Merge IResourceHost2 into IResourceHost (#20576)

* Merge IResourceHost2 into IResourceHost

* Update API suppressions

api/Avalonia.nupkg.xml

@@ -97,6 +97,12 @@
     <Left>baseline/Avalonia/lib/netstandard2.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/netstandard2.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>F:Avalonia.Controls.ResourcesChangedEventArgs.Empty</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>F:Avalonia.Media.DrawingImage.ViewboxProperty</Target>
@@ -109,6 +115,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.ResourcesChangedEventArgs.#ctor</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Input.IKeyboardNavigationHandler.Move(Avalonia.Input.IInputElement,Avalonia.Input.NavigationDirection,Avalonia.Input.KeyModifiers)</Target>
@@ -487,6 +499,12 @@
     <Left>baseline/Avalonia/lib/net6.0/Avalonia.Dialogs.dll</Left>
     <Right>current/Avalonia/lib/net6.0/Avalonia.Dialogs.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>F:Avalonia.Controls.ResourcesChangedEventArgs.Empty</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>F:Avalonia.Media.DrawingImage.ViewboxProperty</Target>
@@ -499,6 +517,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.ResourcesChangedEventArgs.#ctor</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Input.IKeyboardNavigationHandler.Move(Avalonia.Input.IInputElement,Avalonia.Input.NavigationDirection,Avalonia.Input.KeyModifiers)</Target>
@@ -1201,6 +1225,18 @@
     <Left>baseline/Avalonia/lib/netstandard2.0/Avalonia.OpenGL.dll</Left>
     <Right>current/Avalonia/lib/netstandard2.0/Avalonia.OpenGL.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0007</DiagnosticId>
+    <Target>T:Avalonia.Controls.ResourcesChangedEventArgs</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0007</DiagnosticId>
+    <Target>T:Avalonia.Controls.ResourcesChangedEventArgs</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Media.StreamGeometryContext</Target>
@@ -1225,12 +1261,24 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0009</DiagnosticId>
+    <Target>T:Avalonia.Controls.ResourcesChangedEventArgs</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0009</DiagnosticId>
     <Target>T:Avalonia.Platform.Screen</Target>
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0009</DiagnosticId>
+    <Target>T:Avalonia.Controls.ResourcesChangedEventArgs</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0009</DiagnosticId>
     <Target>T:Avalonia.Platform.Screen</Target>

src/Avalonia.Base/Controls/IResourceHost.cs

@@ -29,12 +29,4 @@ namespace Avalonia.Controls
         /// </remarks>
         void NotifyHostedResourcesChanged(ResourcesChangedEventArgs e);
     }
-
-    // TODO12: merge with IResourceHost
-    internal interface IResourceHost2 : IResourceHost
-    {
-        event EventHandler<ResourcesChangedToken> ResourcesChanged2;
-
-        void NotifyHostedResourcesChanged(ResourcesChangedToken token);
-    }
 }

src/Avalonia.Base/Controls/ResourceDictionary.cs

@@ -358,7 +358,7 @@ namespace Avalonia.Controls
 
             if (hasResources)
             {
-                owner.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+                owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
             }
         }
 
@@ -385,7 +385,7 @@ namespace Avalonia.Controls
 
             if (hasResources)
             {
-                owner.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+                owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
             }
         }
 

src/Avalonia.Base/Controls/ResourceNodeExtensions.cs

@@ -158,7 +158,7 @@ namespace Avalonia.Controls
 
             protected override void Initialize()
             {
-                _target.SubscribeToResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _target.ResourcesChanged += ResourcesChanged;
 
                 if (_target is IThemeVariantHost themeVariantHost)
                 {
@@ -168,7 +168,7 @@ namespace Avalonia.Controls
 
             protected override void Deinitialize()
             {
-                _target.UnsubscribeFromResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _target.ResourcesChanged -= ResourcesChanged;
 
                 if (_target is IThemeVariantHost themeVariantHost)
                 {
@@ -186,11 +186,6 @@ namespace Avalonia.Controls
                 PublishNext(GetValue());
             }
 
