Use a receptor model instead

osu.Game.Tests/Visual/UserInterface/TestSceneBackButton.cs

@@ -22,6 +22,7 @@ namespace osu.Game.Tests.Visual.UserInterface
         public TestSceneBackButton()
         {
             BackButton button;
+            BackButton.BackButtonReceptor receptor = new BackButton.BackButtonReceptor();
 
             Child = new Container
             {
@@ -31,12 +32,13 @@ namespace osu.Game.Tests.Visual.UserInterface
                 Masking = true,
                 Children = new Drawable[]
                 {
+                    receptor,
                     new Box
                     {
                         RelativeSizeAxes = Axes.Both,
                         Colour = Color4.SlateGray
                     },
-                    button = new BackButton
+                    button = new BackButton(receptor)
                     {
                         Anchor = Anchor.BottomLeft,
                         Origin = Anchor.BottomLeft,

osu.Game/Graphics/UserInterface/BackButton.cs

@@ -10,14 +10,16 @@ using osu.Game.Input.Bindings;
 
 namespace osu.Game.Graphics.UserInterface
 {
-    public class BackButton : VisibilityContainer, IKeyBindingHandler<GlobalAction>
+    public class BackButton : VisibilityContainer
     {
         public Action Action;
 
         private readonly TwoLayerButton button;
 
-        public BackButton()
+        public BackButton(BackButtonReceptor receptor)
         {
+            receptor.OnBackPressed += () => Action.Invoke();
+
             Size = TwoLayerButton.SIZE_EXTENDED;
 
             Child = button = new TwoLayerButton
@@ -37,19 +39,6 @@ namespace osu.Game.Graphics.UserInterface
             button.HoverColour = colours.PinkDark;
         }
 
-        public bool OnPressed(GlobalAction action)
-        {
-            if (action == GlobalAction.Back)
-            {
-                Action?.Invoke();
-                return true;
-            }
-
-            return false;
-        }
-
-        public bool OnReleased(GlobalAction action) => action == GlobalAction.Back;
-
         protected override void PopIn()
         {
             button.MoveToX(0, 400, Easing.OutQuint);
@@ -61,5 +50,24 @@ namespace osu.Game.Graphics.UserInterface
             button.MoveToX(-TwoLayerButton.SIZE_EXTENDED.X / 2, 400, Easing.OutQuint);
             button.FadeOut(400, Easing.OutQuint);
         }
+
+        public class BackButtonReceptor : Drawable, IKeyBindingHandler<GlobalAction>
+        {
+            public Action OnBackPressed;
+
+            public bool OnPressed(GlobalAction action)
+            {
+                switch (action)
+                {
+                    case GlobalAction.Back:
+                        OnBackPressed.Invoke();
+                        return true;
+                }
+
+                return false;
+            }
+
+            public bool OnReleased(GlobalAction action) => action == GlobalAction.Back;
+        }
     }
 }

osu.Game/Input/Bindings/GlobalActionContainer.cs

@@ -7,7 +7,6 @@ using System.Linq;
 using osu.Framework.Graphics;
 using osu.Framework.Input;
 using osu.Framework.Input.Bindings;
-using osu.Game.Graphics.UserInterface;
 
 namespace osu.Game.Input.Bindings
 {
@@ -56,32 +55,8 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(new[] { InputKey.Control, InputKey.Minus }, GlobalAction.DecreaseScrollSpeed),
         };
 
-        protected override IEnumerable<Drawable> KeyBindingInputQueue
+        protected override IEnumerable<Drawable> KeyBindingInputQueue =>
-        {
+            handler == null ? base.KeyBindingInputQueue : base.KeyBindingInputQueue.Prepend(handler);
-            get
-            {
-                var queue = base.KeyBindingInputQueue.ToList();
-
-                if (handler != null)
-                    yield return handler;
-
-                BackButton backButton = null;
-
-                foreach (var drawable in queue)
-                {
-                    if (drawable is BackButton button)
-                    {
-                        backButton = button;
-                        continue;
-                    }
-
-                    yield return drawable;
-                }
-
-                if (backButton != null)
-                    yield return backButton;
-            }
-        }
     }
 
     public enum GlobalAction

osu.Game/OsuGame.cs

@@ -84,6 +84,8 @@ namespace osu.Game
         protected OsuScreenStack ScreenStack;
         protected BackButton BackButton;
 
+        private BackButton.BackButtonReceptor backButtonReceptor;
+
         private VolumeOverlay volume;
         private OsuLogo osuLogo;
 
@@ -407,8 +409,9 @@ namespace osu.Game
                     RelativeSizeAxes = Axes.Both,
                     Children = new Drawable[]
                     {
+                        backButtonReceptor = new BackButton.BackButtonReceptor(),
                         ScreenStack = new OsuScreenStack { RelativeSizeAxes = Axes.Both },
-                        BackButton = new BackButton
+                        BackButton = new BackButton(backButtonReceptor)
                         {
                             Anchor = Anchor.BottomLeft,
                             Origin = Anchor.BottomLeft,