Merge branch 'master' into fix-taiko-whistle

osu.Game.Tests/Beatmaps/IO/ImportBeatmapTest.cs

@@ -156,8 +156,8 @@ namespace osu.Game.Tests.Beatmaps.IO
                     var manager = osu.Dependencies.Get<BeatmapManager>();
 
                     // ReSharper disable once AccessToModifiedClosure
-                    manager.ItemAdded += _ => Interlocked.Increment(ref itemAddRemoveFireCount);
+                    manager.ItemAdded.BindValueChanged(_ => Interlocked.Increment(ref itemAddRemoveFireCount));
-                    manager.ItemRemoved += _ => Interlocked.Increment(ref itemAddRemoveFireCount);
+                    manager.ItemRemoved.BindValueChanged(_ => Interlocked.Increment(ref itemAddRemoveFireCount));
 
                     var imported = await LoadOszIntoOsu(osu);
 

osu.Game/Beatmaps/BeatmapManager.cs

@@ -12,6 +12,7 @@ using System.Threading.Tasks;
 using Microsoft.EntityFrameworkCore;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Track;
+using osu.Framework.Bindables;
 using osu.Framework.Extensions;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Lists;
@@ -38,12 +39,16 @@ namespace osu.Game.Beatmaps
         /// <summary>
         /// Fired when a single difficulty has been hidden.
         /// </summary>
-        public event Action<BeatmapInfo> BeatmapHidden;
+        public IBindable<WeakReference<BeatmapInfo>> BeatmapHidden => beatmapHidden;
+
+        private readonly Bindable<WeakReference<BeatmapInfo>> beatmapHidden = new Bindable<WeakReference<BeatmapInfo>>();
 
         /// <summary>
         /// Fired when a single difficulty has been restored.
         /// </summary>
-        public event Action<BeatmapInfo> BeatmapRestored;
+        public IBindable<WeakReference<BeatmapInfo>> BeatmapRestored => beatmapRestored;
+
+        private readonly Bindable<WeakReference<BeatmapInfo>> beatmapRestored = new Bindable<WeakReference<BeatmapInfo>>();
 
         /// <summary>
         /// A default representation of a WorkingBeatmap to use when no beatmap is available.
@@ -74,8 +79,8 @@ namespace osu.Game.Beatmaps
             DefaultBeatmap = defaultBeatmap;
 
             beatmaps = (BeatmapStore)ModelStore;
-            beatmaps.BeatmapHidden += b => BeatmapHidden?.Invoke(b);
+            beatmaps.BeatmapHidden += b => beatmapHidden.Value = new WeakReference<BeatmapInfo>(b);
-            beatmaps.BeatmapRestored += b => BeatmapRestored?.Invoke(b);
+            beatmaps.BeatmapRestored += b => beatmapRestored.Value = new WeakReference<BeatmapInfo>(b);
 
             onlineLookupQueue = new BeatmapOnlineLookupQueue(api, storage);
             exportStorage = storage.GetStorageForDirectory("exports");

osu.Game/Database/ArchiveModelManager.cs

@@ -11,6 +11,7 @@ using Humanizer;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore;
 using osu.Framework;
+using osu.Framework.Bindables;
 using osu.Framework.Extensions;
 using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Logging;
@@ -56,13 +57,17 @@ namespace osu.Game.Database
         /// Fired when a new <typeparamref name="TModel"/> becomes available in the database.
         /// This is not guaranteed to run on the update thread.
         /// </summary>
-        public event Action<TModel> ItemAdded;
+        public IBindable<WeakReference<TModel>> ItemAdded => itemAdded;
+
+        private readonly Bindable<WeakReference<TModel>> itemAdded = new Bindable<WeakReference<TModel>>();
 
         /// <summary>
         /// Fired when a <typeparamref name="TModel"/> is removed from the database.
         /// This is not guaranteed to run on the update thread.
         /// </summary>
-        public event Action<TModel> ItemRemoved;
+        public IBindable<WeakReference<TModel>> ItemRemoved => itemRemoved;
+
+        private readonly Bindable<WeakReference<TModel>> itemRemoved = new Bindable<WeakReference<TModel>>();
 
         public virtual string[] HandledExtensions => new[] { ".zip" };
 
