[net11.0][XSG] Trimmable Styles

src/Controls/src/Build.Tasks/CompiledConverters/BindablePropertyConverter.cs

@@ -38,7 +38,7 @@ public FieldReference GetBindablePropertyFieldReference(string value, ILContext
 				{
 					if (parent.XmlType.IsOfAnyType(nameof(Trigger), nameof(DataTrigger), nameof(MultiTrigger), nameof(Style)))
 					{
-						typeName = GetTargetTypeName(parent);
+						typeName = GetTargetTypeFromElement(parent, node.NamespaceResolver, (IXmlLineInfo)node);
 					}
 					else if (parent.XmlType.IsOfAnyType(nameof(VisualState)))
 					{
@@ -47,7 +47,7 @@ public FieldReference GetBindablePropertyFieldReference(string value, ILContext
 				}
 				else if (node.Parent is ElementNode { XmlType: XmlType xt1 } && xt1.IsOfAnyType(nameof(Trigger)))
 				{
-					typeName = GetTargetTypeName(node.Parent);
+					typeName = GetTargetTypeFromElement(node.Parent as ElementNode, node.NamespaceResolver, (IXmlLineInfo)node);
 				}
 				propertyName = parts[0];
 			}
@@ -71,38 +71,44 @@ public FieldReference GetBindablePropertyFieldReference(string value, ILContext
 			if (bpRef == null)
 				throw new BuildException(PropertyResolution, node, null, propertyName, typeRef.Name);
 			return bpRef;
-
-			static XmlType GetTargetTypeName(INode node)
-			{
-				var targetType = ((node as ElementNode).Properties[new XmlName("", "TargetType")] as ValueNode)?.Value as string;
-				return TypeArgumentsParser.ParseSingle(targetType, node.NamespaceResolver, (IXmlLineInfo)node);
-			}
 		}
 
 		static XmlType FindTypeNameForVisualState(ElementNode parent, IXmlLineInfo lineInfo, ILContext context)
 		{
-			//1. parent is VisualState, don't check that
+			// 1. parent is VisualState, don't check that
 
-			//2. check that the VS is in a VSG
-			// if (!(parent.Parent is IElementNode target) || target.XmlType.NamespaceUri != XamlParser.MauiUri || target.XmlType.Name != nameof(VisualStateGroup))
+			// 2. check that the VS is in a VSG
 			if (parent.Parent is not ElementNode target || !target.XmlType.IsOfAnyType(nameof(VisualStateGroup)))
 				throw new XamlParseException($"Expected {nameof(VisualStateGroup)} but found {parent.Parent}", lineInfo);
 
-			//3. if the VSG is in a VSGL, skip that as it could be implicit
-			if (   target.Parent is ListNode
+			// 3. if the VSG is in a VSGL, skip that as it could be implicit
+			if (target.Parent is ListNode
 				|| target.Parent is ElementNode { XmlType: XmlType xt } && xt.IsOfAnyType(nameof(VisualStateGroupList)))
 				target = target.Parent.Parent as ElementNode;
 			else
 				target = target.Parent as ElementNode;
 
-			//4. target is now a Setter in a Style, or a VE
+			// 4. target is now a Setter in a Style, or a VE
 			if (target.XmlType.IsOfAnyType(nameof(Setter)))
-			{
-				var targetType = ((target?.Parent as ElementNode)?.Properties[new XmlName("", "TargetType")] as ValueNode)?.Value as string;
-				return TypeArgumentsParser.ParseSingle(targetType, parent.NamespaceResolver, lineInfo);
-			}
-			else
-				return target.XmlType;
+				return GetTargetTypeFromElement(target?.Parent as ElementNode, parent.NamespaceResolver, lineInfo);
+
+			return target.XmlType;
+		}
+
+		/// <summary>
+		/// Extracts the TargetType attribute from an element node and parses it as an XmlType.
+		/// Returns null if the element is null, has no TargetType, or TargetType is empty.
+		/// </summary>
+		static XmlType GetTargetTypeFromElement(ElementNode element, IXmlNamespaceResolver namespaceResolver, IXmlLineInfo lineInfo)
+		{
+			if (element?.Properties.TryGetValue(new XmlName("", "TargetType"), out var targetTypeNode) != true)
+				return null;
+
+			var targetType = (targetTypeNode as ValueNode)?.Value as string;
+			if (string.IsNullOrEmpty(targetType))
+				return null;
+
+			return TypeArgumentsParser.ParseSingle(targetType, namespaceResolver, lineInfo);
 		}
 
