Implement `IOverlayManager` in `ScreenTestScene`

osu.Game/Tests/Visual/ScreenTestScene.cs

@@ -1,12 +1,15 @@
 // 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 System;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Development;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Logging;
 using osu.Framework.Testing;
+using osu.Game.Graphics;
 using osu.Game.Overlays;
 using osu.Game.Screens;
 
@@ -15,11 +18,12 @@ namespace osu.Game.Tests.Visual
     /// <summary>
     /// A test case which can be used to test a screen (that relies on OnEntering being called to execute startup instructions).
     /// </summary>
-    public abstract class ScreenTestScene : OsuManualInputManagerTestScene
+    public abstract class ScreenTestScene : OsuManualInputManagerTestScene, IOverlayManager
     {
         protected readonly OsuScreenStack Stack;
 
         private readonly Container content;
+        private readonly Container overlayContent;
 
         protected override Container<Drawable> Content => content;
 
@@ -36,7 +40,11 @@ protected ScreenTestScene()
                     RelativeSizeAxes = Axes.Both
                 },
                 content = new Container { RelativeSizeAxes = Axes.Both },
-                DialogOverlay = new DialogOverlay()
+                overlayContent = new Container
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Child = DialogOverlay = new DialogOverlay()
+                }
             });
 
             Stack.ScreenPushed += (lastScreen, newScreen) => Logger.Log($"{nameof(ScreenTestScene)} screen changed → {newScreen}");
@@ -65,5 +73,26 @@ private void addExitAllScreensStep()
                 return false;
             });
         }
+
+        #region IOverlayManager
+
+        IBindable<OverlayActivation> IOverlayManager.OverlayActivationMode { get; } = new Bindable<OverlayActivation>(OverlayActivation.All);
+
+        // in the blocking methods below it is important to be careful about threading (e.g. use `Expire()` rather than `Remove()`, and schedule transforms),
+        // because in the worst case the clean-up methods could be called from async disposal.
+
+        IDisposable IOverlayManager.RegisterBlockingOverlay(OverlayContainer overlayContainer)
+        {
+            overlayContent.Add(overlayContainer);
+            return new InvokeOnDisposal(() => overlayContainer.Expire());
+        }
+
+        void IOverlayManager.ShowBlockingOverlay(OverlayContainer overlay)
+            => Schedule(() => Stack.FadeColour(OsuColour.Gray(0.5f), 500, Easing.OutQuint));
+
+        void IOverlayManager.HideBlockingOverlay(OverlayContainer overlay)
+            => Schedule(() => Stack.FadeColour(Colour4.White, 500, Easing.OutQuint));
+
+        #endregion
     }
 }