@@ -82,8 +87,8 @@ namespace osu.Game.Database
             ContextFactory = contextFactory;
 
             ModelStore = modelStore;
-            ModelStore.ItemAdded += item => handleEvent(() => ItemAdded?.Invoke(item));
+            ModelStore.ItemAdded += item => handleEvent(() => itemAdded.Value = new WeakReference<TModel>(item));
-            ModelStore.ItemRemoved += s => handleEvent(() => ItemRemoved?.Invoke(s));
+            ModelStore.ItemRemoved += item => handleEvent(() => itemRemoved.Value = new WeakReference<TModel>(item));
 
             Files = new FileStore(contextFactory, storage);
 

osu.Game/Database/DownloadableArchiveModelManager.cs

@@ -10,6 +10,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using osu.Framework.Bindables;
 
 namespace osu.Game.Database
 {
@@ -23,9 +24,13 @@ namespace osu.Game.Database
         where TModel : class, IHasFiles<TFileModel>, IHasPrimaryKey, ISoftDelete, IEquatable<TModel>
         where TFileModel : class, INamedFileInfo, new()
     {
-        public event Action<ArchiveDownloadRequest<TModel>> DownloadBegan;
+        public IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> DownloadBegan => downloadBegan;
 
-        public event Action<ArchiveDownloadRequest<TModel>> DownloadFailed;
+        private readonly Bindable<WeakReference<ArchiveDownloadRequest<TModel>>> downloadBegan = new Bindable<WeakReference<ArchiveDownloadRequest<TModel>>>();
+
+        public IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> DownloadFailed => downloadFailed;
+
+        private readonly Bindable<WeakReference<ArchiveDownloadRequest<TModel>>> downloadFailed = new Bindable<WeakReference<ArchiveDownloadRequest<TModel>>>();
 
         private readonly IAPIProvider api;
 
@@ -81,7 +86,7 @@ namespace osu.Game.Database
 
                     // for now a failed import will be marked as a failed download for simplicity.
                     if (!imported.Any())
-                        DownloadFailed?.Invoke(request);
+                        downloadFailed.Value = new WeakReference<ArchiveDownloadRequest<TModel>>(request);
 
                     currentDownloads.Remove(request);
                 }, TaskCreationOptions.LongRunning);
@@ -100,14 +105,14 @@ namespace osu.Game.Database
 
             api.PerformAsync(request);
 
-            DownloadBegan?.Invoke(request);
+            downloadBegan.Value = new WeakReference<ArchiveDownloadRequest<TModel>>(request);
             return true;
 
             void triggerFailure(Exception error)
             {
                 currentDownloads.Remove(request);
 
-                DownloadFailed?.Invoke(request);
+                downloadFailed.Value = new WeakReference<ArchiveDownloadRequest<TModel>>(request);
 
                 notification.State = ProgressNotificationState.Cancelled;
 

osu.Game/Database/IModelDownloader.cs

@@ -1,8 +1,9 @@
 // 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.Game.Online.API;
 using System;
+using osu.Game.Online.API;
+using osu.Framework.Bindables;
 
 namespace osu.Game.Database
 {
@@ -17,13 +18,13 @@ namespace osu.Game.Database
         /// Fired when a <typeparamref name="TModel"/> download begins.
         /// This is NOT run on the update thread and should be scheduled.
         /// </summary>
-        event Action<ArchiveDownloadRequest<TModel>> DownloadBegan;
+        IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> DownloadBegan { get; }
 
         /// <summary>
         /// Fired when a <typeparamref name="TModel"/> download is interrupted, either due to user cancellation or failure.
         /// This is NOT run on the update thread and should be scheduled.
         /// </summary>
-        event Action<ArchiveDownloadRequest<TModel>> DownloadFailed;
+        IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> DownloadFailed { get; }
 
         /// <summary>
         /// Checks whether a given <typeparamref name="TModel"/> is already available in the local store.