 		public static FieldReference GetBindablePropertyFieldReference(XamlCache cache, TypeReference typeRef, string propertyName, ModuleDefinition module)

src/Controls/src/Build.Tasks/CreateObjectVisitor.cs

@@ -20,6 +20,8 @@ class CreateObjectVisitor(ILContext context) : IXamlNodeVisitor
 		public bool StopOnDataTemplate => true;
 		public bool StopOnResourceDictionary => false;
 		public bool VisitNodeOnDataTemplate => false;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
 		public bool SkipChildren(INode node, INode parentNode) => false;
 
 		public bool IsResourceDictionary(ElementNode node)
@@ -29,6 +31,8 @@ public bool IsResourceDictionary(ElementNode node)
 				|| parentVar.VariableType.Resolve().BaseType?.FullName == "Microsoft.Maui.Controls.ResourceDictionary";
 		}
 
+		public bool IsStyle(ElementNode node) => false;
+
 		public void Visit(ValueNode node, INode parentNode)
 		{
 			Context.Values[node] = node.Value;

src/Controls/src/Build.Tasks/ExpandMarkupsVisitor.cs

@@ -22,6 +22,8 @@ class ExpandMarkupsVisitor(ILContext context) : IXamlNodeVisitor
 		public bool StopOnDataTemplate => false;
 		public bool StopOnResourceDictionary => false;
 		public bool VisitNodeOnDataTemplate => true;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
 		public bool SkipChildren(INode node, INode parentNode) => false;
 
 		public bool IsResourceDictionary(ElementNode node)
@@ -31,6 +33,8 @@ public bool IsResourceDictionary(ElementNode node)
 				|| parentVar.VariableType.Resolve().BaseType?.FullName == "Microsoft.Maui.Controls.ResourceDictionary";
 		}
 
+		public bool IsStyle(ElementNode node) => false;
+
 		public void Visit(ValueNode node, INode parentNode)
 		{
 		}

src/Controls/src/Build.Tasks/SetFieldVisitor.cs

@@ -12,6 +12,8 @@ class SetFieldVisitor(ILContext context) : IXamlNodeVisitor
 		public bool StopOnDataTemplate => true;
 		public bool StopOnResourceDictionary => false;
 		public bool VisitNodeOnDataTemplate => false;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
 		public bool SkipChildren(INode node, INode parentNode) => false;
 
 		public bool IsResourceDictionary(ElementNode node)
@@ -21,6 +23,8 @@ public bool IsResourceDictionary(ElementNode node)
 				|| parentVar.VariableType.Resolve().BaseType?.FullName == "Microsoft.Maui.Controls.ResourceDictionary";
 		}
 
+		public bool IsStyle(ElementNode node) => false;
+
 		public void Visit(ValueNode node, INode parentNode)
 		{
 			if (!IsXNameProperty(node, parentNode))

src/Controls/src/Build.Tasks/SetNamescopesAndRegisterNamesVisitor.cs

@@ -14,6 +14,8 @@ class SetNamescopesAndRegisterNamesVisitor(ILContext context) : IXamlNodeVisitor
 		public bool StopOnDataTemplate => true;
 		public bool StopOnResourceDictionary => false;
 		public bool VisitNodeOnDataTemplate => false;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
 		public bool SkipChildren(INode node, INode parentNode) => false;
 
 		public bool IsResourceDictionary(ElementNode node)
@@ -23,6 +25,8 @@ public bool IsResourceDictionary(ElementNode node)
 				|| parentVar.VariableType.Resolve().BaseType?.FullName == "Microsoft.Maui.Controls.ResourceDictionary";
 		}
 
