make all former LegacyManiaElement subclasses use extension method

Remove LegacyManiaElement

osu.Game.Rulesets.Mania/Skinning/LegacyHitTarget.cs

@@ -14,7 +14,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Rulesets.Mania.Skinning
 {
-    public class LegacyHitTarget : LegacyManiaElement
+    public class LegacyHitTarget : CompositeDrawable
     {
         private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();
 
@@ -28,13 +28,13 @@ namespace osu.Game.Rulesets.Mania.Skinning
         [BackgroundDependencyLoader]
         private void load(ISkinSource skin, IScrollingInfo scrollingInfo)
         {
-            string targetImage = GetManiaSkinConfig<string>(skin, LegacyManiaSkinConfigurationLookups.HitTargetImage)?.Value
+            string targetImage = skin.GetManiaSkinConfig<string>(LegacyManiaSkinConfigurationLookups.HitTargetImage)?.Value
                                  ?? "mania-stage-hint";
 
-            bool showJudgementLine = GetManiaSkinConfig<bool>(skin, LegacyManiaSkinConfigurationLookups.ShowJudgementLine)?.Value
+            bool showJudgementLine = skin.GetManiaSkinConfig<bool>(LegacyManiaSkinConfigurationLookups.ShowJudgementLine)?.Value
                                      ?? true;
 
-            Color4 lineColour = GetManiaSkinConfig<Color4>(skin, LegacyManiaSkinConfigurationLookups.JudgementLineColour)?.Value
+            Color4 lineColour = skin.GetManiaSkinConfig<Color4>(LegacyManiaSkinConfigurationLookups.JudgementLineColour)?.Value
                                 ?? Color4.White;
 
             InternalChild = directionContainer = new Container

osu.Game.Rulesets.Mania/Skinning/LegacyManiaColumnElement.cs

@@ -13,7 +13,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
     /// <summary>
     /// A <see cref="CompositeDrawable"/> which is placed somewhere within a <see cref="Column"/>.
     /// </summary>
-    public class LegacyManiaColumnElement : LegacyManiaElement
+    public class LegacyManiaColumnElement : CompositeDrawable
     {
         [Resolved]
         protected Column Column { get; private set; }
@@ -42,7 +42,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
             }
         }
 
-        protected override IBindable<T> GetManiaSkinConfig<T>(ISkin skin, LegacyManiaSkinConfigurationLookups lookup, int? index = null)
+        protected IBindable<T> GetManiaSkinConfig<T>(ISkin skin, LegacyManiaSkinConfigurationLookups lookup, int? index = null)
-            => base.GetManiaSkinConfig<T>(skin, lookup, index ?? Column.Index);
+            => skin.GetManiaSkinConfig<T>(lookup, index ?? Column.Index);
     }
 }

osu.Game.Rulesets.Mania/Skinning/LegacyManiaElement.cs

@@ -1,25 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using osu.Framework.Bindables;
-using osu.Framework.Graphics.Containers;
-using osu.Game.Skinning;
-
-namespace osu.Game.Rulesets.Mania.Skinning
-{
-    /// <summary>
-    /// A mania legacy skin element.
-    /// </summary>
-    public class LegacyManiaElement : CompositeDrawable
-    {
-        /// <summary>
-        /// Retrieve a per-column-count skin configuration.
-        /// </summary>
-        /// <param name="skin">The skin from which configuration is retrieved.</param>
-        /// <param name="lookup">The value to retrieve.</param>
-        /// <param name="index">If not null, denotes the index of the column to which the entry applies.</param>
-        protected virtual IBindable<T> GetManiaSkinConfig<T>(ISkin skin, LegacyManiaSkinConfigurationLookups lookup, int? index = null)
-            => skin.GetConfig<ManiaSkinConfigurationLookup, T>(
-                new ManiaSkinConfigurationLookup(lookup, index));
-    }
-}

osu.Game.Rulesets.Mania/Skinning/LegacyStageBackground.cs

@@ -3,13 +3,14 @@
 
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Sprites;
 using osu.Game.Skinning;
 using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Skinning
 {
-    public class LegacyStageBackground : LegacyManiaElement
+    public class LegacyStageBackground : CompositeDrawable
     {
         private Drawable leftSprite;
         private Drawable rightSprite;
@@ -22,10 +23,10 @@ namespace osu.Game.Rulesets.Mania.Skinning
         [BackgroundDependencyLoader]
         private void load(ISkinSource skin)
         {
-            string leftImage = GetManiaSkinConfig<string>(skin, LegacyManiaSkinConfigurationLookups.LeftStageImage)?.Value
+            string leftImage = skin.GetManiaSkinConfig<string>(LegacyManiaSkinConfigurationLookups.LeftStageImage)?.Value
                                ?? "mania-stage-left";
 
-            string rightImage = GetManiaSkinConfig<string>(skin, LegacyManiaSkinConfigurationLookups.RightStageImage)?.Value
+            string rightImage = skin.GetManiaSkinConfig<string>(LegacyManiaSkinConfigurationLookups.RightStageImage)?.Value
                                 ?? "mania-stage-right";
 
             InternalChildren = new[]

osu.Game.Rulesets.Mania/Skinning/LegacyStageForeground.cs

@@ -4,13 +4,14 @@
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Game.Rulesets.UI.Scrolling;
 using osu.Game.Skinning;
 using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Skinning
 {
-    public class LegacyStageForeground : LegacyManiaElement
+    public class LegacyStageForeground : CompositeDrawable
     {
         private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();
 
@@ -24,7 +25,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
         [BackgroundDependencyLoader]
         private void load(ISkinSource skin, IScrollingInfo scrollingInfo)
         {
-            string bottomImage = GetManiaSkinConfig<string>(skin, LegacyManiaSkinConfigurationLookups.BottomStageImage)?.Value
+            string bottomImage = skin.GetManiaSkinConfig<string>(LegacyManiaSkinConfigurationLookups.BottomStageImage)?.Value
                                  ?? "mania-stage-bottom";
 
             sprite = skin.GetAnimation(bottomImage, true, true)?.With(d =>