osu.Game/Database/IModelManager.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using osu.Framework.Bindables;
 
 namespace osu.Game.Database
 {
@@ -9,11 +10,11 @@ namespace osu.Game.Database
     /// Represents a model manager that publishes events when <typeparamref name="TModel"/>s are added or removed.
     /// </summary>
     /// <typeparam name="TModel">The model type.</typeparam>
-    public interface IModelManager<out TModel>
+    public interface IModelManager<TModel>
         where TModel : class
     {
-        event Action<TModel> ItemAdded;
+        IBindable<WeakReference<TModel>> ItemAdded { get; }
 
-        event Action<TModel> ItemRemoved;
+        IBindable<WeakReference<TModel>> ItemRemoved { get; }
     }
 }

osu.Game/Online/DownloadTrackingComposite.cs

@@ -34,6 +34,11 @@ namespace osu.Game.Online
             Model.Value = model;
         }
 
+        private IBindable<WeakReference<TModel>> managerAdded;
+        private IBindable<WeakReference<TModel>> managerRemoved;
+        private IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> managerDownloadBegan;
+        private IBindable<WeakReference<ArchiveDownloadRequest<TModel>>> managerDownloadFailed;
+
         [BackgroundDependencyLoader(true)]
         private void load()
         {
@@ -47,23 +52,39 @@ namespace osu.Game.Online
                     attachDownload(manager.GetExistingDownload(modelInfo.NewValue));
             }, true);
 
-            manager.DownloadBegan += downloadBegan;
+            managerDownloadBegan = manager.DownloadBegan.GetBoundCopy();
-            manager.DownloadFailed += downloadFailed;
+            managerDownloadBegan.BindValueChanged(downloadBegan);
-            manager.ItemAdded += itemAdded;
+            managerDownloadFailed = manager.DownloadFailed.GetBoundCopy();
-            manager.ItemRemoved += itemRemoved;
+            managerDownloadFailed.BindValueChanged(downloadFailed);
+            managerAdded = manager.ItemAdded.GetBoundCopy();
+            managerAdded.BindValueChanged(itemAdded);
+            managerRemoved = manager.ItemRemoved.GetBoundCopy();
+            managerRemoved.BindValueChanged(itemRemoved);
         }
 
-        private void downloadBegan(ArchiveDownloadRequest<TModel> request) => Schedule(() =>
+        private void downloadBegan(ValueChangedEvent<WeakReference<ArchiveDownloadRequest<TModel>>> weakRequest)
         {
-            if (request.Model.Equals(Model.Value))
+            if (weakRequest.NewValue.TryGetTarget(out var request))
-                attachDownload(request);
+            {
-        });
+                Schedule(() =>
+                {
+                    if (request.Model.Equals(Model.Value))
+                        attachDownload(request);
+                });
+            }
+        }
 
-        private void downloadFailed(ArchiveDownloadRequest<TModel> request) => Schedule(() =>
+        private void downloadFailed(ValueChangedEvent<WeakReference<ArchiveDownloadRequest<TModel>>> weakRequest)
         {
-            if (request.Model.Equals(Model.Value))
+            if (weakRequest.NewValue.TryGetTarget(out var request))
-                attachDownload(null);
+            {
-        });
+                Schedule(() =>
+                {
+                    if (request.Model.Equals(Model.Value))
+                        attachDownload(null);
+                });
+            }
+        }
 
         private ArchiveDownloadRequest<TModel> attachedRequest;
 
@@ -107,9 +128,17 @@ namespace osu.Game.Online
 
         private void onRequestFailure(Exception e) => Schedule(() => attachDownload(null));
 
-        private void itemAdded(TModel s) => setDownloadStateFromManager(s, DownloadState.LocallyAvailable);
+        private void itemAdded(ValueChangedEvent<WeakReference<TModel>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var item))
+                setDownloadStateFromManager(item, DownloadState.LocallyAvailable);
+        }
 
-        private void itemRemoved(TModel s) => setDownloadStateFromManager(s, DownloadState.NotDownloaded);
+        private void itemRemoved(ValueChangedEvent<WeakReference<TModel>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var item))
+                setDownloadStateFromManager(item, DownloadState.NotDownloaded);
+        }
 
         private void setDownloadStateFromManager(TModel s, DownloadState state) => Schedule(() =>
         {
@@ -125,14 +154,6 @@ namespace osu.Game.Online
         {
             base.Dispose(isDisposing);
 
