Listen to layout changes for ancestor visuals in text selection canvas (#21536)

* listen to layout changes for ancestor visuals in text selection canvas

* add tests

src/Avalonia.Controls/Primitives/TextSelectionCanvas.cs

@@ -5,9 +5,12 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives.PopupPositioning;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Avalonia.Layout;
 using Avalonia.Media.TextFormatting;
+using Avalonia.Reactive;
 using Avalonia.Threading;
 using Avalonia.VisualTree;
+using static Avalonia.Reactive.Disposable;
 
 namespace Avalonia.Controls.Primitives
 {
@@ -97,9 +100,16 @@ namespace Avalonia.Controls.Primitives
         }
 
         private void LayoutListener_Invalidated(object? sender, EventArgs e)
+        {
+            InvalidateMeasure();
+        }
+
+        protected override Size MeasureOverride(Size availableSize)
         {
             if (ShowHandles)
                 MoveHandlesToSelection();
+
+            return base.MeasureOverride(availableSize);
         }
 
         private void Caret_ContextCanceled(object? sender, RoutedEventArgs e)
@@ -610,15 +620,48 @@ namespace Avalonia.Controls.Primitives
             private TextPresenter? _presenter;
 
             public event EventHandler? Invalidated;
+            
+            private CompositeDisposable? _disposables;
 
             public void Attach(TextPresenter presenter)
             {
                 if (_presenter != null)
                     throw new InvalidOperationException("Listener is already attached to a TextPresenter");
 
+                _disposables?.Dispose();
+                _disposables = new CompositeDisposable();
                 _presenter = presenter;
-                presenter.SizeChanged += Presenter_SizeChanged;
-                presenter.EffectiveViewportChanged += Visual_EffectiveViewportChanged;
+
+                Visual? current = presenter;
+                do
+                {
+                    AttachEvents(current);
+                    current = current?.VisualParent;
+                }
+                while (current != null);
+            }
+
+            private void AttachEvents(Visual? visual)
+            {
+                if (visual != null)
+                {
+                    if (visual is Layoutable layoutable)
+                    {
+                        layoutable.EffectiveViewportChanged += Visual_EffectiveViewportChanged;
+                        _disposables?.Add(new AnonymousDisposable(() =>
+                        {
+                            layoutable.EffectiveViewportChanged -= Visual_EffectiveViewportChanged;
+                        }));
+                    }
+                    if (visual is Control control)
+                    {
+                        control.SizeChanged += Visual_SizeChanged;
+                        _disposables?.Add(new AnonymousDisposable(() =>
+                        {
+                            control.SizeChanged -= Visual_SizeChanged;
+                        }));
+                    }
+                }
             }
 
             private void Visual_EffectiveViewportChanged(object? sender, Layout.EffectiveViewportChangedEventArgs e)
@@ -626,18 +669,15 @@ namespace Avalonia.Controls.Primitives
                 OnInvalidated();
             }
 
-            private void Presenter_SizeChanged(object? sender, SizeChangedEventArgs e)
+            private void Visual_SizeChanged(object? sender, SizeChangedEventArgs e)
             {
                 OnInvalidated();
             }
 
             public void Detach()
             {
-                if (_presenter is { } presenter)
-                {
-                    presenter.SizeChanged -= Presenter_SizeChanged;
-                    presenter.EffectiveViewportChanged -= Visual_EffectiveViewportChanged;
-                }
+                _disposables?.Dispose();
+                _disposables = null;
 
