Move music global action handling to an own component

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

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)
+            {
+            }
+        }
+    }
+}