Merge pull request #34958 from smoogipoo/fix-skin-editor-initial-state

Fix mangled initial undo state on fresh skins

osu.Game/Overlays/SkinEditor/SkinEditor.cs

@@ -391,10 +391,10 @@ namespace osu.Game.Overlays.SkinEditor
                 return;
             }
 
-            if (skinComponentsContainer.IsLoaded)
+            if (skinComponentsContainer.ComponentsLoaded)
                 bindChangeHandler(skinComponentsContainer);
             else
-                skinComponentsContainer.OnLoadComplete += d => Schedule(() => bindChangeHandler((SkinnableContainer)d));
+                skinComponentsContainer.OnComponentsLoaded += onComponentsLoaded;
 
             content.Child = new SkinBlueprintContainer(skinComponentsContainer);
 
@@ -428,6 +428,13 @@ namespace osu.Game.Overlays.SkinEditor
                 RequestPlacement = requestPlacement
             });
 
+            void onComponentsLoaded(Drawable d)
+            {
+                SkinnableContainer container = (SkinnableContainer)d;
+                container.OnComponentsLoaded -= onComponentsLoaded;
+                Schedule(() => bindChangeHandler(container));
+            }
+
             void requestPlacement(Type type)
             {
                 if (!(Activator.CreateInstance(type) is ISerialisableDrawable component))

osu.Game/Skinning/SkinnableContainer.cs

@@ -21,6 +21,11 @@ namespace osu.Game.Skinning
     /// </remarks>
     public partial class SkinnableContainer : SkinReloadableDrawable, ISerialisableDrawableContainer
     {
+        /// <summary>
+        /// Invoked when the skinnable components of this container finish loading.
+        /// </summary>
+        public event Action<Drawable>? OnComponentsLoaded;
+
         private Container? content;
 
         /// <summary>
@@ -67,6 +72,7 @@ namespace osu.Game.Skinning
                 AddInternal(wrapper);
                 components.AddRange(wrapper.Children.OfType<ISerialisableDrawable>());
                 ComponentsLoaded = true;
+                OnComponentsLoaded?.Invoke(this);
             }, (cancellationSource = new CancellationTokenSource()).Token);
         }
 
@@ -106,5 +112,12 @@ namespace osu.Game.Skinning
 
             Reload();
         }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+
+            OnComponentsLoaded = null;
+        }
     }
 }