-            private void ResourcesChanged2(object? sender, ResourcesChangedToken token)
-            {
-                PublishNext(GetValue());
-            }
-
             private void ActualThemeVariantChanged(object? sender, EventArgs e)
             {
                 PublishNext(GetValue());
@@ -230,7 +225,7 @@ namespace Avalonia.Controls
                 _target.OwnerChanged += OwnerChanged;
                 _owner = _target.Owner;
 
-                _owner?.SubscribeToResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _owner?.ResourcesChanged += ResourcesChanged;
 
                 if (_overrideThemeVariant is null && _owner is IThemeVariantHost themeVariantHost)
                 {
@@ -242,7 +237,7 @@ namespace Avalonia.Controls
             {
                 _target.OwnerChanged -= OwnerChanged;
 
-                _owner?.UnsubscribeFromResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _owner?.ResourcesChanged -= ResourcesChanged;
 
                 if (_overrideThemeVariant is null && _owner is IThemeVariantHost themeVariantHost)
                 {
@@ -270,7 +265,7 @@ namespace Avalonia.Controls
 
             private void OwnerChanged(object? sender, EventArgs e)
             {
-                _owner?.UnsubscribeFromResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _owner?.ResourcesChanged -= ResourcesChanged;
 
                 if (_overrideThemeVariant is null && _owner is IThemeVariantHost themeVariantHost)
                 {
@@ -279,7 +274,7 @@ namespace Avalonia.Controls
 
                 _owner = _target.Owner;
 
-                _owner?.SubscribeToResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                _owner?.ResourcesChanged += ResourcesChanged;
 
                 if (_overrideThemeVariant is null && _owner is IThemeVariantHost themeVariantHost2)
                 {
@@ -299,11 +294,6 @@ namespace Avalonia.Controls
                 PublishNext();
             }
 
-            private void ResourcesChanged2(object? sender, ResourcesChangedToken token)
-            {
-                PublishNext();
-            }
-
             private object? GetValue()
             {
                 var theme = _overrideThemeVariant ?? (_target.Owner as IThemeVariantHost)?.ActualThemeVariant; 

src/Avalonia.Base/Controls/ResourceProvider.cs

@@ -45,7 +45,7 @@ public abstract class ResourceProvider : AvaloniaObject, IResourceProvider
 
     protected void RaiseResourcesChanged()
     {
-        Owner?.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+        Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
     }
 
     /// <summary>
@@ -57,7 +57,7 @@ public abstract class ResourceProvider : AvaloniaObject, IResourceProvider
     {
         if (HasResources)
         {
-            owner.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+            owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
         }
     }
 
@@ -70,7 +70,7 @@ public abstract class ResourceProvider : AvaloniaObject, IResourceProvider
     {
         if (HasResources)
         {
-            owner.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+            owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
         }
     }
 

src/Avalonia.Base/Controls/ResourcesChangedEventArgs.cs

@@ -1,10 +1,24 @@
-using System;
+using System.Threading;
 
-namespace Avalonia.Controls
+namespace Avalonia.Controls;
+
+/// <summary>
+/// Represents the event arguments of <see cref="IResourceHost.ResourcesChanged"/>.
+/// The <see cref="SequenceNumber"/> identifies the changes.
+/// </summary>
+/// <param name="SequenceNumber">The sequence number used to identify the changes.</param>
+/// <remarks>
+/// For performance reasons, this type is a struct.
+/// Avoid using a default instance of this type or its default constructor, call <see cref="Create"/> instead.
+/// </remarks>
+public readonly record struct ResourcesChangedEventArgs(int SequenceNumber)
 {
-    // TODO12: change this to be a struct, remove ResourcesChangedToken
+    private static int s_lastSequenceNumber;
-    public class ResourcesChangedEventArgs : EventArgs
+
-    {
+    /// <summary>
-        public static new readonly ResourcesChangedEventArgs Empty = new ResourcesChangedEventArgs();
+    /// Creates a new instance of <see cref="ResourcesChangedEventArgs"/> with an auto-incremented sequence number.
-    }
+    /// </summary>
+    /// <returns></returns>
+    public static ResourcesChangedEventArgs Create()
+        => new(Interlocked.Increment(ref s_lastSequenceNumber));
 }