-            if (manager != null)
-            {
-                manager.DownloadBegan -= downloadBegan;
-                manager.DownloadFailed -= downloadFailed;
-                manager.ItemAdded -= itemAdded;
-                manager.ItemRemoved -= itemRemoved;
-            }
-
             State.UnbindAll();
 
             attachDownload(null);

osu.Game/OsuGameBase.cs

@@ -186,8 +186,17 @@ namespace osu.Game
                 return ScoreManager.QueryScores(s => beatmapIds.Contains(s.Beatmap.ID)).ToList();
             }
 
-            BeatmapManager.ItemRemoved += i => ScoreManager.Delete(getBeatmapScores(i), true);
+            BeatmapManager.ItemRemoved.BindValueChanged(i =>
-            BeatmapManager.ItemAdded += i => ScoreManager.Undelete(getBeatmapScores(i), true);
+            {
+                if (i.NewValue.TryGetTarget(out var item))
+                    ScoreManager.Delete(getBeatmapScores(item), true);
+            });
+
+            BeatmapManager.ItemAdded.BindValueChanged(i =>
+            {
+                if (i.NewValue.TryGetTarget(out var item))
+                    ScoreManager.Undelete(getBeatmapScores(item), true);
+            });
 
             dependencies.Cache(KeyBindingStore = new KeyBindingStore(contextFactory, RulesetStore));
             dependencies.Cache(SettingsStore = new SettingsStore(contextFactory));

osu.Game/Overlays/MusicController.cs

@@ -60,11 +60,16 @@ namespace osu.Game.Overlays
         [Resolved(canBeNull: true)]
         private OnScreenDisplay onScreenDisplay { get; set; }
 
+        private IBindable<WeakReference<BeatmapSetInfo>> managerAdded;
+        private IBindable<WeakReference<BeatmapSetInfo>> managerRemoved;
+
         [BackgroundDependencyLoader]
         private void load()
         {
-            beatmaps.ItemAdded += handleBeatmapAdded;
+            managerAdded = beatmaps.ItemAdded.GetBoundCopy();
-            beatmaps.ItemRemoved += handleBeatmapRemoved;
+            managerAdded.BindValueChanged(beatmapAdded);
+            managerRemoved = beatmaps.ItemRemoved.GetBoundCopy();
+            managerRemoved.BindValueChanged(beatmapRemoved);
 
             beatmapSets.AddRange(beatmaps.GetAllUsableBeatmapSets(IncludedDetails.Minimal).OrderBy(_ => RNG.Next()));
         }
@@ -93,16 +98,28 @@ namespace osu.Game.Overlays
         /// </summary>
         public bool IsPlaying => current?.Track.IsRunning ?? false;
 
-        private void handleBeatmapAdded(BeatmapSetInfo set) => Schedule(() =>
+        private void beatmapAdded(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakSet)
         {
-            if (!beatmapSets.Contains(set))
+            if (weakSet.NewValue.TryGetTarget(out var set))
-                beatmapSets.Add(set);
+            {
-        });
+                Schedule(() =>
+                {
+                    if (!beatmapSets.Contains(set))
+                        beatmapSets.Add(set);
+                });
+            }
+        }
 
-        private void handleBeatmapRemoved(BeatmapSetInfo set) => Schedule(() =>
+        private void beatmapRemoved(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakSet)
         {
-            beatmapSets.RemoveAll(s => s.ID == set.ID);
+            if (weakSet.NewValue.TryGetTarget(out var set))
-        });
+            {
+                Schedule(() =>
+                {
+                    beatmapSets.RemoveAll(s => s.ID == set.ID);
+                });
+            }
+        }
 
         private ScheduledDelegate seekDelegate;
 
