Add automated test

src/Controls/tests/DeviceTests/Elements/Layout/LayoutTests.iOS.cs

@@ -3,10 +3,14 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using CoreGraphics;
 using Microsoft.Maui.Controls;
 using Microsoft.Maui.Graphics;
 using Microsoft.Maui.Handlers;
+using Microsoft.Maui.Hosting;
 using Microsoft.Maui.Platform;
+using Microsoft.VisualBasic;
+using UIKit;
 using Xunit;
 
 namespace Microsoft.Maui.DeviceTests
@@ -162,5 +166,63 @@ void ValidateInputTransparentOnPlatformView(IView view)
 			Assert.True(view.InputTransparent == !value,
 				$"InputTransparent: {view.InputTransparent}. UserInteractionEnabled: {platformView.UserInteractionEnabled}");
 		}
+
+		async Task WaitForLayout(UIView view, CGRect initialFrame, int timeout) 
+		{
+			int interval = 100;
+
+			while (timeout > 0)
+			{
+				if (view.Frame != initialFrame)
+				{
+					return;
+				}
+
+				await Task.Delay(interval);
+				timeout -= interval;
+			}
+		}
+
+		[Fact]
+		public async Task NestedLayoutsInRTLRemainOnScreen()
+		{
+			EnsureHandlerCreated((builder) =>
+			{
+				builder.ConfigureMauiHandlers(handler =>
+				{
+					handler.AddHandler(typeof(Button), typeof(ButtonHandler));
+					handler.AddHandler(typeof(Layout), typeof(LayoutHandler));
+					handler.AddHandler(typeof(Controls.ContentView), typeof(ContentViewHandler));
+				});
+			});
+
+			var level0 = new Controls.ContentView() { FlowDirection = FlowDirection.RightToLeft};
+			var level1 = new Grid() { HorizontalOptions = LayoutOptions.End, WidthRequest = 200 };
+			var level2 = new Grid() { HorizontalOptions = LayoutOptions.Start, WidthRequest = 200 };
+			var button = new Button() { Text = "Hello", HorizontalOptions = LayoutOptions.Start, WidthRequest = 100 };
+
+			level0.Content = level1;
+			level1.Add(level2);
+			level2.Add(button);
+
+			await AttachAndRun(level0, async (handler) =>
+			{
+				var root = handler.ToPlatform();
+
+				await WaitForLayout(root, CGRect.Empty, 5000);
+
+				UIKit.UIView nativeView = button.Handler.PlatformView as UIKit.UIView;
+				Assert.NotNull(nativeView);
+
+				// Work our way up the tree and verify that no one
+				// has a negative X position (which would make the view not 
+				// show up on screen)
+				while (nativeView != null)
+				{
+					Assert.True(nativeView.Bounds.X >= 0);
+					nativeView = nativeView.Superview;
+				}
+			});
+		}
 	}
 }