1201,6 +1249,10 @@ class _InkResponseState extends State<_InkResponseStateWidget>
 /// during animation. You should avoid using InkWells within [Material] widgets
 /// that are changing size.
 ///
+/// Animations triggered by an [InkWell] will survive their widget moving due
+/// to [GlobalKey] reparenting, as long as the nearest [Material] ancestor is
+/// the same before and after the move.
+///
 /// See also:
 ///
 ///  * [GestureDetector], for listening for gestures without ink splashes.

packages/flutter/lib/src/material/material.dart

@@ -544,12 +544,20 @@ class _RenderInkFeatures extends RenderProxyBox implements MaterialInkController
       canvas.save();
       canvas.translate(offset.dx, offset.dy);
       canvas.clipRect(Offset.zero & size);
-      for (final InkFeature inkFeature in _inkFeatures!)
-        inkFeature._paint(canvas);
+      for (final InkFeature inkFeature in _inkFeatures!) {
+        if (inkFeature.visible)
+          inkFeature._paint(canvas);
+      }
       canvas.restore();
     }
     super.paint(context, offset);
   }
+
+  void dispose() {
+    // [InkFeature.dispose] will eventually call [_inkFeatures!.remove].
+    while (_inkFeatures?.isNotEmpty == true)
+      _inkFeatures!.first.dispose();
+  }
 }
 
 class _InkFeatures extends SingleChildRenderObjectWidget {
@@ -585,6 +593,11 @@ class _InkFeatures extends SingleChildRenderObjectWidget {
                 ..absorbHitTest = absorbHitTest;
     assert(vsync == renderObject.vsync);
   }
+
+  @override
+  void didUnmountRenderObject(_RenderInkFeatures renderObject) {
+    renderObject.dispose();
+  }
 }
 
 /// A visual reaction on a piece of [Material].
@@ -617,6 +630,15 @@ abstract class InkFeature {
 
   bool _debugDisposed = false;
 
+  /// Whether or not visual reaction is activated.
+  ///
+  /// Change this field will affect whether this InkFeature is render in next
+  /// frame.
+  ///
+  /// For this InkFeature to render properly, it should usually be change in
+  /// [State.deactivate] and [State.reactivate].
+  bool visible = true;
+
   /// Free up the resources associated with this ink feature.
   @mustCallSuper
   void dispose() {

packages/flutter/lib/src/material/mergeable_material.dart

@@ -584,7 +584,6 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
           }
 
           child = AnimatedContainer(
-            key: _MergeableMaterialSliceKey(_children[i].key),
             decoration: BoxDecoration(border: border),
             duration: kThemeAnimationDuration,
             curve: Curves.fastOutSlowIn,
@@ -600,6 +599,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
               shape: BoxShape.rectangle,
             ),
             child: Material(
+              key: _MergeableMaterialSliceKey(_children[i].key),
               type: MaterialType.transparency,
               child: child,
             ),

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

@@ -930,6 +930,12 @@ abstract class State<T extends StatefulWidget> with Diagnosticable {
   /// It is an error to call [setState] unless [mounted] is true.
   bool get mounted => _element != null;
 
+  /// This field is used tracks [reactivate] and [deactivate], to assert that
+  /// they are called alternatively.
+  ///
+  /// This field is not set in release mode.
+  bool _debugActive = true;
+
   /// Called when this object is inserted into the tree.
   ///
   /// The framework will call this method exactly once for each [State] object
@@ -1110,17 +1116,17 @@ abstract class State<T extends StatefulWidget> with Diagnosticable {
     _element!.markNeedsBuild();
   }
 
-  /// Called when this object is removed from the tree.
+  /// Whenever the framework removes this [State] object from the tree, the
+  /// framework will call this method.
   ///
-  /// The framework calls this method whenever it removes this [State] object
-  /// from the tree. In some cases, the framework will reinsert the [State]
-  /// object into another part of the tree (e.g., if the subtree containing this
-  /// [State] object is grafted from one location in the tree to another). If
-  /// that happens, the framework will ensure that it calls [build] to give the
-  /// [State] object a chance to adapt to its new location in the tree. If
-  /// the framework does reinsert this subtree, it will do so before the end of
-  /// the animation frame in which the subtree was removed from the tree. For
-  /// this reason, [State] objects can defer releasing most resources until the
+  /// In some cases, the framework will reinsert the [State] object into
+  /// another part of the tree (e.g., if the subtree containing this [State]
+  /// object is grafted from one location in the tree to another). If that
+  /// happens, the framework will ensure that it calls [reactivate] to give the
+  /// [State] object a chance to adapt to its new location in the tree. If the
+  /// framework does reinsert this subtree, it will do so before the end of the
+  /// animation frame in which the subtree was removed from the tree. For this
+  /// reason, [State] objects can defer releasing most resources until the
   /// framework calls their [dispose] method.
   ///
   /// Subclasses should override this method to clean up any links between
@@ -1136,7 +1142,35 @@ abstract class State<T extends StatefulWidget> with Diagnosticable {
   ///    from the tree permanently.
   @protected
   @mustCallSuper
-  void deactivate() { }
+  void deactivate() {
+    assert(() {
+      _debugActive = !_debugActive;
+      return !_debugActive;
+    }());
+  }
+
+  /// Called when this object is reactivated.
+  ///
+  /// If the [widget] or one of its ancestors has a [GlobalKey], the framework
+  /// will mark this object as inactive when it is removed and call
+  /// [deactivate].
+  ///
+  /// If the object is reinserted to the tree in the next frame (e.g. by
+  /// changing position), it will be marked as active again and this method will be
+  /// called.
+  ///
+  /// See also:
+  ///
+  ///  * [Element.activate] and [Element.deactivate] for more information about
+  ///  lifecycle.
+  @protected
+  @mustCallSuper
+  void reactivate() {
+    assert(() {
+      _debugActive = !_debugActive;
+      return _debugActive;
+    }());
+  }
 
