Add structure for legacy hit explosions

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

@@ -0,0 +1,45 @@
+// 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.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Rulesets.UI.Scrolling;
+
+namespace osu.Game.Rulesets.Mania.Skinning
+{
+    public class LegacyHitExplosion : LegacyManiaColumnElement
+    {
+        private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();
+
+        private Drawable explosion;
+
+        [BackgroundDependencyLoader]
+        private void load(IScrollingInfo scrollingInfo)
+        {
+            InternalChild = explosion = new Sprite
+            {
+            };
+
+            direction.BindTo(scrollingInfo.Direction);
+            direction.BindValueChanged(onDirectionChanged, true);
+
+            // Todo: LightingN
+            // Todo: LightingL
+        }
+
+        private void onDirectionChanged(ValueChangedEvent<ScrollingDirection> obj)
+        {
+            throw new System.NotImplementedException();
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            lighting.FadeInFromZero(80)
+                    .Then().FadeOut(120);
+        }
+    }
+}