Locate MAUI View for PlatformView

src/Controls/tests/DeviceTests/ControlsHandlerTestBase.cs

@@ -97,13 +97,30 @@ IWindow CreateWindowForContent(IElement view)
 			return window;
 		}
 
+		protected Task CreateHandlerAndAddToWindow(IElement view, Func<Task> action)
+		{
+			return CreateHandlerAndAddToWindow<IWindowHandler>(CreateWindowForContent(view), handler =>
+			{
+				return action();
+			}, MauiContext, null);
+		}
+
+		protected Task CreateHandlerAndAddToWindow<THandler>(IElement view, Func<THandler, Task> action)
+			where THandler : class, IElementHandler
+		{
+			return CreateHandlerAndAddToWindow<THandler>(view, handler =>
+			{
+				return action(handler);
+			}, MauiContext, null);
+		}
+
 		protected Task CreateHandlerAndAddToWindow(IElement view, Action action)
 		{
 			return CreateHandlerAndAddToWindow<IWindowHandler>(CreateWindowForContent(view), handler =>
 			{
 				action();
 				return Task.CompletedTask;
-			});
+			}, MauiContext, null);
 		}
 
 		protected Task CreateHandlerAndAddToWindow<THandler>(IElement view, Action<THandler> action)
@@ -113,7 +130,7 @@ protected Task CreateHandlerAndAddToWindow<THandler>(IElement view, Action<THand
 			{
 				action(handler);
 				return Task.CompletedTask;
-			});
+			}, MauiContext, null);
 		}
 
 		static SemaphoreSlim _takeOverMainContentSempahore = new SemaphoreSlim(1);
@@ -175,6 +192,8 @@ await SetupWindowForTests<THandler>(window, async () =>
 
 						await OnLoadedAsync(content as VisualElement);
 
+						// Gives time for the measure/layout pass to settle
+						await Task.Yield();
 						if (view is VisualElement veBeingTested)
 							await OnLoadedAsync(veBeingTested);
 

src/Controls/tests/DeviceTests/Elements/TabbedPage/TabbedPageTests.Android.cs

@@ -113,7 +113,7 @@ await CreateHandlerAndAddToWindow<WindowHandlerStub>(new Window(tabbedPage), asy
 
 		BottomNavigationView GetBottomNavigationView(TabbedViewHandler tabViewHandler)
 		{
-			var layout = (tabViewHandler.PlatformView as Android.Views.IViewParent).FindParent((view) => view is CoordinatorLayout)
+			var layout = tabViewHandler.PlatformView.FindParent((view) => view is CoordinatorLayout)
 				as CoordinatorLayout;
 
 			return layout.GetFirstChildOfType<BottomNavigationView>();

src/Controls/tests/DeviceTests/Elements/VisualElementTree/FindVisualTreeElementInsideTestCase.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Xunit.Abstractions;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	public class FindVisualTreeElementInsideTestCase : IXunitSerializable
+	{
+
+		public string TestCaseName { get; private set; }
+
+		public FindVisualTreeElementInsideTestCase() { }
+
+		public FindVisualTreeElementInsideTestCase(string testCaseName)
+		{
+			TestCaseName = testCaseName;
+		}
+
+		public void Deserialize(IXunitSerializationInfo info)
+		{
+			TestCaseName = info.GetValue<string>(nameof(TestCaseName));
+		}
+
+		public void Serialize(IXunitSerializationInfo info)
+		{
+			info.AddValue(nameof(TestCaseName), TestCaseName, typeof(string));
+		}
+
+		public override string ToString()
+		{
+			return TestCaseName;
+		}
+
+		public (VisualElement rootView, VisualElement testView) CreateVisualElement()
+		{
+			switch (TestCaseName)
+			{
+				case "CollectionView":
+					{
+						var cv = new CollectionView();
+						NestingView view = new NestingView();
+						cv.ItemTemplate = new DataTemplate(() =>
+						{
+							return view;
+						});
+						cv.ItemsSource = new[] { 0 };
+						return (cv, view);
+					}
+				case "ContentView":
+					{
+						var contentView = new ContentView();
+						NestingView view = new NestingView();
+						contentView.ControlTemplate = new ControlTemplate(() =>
+						{
+							return view;
+						});
+						return (contentView, view);
+					}
+			}
+
+			throw new Exception(String.Concat(TestCaseName, " ", "Not Found"));
+		}
+	}
+
+	public class FindVisualTreeElementInsideTestCases : IEnumerable<object[]>
+	{
+		private readonly List<object[]> _data = new()
+			{
+				new object[] { new FindVisualTreeElementInsideTestCase("CollectionView") },
+				new object[] { new FindVisualTreeElementInsideTestCase("ContentView") }
+			};
+
+		public IEnumerator<object[]> GetEnumerator()
+			=> _data.GetEnumerator();
+
+		IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+	}
+}

