Move music global action handling to an own component

Due to requiring components that are added at an OsuGame-level

osu.Game/OsuGame.cs

@@ -38,6 +38,7 @@ using osu.Game.Input;
 using osu.Game.Overlays.Notifications;
 using osu.Game.Input.Bindings;
 using osu.Game.Online.Chat;
+using osu.Game.Overlays.Music;
 using osu.Game.Skinning;
 using osuTK.Graphics;
 using osu.Game.Overlays.Volume;
@@ -647,6 +648,7 @@ namespace osu.Game
             chatOverlay.State.ValueChanged += state => channelManager.HighPollRate.Value = state.NewValue == Visibility.Visible;
 
             Add(externalLinkOpener = new ExternalLinkOpener());
+            Add(new MusicActionHandler());
 
             // side overlays which cancel each other.
             var singleDisplaySideOverlays = new OverlayContainer[] { Settings, notifications };

osu.Game/Overlays/Music/MusicActionHandler.cs

@@ -0,0 +1,82 @@
+// 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.Input.Bindings;
+using osu.Game.Beatmaps;
+using osu.Game.Input.Bindings;
+using osu.Game.Overlays.OSD;
+
+namespace osu.Game.Overlays.Music
+{
+    /// <summary>
+    /// Handles <see cref="GlobalAction"/> relating to music playback, and displays a <see cref="Toast"/> via the cached <see cref="OnScreenDisplay"/> accordingly.
+    /// </summary>
+    public class MusicActionHandler : Component, IKeyBindingHandler<GlobalAction>
+    {
+        [Resolved]
+        private IBindable<WorkingBeatmap> beatmap { get; set; }
+
+        [Resolved]
+        private MusicController musicController { get; set; }
+
+        [Resolved]
+        private OnScreenDisplay onScreenDisplay { get; set; }
+
+        public bool OnPressed(GlobalAction action)
+        {
+            if (beatmap.Disabled)
+                return false;
+
+            switch (action)
+            {
+                case GlobalAction.MusicPlay:
+                    if (musicController.TogglePause())
+                        onScreenDisplay.Display(new MusicActionToast(musicController.IsPlaying ? "Play track" : "Pause track"));
+
+                    return true;
+
+                case GlobalAction.MusicNext:
+                    musicController.NextTrack(() =>
+                    {
+                        onScreenDisplay.Display(new MusicActionToast("Next track"));
+                    }).RunTask();
+
+                    return true;
+
+                case GlobalAction.MusicPrev:
+                    musicController.PreviousTrack(res =>
+                    {
+                        switch (res)
+                        {
+                            case PreviousTrackResult.Restart:
+                                onScreenDisplay.Display(new MusicActionToast("Restart track"));
+                                break;
+
+                            case PreviousTrackResult.Previous:
+                                onScreenDisplay.Display(new MusicActionToast("Previous track"));
+                                break;
+                        }
+                    }).RunTask();
+
+                    return true;
+            }
+
+            return false;
+        }
+
+        public void OnReleased(GlobalAction action)
+        {
+        }
+
+        private class MusicActionToast : Toast
+        {
+            public MusicActionToast(string action)
+                : base("Music Playback", action, string.Empty)
+            {
+            }
+        }
+    }
+}

osu.Game/Overlays/MusicController.cs

@@ -12,12 +12,9 @@ using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Audio;
 using osu.Framework.Graphics.Containers;
-using osu.Framework.Input.Bindings;
 using osu.Framework.Utils;
 using osu.Framework.Threading;
 using osu.Game.Beatmaps;
-using osu.Game.Input.Bindings;
-using osu.Game.Overlays.OSD;
 using osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Overlays
@@ -25,7 +22,7 @@ namespace osu.Game.Overlays
     /// <summary>
     /// Handles playback of the global music track.
     /// </summary>
-    public class MusicController : CompositeDrawable, IKeyBindingHandler<GlobalAction>
+    public class MusicController : CompositeDrawable
     {
         [Resolved]
         private BeatmapManager beatmaps { get; set; }
@@ -62,9 +59,6 @@ namespace osu.Game.Overlays
         [Resolved]
         private IBindable<IReadOnlyList<Mod>> mods { get; set; }
 
-        [Resolved(canBeNull: true)]
-        private OnScreenDisplay onScreenDisplay { get; set; }
-
         [NotNull]
         public DrawableTrack CurrentTrack { get; private set; } = new DrawableTrack(new TrackVirtual(1000));
 
@@ -428,54 +422,6 @@ namespace osu.Game.Overlays
                     mod.ApplyToTrack(CurrentTrack);
             }
         }
-
-        public bool OnPressed(GlobalAction action)
-        {
-            if (beatmap.Disabled)
-                return false;
-
-            switch (action)
-            {
-                case GlobalAction.MusicPlay:
-                    if (TogglePause())
-                        onScreenDisplay?.Display(new MusicControllerToast(IsPlaying ? "Play track" : "Pause track"));
-                    return true;
-
-                case GlobalAction.MusicNext:
-                    if (next())
-                        onScreenDisplay?.Display(new MusicControllerToast("Next track"));
-
-                    return true;
-
-                case GlobalAction.MusicPrev:
-                    switch (prev())
-                    {
-                        case PreviousTrackResult.Restart:
-                            onScreenDisplay?.Display(new MusicControllerToast("Restart track"));
-                            break;
-
-                        case PreviousTrackResult.Previous:
-                            onScreenDisplay?.Display(new MusicControllerToast("Previous track"));
-                            break;
-                    }
-
-                    return true;
-            }
-
-            return false;
-        }
-
-        public void OnReleased(GlobalAction action)
-        {
-        }
-
-        public class MusicControllerToast : Toast
-        {
-            public MusicControllerToast(string action)
-                : base("Music Playback", action, string.Empty)
-            {
-            }
-        }
     }
 
     public enum TrackChangeDirection