From 935fbe7cc627f78deba63f33f1b0057d0470eb7b Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 6 Jul 2021 16:41:48 +0900
Subject: [PATCH] Remove double fetch/binding of parent source

---
 .../Skinning/RulesetSkinProvidingContainer.cs | 17 +++----
 osu.Game/Skinning/SkinProvidingContainer.cs   | 44 ++++++++++++-------
 2 files changed, 35 insertions(+), 26 deletions(-)

diff --git a/osu.Game/Skinning/RulesetSkinProvidingContainer.cs b/osu.Game/Skinning/RulesetSkinProvidingContainer.cs
index 4dea1ff51e..d5be5d9394 100644
--- a/osu.Game/Skinning/RulesetSkinProvidingContainer.cs
+++ b/osu.Game/Skinning/RulesetSkinProvidingContainer.cs
@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
@@ -47,22 +48,19 @@ namespace osu.Game.Skinning
             };
         }
 
-        private ISkinSource parentSource;
-
         private ResourceStoreBackedSkin rulesetResourcesSkin;
 
         protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
         {
-            parentSource = parent.Get<ISkinSource>();
-            parentSource.SourceChanged += OnSourceChanged;
-
             if (Ruleset.CreateResourceStore() is IResourceStore<byte[]> resources)
                 rulesetResourcesSkin = new ResourceStoreBackedSkin(resources, parent.Get<GameHost>(), parent.Get<AudioManager>());
 
+            var dependencies = base.CreateChildDependencies(parent);
+
             // ensure sources are populated and ready for use before childrens' asynchronous load flow.
             UpdateSkinSources();
 
-            return base.CreateChildDependencies(parent);
+            return dependencies;
         }
 
         protected override void OnSourceChanged()
@@ -77,7 +75,9 @@ namespace osu.Game.Skinning
 
             var skinSources = new List<ISkin>();
 
-            foreach (var skin in parentSource.AllSources)
+            Debug.Assert(ParentSource != null);
+
+            foreach (var skin in ParentSource.AllSources)
             {
                 switch (skin)
                 {
@@ -121,9 +121,6 @@ namespace osu.Game.Skinning
         {
             base.Dispose(isDisposing);
 
-            if (parentSource != null)
-                parentSource.SourceChanged -= OnSourceChanged;
-
             rulesetResourcesSkin?.Dispose();
         }
     }
diff --git a/osu.Game/Skinning/SkinProvidingContainer.cs b/osu.Game/Skinning/SkinProvidingContainer.cs
index b1ada54a26..a1e71502b9 100644
--- a/osu.Game/Skinning/SkinProvidingContainer.cs
+++ b/osu.Game/Skinning/SkinProvidingContainer.cs
@@ -35,7 +35,7 @@ namespace osu.Game.Skinning
         private readonly Dictionary<ISkin, DisableableSkinSource> skinSources = new Dictionary<ISkin, DisableableSkinSource>();
 
         [CanBeNull]
-        private ISkinSource fallbackSource;
+        protected ISkinSource ParentSource { get; private set; }
 
         /// <summary>
         /// Whether falling back to parent <see cref="ISkinSource"/>s is allowed in this container.
@@ -101,7 +101,10 @@ namespace osu.Game.Skinning
                     return skin;
             }
 
-            return fallbackSource?.FindProvider(lookupFunction);
+            if (!AllowFallingBackToParent)
+                return null;
+
+            return ParentSource?.FindProvider(lookupFunction);
         }
 
         public IEnumerable<ISkin> AllSources
@@ -111,9 +114,9 @@ namespace osu.Game.Skinning
                 foreach (var skin in SkinSources)
                     yield return skin;
 
-                if (fallbackSource != null)
+                if (AllowFallingBackToParent && ParentSource != null)
                 {
-                    foreach (var skin in fallbackSource.AllSources)
+                    foreach (var skin in ParentSource.AllSources)
                         yield return skin;
                 }
             }
@@ -128,7 +131,10 @@ namespace osu.Game.Skinning
                     return sourceDrawable;
             }
 
-            return fallbackSource?.GetDrawableComponent(component);
+            if (!AllowFallingBackToParent)
+                return null;
+
+            return ParentSource?.GetDrawableComponent(component);
         }
 
         public Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT)
@@ -140,7 +146,10 @@ namespace osu.Game.Skinning
                     return sourceTexture;
             }
 
-            return fallbackSource?.GetTexture(componentName, wrapModeS, wrapModeT);
+            if (!AllowFallingBackToParent)
+                return null;
+
+            return ParentSource?.GetTexture(componentName, wrapModeS, wrapModeT);
         }
 
         public ISample GetSample(ISampleInfo sampleInfo)
@@ -152,7 +161,10 @@ namespace osu.Game.Skinning
                     return sourceSample;
             }
 
-            return fallbackSource?.GetSample(sampleInfo);
+            if (!AllowFallingBackToParent)
+                return null;
+
+            return ParentSource?.GetSample(sampleInfo);
         }
 
         public IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup)
@@ -164,7 +176,10 @@ namespace osu.Game.Skinning
                     return bindable;
             }
 
-            return fallbackSource?.GetConfig<TLookup, TValue>(lookup);
+            if (!AllowFallingBackToParent)
+                return null;
+
+            return ParentSource?.GetConfig<TLookup, TValue>(lookup);
         }
 
         protected virtual void OnSourceChanged() => SourceChanged?.Invoke();
@@ -173,12 +188,9 @@ namespace osu.Game.Skinning
         {
             var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
 
-            if (AllowFallingBackToParent)
-            {
-                fallbackSource = dependencies.Get<ISkinSource>();
-                if (fallbackSource != null)
-                    fallbackSource.SourceChanged += OnSourceChanged;
-            }
+            ParentSource = dependencies.Get<ISkinSource>();
+            if (ParentSource != null)
+                ParentSource.SourceChanged += OnSourceChanged;
 
             dependencies.CacheAs<ISkinSource>(this);
 
@@ -192,8 +204,8 @@ namespace osu.Game.Skinning
 
             base.Dispose(isDisposing);
 
-            if (fallbackSource != null)
-                fallbackSource.SourceChanged -= OnSourceChanged;
+            if (ParentSource != null)
+                ParentSource.SourceChanged -= OnSourceChanged;
 
             foreach (var source in SkinSources.OfType<ISkinSource>())
                 source.SourceChanged -= OnSourceChanged;