@@ -299,17 +316,6 @@ namespace osu.Game.Overlays
             }
         }
 
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            if (beatmaps != null)
-            {
-                beatmaps.ItemAdded -= handleBeatmapAdded;
-                beatmaps.ItemRemoved -= handleBeatmapRemoved;
-            }
-        }
-
         public bool OnPressed(GlobalAction action)
         {
             if (beatmap.Disabled)

osu.Game/Overlays/Settings/Sections/SkinSection.cs

@@ -1,6 +1,7 @@
 // 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 System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -30,6 +31,9 @@ namespace osu.Game.Overlays.Settings.Sections
         [Resolved]
         private SkinManager skins { get; set; }
 
+        private IBindable<WeakReference<SkinInfo>> managerAdded;
+        private IBindable<WeakReference<SkinInfo>> managerRemoved;
+
         [BackgroundDependencyLoader]
         private void load(OsuConfigManager config)
         {
@@ -66,8 +70,11 @@ namespace osu.Game.Overlays.Settings.Sections
                 },
             };
 
-            skins.ItemAdded += itemAdded;
+            managerAdded = skins.ItemAdded.GetBoundCopy();
-            skins.ItemRemoved += itemRemoved;
+            managerAdded.BindValueChanged(itemAdded);
+
+            managerRemoved = skins.ItemRemoved.GetBoundCopy();
+            managerRemoved.BindValueChanged(itemRemoved);
 
             config.BindWith(OsuSetting.Skin, configBindable);
 
@@ -82,19 +89,16 @@ namespace osu.Game.Overlays.Settings.Sections
             dropdownBindable.BindValueChanged(skin => configBindable.Value = skin.NewValue.ID);
         }
 
-        private void itemRemoved(SkinInfo s) => Schedule(() => skinDropdown.Items = skinDropdown.Items.Where(i => i.ID != s.ID).ToArray());
+        private void itemAdded(ValueChangedEvent<WeakReference<SkinInfo>> weakItem)
-
-        private void itemAdded(SkinInfo s) => Schedule(() => skinDropdown.Items = skinDropdown.Items.Append(s).ToArray());
-
-        protected override void Dispose(bool isDisposing)
         {
-            base.Dispose(isDisposing);
+            if (weakItem.NewValue.TryGetTarget(out var item))
+                Schedule(() => skinDropdown.Items = skinDropdown.Items.Append(item).ToArray());
+        }
 
-            if (skins != null)
+        private void itemRemoved(ValueChangedEvent<WeakReference<SkinInfo>> weakItem)
-            {
+        {
-                skins.ItemAdded -= itemAdded;
+            if (weakItem.NewValue.TryGetTarget(out var item))
-                skins.ItemRemoved -= itemRemoved;
+                Schedule(() => skinDropdown.Items = skinDropdown.Items.Where(i => i.ID != item.ID).ToArray());
-            }
         }
 
         private class SizeSlider : OsuSliderBar<float>

osu.Game/Screens/Multi/Match/Components/ReadyButton.cs

@@ -32,11 +32,16 @@ namespace osu.Game.Screens.Multi.Match.Components
             Text = "Start";
         }
 
+        private IBindable<WeakReference<BeatmapSetInfo>> managerAdded;
+        private IBindable<WeakReference<BeatmapSetInfo>> managerRemoved;
+
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
-            beatmaps.ItemAdded += beatmapAdded;
+            managerAdded = beatmaps.ItemAdded.GetBoundCopy();
-            beatmaps.ItemRemoved += beatmapRemoved;
+            managerAdded.BindValueChanged(beatmapAdded);
+            managerRemoved = beatmaps.ItemRemoved.GetBoundCopy();
+            managerRemoved.BindValueChanged(beatmapRemoved);
 
             SelectedItem.BindValueChanged(item => updateSelectedItem(item.NewValue), true);
 
@@ -56,24 +61,30 @@ namespace osu.Game.Screens.Multi.Match.Components
             hasBeatmap = beatmaps.QueryBeatmap(b => b.OnlineBeatmapID == beatmapId) != null;
         }
 
-        private void beatmapAdded(BeatmapSetInfo model)
+        private void beatmapAdded(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakSet)
         {
-            int? beatmapId = SelectedItem.Value?.Beatmap.Value?.OnlineBeatmapID;
+            if (weakSet.NewValue.TryGetTarget(out var set))
-            if (beatmapId == null)
+            {
-                return;
+                int? beatmapId = SelectedItem.Value?.Beatmap.Value?.OnlineBeatmapID;
+                if (beatmapId == null)
+                    return;
 
