Ensure that UIScrollView ContentSize is set; Fixes #9209; also fixes #…

…11017.

src/Controls/src/Core/HandlerImpl/ScrollView/ScrollView.Impl.cs

@@ -87,17 +87,9 @@ protected override Size ArrangeOverride(Rect bounds)
 
 		Size IContentView.CrossPlatformArrange(Rect bounds)
 		{
-			if ((this as IContentView).PresentedContent is IView presentedContent)
+			if (this is IScrollView scrollView)
 			{
-				var padding = Padding;
-
-				// Normally we'd just want the content to be arranged within the ContentView's Frame,
-				// but ScrollView content might be larger than the ScrollView itself (for obvious reasons)
-				// So in each dimension, we assume the larger of the two values.
-				bounds.Width = Math.Max(bounds.Width, presentedContent.DesiredSize.Width + padding.HorizontalThickness);
-				bounds.Height = Math.Max(bounds.Height, presentedContent.DesiredSize.Height + padding.VerticalThickness);
-
-				this.ArrangeContent(bounds);
+				return scrollView.ArrangeScrollViewContent(bounds);
 			}
 
 			return bounds.Size;

src/Core/src/Handlers/ScrollView/ScrollViewHandler.iOS.cs

@@ -150,21 +150,21 @@ static void InsertContentView(UIScrollView platformScrollView, IScrollView scrol
 				Tag = ContentPanelTag
 			};
 
-			contentContainer.CrossPlatformArrange = ArrangeScrollViewContent(scrollView.CrossPlatformArrange, contentContainer);
+			contentContainer.CrossPlatformArrange = ArrangeScrollViewContent(scrollView.CrossPlatformArrange, contentContainer, platformScrollView);
 
 			platformScrollView.ClearSubviews();
 			contentContainer.AddSubview(platformContent);
 			platformScrollView.AddSubview(contentContainer);
 		}
 
-		static Func<Rect, Size> ArrangeScrollViewContent(Func<Rect, Size> internalArrange, ContentView container)
+		static Func<Rect, Size> ArrangeScrollViewContent(Func<Rect, Size> internalArrange, ContentView container, UIScrollView platformScrollView)
 		{
 			return (rect) =>
 			{
 				if (container.Superview is UIScrollView scrollView)
 				{
 					// Ensure the container is at least the size of the UIScrollView itself, so that the 
-					// cross-platform layout logic makes sense and the contents don't arrange out side the 
+					// cross-platform layout logic makes sense and the contents don't arrange outside the 
 					// container. (Everything will look correct if they do, but hit testing won't work properly.)
 
 					var scrollViewBounds = scrollView.Bounds;
@@ -176,7 +176,9 @@ static Func<Rect, Size> ArrangeScrollViewContent(Func<Rect, Size> internalArrang
 					container.Center = new CGPoint(container.Bounds.GetMidX(), container.Bounds.GetMidY());
 				}
 
-				return internalArrange(rect);
+				var contentSize = internalArrange(rect);
+				platformScrollView.ContentSize = contentSize;
+				return contentSize;
 			};
 		}
 
@@ -223,7 +225,7 @@ public override Size GetDesiredSize(double widthConstraint, double heightConstra
 			var virtualView = VirtualView;
 			var platformView = PlatformView;
 
-			if (platformView == null || virtualView == null || virtualView.PresentedContent == null)
+			if (platformView == null || virtualView == null)
 			{
 				return new Size(widthConstraint, heightConstraint);
 			}

src/Core/src/Layouts/LayoutExtensions.cs

@@ -188,5 +188,27 @@ public static Size AdjustForFill(this Size size, Rect bounds, IView view)
 
 			return size;
 		}
+
+		internal static Size ArrangeScrollViewContent(this IScrollView scrollView, Rect bounds) 
+		{
+			var presentedContent = scrollView.PresentedContent;
+
+			if (presentedContent == null)
+			{
+				return Size.Zero;
+			}
+
+			var padding = scrollView.Padding;
+
+			// Normally we'd just want the content to be arranged within the ContentView's Frame,
+			// but ScrollView content might be larger than the ScrollView itself (for obvious reasons)
+			// So in each dimension, we assume the larger of the two values.
+			bounds.Width = Math.Max(bounds.Width, presentedContent.DesiredSize.Width + padding.HorizontalThickness);
+			bounds.Height = Math.Max(bounds.Height, presentedContent.DesiredSize.Height + padding.VerticalThickness);
+
+			scrollView.ArrangeContent(bounds);
+
+			return bounds.Size;
+		}
 	}
 }

src/Core/tests/DeviceTests.Shared/HandlerTests/HandlerTestBase.cs

@@ -107,11 +107,9 @@ protected void InitializeViewHandler(IElement element, IElementHandler handler,
 				var w = size.Width;
 				var h = size.Height;
 
