Ignore pointer capture for PointerEntered and PointerExited events following UWP behavior

src/Avalonia.Base/Input/PointerOverPreProcessor.cs

@@ -67,7 +67,9 @@ public void OnNext(RawInputEventArgs value)
  else if (pointerDevice.TryGetPointer(args) is { } pointer &&
  pointer.Type != PointerType.Touch)
  {
- var element = pointer.Captured ?? args.InputHitTestResult.firstEnabledAncestor;
+ // See PointerOver_Or_Exited_Should_Ignore_Capture test.
+ // Following UWP behavior, PointerEntered and PointerExited events should always ignore captured element. 
+ var element = args.InputHitTestResult.firstEnabledAncestor;
 
  SetPointerOver(pointer, args.Root, element, args.Timestamp, args.Position,
  new PointerPointProperties(args.InputModifiers, args.Type.ToUpdateKind()),
@@ -84,7 +86,7 @@ public void SceneInvalidated(Rect dirtyRect)
 
  if (dirtyRect.Contains(clientPoint))
  {
- var element = pointer.Captured ?? _inputRoot.InputHitTest(clientPoint);
+ var element = _inputRoot.InputHitTest(clientPoint);
  SetPointerOver(pointer, _inputRoot, element, 0, clientPoint, PointerPointProperties.None, KeyModifiers.None);
  }
  else if (!((Visual)_inputRoot).Bounds.Contains(clientPoint))

src/Avalonia.Diagnostics/Diagnostics/ViewModels/FiredEvent.cs

@@ -8,24 +8,28 @@ namespace Avalonia.Diagnostics.ViewModels
  internal class FiredEvent : ViewModelBase
  {
  private readonly RoutedEventArgs _eventArgs;
+ private readonly RoutedEvent? _originalEvent;
  private EventChainLink? _handledBy;
 
  public FiredEvent(RoutedEventArgs eventArgs, EventChainLink originator, DateTime triggerTime)
  {
  _eventArgs = eventArgs ?? throw new ArgumentNullException(nameof(eventArgs));
  Originator = originator ?? throw new ArgumentNullException(nameof(originator));
+ _originalEvent = _eventArgs.RoutedEvent;
  AddToChain(originator);
  TriggerTime = triggerTime;
  }
 
  public bool IsPartOfSameEventChain(RoutedEventArgs e)
  {
- return e == _eventArgs;
+ // Note, Avalonia might reuse RoutedEventArgs for different events to avoid extra allocations.
+ // Like, PointerEntered and PointerExited will use the same instance of RoutedEventArgs. 
+ return e == _eventArgs && e.RoutedEvent == _originalEvent;
  }
 
  public DateTime TriggerTime { get; }
 
- public RoutedEvent Event => _eventArgs.RoutedEvent!;
+ public RoutedEvent Event => _originalEvent!;
 
  public bool IsHandled => HandledBy?.Handled == true;
 

tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs

@@ -116,42 +116,6 @@ public void TouchMove_Should_Not_Set_IsPointerOver()
  Assert.False(root.IsPointerOver);
  }
 
- [Fact]
- public void HitTest_Should_Be_Ignored_If_Element_Captured()
- {
- using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
-
- var renderer = new Mock<IHitTester>();
- var pointer = new Mock<IPointer>();
- var device = CreatePointerDeviceMock(pointer.Object).Object;
- var impl = CreateTopLevelImplMock();
-
- Canvas canvas;
- Border border;
- Decorator decorator;
-
- var root = CreateInputRoot(impl.Object, new Panel
- {
- Children =
- {
- (canvas = new Canvas()),
- (border = new Border
- {
- Child = decorator = new Decorator(),
- })
- }
- }, renderer.Object);
-
- SetHit(renderer, canvas);
- pointer.SetupGet(p => p.Captured).Returns(decorator);
- impl.Object.Input!(CreateRawPointerMovedArgs(device, root));
-
- Assert.True(decorator.IsPointerOver);
- Assert.True(border.IsPointerOver);
- Assert.False(canvas.IsPointerOver);
- Assert.True(root.IsPointerOver);
- }
-
  [Fact]
  public void IsPointerOver_Should_Be_Updated_When_Child_Sets_Handled_True()
  {
@@ -492,16 +456,63 @@ void HandleEvent(object? sender, PointerEventArgs e)
  result);
  }
 
