Fix ImageHandler Vertical&Horizontal Options with AspectFit

Author: morning4coffe-dev

src/Controls/tests/TestCases.HostApp/Issues/Issue30403.cs

@@ -0,0 +1,26 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 30403, "Image under WinUI does not respect VerticalOptions and HorizontalOptions with AspectFit", PlatformAffected.UWP)]
+public class Issue30403 : TestContentPage
+{
+	protected override void Init()
+	{
+		Title = "Issue 30403";
+
+		Content = new Grid
+		{
+			BackgroundColor = Colors.LightGray,
+			Children =
+			{
+				new Image
+				{
+					AutomationId = "TestImage",
+					Source = "dotnet_bot.png",
+					Aspect = Aspect.AspectFit,
+					VerticalOptions = LayoutOptions.Center,
+					HorizontalOptions = LayoutOptions.Center,
+				}
+			}
+		};
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue30403.cs

@@ -0,0 +1,25 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue30403 : _IssuesUITest
+{
+	public Issue30403(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "Image under WinUI does not respect VerticalOptions and HorizontalOptions with AspectFit";
+
+	[Test]
+	[Category(UITestCategories.Image)]
+	public void ImageRespectsVerticalAndHorizontalOptionsWithAspectFit()
+	{
+		App.WaitForElement("TestImage");
+
+		// Verify that the image is positioned correctly according to VerticalOptions.Center and HorizontalOptions.Center
+		// with AspectFit aspect ratio. The image should appear in the center of the Grid.
+		VerifyScreenshot();
+	}
+}

src/Core/src/Handlers/Image/ImageHandler.Windows.cs

@@ -1,7 +1,9 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Media;
+using Microsoft.UI.Xaml.Media.Imaging;
 using WImage = Microsoft.UI.Xaml.Controls.Image;
 
 namespace Microsoft.Maui.Handlers
@@ -55,6 +57,38 @@ protected override void RemoveContainer()
 			UpdateValue(nameof(IView.Width));
 		}
 
+		/// <inheritdoc/>
+		public override Graphics.Size GetDesiredSize(double widthConstraint, double heightConstraint)
+		{
+			if (VirtualView.Aspect == Aspect.AspectFit
+				&& VirtualView.HorizontalLayoutAlignment != Primitives.LayoutAlignment.Fill
+				&& VirtualView.VerticalLayoutAlignment != Primitives.LayoutAlignment.Fill)
+			{
+				if (PlatformView.MaxWidth == double.PositiveInfinity
+					&& PlatformView.MaxHeight == double.PositiveInfinity)
+				{
+					var imageSize = GetImageSize();
+
+					if (imageSize.Width != 0 && imageSize.Height != 0)
+					{
+						PlatformView.MaxWidth = imageSize.Width;
+						PlatformView.MaxHeight = imageSize.Height;
+					}
+				}
+			}
+			else
+			{
+				if (VirtualView.MaximumHeight != PlatformView.MaxHeight
+					|| VirtualView.MaximumWidth != PlatformView.MaxWidth)
+				{
+					PlatformView.MaxWidth = VirtualView.MaximumWidth;
+					PlatformView.MaxHeight = VirtualView.MaximumHeight;
+				}
+			}
+
+			return base.GetDesiredSize(widthConstraint, heightConstraint);
+		}
+
 		/// <summary>
 		/// Maps the abstract <see cref="IView.Height"/> property to the platform-specific implementations.
 		/// </summary>
@@ -146,6 +180,20 @@ void OnImageOpened(object sender, RoutedEventArgs e)
 				UpdateValue(nameof(IImage.IsAnimationPlaying));
 		}
 
+		private Graphics.Size GetImageSize()
+		{
+			if (PlatformView.Source is BitmapSource bitmap)
+			{
+				// BitmapSource may not have PixelWidth/PixelHeight set until image is loaded
+				if (bitmap.PixelWidth > 0 && bitmap.PixelHeight > 0)
+				{
+					return new Graphics.Size(bitmap.PixelWidth, bitmap.PixelHeight);
+				}
+				// If not available, set to zero
+			}
+			return Graphics.Size.Zero;
+		}
+
 		partial class ImageImageSourcePartSetter
 		{
 			public override void SetImageSource(ImageSource? platformImage)

src/Core/src/PublicAPI/net-windows/PublicAPI.Unshipped.txt

@@ -26,6 +26,7 @@ Microsoft.Maui.SwipeViewSwipeEnded.Deconstruct(out Microsoft.Maui.SwipeDirection
 Microsoft.Maui.SwipeViewSwipeEnded.SwipeViewSwipeEnded(Microsoft.Maui.SwipeViewSwipeEnded! original) -> void
 Microsoft.Maui.SwipeViewSwipeStarted.Deconstruct(out Microsoft.Maui.SwipeDirection SwipeDirection) -> void
 Microsoft.Maui.SwipeViewSwipeStarted.SwipeViewSwipeStarted(Microsoft.Maui.SwipeViewSwipeStarted! original) -> void
+override Microsoft.Maui.Handlers.ImageHandler.GetDesiredSize(double widthConstraint, double heightConstraint) -> Microsoft.Maui.Graphics.Size
 override Microsoft.Maui.Handlers.ContextFlyoutItemHandlerUpdate.Equals(object? obj) -> bool
 override Microsoft.Maui.Handlers.ContextFlyoutItemHandlerUpdate.GetHashCode() -> int
 override Microsoft.Maui.Handlers.ContextFlyoutItemHandlerUpdate.ToString() -> string!