   /// Called when this object is removed from the tree permanently.
   ///
@@ -4777,6 +4811,7 @@ class StatefulElement extends ComponentElement {
   @override
   void activate() {
     super.activate();
+    state.reactivate();
     // Since the State could have observed the deactivate() and thus disposed of
     // resources allocated in the build method, we have to rebuild the widget
     // so that its State can reallocate its resources.

packages/flutter/test/material/ink_paint_test.dart

@@ -431,4 +431,67 @@ void main() {
       throw 'Expected: paint.color.alpha == 0, found: ${paint.color.alpha}';
     }));
   });
+
+  // Regression test for https://github.com/flutter/flutter/issues/6751
+  testWidgets('When Ink has a GlobalKey and changes position, splash should not stop', (WidgetTester tester) async {
+    const Color color = Colors.blue;
+    const Color splashColor = Colors.green;
+
+    void expectTest(bool painted) {
+      final PaintPattern paintPattern = paints
+        ..rect(color: Color(color.value))
+        ..circle(color: Color(splashColor.value));
+
+      expect(
+        Material.of(tester.element(find.byType(InkWell)))! as RenderBox,
+        painted ? paintPattern : isNot(paintPattern),
+      );
+    }
+
+    bool wrap = false;
+    final Key globalKey = GlobalKey();
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: Material(
+        child: Center(
+          child: StatefulBuilder(
+            builder: (BuildContext context, void Function(void Function()) setState) {
+              Widget child = Ink(
+                key: globalKey,
+                color: color,
+                width: 200.0,
+                height: 200.0,
+                child: InkWell(
+                  splashColor: splashColor,
+                  onTap: () { },
+                  onTapDown: (_) async {
+                    await Future<void>.delayed(const Duration(milliseconds: 50));
+
+                    setState(() {
+                      wrap = !wrap;
+                    });
+                  }
+                ),
+              );
+
+              if (wrap) {
+                child = Container(
+                  margin: const EdgeInsets.only(top: 320),
+                  child: child,
+                );
+              }
+
+              return child;
+            }
+          ),
+        ),
+      ),
+    ));
+    final TestGesture testGesture = await tester.startGesture(tester.getRect(find.byType(InkWell)).center);
+    await tester.pump(const Duration(milliseconds: 60));
+    expectTest(true);
+    await testGesture.up();
+    await tester.pumpAndSettle();
+    expectTest(false);
+  });
 }

packages/flutter/test/widgets/framework_test.dart

@@ -1331,24 +1331,28 @@ void main() {
     expect(key.currentState, isNotNull);
     expect(state.didChangeDependenciesCount, 1);
     expect(state.deactivatedCount, 0);
+    expect(state.reactivatedCount, 0);
 
     /// Rebuild with updated value - should call didChangeDependencies
     await tester.pumpWidget(Inherited(2, child: DependentStatefulWidget(key: key)));
     expect(key.currentState, isNotNull);
     expect(state.didChangeDependenciesCount, 2);
     expect(state.deactivatedCount, 0);
+    expect(state.reactivatedCount, 0);
 
-    // reparent it - should call deactivate and didChangeDependencies
+    // reparent it - should call deactivate, reactivate, didChangeDependencies
     await tester.pumpWidget(Inherited(3, child: SizedBox(child: DependentStatefulWidget(key: key))));
     expect(key.currentState, isNotNull);
     expect(state.didChangeDependenciesCount, 3);
     expect(state.deactivatedCount, 1);
+    expect(state.reactivatedCount, 1);
 
