Renamed ISetter as SetterBase.

Allows us to hide the mechanics of initializing a setter.

src/Avalonia.Base/Styling/ISetter.cs

@@ -1,24 +0,0 @@
-using System;
-using Avalonia.Metadata;
-
-namespace Avalonia.Styling
-{
-    /// <summary>
-    /// Represents a setter for a <see cref="Style"/>.
-    /// </summary>
-    [NotClientImplementable]
-    public interface ISetter
-    {
-        /// <summary>
-        /// Instances a setter on a control.
-        /// </summary>
-        /// <param name="styleInstance">The style which contains the setter.</param>
-        /// <param name="target">The control.</param>
-        /// <returns>An <see cref="ISetterInstance"/>.</returns>
-        /// <remarks>
-        /// This method should return an <see cref="ISetterInstance"/> which can be used to apply
-        /// the setter to the specified control.
-        /// </remarks>
-        ISetterInstance Instance(IStyleInstance styleInstance, StyledElement target);
-    }
-}

src/Avalonia.Base/Styling/ISetterInstance.cs

@@ -3,7 +3,7 @@
 namespace Avalonia.Styling
 {
     /// <summary>
-    /// Represents an <see cref="ISetter"/> that has been instanced on a control.
+    /// Represents a <see cref="Setter"/> that has been instanced on a control.
     /// </summary>
     [Unstable]
     public interface ISetterInstance

src/Avalonia.Base/Styling/ISetterValue.cs

@@ -3,13 +3,13 @@
 namespace Avalonia.Styling
 {
     /// <summary>
-    /// Customizes the behavior of a class when added as a value to an <see cref="ISetter"/>.
+    /// Customizes the behavior of a class when added as a value to a <see cref="SetterBase"/>.
     /// </summary>
     public interface ISetterValue
     {
         /// <summary>
         /// Notifies that the object has been added as a setter value.
         /// </summary>
-        void Initialize(ISetter setter);
+        void Initialize(SetterBase setter);
     }
 }

src/Avalonia.Base/Styling/Setter.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Styling
     /// A <see cref="Setter"/> is used to set a <see cref="AvaloniaProperty"/> value on a
     /// <see cref="AvaloniaObject"/> depending on a condition.
     /// </remarks>
-    public class Setter : ISetter, IValueEntry, ISetterInstance, IAnimationSetter
+    public class Setter : SetterBase, IValueEntry, ISetterInstance, IAnimationSetter
     {
         private object? _value;
         private DirectPropertySetterInstance? _direct;
@@ -66,7 +66,7 @@ namespace Avalonia.Styling
         void IValueEntry.Unsubscribe() { }
 
         [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = TrimmingMessages.ImplicitTypeConvertionSupressWarningMessage)]
-        ISetterInstance ISetter.Instance(IStyleInstance instance, StyledElement target)
+        internal override ISetterInstance Instance(IStyleInstance instance, StyledElement target)
         {
             if (target is not AvaloniaObject ao)
                 throw new InvalidOperationException("Don't know how to instance a style on this type.");

src/Avalonia.Base/Styling/SetterBase.cs

@@ -0,0 +1,12 @@
+namespace Avalonia.Styling
+{
+    /// <summary>
+    /// Represents the base class for value setters.
+    /// </summary>
+    public abstract class SetterBase
+    {
+        internal abstract ISetterInstance Instance(
+            IStyleInstance styleInstance,
+            StyledElement target);
+    }
+}

src/Avalonia.Base/Styling/StyleBase.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Styling
         private IResourceHost? _owner;
         private StyleChildren? _children;
         private IResourceDictionary? _resources;
-        private List<ISetter>? _setters;
+        private List<SetterBase>? _setters;
         private List<IAnimation>? _animations;
         private StyleInstance? _sharedInstance;
 
