Add unread count to `INotificationOverlay` and fix toolbar button DI logic

osu.Game.Tests/Visual/Menus/TestSceneToolbar.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Linq;
+using Moq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -22,6 +23,17 @@ public class TestSceneToolbar : OsuManualInputManagerTestScene
         [Resolved]
         private IRulesetStore rulesets { get; set; }
 
+        private readonly Mock<INotificationOverlay> notifications = new Mock<INotificationOverlay>();
+
+        private readonly BindableInt unreadNotificationCount = new BindableInt();
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            Dependencies.CacheAs(notifications.Object);
+            notifications.SetupGet(n => n.UnreadCount).Returns(unreadNotificationCount);
+        }
+
         [SetUp]
         public void SetUp() => Schedule(() =>
         {
@@ -31,10 +43,6 @@ public void SetUp() => Schedule(() =>
         [Test]
         public void TestNotificationCounter()
         {
-            ToolbarNotificationButton notificationButton = null;
-
-            AddStep("retrieve notification button", () => notificationButton = toolbar.ChildrenOfType<ToolbarNotificationButton>().Single());
-
             setNotifications(1);
             setNotifications(2);
             setNotifications(3);
@@ -43,7 +51,7 @@ public void TestNotificationCounter()
 
             void setNotifications(int count)
                 => AddStep($"set notification count to {count}",
-                    () => notificationButton.NotificationCount.Value = count);
+                    () => unreadNotificationCount.Value = count);
         }
 
         [TestCase(false)]

osu.Game/Overlays/INotificationOverlay.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Game.Overlays.Notifications;
 
 namespace osu.Game.Overlays
@@ -22,5 +23,10 @@ public interface INotificationOverlay
         /// Hide the overlay, if it is currently visible.
         /// </summary>
         void Hide();
+
+        /// <summary>
+        /// Current number of unread notifications.
+        /// </summary>
+        IBindable<int> UnreadCount { get; }
     }
 }

osu.Game/Overlays/NotificationOverlay.cs

@@ -99,7 +99,9 @@ protected override void LoadComplete()
             OverlayActivationMode.BindValueChanged(_ => updateProcessingMode(), true);
         }
 
-        public readonly BindableInt UnreadCount = new BindableInt();
+        public IBindable<int> UnreadCount => unreadCount;
+
+        private readonly BindableInt unreadCount = new BindableInt();
 
         private int runningDepth;
 
@@ -180,7 +182,7 @@ private void playDebouncedSample(string sampleName)
 
         private void updateCounts()
         {
-            UnreadCount.Value = sections.Select(c => c.UnreadCount).Sum();
+            unreadCount.Value = sections.Select(c => c.UnreadCount).Sum();
         }
 
         private void markAllRead()

osu.Game/Overlays/Toolbar/ToolbarNotificationButton.cs

@@ -18,7 +18,7 @@ public class ToolbarNotificationButton : ToolbarOverlayToggleButton
     {
         protected override Anchor TooltipAnchor => Anchor.TopRight;
 
-        public BindableInt NotificationCount = new BindableInt();
+        public IBindable<int> NotificationCount = new BindableInt();
 
         private readonly CountCircle countDisplay;
 
@@ -36,10 +36,10 @@ public ToolbarNotificationButton()
             });
         }
 
-        [BackgroundDependencyLoader(true)]
+        [BackgroundDependencyLoader]
-        private void load(NotificationOverlay notificationOverlay)
+        private void load(INotificationOverlay notificationOverlay)
         {
-            StateContainer = notificationOverlay;
+            StateContainer = notificationOverlay as NotificationOverlay;
 
             if (notificationOverlay != null)
                 NotificationCount.BindTo(notificationOverlay.UnreadCount);