Merge pull request #22006 from unoplatform/copilot/mark-uno-foundation-types-bindable

feat: Mark Windows.Foundation value types as bindable for NAOT trimmer support

Author: jeromelaban

src/SourceGenerators/Uno.UI.SourceGenerators/BindableTypeProviders/BindableTypeProvidersGenerationTask.cs

@@ -364,10 +364,15 @@ where field.IsStatic
 								continue;
 							}
 
+							// For value types (structs), we cannot generate setters because modifying an unboxed value type
+							// creates a temporary copy that is immediately discarded. Only generate getters for structs.
+							var isValueType = ownerType.TypeKind == TypeKind.Struct;
+
 							if (
 								property.SetMethod != null
 								&& !property.SetMethod.IsInitOnly
 								&& property.SetMethod.IsLocallyPublic(_currentModule!)
+								&& !isValueType
 								)
 							{
 								writer.AppendLineIndented($@"bindableType.AddProperty(""{propertyName}"", typeof({propertyTypeName}), Get{propertyName}, Set{propertyName});");

src/SourceGenerators/Uno.UI.SourceGenerators/Uno.UI.SourceGenerators.csproj

@@ -23,6 +23,9 @@
 	</ItemGroup>
 
 	<ItemGroup>
+		<Compile Include="..\..\Uno.Foundation\Internals\BindableAttribute.cs">
+			<Link>XamlGenerator\XamlPathParser\BindableAttribute.cs</Link>
+		</Compile>
 		<Compile Include="..\..\Uno.Foundation\Point.cs">
 			<Link>XamlGenerator\XamlPathParser\Point.cs</Link>
 		</Compile>

src/Uno.Foundation/Internals/BindableAttribute.cs

@@ -0,0 +1,16 @@
+#nullable enable
+
+using System;
+
+namespace Uno.Foundation.Internals
+{
+	/// <summary>
+	/// Marks a type as bindable for the NAOT trimmer.
+	/// This attribute is used by the BindableTypeProvidersSourceGenerator to identify types
+	/// that should have binding metadata generated, preventing them from being trimmed.
+	/// </summary>
+	[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, Inherited = false, AllowMultiple = false)]
+	internal sealed class BindableAttribute : Attribute
+	{
+	}
+}

src/Uno.Foundation/Point.cs

@@ -11,6 +11,7 @@
 namespace Windows.Foundation;
 
 [DebuggerDisplay("{DebugDisplay,nq}")]
+[Uno.Foundation.Internals.Bindable]
 public partial struct Point
 {
 	// These are public in WinUI (with the underscore!), but we don't want to expose it for now at least.

src/Uno.Foundation/Rect.cs

@@ -9,6 +9,7 @@
 namespace Windows.Foundation;
 
 [DebuggerDisplay("[Rect {Size}@{Location}]")]
+[Uno.Foundation.Internals.Bindable]
 public partial struct Rect
 {
 	// These are public in WinUI (with the underscore!), but we don't want to expose it for now at least.

src/Uno.Foundation/Size.cs

@@ -9,6 +9,7 @@ namespace Windows.Foundation;
 
 [DebuggerDisplay("{DebugDisplay,nq}")]
 [TypeConverter(typeof(SizeConverter))]
+[Uno.Foundation.Internals.Bindable]
 public partial struct Size
 {
 	// These are public in WinUI (with the underscore!), but we don't want to expose it for now at least.

src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Data/BindableFoundationStructsTestPage.xaml

@@ -0,0 +1,23 @@
+<Page
+    x:Class="Uno.UI.RuntimeTests.Tests.Windows_UI_Xaml_Data.BindableFoundationStructsTestPage"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:Uno.UI.RuntimeTests.Tests.Windows_UI_Xaml_Data"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+
+    <Grid>
+		<StackPanel>
+			<!-- Test binding to Rect.Width property -->
+			<TextBlock Tag="{Binding TestRect.Width}" x:FieldModifier="public" x:Name="RectTextBlock" />
+			
+			<!-- Test binding to Size.Height property -->
+			<TextBlock Tag="{Binding TestSize.Height}" x:FieldModifier="public" x:Name="SizeTextBlock" />
+			
+			<!-- Test binding to Point.X property -->
+			<TextBlock Tag="{Binding TestPoint.X}" x:FieldModifier="public" x:Name="PointTextBlock" />
+		</StackPanel>
+	</Grid>
+</Page>

src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Data/BindableFoundationStructsTestPage.xaml.cs