src/Avalonia.Base/Controls/ResourcesChangedHelper.cs

@@ -1,45 +0,0 @@
-using System;
-using Avalonia.LogicalTree;
-
-namespace Avalonia.Controls;
-
-internal static class ResourcesChangedHelper
-{
-    internal static void NotifyHostedResourcesChanged(this IResourceHost host, ResourcesChangedToken token)
-    {
-        if (host is IResourceHost2 host2)
-            host2.NotifyHostedResourcesChanged(token);
-        else
-            host.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
-    }
-
-    internal static void NotifyResourcesChanged(this ILogical logical, ResourcesChangedToken token)
-    {
-        if (logical is StyledElement styledElement)
-            styledElement.NotifyResourcesChanged(token);
-        else
-            logical.NotifyResourcesChanged(ResourcesChangedEventArgs.Empty);
-    }
-
-    internal static void SubscribeToResourcesChanged(
-        this IResourceHost host,
-        EventHandler<ResourcesChangedEventArgs> handler,
-        EventHandler<ResourcesChangedToken> handler2)
-    {
-        if (host is IResourceHost2 host2)
-            host2.ResourcesChanged2 += handler2;
-        else
-            host.ResourcesChanged += handler;
-    }
-
-    internal static void UnsubscribeFromResourcesChanged(
-        this IResourceHost host,
-        EventHandler<ResourcesChangedEventArgs> handler,
-        EventHandler<ResourcesChangedToken> handler2)
-    {
-        if (host is IResourceHost2 host2)
-            host2.ResourcesChanged2 -= handler2;
-        else
-            host.ResourcesChanged -= handler;
-    }
-}

src/Avalonia.Base/Controls/ResourcesChangedToken.cs

@@ -1,11 +0,0 @@
-using System.Threading;
-
-namespace Avalonia.Controls;
-
-internal record struct ResourcesChangedToken(int SequenceNumber)
-{
-    private static int s_lastSequenceNumber;
-
-    public static ResourcesChangedToken Create()
-        => new(Interlocked.Increment(ref s_lastSequenceNumber));
-}

src/Avalonia.Base/StyledElement.cs

@@ -29,7 +29,7 @@ namespace Avalonia
         IDataContextProvider, 
         ILogical,
         IThemeVariantHost,
-        IResourceHost2,
+        IResourceHost,
         IStyleHost,
         ISetLogicalParent,
         ISetInheritanceParent,
@@ -94,8 +94,7 @@ namespace Avalonia
         private AvaloniaObject? _templatedParent;
         private bool _dataContextUpdating;
         private ControlTheme? _implicitTheme;
-        private EventHandler<ResourcesChangedToken>? _resourcesChanged2;
+        private ResourcesChangedEventArgs _lastResourcesChangedEventArgs;
-        private ResourcesChangedToken _lastResourcesChangedToken;
 
         /// <summary>
         /// Initializes static members of the <see cref="StyledElement"/> class.
@@ -150,12 +149,6 @@ namespace Avalonia
         /// </summary>
         public event EventHandler<ResourcesChangedEventArgs>? ResourcesChanged;
 
-        event EventHandler<ResourcesChangedToken>? IResourceHost2.ResourcesChanged2
-        {
-            add => _resourcesChanged2 += value;
-            remove => _resourcesChanged2 -= value;
-        }
-
         /// <inheritdoc />
         public event EventHandler? ActualThemeVariantChanged;
         
@@ -437,14 +430,11 @@ namespace Avalonia
 
         /// <inheritdoc/>
         void ILogical.NotifyResourcesChanged(ResourcesChangedEventArgs e)
-            => NotifyResourcesChanged(ResourcesChangedToken.Create());
+            => NotifyResourcesChanged(e);
 
