From 40c3ef4f58edd07a28324d5c4fc9c8a2097ea196 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wies=C5=82aw=20S=CC=8Colte=CC=81s?=
 <wieslaw.soltes@gmail.com>
Date: Tue, 6 May 2025 12:04:14 +0200
Subject: [PATCH] Add IAddChild implementation too StyleBase

---
 src/Avalonia.Base/Styling/StyleBase.cs | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Base/Styling/StyleBase.cs b/src/Avalonia.Base/Styling/StyleBase.cs
index 3b12fda731..fc293f4bda 100644
--- a/src/Avalonia.Base/Styling/StyleBase.cs
+++ b/src/Avalonia.Base/Styling/StyleBase.cs
@@ -11,7 +11,7 @@ namespace Avalonia.Styling
     /// <summary>
     /// Base class for <see cref="Style"/> and <see cref="ControlTheme"/>.
     /// </summary>
-    public abstract class StyleBase : AvaloniaObject, IStyle, IResourceProvider
+    public abstract class StyleBase : AvaloniaObject, IStyle, IResourceProvider, IAddChild, IAddChild<IStyle>, IAddChild<SetterBase>
     {
         private IResourceHost? _owner;
         private StyleChildren? _children;
@@ -72,6 +72,25 @@ namespace Avalonia.Styling
         public void Add(SetterBase setter) => Setters.Add(setter);
         public void Add(IStyle style) => Children.Add(style);
 
+        void IAddChild.AddChild(object child)
+        {
+            switch (child)
+            {
+                case SetterBase setter:
+                    Setters.Add(setter);
+                    break;
+                case IStyle style:
+                    Children.Add(style);
+                    break;
+                default:
+                    throw new InvalidOperationException($"Cannot add {child.GetType()} to a style.");
+            }
+        }
+
+        void IAddChild<SetterBase>.AddChild(SetterBase setter) => Setters.Add(setter); 
+
+        void IAddChild<IStyle>.AddChild(IStyle style) => Children.Add(style);
+
         public event EventHandler? OwnerChanged;
 
         public bool TryGetResource(object key, ThemeVariant? themeVariant, out object? result)