Expose ignoringPointer property for Draggable and LongPressDraggable (flutter#100475)

Author: xu-baolin

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

@@ -154,6 +154,11 @@ enum DragAnchor {
 /// user lifts their finger while on top of a [DragTarget], that target is given
 /// the opportunity to accept the [data] carried by the draggable.
 ///
+/// The [ignoringFeedbackPointer] defaults to true, which means that
+/// the [feedback] widget ignores the pointer during hit testing. Similarly,
+/// [ignoringFeedbackSemantics] defaults to true, and the [feedback] also ignores
+/// semantics when building the semantics tree.
+///
 /// On multitouch devices, multiple drags can occur simultaneously because there
 /// can be multiple pointers in contact with the device at once. To limit the
 /// number of simultaneous drags, use the [maxSimultaneousDrags] property. The
@@ -207,11 +212,13 @@ class Draggable<T extends Object> extends StatefulWidget {
     this.onDragEnd,
     this.onDragCompleted,
     this.ignoringFeedbackSemantics = true,
+    this.ignoringFeedbackPointer = true,
     this.rootOverlay = false,
     this.hitTestBehavior = HitTestBehavior.deferToChild,
   }) : assert(child != null),
        assert(feedback != null),
        assert(ignoringFeedbackSemantics != null),
+       assert(ignoringFeedbackPointer != null),
        assert(maxSimultaneousDrags == null || maxSimultaneousDrags >= 0);
 
   /// The data that will be dropped by this draggable.
@@ -310,6 +317,14 @@ class Draggable<T extends Object> extends StatefulWidget {
   /// Defaults to true.
   final bool ignoringFeedbackSemantics;
 
+  /// Whether the [feedback] widget is ignored during hit testing.
+  ///
+  /// Regardless of whether this widget is ignored during hit testing, it will
+  /// still consume space during layout and be visible during painting.
+  ///
+  /// Defaults to true.
+  final bool ignoringFeedbackPointer;
+
   /// Controls how this widget competes with other gestures to initiate a drag.
   ///
   /// If affinity is null, this widget initiates a drag as soon as it recognizes
@@ -447,6 +462,7 @@ class LongPressDraggable<T extends Object> extends Draggable<T> {
     super.onDragCompleted,
     this.hapticFeedbackOnStart = true,
     super.ignoringFeedbackSemantics,
+    super.ignoringFeedbackPointer,
     this.delay = kLongPressTimeout,
   });
 
@@ -542,6 +558,7 @@ class _DraggableState<T extends Object> extends State<Draggable<T>> {
       feedback: widget.feedback,
       feedbackOffset: widget.feedbackOffset,
       ignoringFeedbackSemantics: widget.ignoringFeedbackSemantics,
+      ignoringFeedbackPointer: widget.ignoringFeedbackPointer,
       onDragUpdate: (DragUpdateDetails details) {
         if (mounted && widget.onDragUpdate != null) {
           widget.onDragUpdate!(details);
@@ -796,8 +813,10 @@ class _DragAvatar<T extends Object> extends Drag {
     this.onDragUpdate,
     this.onDragEnd,
     required this.ignoringFeedbackSemantics,
+    required this.ignoringFeedbackPointer,
   }) : assert(overlayState != null),
        assert(ignoringFeedbackSemantics != null),
+       assert(ignoringFeedbackPointer != null),
        assert(dragStartPoint != null),
        assert(feedbackOffset != null),
        _position = initialPosition {
@@ -815,6 +834,7 @@ class _DragAvatar<T extends Object> extends Drag {
   final _OnDragEnd? onDragEnd;
   final OverlayState overlayState;
   final bool ignoringFeedbackSemantics;
+  final bool ignoringFeedbackPointer;
 
   _DragTargetState<Object>? _activeTarget;
   final List<_DragTargetState<Object>> _enteredTargets = <_DragTargetState<Object>>[];
@@ -937,6 +957,7 @@ class _DragAvatar<T extends Object> extends Drag {
       left: _lastOffset!.dx - overlayTopLeft.dx,
       top: _lastOffset!.dy - overlayTopLeft.dy,
       child: IgnorePointer(
+        ignoring: ignoringFeedbackPointer,
         ignoringSemantics: ignoringFeedbackSemantics,
         child: feedback,
       ),

packages/flutter/test/widgets/draggable_test.dart

@@ -10,7 +10,7 @@
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/semantics.dart';
+import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -3074,6 +3074,96 @@ void main() {
     expect(tester.widget<Listener>(find.byType(Listener).first).behavior, hitTestBehavior);
   });
 
+  // Regression test for https://github.com/flutter/flutter/issues/92083
+  testWidgets('feedback respect the MouseRegion cursor configure', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Column(
+          children: const <Widget>[
+            Draggable<int>(
+              ignoringFeedbackPointer: false,
+              feedback: MouseRegion(
+                cursor: SystemMouseCursors.grabbing,
+                child: SizedBox(height: 50.0, child: Text('Draggable')),
+              ),
+              child: SizedBox(height: 50.0, child: Text('Target')),
+            ),
+          ],
+        ),
+      ),
+    );
+
+    final Offset location = tester.getCenter(find.text('Target'));
+    final TestGesture gesture = await tester.createGesture(kind: PointerDeviceKind.mouse);
+    await gesture.addPointer(location: location);
+    addTearDown(gesture.removePointer);
+
+    await gesture.down(location);
+    await tester.pump();
+
+    expect(RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1), SystemMouseCursors.grabbing);
+  });
+
+  testWidgets('configurable feedback ignore pointer behavior', (WidgetTester tester) async {
+    bool onTap = false;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Column(
+          children: <Widget>[
+            Draggable<int>(
+              ignoringFeedbackPointer: false,
+              feedback: GestureDetector(
+                onTap: () => onTap = true,
+                child: const SizedBox(height: 50.0, child: Text('Draggable')),
+              ),
+              child: const SizedBox(height: 50.0, child: Text('Target')),
+            ),
+          ],
+        ),
+      ),
+    );
+
+    final Offset location = tester.getCenter(find.text('Target'));
+    final TestGesture gesture = await tester.startGesture(location, pointer: 7);
+    final Offset secondLocation = location + const Offset(7.0, 7.0);
+    await gesture.moveTo(secondLocation);
+    await tester.pump();
+
+    await tester.tap(find.text('Draggable'));
+    expect(onTap, true);
+  });
+
+  testWidgets('configurable feedback ignore pointer behavior - LongPressDraggable', (WidgetTester tester) async {
+    bool onTap = false;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Column(
+          children: <Widget>[
+            LongPressDraggable<int>(
+              ignoringFeedbackPointer: false,
+              feedback: GestureDetector(
+                onTap: () => onTap = true,
+                child: const SizedBox(height: 50.0, child: Text('Draggable')),
+              ),
+              child: const SizedBox(height: 50.0, child: Text('Target')),
+            ),
+          ],
+        ),
+      ),
+    );
+
+    final Offset location = tester.getCenter(find.text('Target'));
+    final TestGesture gesture = await tester.startGesture(location, pointer: 7);
+    await tester.pump(kLongPressTimeout);
+
+    final Offset secondLocation = location + const Offset(7.0, 7.0);
+    await gesture.moveTo(secondLocation);
+    await tester.pump();
+
+    await tester.tap(find.text('Draggable'));
+    expect(onTap, true);
+  });
+
   testWidgets('configurable DragTarget hit test behavior', (WidgetTester tester) async {
     const HitTestBehavior hitTestBehavior = HitTestBehavior.deferToChild;