         /// <inheritdoc/>
         void IResourceHost.NotifyHostedResourcesChanged(ResourcesChangedEventArgs e)
-            => NotifyResourcesChanged(ResourcesChangedToken.Create());
+            => NotifyResourcesChanged(e);
-
-        void IResourceHost2.NotifyHostedResourcesChanged(ResourcesChangedToken token)
-            => NotifyResourcesChanged(token);
 
         /// <inheritdoc/>
         public bool TryGetResource(object key, ThemeVariant? theme, out object? value)
@@ -499,7 +489,7 @@ namespace Avalonia
                     // non-rooted control beacuse it's unlikely that dynamic resources need to be 
                     // correct until the control is added to the tree, and it causes a *lot* of
                     // notifications.
-                    NotifyResourcesChanged(ResourcesChangedToken.Create());
+                    NotifyResourcesChanged(ResourcesChangedEventArgs.Create());
                 }
 
                 RaisePropertyChanged(ParentProperty, old, Parent);
@@ -552,8 +542,8 @@ namespace Avalonia
         /// <summary>
         /// Notifies child controls that a change has been made to resources that apply to them.
         /// </summary>
-        /// <param name="token">The change token.</param>
+        /// <param name="e">The change token.</param>
-        internal virtual void NotifyChildResourcesChanged(ResourcesChangedToken token)
+        internal virtual void NotifyChildResourcesChanged(ResourcesChangedEventArgs e)
         {
             if (_logicalChildren is object)
             {
@@ -563,7 +553,7 @@ namespace Avalonia
                 {
                     for (var i = 0; i < count; ++i)
                     {
-                        _logicalChildren[i].NotifyResourcesChanged(token);
+                        _logicalChildren[i].NotifyResourcesChanged(e);
                     }
                 }
             }
@@ -895,7 +885,7 @@ namespace Avalonia
 
                 ReevaluateImplicitTheme();
                 ApplyStyling();
-                NotifyResourcesChanged(ResourcesChangedToken.Create(), propagate: false);
+                NotifyResourcesChanged(ResourcesChangedEventArgs.Create(), propagate: false);
 
                 OnAttachedToLogicalTree(e);
                 AttachedToLogicalTree?.Invoke(this, e);
@@ -999,23 +989,22 @@ namespace Avalonia
         }
 
         internal void NotifyResourcesChanged(
-            ResourcesChangedToken token,
+            ResourcesChangedEventArgs e,
             bool propagate = true)
         {
             // We already got a notification for this element, ignore.
-            if (token.Equals(_lastResourcesChangedToken))
+            if (e.Equals(_lastResourcesChangedEventArgs))
             {
                 return;
             }
 
-            _lastResourcesChangedToken = token;
+            _lastResourcesChangedEventArgs = e;
 
-            _resourcesChanged2?.Invoke(this, token);
+            ResourcesChanged?.Invoke(this, e);
-            ResourcesChanged?.Invoke(this, ResourcesChangedEventArgs.Empty);
 
             if (propagate)
             {
-                NotifyChildResourcesChanged(token);
+                NotifyChildResourcesChanged(e);
             }
         }
 

src/Avalonia.Base/Styling/StyleBase.cs

@@ -54,7 +54,7 @@ namespace Avalonia.Styling
 
                     if (hadResources || _resources.HasResources)
                     {
-                        Owner.NotifyHostedResourcesChanged(ResourcesChangedToken.Create());
+                        Owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
                     }
                 }
             }

src/Avalonia.Controls/Application.cs

@@ -30,7 +30,7 @@ namespace Avalonia
     /// method.
     /// - Tracks the lifetime of the application.
     /// </remarks>
-    public class Application : AvaloniaObject, IDataContextProvider, IGlobalDataTemplates, IGlobalStyles, IThemeVariantHost, IResourceHost2, IApplicationPlatformEvents, IOptionalFeatureProvider
+    public class Application : AvaloniaObject, IDataContextProvider, IGlobalDataTemplates, IGlobalStyles, IThemeVariantHost, IResourceHost, IApplicationPlatformEvents, IOptionalFeatureProvider
     {
         /// <summary>
         /// The application-global data templates.
@@ -43,7 +43,6 @@ namespace Avalonia
         private Action<IReadOnlyList<IStyle>>? _stylesRemoved;
         private IApplicationLifetime? _applicationLifetime;
         private bool _setupCompleted;
-        private EventHandler<ResourcesChangedToken>? _resourcesChanged2;
 
