Move user dim logic into UserDimContainer instead

osu.Game/Graphics/Containers/UserDimContainer.cs

@@ -0,0 +1,36 @@
+// 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.Configuration;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Configuration;
+using osuTK.Graphics;
+
+namespace osu.Game.Graphics.Containers
+{
+    public class UserDimContainer : Container
+    {
+        #region User Settings
+
+        protected Bindable<double> DimLevel;
+
+        #endregion
+
+        public Bindable<bool> EnableUserDim = new Bindable<bool>();
+
+        [BackgroundDependencyLoader]
+        private void load(OsuConfigManager config)
+        {
+            DimLevel = config.GetBindable<double>(OsuSetting.DimLevel);
+            EnableUserDim.ValueChanged  += _ => updateBackgroundDim();
+            DimLevel.ValueChanged  += _ => updateBackgroundDim();
+        }
+
+        private void updateBackgroundDim()
+        {
+            this.FadeColour(EnableUserDim ? OsuColour.Gray(1 - (float)DimLevel) : Color4.White, 800, Easing.OutQuint);
+        }
+    }
+}