-    // Remove it - should call deactivate, but not didChangeDependencies
+    // Remove it - should call deactivate, but not reactivate or didChangeDependencies
     await tester.pumpWidget(const Inherited(4, child: SizedBox()));
     expect(key.currentState, isNull);
     expect(state.didChangeDependenciesCount, 3);
     expect(state.deactivatedCount, 2);
+    expect(state.reactivatedCount, 1);
   });
 
   testWidgets('StatefulElement subclass can decorate State.build', (WidgetTester tester) async {
@@ -1391,17 +1395,21 @@ void main() {
       expect(debugDoingBuildOnBuild, isTrue);
     });
     testWidgets('StatefulWidget', (WidgetTester tester) async {
+      final Key key = GlobalKey();
+
       late bool debugDoingBuildOnBuild;
       late bool debugDoingBuildOnInitState;
       late bool debugDoingBuildOnDidChangeDependencies;
       late bool debugDoingBuildOnDidUpdateWidget;
       bool? debugDoingBuildOnDispose;
       bool? debugDoingBuildOnDeactivate;
+      bool? debugDoingBuildOnReactivate;
 
       await tester.pumpWidget(
         Inherited(
           0,
           child: StatefulWidgetSpy(
+            key: key,
             onInitState: (BuildContext context) {
               debugDoingBuildOnInitState = context.debugDoingBuild;
             },
@@ -1427,6 +1435,7 @@ void main() {
         Inherited(
           1,
           child: StatefulWidgetSpy(
+            key: key,
             onDidUpdateWidget: (BuildContext context) {
               debugDoingBuildOnDidUpdateWidget = context.debugDoingBuild;
             },
@@ -1442,6 +1451,9 @@ void main() {
             onDeactivate: (BuildContext context) {
               debugDoingBuildOnDeactivate = context.debugDoingBuild;
             },
+            onReactivate: (BuildContext context) {
+              debugDoingBuildOnReactivate = context.debugDoingBuild;
+            },
           ),
         ),
       );
@@ -1451,6 +1463,35 @@ void main() {
       expect(debugDoingBuildOnDidUpdateWidget, isFalse);
       expect(debugDoingBuildOnDidChangeDependencies, isFalse);
       expect(debugDoingBuildOnDeactivate, isNull);
+      expect(debugDoingBuildOnReactivate, isNull);
+      expect(debugDoingBuildOnDispose, isNull);
+
+      await tester.pumpWidget(
+        Inherited(
+          1,
+          child: SizedBox(
+            child: StatefulWidgetSpy(
+              key: key,
+              onBuild: (BuildContext context) {
+                debugDoingBuildOnBuild = context.debugDoingBuild;
+              },
+              onDispose: (BuildContext context) {
+                debugDoingBuildOnDispose = context.debugDoingBuild;
+              },
+              onDeactivate: (BuildContext context) {
+                debugDoingBuildOnDeactivate = context.debugDoingBuild;
+              },
+              onReactivate: (BuildContext context) {
+                debugDoingBuildOnReactivate = context.debugDoingBuild;
+              },
+            ),
+          ),
+        ),
+      );
+
+      expect(debugDoingBuildOnBuild, isTrue);
+      expect(debugDoingBuildOnDeactivate, isFalse);
+      expect(debugDoingBuildOnReactivate, isFalse);
       expect(debugDoingBuildOnDispose, isNull);
 
       await tester.pumpWidget(Container());
@@ -1705,6 +1746,7 @@ class DependentStatefulWidget extends StatefulWidget {
 class DependentState extends State<DependentStatefulWidget> {
   int didChangeDependenciesCount = 0;
   int deactivatedCount = 0;
+  int reactivatedCount = 0;
 
   @override
   void didChangeDependencies() {
@@ -1723,6 +1765,12 @@ class DependentState extends State<DependentStatefulWidget> {
     super.deactivate();
     deactivatedCount += 1;
   }
+
+  @override
+  void reactivate() {
+    super.reactivate();
+    reactivatedCount += 1;
+  }
 }
 
 class SwapKeyWidget extends StatefulWidget {
@@ -1810,6 +1858,7 @@ class StatefulWidgetSpy extends StatefulWidget {
     this.onDidChangeDependencies,
     this.onDispose,
     this.onDeactivate,
+    this.onReactivate,
     this.onDidUpdateWidget,
   })  : super(key: key);
 
@@ -1818,6 +1867,7 @@ class StatefulWidgetSpy extends StatefulWidget {
   final void Function(BuildContext)? onDidChangeDependencies;
   final void Function(BuildContext)? onDispose;
   final void Function(BuildContext)? onDeactivate;
+  final void Function(BuildContext)? onReactivate;
   final void Function(BuildContext)? onDidUpdateWidget;
 
   @override
@@ -1837,6 +1887,12 @@ class _StatefulWidgetSpyState extends State<StatefulWidgetSpy> {
     widget.onDeactivate?.call(context);
   }
 
+  @override
+  void reactivate() {
+   super.reactivate();
+   widget.onReactivate?.call(context);
+  }
+
   @override
   void dispose() {
     super.dispose();