         /// <summary>
         /// Defines the <see cref="DataContext"/> property.
@@ -62,12 +61,6 @@ namespace Avalonia
         /// <inheritdoc/>
         public event EventHandler<ResourcesChangedEventArgs>? ResourcesChanged;
 
-        event EventHandler<ResourcesChangedToken>? IResourceHost2.ResourcesChanged2
-        {
-            add => _resourcesChanged2 += value;
-            remove => _resourcesChanged2 -= value;
-        }
-
         [Obsolete("Use Application.Current.TryGetFeature<IActivatableLifetime>() instead.")]
         public event EventHandler<UrlOpenedEventArgs>? UrlsOpened;
 
@@ -239,16 +232,9 @@ namespace Avalonia
 
         void IResourceHost.NotifyHostedResourcesChanged(ResourcesChangedEventArgs e)
         {
-            _resourcesChanged2?.Invoke(this, ResourcesChangedToken.Create());
             ResourcesChanged?.Invoke(this, e);
         }
 
-        void IResourceHost2.NotifyHostedResourcesChanged(ResourcesChangedToken token)
-        {
-            _resourcesChanged2?.Invoke(this, token);
-            ResourcesChanged?.Invoke(this, ResourcesChangedEventArgs.Empty);
-        }
-
         void IStyleHost.StylesAdded(IReadOnlyList<IStyle> styles)
         {
             _stylesAdded?.Invoke(styles);

src/Avalonia.Controls/Primitives/TemplatedControl.cs

@@ -362,7 +362,7 @@ namespace Avalonia.Controls.Primitives
         }
 
         /// <inheritdoc />
-        internal sealed override void NotifyChildResourcesChanged(ResourcesChangedToken token)
+        internal sealed override void NotifyChildResourcesChanged(ResourcesChangedEventArgs e)
         {
             var count = VisualChildren.Count;
 
@@ -370,11 +370,11 @@ namespace Avalonia.Controls.Primitives
             {
                 if (VisualChildren[i] is ILogical logical)
                 {
-                    logical.NotifyResourcesChanged(token);
+                    logical.NotifyResourcesChanged(e);
                 }
             }
 
-            base.NotifyChildResourcesChanged(token);
+            base.NotifyChildResourcesChanged(e);
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/Primitives/VisualLayerManager.cs

@@ -118,12 +118,12 @@ namespace Avalonia.Controls.Primitives
         }
 
         /// <inheritdoc />
-        internal override void NotifyChildResourcesChanged(ResourcesChangedToken token)
+        internal override void NotifyChildResourcesChanged(ResourcesChangedEventArgs e)
         {
             foreach (var l in _layers)
-                l.NotifyResourcesChanged(token);
+                l.NotifyResourcesChanged(e);
 
-            base.NotifyChildResourcesChanged(token);
+            base.NotifyChildResourcesChanged(e);
         }
 
         /// <inheritdoc />

src/Avalonia.Controls/TopLevel.cs

@@ -121,12 +121,6 @@ namespace Avalonia.Controls
                 (s, h) => s.ResourcesChanged -= h
             );
 