-            if (model.Beatmaps.Any(b => b.OnlineBeatmapID == beatmapId))
+                if (set.Beatmaps.Any(b => b.OnlineBeatmapID == beatmapId))
-                Schedule(() => hasBeatmap = true);
+                    Schedule(() => hasBeatmap = true);
+            }
         }
 
-        private void beatmapRemoved(BeatmapSetInfo model)
+        private void beatmapRemoved(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakSet)
         {
-            int? beatmapId = SelectedItem.Value?.Beatmap.Value?.OnlineBeatmapID;
+            if (weakSet.NewValue.TryGetTarget(out var set))
-            if (beatmapId == null)
+            {
-                return;
+                int? beatmapId = SelectedItem.Value?.Beatmap.Value?.OnlineBeatmapID;
+                if (beatmapId == null)
+                    return;
 
-            if (model.Beatmaps.Any(b => b.OnlineBeatmapID == beatmapId))
+                if (set.Beatmaps.Any(b => b.OnlineBeatmapID == beatmapId))
-                Schedule(() => hasBeatmap = false);
+                    Schedule(() => hasBeatmap = false);
+            }
         }
 
         protected override void Update()
@@ -95,16 +106,5 @@ namespace osu.Game.Screens.Multi.Match.Components
 
             Enabled.Value = hasBeatmap && hasEnoughTime;
         }
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            if (beatmaps != null)
-            {
-                beatmaps.ItemAdded -= beatmapAdded;
-                beatmaps.ItemRemoved -= beatmapRemoved;
-            }
-        }
     }
 }

osu.Game/Screens/Multi/Match/MatchSubScreen.cs

@@ -50,6 +50,8 @@ namespace osu.Game.Screens.Multi.Match
         private LeaderboardChatDisplay leaderboardChatDisplay;
         private MatchSettingsOverlay settingsOverlay;
 
+        private IBindable<WeakReference<BeatmapSetInfo>> managerAdded;
+
         public MatchSubScreen(Room room)
         {
             Title = room.RoomID.Value == null ? "New room" : room.Name.Value;
@@ -181,7 +183,8 @@ namespace osu.Game.Screens.Multi.Match
             SelectedItem.BindValueChanged(_ => Scheduler.AddOnce(selectedItemChanged));
             SelectedItem.Value = playlist.FirstOrDefault();
 
-            beatmapManager.ItemAdded += beatmapAdded;
+            managerAdded = beatmapManager.ItemAdded.GetBoundCopy();
+            managerAdded.BindValueChanged(beatmapAdded);
         }
 
         public override bool OnExiting(IScreen next)
@@ -214,13 +217,16 @@ namespace osu.Game.Screens.Multi.Match
             Beatmap.Value = beatmapManager.GetWorkingBeatmap(localBeatmap);
         }
 
-        private void beatmapAdded(BeatmapSetInfo model) => Schedule(() =>
+        private void beatmapAdded(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakSet)
         {
-            if (Beatmap.Value != beatmapManager.DefaultBeatmap)
+            Schedule(() =>
-                return;
+            {
+                if (Beatmap.Value != beatmapManager.DefaultBeatmap)
+                    return;
 
-            updateWorkingBeatmap();
+                updateWorkingBeatmap();
-        });
+            });
+        }
 
         private void onStart()
         {
@@ -235,13 +241,5 @@ namespace osu.Game.Screens.Multi.Match
                     break;
             }
         }
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            if (beatmapManager != null)
-                beatmapManager.ItemAdded -= beatmapAdded;
-        }
     }
 }

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -131,6 +131,11 @@ namespace osu.Game.Screens.Select
 
         private CarouselRoot root;
 