                 _presenter = null;
             }

tests/Avalonia.Controls.UnitTests/TextSelectionCanvasTests.cs

@@ -0,0 +1,152 @@
+using System.Linq;
+using Avalonia.Controls.Presenters;
+using Avalonia.Controls.Primitives;
+using Avalonia.Controls.Templates;
+using Avalonia.Harfbuzz;
+using Avalonia.Headless;
+using Avalonia.Input;
+using Avalonia.Platform;
+using Avalonia.UnitTests;
+using Avalonia.VisualTree;
+using Moq;
+using Xunit;
+
+namespace Avalonia.Controls.UnitTests
+{
+    public class TextSelectionCanvasTests : ScopedTestBase
+    {
+        [Fact]
+        public void Text_Selection_Handle_Moves_With_Scrolling()
+        {
+            using (UnitTestApplication.Start(Services))
+            {
+                var touchHelper = new TouchTestHelper();
+                Border rootBorder = new Border()
+                {
+                    Width = 200,
+                    Height = 600
+                };
+                var visualLayerManager = new VisualLayerManager()
+                {
+                    Child = rootBorder,
+                    EnableTextSelectorLayer = true
+                };
+                var impl = CreateMockTopLevelImpl();
+                var topLevel = new TestTopLevel(impl.Object)
+                {
+                    Template = CreateTopLevelTemplate(),
+                    Content = visualLayerManager
+                };
+
+                var focusedTextBox = CreateTextBox();
+
+                var panel = new StackPanel()
+                {
+                    Orientation = Layout.Orientation.Vertical,
+                    Spacing = 20,
+                    Children =
+                    {
+                        focusedTextBox,
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                        CreateTextBox(),
+                    }
+                };
+
+                var scrollViewer = new ScrollViewer
+                {
+                    Template = new FuncControlTemplate<ScrollViewer>(ScrollViewerTests.CreateTemplate),
+                    Content = panel
+                };
+
+                rootBorder.Child = scrollViewer;
+
+                topLevel.LayoutManager.ExecuteInitialLayoutPass();
+
+                touchHelper.Tap(focusedTextBox);
+
+                topLevel.LayoutManager.ExecuteLayoutPass();
+
+                var presenter = focusedTextBox.FindDescendantOfType<TextPresenter>()!;
+                var canvas = presenter.TextSelectionHandleCanvas;
+
+                Assert.NotNull(canvas);
+
+                var handle = canvas.Children.FirstOrDefault() as TextSelectionHandle;
+
+                Assert.NotNull(handle);
+
+                Assert.Equal(new Point(25.5, 14.5), handle.GetTopLeft());
+
+                scrollViewer.Offset = new Vector(0, 50);
+
+                topLevel.LayoutManager.ExecuteLayoutPass();
+
+                Assert.Equal(new Point(25.5, -35.5), handle.GetTopLeft());
+            }
+
+            TextBox CreateTextBox()
+            {
+                return new TextBox
+                {
+                    Template = TextBoxTests.CreateTemplate(),
+                    Text = "Test",
+                    Width = 150
+                };
+            }
+        }
+
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
+        {
+
+        }
+
+        static Mock<ITopLevelImpl> CreateMockTopLevelImpl()
+        {
+            var topLevel = new Mock<ITopLevelImpl>();
+            topLevel.Setup(x => x.RenderScaling).Returns(1);
+            topLevel.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
+            return topLevel;
+        }
+
+        private static FuncControlTemplate<TestTopLevel> CreateTopLevelTemplate()
+        {
+            return new FuncControlTemplate<TestTopLevel>((x, scope) =>
+                new ContentPresenter
+                {
+                    Name = "PART_ContentPresenter",
+                    [!ContentPresenter.ContentProperty] = x[!ContentControl.ContentProperty],
+                }.RegisterInNameScope(scope));
+        }
+
+        private static TestServices Services => TestServices.MockThreadingInterface.With(
+            standardCursorFactory: Mock.Of<ICursorFactory>(),
+            renderInterface: new HeadlessPlatformRenderInterface(),
+            textShaperImpl: new HarfBuzzTextShaper(),
+            fontManagerImpl: new TestFontManager(),
+            keyboardDevice: () => new KeyboardDevice(),
+            keyboardNavigation: () => new KeyboardNavigationHandler(),
+            inputManager: new InputManager(),
+            assetLoader: new StandardAssetLoader());
+    }
+}