@@ -0,0 +1,61 @@
+#nullable enable
+
+using System.ComponentModel;
+using Microsoft.UI.Xaml.Controls;
+using Windows.Foundation;
+
+namespace Uno.UI.RuntimeTests.Tests.Windows_UI_Xaml_Data;
+
+public sealed partial class BindableFoundationStructsTestPage : Page, INotifyPropertyChanged
+{
+	private Rect _testRect;
+	private Size _testSize;
+	private Point _testPoint;
+
+	public BindableFoundationStructsTestPage()
+	{
+		this.InitializeComponent();
+		this.DataContext = this;
+	}
+
+	public event PropertyChangedEventHandler? PropertyChanged;
+
+	public Rect TestRect
+	{
+		get => _testRect;
+		set
+		{
+			if (_testRect != value)
+			{
+				_testRect = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(TestRect)));
+			}
+		}
+	}
+
+	public Size TestSize
+	{
+		get => _testSize;
+		set
+		{
+			if (_testSize != value)
+			{
+				_testSize = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(TestSize)));
+			}
+		}
+	}
+
+	public Point TestPoint
+	{
+		get => _testPoint;
+		set
+		{
+			if (_testPoint != value)
+			{
+				_testPoint = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(TestPoint)));
+			}
+		}
+	}
+}

src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Data/Given_BindableFoundationStructs.cs

@@ -0,0 +1,56 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Windows.Foundation;
+
+namespace Uno.UI.RuntimeTests.Tests.Windows_UI_Xaml_Data;
+
+[TestClass]
+public class Given_BindableFoundationStructs
+{
+	[TestMethod]
+	[RunsOnUIThread]
+	public void When_Binding_To_Rect_Property()
+	{
+		var page = new BindableFoundationStructsTestPage();
+		var rectTextBlock = page.RectTextBlock;
+
+		// Verify binding to Rect.Width works
+		page.TestRect = new Rect(10, 20, 100, 200);
+		Assert.AreEqual(100.0, rectTextBlock.Tag);
+
+		// Verify binding updates when property changes
+		page.TestRect = new Rect(0, 0, 250, 300);
+		Assert.AreEqual(250.0, rectTextBlock.Tag);
+	}
+
+	[TestMethod]
+	[RunsOnUIThread]
+	public void When_Binding_To_Size_Property()
+	{
+		var page = new BindableFoundationStructsTestPage();
+		var sizeTextBlock = page.SizeTextBlock;
+
+		// Verify binding to Size.Height works
+		page.TestSize = new Size(100, 200);
+		Assert.AreEqual(200.0, sizeTextBlock.Tag);
+
+		// Verify binding updates when property changes
+		page.TestSize = new Size(50, 150);
+		Assert.AreEqual(150.0, sizeTextBlock.Tag);
+	}
+
+	[TestMethod]
+	[RunsOnUIThread]
+	public void When_Binding_To_Point_Property()
+	{
+		var page = new BindableFoundationStructsTestPage();
+		var pointTextBlock = page.PointTextBlock;
+
+		// Verify binding to Point.X works
+		page.TestPoint = new Point(10, 20);
+		Assert.AreEqual(10.0, pointTextBlock.Tag);
+
+		// Verify binding updates when property changes
+		page.TestPoint = new Point(50, 60);
+		Assert.AreEqual(50.0, pointTextBlock.Tag);
+	}
+}

src/Uno.UI/DataBinding/BindingPropertyHelper.cs

@@ -1358,7 +1358,7 @@ private static void UnsetValueUnsetter(object unused) { }
 		/// </summary>
 		/// <remarks>This method needs to be aligned with the symbols query in BindableTypeProvidersSourceGenerator.</remarks>
 		private static bool IsValidMetadataProviderType(Type type)
-			=> type.IsPublic && type.IsClass;
+			=> type.IsPublic && (type.IsClass || type.IsValueType);
 	}
 }
 #endif