@@ -60,7 +60,7 @@ namespace Avalonia.Styling
             }
         }
 
-        public IList<ISetter> Setters => _setters ??= new List<ISetter>();
+        public IList<SetterBase> Setters => _setters ??= new();
         public IList<IAnimation> Animations => _animations ??= new List<IAnimation>();
 
         bool IResourceNode.HasResources => _resources?.Count > 0;
@@ -69,7 +69,7 @@ namespace Avalonia.Styling
         internal bool HasChildren => _children?.Count > 0;
         internal bool HasSettersOrAnimations => _setters?.Count > 0 || _animations?.Count > 0;
 
-        public void Add(ISetter setter) => Setters.Add(setter);
+        public void Add(SetterBase setter) => Setters.Add(setter);
         public void Add(IStyle style) => Children.Add(style);
 
         public event EventHandler? OwnerChanged;

src/Avalonia.Controls/ContextMenu.cs

@@ -285,7 +285,7 @@ namespace Avalonia.Controls
             }
         }
 
-        void ISetterValue.Initialize(ISetter setter)
+        void ISetterValue.Initialize(SetterBase setter)
         {
             // ContextMenu can be assigned to the ContextMenu property in a setter. This overrides
             // the behavior defined in Control which requires controls to be wrapped in a <template>.

src/Avalonia.Controls/Control.cs

@@ -213,7 +213,7 @@ namespace Avalonia.Controls
         bool IDataTemplateHost.IsDataTemplatesInitialized => _dataTemplates != null;
 
         /// <inheritdoc/>
-        void ISetterValue.Initialize(ISetter setter)
+        void ISetterValue.Initialize(SetterBase setter)
         {
             if (setter is Setter s && s.Property == ContextFlyoutProperty)
             {

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs

@@ -125,7 +125,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 var selfType = context.ParentNodes().OfType<XamlAstConstructableObjectNode>().First().Type.GetClrType();
                 
                 // When using self bindings with setters we need to change target type to resolved selector type.
-                if (context.GetAvaloniaTypes().ISetter.IsAssignableFrom(selfType))
+                if (context.GetAvaloniaTypes().SetterBase.IsAssignableFrom(selfType))
                 {
                     selfType = context.ParentNodes().OfType<AvaloniaXamlIlTargetTypeMetadataNode>().First().TargetType.GetClrType();
                 }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs

@@ -104,7 +104,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType TextDecorationCollection { get; }
         public IXamlType TextDecorations { get; }
         public IXamlType TextTrimming { get; }
-        public IXamlType ISetter { get; }
+        public IXamlType SetterBase { get; }
         public IXamlType IStyle { get; }
         public IXamlType StyleInclude { get; }
         public IXamlType ResourceInclude { get; }
@@ -244,7 +244,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             TextDecorationCollection = cfg.TypeSystem.GetType("Avalonia.Media.TextDecorationCollection");
             TextDecorations = cfg.TypeSystem.GetType("Avalonia.Media.TextDecorations");
             TextTrimming = cfg.TypeSystem.GetType("Avalonia.Media.TextTrimming");
-            ISetter = cfg.TypeSystem.GetType("Avalonia.Styling.ISetter");
+            SetterBase = cfg.TypeSystem.GetType("Avalonia.Styling.SetterBase");
             IStyle = cfg.TypeSystem.GetType("Avalonia.Styling.IStyle");
             StyleInclude = cfg.TypeSystem.GetType("Avalonia.Markup.Xaml.Styling.StyleInclude");
             ResourceInclude = cfg.TypeSystem.GetType("Avalonia.Markup.Xaml.Styling.ResourceInclude");

src/Markup/Avalonia.Markup/Data/TemplateBinding.cs

@@ -109,7 +109,7 @@ namespace Avalonia.Data
         }
 
         /// <inheritdoc/>
-        void ISetterValue.Initialize(ISetter setter) => _isSetterValue = true;
+        void ISetterValue.Initialize(SetterBase setter) => _isSetterValue = true;
 
         protected override void Subscribed()
         {