- private static void AddEnteredExitedHandlers(
-  EventHandler<PointerEventArgs> handler,
-  params IInputElement[] controls)
+ // https://github.com/AvaloniaUI/Avalonia/issues/15293
+ [Fact]
+ public void PointerOver_Or_Exited_Should_Ignore_Capture()
  {
- foreach (var c in controls)
+ using var app = UnitTestApplication.Start(new TestServices(inputManager: new InputManager()));
+
+ var renderer = new Mock<IHitTester>();
+ var device = new MouseDevice();
+ var impl = CreateTopLevelImplMock();
+
+ var result = new List<(object, string, object?, bool)>();
+
+ Canvas canvas;
+
+ var root = CreateInputRoot(impl.Object, new Panel
+ {
+ Children =
+ {
+ (canvas = new Canvas())
+ }
+ }, renderer.Object);
+
+ void HandleEvent(object? sender, PointerEventArgs e)
  {
- c.PointerEntered += handler;
- c.PointerExited += handler;
- c.PointerMoved += handler;
+ result.Add((sender!, e.RoutedEvent!.Name, e.Pointer.Captured, canvas.IsPointerOver));
  }
+
+ AddEnteredExitedHandlers(HandleEvent, canvas);
+ AddPressedReleasedHandlers(HandleEvent, canvas);
+
+ // Init pointer over.
+ SetHit(renderer, canvas);
+ impl.Object.Input!(CreateRawPointerArgs(device, root, RawPointerEventType.Move));
+
+ // Init capture.
+ impl.Object.Input!(CreateRawPointerArgs(device, root, RawPointerEventType.LeftButtonDown));
+
+ // Leave the control, still captured.
+ impl.Object.Input!(CreateRawPointerArgs(device, root, RawPointerEventType.Move));
+ SetHit(renderer, null);
+ impl.Object.Input!(CreateRawPointerArgs(device, root, RawPointerEventType.Move));
+
+ // Release capture.
+ impl.Object.Input!(CreateRawPointerArgs(device, root, RawPointerEventType.LeftButtonUp));
+
+ Assert.Equal(
+ new[]
+ {
+ ((object)canvas, nameof(InputElement.PointerEntered), (object?)null, true),
+ (canvas, nameof(InputElement.PointerMoved), null, true),
+ (canvas, nameof(InputElement.PointerPressed), canvas, true),
+ (canvas, nameof(InputElement.PointerMoved), canvas, true),
+ (canvas, nameof(InputElement.PointerExited), canvas, false),
+ (canvas, nameof(InputElement.PointerMoved), canvas, false),
+ (canvas, nameof(InputElement.PointerReleased), canvas, false)
+ },
+ result);
  }
  }
 }

tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs

@@ -100,4 +100,27 @@ private protected static TopLevel CreateInputRoot(IWindowImpl impl, Control chil
 
  return pointerDevice;
  }
+
+ protected static void AddEnteredExitedHandlers(
+ EventHandler<PointerEventArgs> handler,
+ params IInputElement[] controls)
+ {
+ foreach (var c in controls)
+ {
+ c.PointerEntered += handler;
+ c.PointerExited += handler;
+ c.PointerMoved += handler;
+ }
+ }
+
+ protected static void AddPressedReleasedHandlers(
+ EventHandler<PointerEventArgs> handler,
+ params IInputElement[] controls)
+ {
+ foreach (var c in controls)
+ {
+ c.PointerPressed += (s, a) => handler(s, a);
+ c.PointerReleased += (s, a) => handler(s, a);
+ }
+ }
 }