src/Controls/tests/DeviceTests/Elements/VisualElementTree/VisualElementTreeTests.cs

@@ -0,0 +1,214 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Handlers;
+using Microsoft.Maui.Handlers;
+using Microsoft.Maui.Hosting;
+using Microsoft.Maui.Platform;
+using Xunit;
+using System.Collections.Generic;
+using ContentView = Microsoft.Maui.Controls.ContentView;
+using Microsoft.Maui.Controls.Handlers.Items;
+#if ANDROID || IOS || MACCATALYST
+using ShellHandler = Microsoft.Maui.Controls.Handlers.Compatibility.ShellRenderer;
+#endif
+
+namespace Microsoft.Maui.DeviceTests
+{
+	[Category(TestCategory.VisualElementTree)]
+#if ANDROID || IOS || MACCATALYST
+	[Collection(ControlsHandlerTestBase.RunInNewWindowCollection)]
+#endif
+	public partial class VisualElementTreeTests : ControlsHandlerTestBase
+	{
+		void SetupBuilder()
+		{
+			EnsureHandlerCreated(builder =>
+			{
+				builder.SetupShellHandlers();
+
+				builder.ConfigureMauiHandlers(handlers =>
+				{
+#if IOS || MACCATALYST
+					handlers.AddHandler(typeof(Controls.NavigationPage), typeof(Controls.Handlers.Compatibility.NavigationRenderer));
+#else
+					handlers.AddHandler(typeof(Controls.NavigationPage), typeof(NavigationViewHandler));
+#endif
+					handlers.AddHandler<NestingView, NestingViewHandler>();
+					handlers.AddHandler<ContentView, ContentViewHandler>();
+					handlers.AddHandler<CollectionView, CollectionViewHandler>();
+				});
+			});
+		}
+
+		[Fact]
+		public async Task GetVisualTreeElements()
+		{
+			SetupBuilder();
+			var label = new Label() { Text = "Find Me" };
+			var page = new ContentPage() { Title = "Title Page" };
+			page.Content = new VerticalStackLayout()
+			{
+				label
+			};
+
+			var rootPage = await InvokeOnMainThreadAsync(() =>
+				new NavigationPage(page)
+			);
+
+			await CreateHandlerAndAddToWindow<IWindowHandler>(rootPage, async handler =>
+			{
+				await OnFrameSetToNotEmpty(label);
+				var locationOnScreen = label.GetLocationOnScreen().Value;
+				var labelFrame = label.Frame;
+				var window = rootPage.Window;
+
+				// Find label at the top left corner
+				var topLeft = new Graphics.Point(locationOnScreen.X + 1, locationOnScreen.Y + 1);
+
+				Assert.True(window.GetVisualTreeElements(topLeft).Contains(label), $"Unable to find label using top left coordinate: {topLeft} with label location: {label.GetBoundingBox()}");
+
+				// find label at the bottom right corner
+				var bottomRight = new Graphics.Point(
+					locationOnScreen.X + labelFrame.Width - 1,
+					locationOnScreen.Y + labelFrame.Height - 1);
+
+				Assert.True(window.GetVisualTreeElements(bottomRight).Contains(label), $"Unable to find label using bottom right coordinate: {bottomRight} with label location: {label.GetBoundingBox()}");
+
+				// Ensure that the point directly outside the bounds of the label doesn't
+				// return the label
+				Assert.DoesNotContain(label, window.GetVisualTreeElements(
+						locationOnScreen.X + labelFrame.Width + 1,
+						locationOnScreen.Y + labelFrame.Height + 1
+					));
+
+			});
+		}
+
+		[Fact]
+		public async Task FindPlatformViewInsideLayout()
+		{