-        private static readonly WeakEvent<IResourceHost2, ResourcesChangedToken>
-            ResourcesChanged2WeakEvent = WeakEvent.Register<IResourceHost2, ResourcesChangedToken>(
-                (s, h) => s.ResourcesChanged2 += h,
-                (s, h) => s.ResourcesChanged2 -= h
-            );
-
         private readonly IInputManager? _inputManager;
         private readonly IToolTipService? _tooltipService;
         private readonly IAccessKeyHandler? _accessKeyHandler;
@@ -144,7 +138,6 @@ namespace Avalonia.Controls
         private ILayoutManager? _layoutManager;
         private Border? _transparencyFallbackBorder;
         private TargetWeakEventSubscriber<TopLevel, ResourcesChangedEventArgs>? _resourcesChangesSubscriber;
-        private TargetWeakEventSubscriber<TopLevel, ResourcesChangedToken>? _resourcesChangesSubscriber2;
         private IStorageProvider? _storageProvider;
         private Screens? _screens;
         private LayoutDiagnosticBridge? _layoutDiagnosticBridge;
@@ -270,25 +263,15 @@ namespace Avalonia.Controls
 
             var stylingParent = ((IStyleHost)this).StylingParent;
 
-            if (stylingParent is IResourceHost2 applicationResources2)
+            if (stylingParent is IResourceHost applicationResources2)
             {
-                _resourcesChangesSubscriber2 = new TargetWeakEventSubscriber<TopLevel, ResourcesChangedToken>(
+                _resourcesChangesSubscriber = new TargetWeakEventSubscriber<TopLevel, ResourcesChangedEventArgs>(
                     this, static (target, _, _, token) =>
                     {
                         target.NotifyResourcesChanged(token);
                     });
 
-                ResourcesChanged2WeakEvent.Subscribe(applicationResources2, _resourcesChangesSubscriber2);
+                ResourcesChangedWeakEvent.Subscribe(applicationResources2, _resourcesChangesSubscriber);
-            }
-            else if (stylingParent is IResourceHost applicationResources)
-            {
-                _resourcesChangesSubscriber = new TargetWeakEventSubscriber<TopLevel, ResourcesChangedEventArgs>(
-                    this, static (target, _, _, _) =>
-                    {
-                        target.NotifyResourcesChanged(ResourcesChangedToken.Create());
-                    });
-
-                ResourcesChangedWeakEvent.Subscribe(applicationResources, _resourcesChangesSubscriber);
             }
 
             impl.LostFocus += PlatformImpl_LostFocus;

src/Avalonia.Themes.Fluent/Accents/SystemAccentColors.cs

@@ -154,6 +154,6 @@ internal sealed class SystemAccentColors : ResourceProvider
     private void PlatformSettingsOnColorValuesChanged(object? sender, PlatformColorValues e)
     {
         _invalidateColors = true;
-        Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
+        Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
     }
 }

src/Avalonia.Themes.Fluent/FluentTheme.xaml.cs

@@ -63,7 +63,7 @@ namespace Avalonia.Themes.Fluent
 
             if (change.Property == DensityStyleProperty)
             {
-                Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
+                Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Create());
             }
         }
 

src/Markup/Avalonia.Markup.Xaml/Data/DynamicResourceExpression.cs

@@ -84,8 +84,6 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         private void ResourcesChanged(object? sender, ResourcesChangedEventArgs e) => PublishValue();
 
-        private void ResourcesChanged2(object? sender, ResourcesChangedToken token) => PublishValue();
-
         private void ActualThemeVariantChanged(object? sender, EventArgs e)
         {
             if (!IsRunning)
@@ -134,7 +132,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
         {
             if (host is not null)
             {
-                host.SubscribeToResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                host.ResourcesChanged += ResourcesChanged;
 
                 if (!_overrideThemeVariant && _host is IThemeVariantHost themeVariantHost)
                 {
@@ -148,7 +146,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
         {
             if (host is not null)
             {
-                host.UnsubscribeFromResourcesChanged(ResourcesChanged, ResourcesChanged2);
+                host.ResourcesChanged -= ResourcesChanged;
 
                 if (!_overrideThemeVariant && _host is IThemeVariantHost themeVariantHost)
                     themeVariantHost.ActualThemeVariantChanged -= ActualThemeVariantChanged;