+		public bool IsStyle(ElementNode node) => false;
+
 		public void Visit(ValueNode node, INode parentNode)
 		{
 			Context.Scopes[node] = Context.Scopes[parentNode];

src/Controls/src/Build.Tasks/SetPropertiesVisitor.cs

@@ -32,6 +32,8 @@ class SetPropertiesVisitor(ILContext context, bool stopOnResourceDictionary = fa
 		public TreeVisitingMode VisitingMode => TreeVisitingMode.BottomUp;
 		public bool StopOnDataTemplate => true;
 		public bool VisitNodeOnDataTemplate => true;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
 		public bool SkipChildren(INode node, INode parentNode) => false;
 
 		public bool IsResourceDictionary(ElementNode node)
@@ -41,6 +43,8 @@ public bool IsResourceDictionary(ElementNode node)
 				|| parentVar.VariableType.Resolve().BaseType?.FullName == "Microsoft.Maui.Controls.ResourceDictionary";
 		}
 
+		public bool IsStyle(ElementNode node) => false;
+
 		ModuleDefinition Module { get; } = context.Body.Method.Module;
 
 		// Track properties that have been set to detect duplicates

src/Controls/src/Build.Tasks/SetResourcesVisitor.cs

@@ -12,6 +12,10 @@ class SetResourcesVisitor(ILContext context) : IXamlNodeVisitor
 		public bool StopOnDataTemplate => true;
 		public bool StopOnResourceDictionary => false;
 		public bool VisitNodeOnDataTemplate => false;
+		public bool StopOnStyle => false;
+		public bool VisitNodeOnStyle => true;
+
+		public bool IsStyle(ElementNode node) => false;
 
 		public void Visit(ValueNode node, INode parentNode)
 		{

src/Controls/src/Core/IStyle.cs

@@ -1,11 +1,13 @@
-#nullable disable
 using System;
 
 namespace Microsoft.Maui.Controls
 {
 	interface IStyle
 	{
-		Type TargetType { get; }
+		/// <summary>
+		/// Gets the target type for this style. May return null for lazy styles if the type was trimmed.
+		/// </summary>
+		Type? TargetType { get; }
 
 		void Apply(BindableObject bindable, SetterSpecificity specificity);
 		void UnApply(BindableObject bindable);

src/Controls/src/Core/MergedStyle.cs

@@ -30,10 +30,12 @@ sealed class MergedStyle : IStyle
 
 		IList<string> _styleClass;
 
+		readonly Type _targetType;
+
 		public MergedStyle(Type targetType, BindableObject target)
 		{
 			Target = target;
-			TargetType = targetType;
+			_targetType = targetType;
 			// RegisterImplicitStyles handles the initial apply via OnImplicitStyleChanged -> SetStyle.
 			// An explicit Apply(Target) call here would double-attach event handlers when
 			// Application.Current.Resources already contains the implicit style (#24152).
@@ -47,8 +49,10 @@ public IStyle Style
 			{
 				if (_style == value)
 					return;
-				if (value != null && !value.TargetType.IsAssignableFrom(TargetType))
-					MauiLogger<Style>.Log(LogLevel.Warning, $"Style TargetType {value.TargetType.FullName} is not compatible with element target type {TargetType}");
+				if (value?.TargetType is Type styleTargetType && !styleTargetType.IsAssignableFrom(_targetType))
+				{
+					MauiLogger<Style>.Log(LogLevel.Warning, $"Style TargetType {styleTargetType.FullName} is not compatible with element target type {_targetType}");
+				}
 				SetStyle(ImplicitStyle, ClassStyles, value);
 			}
 		}
@@ -116,7 +120,7 @@ void Apply(BindableObject bindable)
 			Style?.Apply(bindable, new SetterSpecificity(SetterSpecificity.StyleLocal, 0, 0, 0));
 		}
 
-		public Type TargetType { get; }
+		public Type TargetType => _targetType;
 
 		public void UnApply(BindableObject bindable)
 		{
@@ -129,7 +133,7 @@ public void UnApply(BindableObject bindable)
 
 		void OnClassStyleChanged()
 		{
-			ClassStyles = _classStyleProperties.Select(p => (Target.GetValue(p) as IList<Style>)?.FirstOrDefault(s => s.CanBeAppliedTo(TargetType))).ToList();
+			ClassStyles = _classStyleProperties.Select(p => (Target.GetValue(p) as IList<Style>)?.FirstOrDefault(s => s.CanBeAppliedTo(_targetType))).ToList();
 		}
 
 		void OnImplicitStyleChanged()
@@ -155,7 +159,7 @@ void OnImplicitStyleChanged()
 