+			SetupBuilder();
+			var button = new Button();
+			VerticalStackLayout views = new VerticalStackLayout()
+			{
+				new VerticalStackLayout()
+				{
+					button
+				}
+			};
+
+			await CreateHandlerAndAddToWindow(views, () =>
+			{
+				var platformView = button.ToPlatform();
+				var foundTreeElement = button.ToPlatform().GetVisualTreeElement();
+
+				Assert.Equal(button, foundTreeElement);
+			});
+		}
+
+		[Fact]
+		public async Task FindPlatformViewInsideScrollView()
+		{
+			SetupBuilder();
+			var button = new Button();
+			ScrollView view = new ScrollView()
+			{
+				Content = button
+			};
+
+			await CreateHandlerAndAddToWindow(view, () =>
+			{
+				var platformView = button.ToPlatform();
+				var foundTreeElement = button.ToPlatform().GetVisualTreeElement();
+
+				Assert.Equal(button, foundTreeElement);
+			});
+		}
+
+		[Fact]
+		public async Task FindPlatformViewViaDefaultContainer()
+		{
+			SetupBuilder();
+			var button = new Button();
+			NestingView view = new NestingView();
+			view.AddLogicalChild(button);
+
+			await CreateHandlerAndAddToWindow(view, () =>
+			{
+				var platformView = button.ToPlatform();
+				var foundTreeElement = button.ToPlatform().GetVisualTreeElement();
+
+				Assert.Equal(button, foundTreeElement);
+			});
+		}
+
+		[Fact]
+		public async Task FindVisualTreeElementWithArbitraryPlatformViewsAdded()
+		{
+			SetupBuilder();
+			var button = new Button();
+			NestingView view = new NestingView();
+
+			await CreateHandlerAndAddToWindow<NestingViewHandler>(view, (handler) =>
+			{
+				handler
+					.PlatformView
+					.AddChild()
+					.AddChild()
+					.AddChild()
+					.AddChild(button, view);
+
+				var platformView = button.ToPlatform();
+				var foundTreeElement = button.ToPlatform().GetVisualTreeElement();
+
+				Assert.Equal(button, foundTreeElement);
+			});
+		}
+
+		[Theory]
+		[InlineData(false)]
+		[InlineData(true)]
+		public async Task FindFirstMauiParentElement(bool searchAncestors)
+		{
+			SetupBuilder();
+			var viewToLocate = new NestingView();
+			NestingView view = new NestingView();
+
+			await CreateHandlerAndAddToWindow<NestingViewHandler>(view, (handler) =>
+			{
+				var nestedChild =
+					handler.PlatformView
+						.AddChild<NestingViewPlatformView>(viewToLocate, view)
+						.AddChild()
+						.AddChild()
+						.AddChild();
+
+				var foundTreeElement = nestedChild.GetVisualTreeElement(searchAncestors);
+
+				if (searchAncestors)
+					Assert.Equal(viewToLocate, foundTreeElement);
+				else
+					Assert.Null(foundTreeElement);
+			});
+		}
+
+		[Theory]
+		[ClassData(typeof(FindVisualTreeElementInsideTestCases))]
+		public async Task FindPlatformViewInsideView(FindVisualTreeElementInsideTestCase testCase)
+		{
+			SetupBuilder();
+
+			VisualElement rootView;
+			VisualElement viewToLocate;
+
+			(rootView, viewToLocate) = testCase.CreateVisualElement();
+			await CreateHandlerAndAddToWindow(rootView, () =>
+			{
+				var platformView = viewToLocate.ToPlatform();
+				var foundTreeElement = platformView.GetVisualTreeElement();
+				Assert.Equal(viewToLocate, foundTreeElement);
+			});
+		}
+	}
+}