-				if (double.IsPositiveInfinity(w))
-					w = view.Width;
-
-				if (double.IsPositiveInfinity(h))
-					h = view.Height;
+				// No measure method should be returning infinite values
+				Assert.False(double.IsPositiveInfinity(w));
+				Assert.False(double.IsPositiveInfinity(h));
 
 #else
 				// Windows cannot measure without the view being loaded

src/Core/tests/DeviceTests/Handlers/ScrollView/ScrollViewHandlerTests.iOS.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
 using Microsoft.Maui.DeviceTests.Stubs;
 using Microsoft.Maui.Handlers;
 using Microsoft.Maui.Platform;
@@ -18,7 +19,6 @@ public async Task ContentInitializesCorrectly()
 		{
 			bool result = await InvokeOnMainThreadAsync(() =>
 			{
-
 				var entry = new EntryStub() { Text = "In a ScrollView" };
 				var entryHandler = Activator.CreateInstance<EntryHandler>();
 				entryHandler.SetMauiContext(MauiContext);
@@ -34,8 +34,8 @@ public async Task ContentInitializesCorrectly()
 
 				foreach (var platformView in scrollViewHandler.PlatformView.Subviews)
 				{
-					// ScrollView on iOS uses an intermediate ContentView to handle conetent measurement/arrangement
-					if (platformView is ContentView contentView)
+					// ScrollView on iOS uses an intermediate ContentView to handle content measurement/arrangement
+					if (platformView is Microsoft.Maui.Platform.ContentView contentView)
 					{
 						foreach (var content in contentView.Subviews)
 						{
@@ -52,5 +52,38 @@ public async Task ContentInitializesCorrectly()
 
 			Assert.True(result, $"Expected (but did not find) a {nameof(MauiTextField)} in the Subviews array");
 		}
+
+		[Fact]
+		public async Task ScrollViewContentSizeSet() 
+		{
+			var scrollView = new ScrollViewStub();
+
+			var scrollViewHandler = await InvokeOnMainThreadAsync(() =>
+			{
+				return CreateHandler(scrollView);
+			});
+
+			await InvokeOnMainThreadAsync(async () => {
+				await scrollViewHandler.PlatformView.AttachAndRun(() =>
+				{
+
+					var entry = new EntryStub() { Text = "In a ScrollView", Height = 10000 };
+					var entryHandler = Activator.CreateInstance<EntryHandler>();
+					entryHandler.SetMauiContext(MauiContext);
+					entryHandler.SetVirtualView(entry);
+					entry.Handler = entryHandler;
+
+					scrollView.Content = entry;
+
+					// Simulate a bunch of things that would happen if this were a real app
+					scrollViewHandler.UpdateValue(nameof(IScrollView.Content));
+					scrollViewHandler.PlatformArrange(new Rect(0, 0, 50, 50));
+					scrollViewHandler.PlatformView.SetNeedsLayout();
+					scrollViewHandler.PlatformView.LayoutIfNeeded();
+
+					Assert.Equal(10000, scrollViewHandler.PlatformView.ContentSize.Height);
+				});
+			});
+		}
 	}
 }

src/Core/tests/DeviceTests/Stubs/ScrollViewStub.cs

@@ -1,4 +1,5 @@
 using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Layouts;
 
 namespace Microsoft.Maui.DeviceTests.Stubs
 {
@@ -26,12 +27,22 @@ public void ScrollFinished()
 
 		public Size CrossPlatformArrange(Rect bounds)
 		{
+			if (this is IScrollView scrollView)
+			{
+				return scrollView.ArrangeScrollViewContent(bounds);
+			}
+
 			return bounds.Size;
 		}
 
 		public Size CrossPlatformMeasure(double widthConstraint, double heightConstraint)
 		{
-			return new Size(widthConstraint, heightConstraint);
+			if (PresentedContent != null)
+			{
+				return PresentedContent.Measure(widthConstraint, heightConstraint);
+			}
+
+			return Size.Zero;
 		}
 	}
 }

src/Core/tests/DeviceTests/Stubs/StubBase.cs

@@ -135,7 +135,8 @@ public Size Measure(double widthConstraint, double heightConstraint)
 		{
 			if (Handler != null)
 			{
-				return Handler.GetDesiredSize(widthConstraint, heightConstraint);
+				DesiredSize = Handler.GetDesiredSize(widthConstraint, heightConstraint);
+				return DesiredSize;
 			}
 
 			return new Size(widthConstraint, heightConstraint);