 		void RegisterImplicitStyles()
 		{
-			Type type = TargetType;
+			Type type = _targetType;
 			while (true)
 			{
 				BindableProperty implicitStyleProperty = BindableProperty.Create(nameof(ImplicitStyle), typeof(Style), typeof(NavigableElement), default(Style),

src/Controls/src/Core/PublicAPI/net-android/PublicAPI.Unshipped.txt

@@ -47,3 +47,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~override Microsoft.Maui.Controls.Handlers.Items.MauiRecyclerView<TItemsView, TAdapter, TItemsViewSource>.OnInterceptTouchEvent(Android.Views.MotionEvent e) -> bool
 ~override Microsoft.Maui.Controls.Handlers.Items.MauiRecyclerView<TItemsView, TAdapter, TItemsViewSource>.OnTouchEvent(Android.Views.MotionEvent e) -> bool
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/PublicAPI/net-ios/PublicAPI.Unshipped.txt

@@ -48,3 +48,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~const Microsoft.Maui.Controls.AppThemeBinding.AppThemeResource = "__MAUI_ApplicationTheme__" -> string
 ~override Microsoft.Maui.Controls.Platform.Compatibility.ShellFlyoutRenderer.ViewWillTransitionToSize(CoreGraphics.CGSize toSize, UIKit.IUIViewControllerTransitionCoordinator coordinator) -> void
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/PublicAPI/net-maccatalyst/PublicAPI.Unshipped.txt

@@ -48,3 +48,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~const Microsoft.Maui.Controls.AppThemeBinding.AppThemeResource = "__MAUI_ApplicationTheme__" -> string
 ~override Microsoft.Maui.Controls.Platform.Compatibility.ShellFlyoutRenderer.ViewWillTransitionToSize(CoreGraphics.CGSize toSize, UIKit.IUIViewControllerTransitionCoordinator coordinator) -> void
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/PublicAPI/net-tizen/PublicAPI.Unshipped.txt

@@ -45,3 +45,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~Microsoft.Maui.Controls.ResourceDictionary.AddFactory(string key, System.Func<object> factory, bool shared = true) -> void
 ~const Microsoft.Maui.Controls.AppThemeBinding.AppThemeResource = "__MAUI_ApplicationTheme__" -> string
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

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

@@ -45,3 +45,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~Microsoft.Maui.Controls.ResourceDictionary.AddFactory(string key, System.Func<object> factory, bool shared = true) -> void
 ~const Microsoft.Maui.Controls.AppThemeBinding.AppThemeResource = "__MAUI_ApplicationTheme__" -> string
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/PublicAPI/net/PublicAPI.Unshipped.txt

@@ -45,3 +45,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~Microsoft.Maui.Controls.ResourceDictionary.AddFactory(string key, System.Func<object> factory, bool shared = true) -> void
 ~const Microsoft.Maui.Controls.AppThemeBinding.AppThemeResource = "__MAUI_ApplicationTheme__" -> string
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/PublicAPI/netstandard/PublicAPI.Unshipped.txt

@@ -36,3 +36,5 @@ virtual Microsoft.Maui.Controls.LongPressingEventArgs.GetPosition(Microsoft.Maui
 ~Microsoft.Maui.Controls.ResourceDictionary.AddFactory(System.Type targetType, System.Func<Microsoft.Maui.Controls.Style> factory, bool shared = true) -> void
 ~Microsoft.Maui.Controls.ResourceDictionary.AddFactory(string key, System.Func<object> factory, bool shared = true) -> void
 ~static Microsoft.Maui.Controls.VisualStateManager.GetVisualStateGroups(Microsoft.Maui.Controls.VisualElement visualElement) -> Microsoft.Maui.Controls.VisualStateGroupList
+~Microsoft.Maui.Controls.Style.LazyInitialization.set -> void
+~Microsoft.Maui.Controls.Style.Style(string assemblyQualifiedTargetTypeName) -> void

src/Controls/src/Core/ResourceDictionary.cs

@@ -422,7 +422,7 @@ event EventHandler<ResourcesChangedEventArgs> IResourceDictionary.ValuesChanged
 		public void Add(Style style)
 		{
 			if (string.IsNullOrEmpty(style.Class))
-				Add(style.TargetType.FullName, style);
+				Add(style.TargetTypeFullName, style);
 			else
 			{
 				IList<Style> classes;