+        private IBindable<WeakReference<BeatmapSetInfo>> itemAdded;
+        private IBindable<WeakReference<BeatmapSetInfo>> itemRemoved;
+        private IBindable<WeakReference<BeatmapInfo>> itemHidden;
+        private IBindable<WeakReference<BeatmapInfo>> itemRestored;
+
         public BeatmapCarousel()
         {
             root = new CarouselRoot(this);
@@ -161,10 +166,14 @@ namespace osu.Game.Screens.Select
             RightClickScrollingEnabled.ValueChanged += enabled => scroll.RightMouseScrollbar = enabled.NewValue;
             RightClickScrollingEnabled.TriggerChange();
 
-            beatmaps.ItemAdded += beatmapAdded;
+            itemAdded = beatmaps.ItemAdded.GetBoundCopy();
-            beatmaps.ItemRemoved += beatmapRemoved;
+            itemAdded.BindValueChanged(beatmapAdded);
-            beatmaps.BeatmapHidden += beatmapHidden;
+            itemRemoved = beatmaps.ItemRemoved.GetBoundCopy();
-            beatmaps.BeatmapRestored += beatmapRestored;
+            itemRemoved.BindValueChanged(beatmapRemoved);
+            itemHidden = beatmaps.BeatmapHidden.GetBoundCopy();
+            itemHidden.BindValueChanged(beatmapHidden);
+            itemRestored = beatmaps.BeatmapRestored.GetBoundCopy();
+            itemRestored.BindValueChanged(beatmapRestored);
 
             loadBeatmapSets(GetLoadableBeatmaps());
         }
@@ -562,26 +571,34 @@ namespace osu.Game.Screens.Select
         {
             base.Dispose(isDisposing);
 
-            if (beatmaps != null)
-            {
-                beatmaps.ItemAdded -= beatmapAdded;
-                beatmaps.ItemRemoved -= beatmapRemoved;
-                beatmaps.BeatmapHidden -= beatmapHidden;
-                beatmaps.BeatmapRestored -= beatmapRestored;
-            }
-
             // aggressively dispose "off-screen" items to reduce GC pressure.
             foreach (var i in Items)
                 i.Dispose();
         }
 
-        private void beatmapRemoved(BeatmapSetInfo item) => RemoveBeatmapSet(item);
+        private void beatmapRemoved(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var item))
+                RemoveBeatmapSet(item);
+        }
 
-        private void beatmapAdded(BeatmapSetInfo item) => UpdateBeatmapSet(item);
+        private void beatmapAdded(ValueChangedEvent<WeakReference<BeatmapSetInfo>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var item))
+                UpdateBeatmapSet(item);
+        }
 
-        private void beatmapRestored(BeatmapInfo b) => UpdateBeatmapSet(beatmaps.QueryBeatmapSet(s => s.ID == b.BeatmapSetInfoID));
+        private void beatmapRestored(ValueChangedEvent<WeakReference<BeatmapInfo>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var b))
+                UpdateBeatmapSet(beatmaps.QueryBeatmapSet(s => s.ID == b.BeatmapSetInfoID));
+        }
 
-        private void beatmapHidden(BeatmapInfo b) => UpdateBeatmapSet(beatmaps.QueryBeatmapSet(s => s.ID == b.BeatmapSetInfoID));
+        private void beatmapHidden(ValueChangedEvent<WeakReference<BeatmapInfo>> weakItem)
+        {
+            if (weakItem.NewValue.TryGetTarget(out var b))
+                UpdateBeatmapSet(beatmaps.QueryBeatmapSet(s => s.ID == b.BeatmapSetInfoID));
+        }
 
         private CarouselBeatmapSet createCarouselSet(BeatmapSetInfo beatmapSet)
         {

osu.Game/Screens/Select/Carousel/TopLocalRank.cs

@@ -1,6 +1,7 @@
 // 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 System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -27,6 +28,9 @@ namespace osu.Game.Screens.Select.Carousel
         [Resolved]
         private IAPIProvider api { get; set; }
 
+        private IBindable<WeakReference<ScoreInfo>> itemAdded;
+        private IBindable<WeakReference<ScoreInfo>> itemRemoved;
+
         public TopLocalRank(BeatmapInfo beatmap)
             : base(null)
         {
@@ -36,17 +40,24 @@ namespace osu.Game.Screens.Select.Carousel
         [BackgroundDependencyLoader]
         private void load()
         {
-            scores.ItemAdded += scoreChanged;
+            itemAdded = scores.ItemAdded.GetBoundCopy();
-            scores.ItemRemoved += scoreChanged;
+            itemAdded.BindValueChanged(scoreChanged);
+
+            itemRemoved = scores.ItemRemoved.GetBoundCopy();
+            itemRemoved.BindValueChanged(scoreChanged);
+
             ruleset.ValueChanged += _ => fetchAndLoadTopScore();
 
             fetchAndLoadTopScore();
         }
 
-        private void scoreChanged(ScoreInfo score)
+        private void scoreChanged(ValueChangedEvent<WeakReference<ScoreInfo>> weakScore)
         {
-            if (score.BeatmapInfoID == beatmap.ID)
+            if (weakScore.NewValue.TryGetTarget(out var score))
-                fetchAndLoadTopScore();
+            {
+                if (score.BeatmapInfoID == beatmap.ID)
+                    fetchAndLoadTopScore();
+            }
         }
 
         private ScheduledDelegate scheduledRankUpdate;
@@ -75,16 +86,5 @@ namespace osu.Game.Screens.Select.Carousel
                          .OrderByDescending(s => s.TotalScore)
                          .FirstOrDefault();
         }
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            if (scores != null)
-            {
-                scores.ItemAdded -= scoreChanged;
-                scores.ItemRemoved -= scoreChanged;
-            }
-        }
     }
 }

osu.Game/Screens/Select/Leaderboards/BeatmapLeaderboard.cs

@@ -60,6 +60,8 @@ namespace osu.Game.Screens.Select.Leaderboards
 
         private UserTopScoreContainer topScoreContainer;
 
+        private IBindable<WeakReference<ScoreInfo>> itemRemoved;
+
         /// <summary>
         /// Whether to apply the game's currently selected mods as a filter when retrieving scores.
         /// </summary>
@@ -104,7 +106,8 @@ namespace osu.Game.Screens.Select.Leaderboards
                 ScoreSelected = s => ScoreSelected?.Invoke(s)
             });
 
-            scoreManager.ItemRemoved += onScoreRemoved;
+            itemRemoved = scoreManager.ItemRemoved.GetBoundCopy();
+            itemRemoved.BindValueChanged(onScoreRemoved);
         }
 
         protected override void Reset()
@@ -113,7 +116,7 @@ namespace osu.Game.Screens.Select.Leaderboards
             TopScore = null;
         }
 
-        private void onScoreRemoved(ScoreInfo score) => Schedule(RefreshScores);
+        private void onScoreRemoved(ValueChangedEvent<WeakReference<ScoreInfo>> score) => Schedule(RefreshScores);
 
         protected override bool IsOnlineScope => Scope != BeatmapLeaderboardScope.Local;
 
@@ -190,13 +193,5 @@ namespace osu.Game.Screens.Select.Leaderboards
         {
             Action = () => ScoreSelected?.Invoke(model)
         };
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            if (scoreManager != null)
-                scoreManager.ItemRemoved -= onScoreRemoved;
-        }
     }
 }

osu.Game/Skinning/SkinManager.cs

@@ -43,12 +43,15 @@ namespace osu.Game.Skinning
             this.audio = audio;
             this.legacyDefaultResources = legacyDefaultResources;
 
-            ItemRemoved += removedInfo =>
+            ItemRemoved.BindValueChanged(weakRemovedInfo =>
             {
-                // check the removed skin is not the current user choice. if it is, switch back to default.
+                if (weakRemovedInfo.NewValue.TryGetTarget(out var removedInfo))
-                if (removedInfo.ID == CurrentSkinInfo.Value.ID)
+                {
-                    CurrentSkinInfo.Value = SkinInfo.Default;
+                    // check the removed skin is not the current user choice. if it is, switch back to default.
-            };
+                    if (removedInfo.ID == CurrentSkinInfo.Value.ID)
+                        CurrentSkinInfo.Value = SkinInfo.Default;
+                }
+            });
 
             CurrentSkinInfo.ValueChanged += skin => CurrentSkin.Value = GetSkin(skin.NewValue);
             CurrentSkin.ValueChanged += skin =>