Merge branch 'master' into countdown-button-ux

osu.Android.props

@@ -51,8 +51,8 @@
     <Reference Include="Java.Interop" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.304.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.325.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.314.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.325.0" />
   </ItemGroup>
   <ItemGroup Label="Transitive Dependencies">
     <!-- Realm needs to be directly referenced in all Xamarin projects, as it will not pull in its transitive dependencies otherwise. -->

osu.Game.Rulesets.Catch.Tests/CatchSkinColourDecodingTest.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Rulesets.Catch.Tests
         {
             public TestLegacySkin(SkinInfo skin, IResourceStore<byte[]> storage)
                 // Bypass LegacySkinResourceStore to avoid returning null for retrieving files due to bad skin info (SkinInfo.Files = null).
-                : base(skin, storage, null, "skin.ini")
+                : base(skin, null, storage)
             {
             }
         }

osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapEncoderTest.cs

@@ -175,7 +175,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
         private class TestLegacySkin : LegacySkin
         {
             public TestLegacySkin(IResourceStore<byte[]> storage, string fileName)
-                : base(new SkinInfo { Name = "Test Skin", Creator = "Craftplacer" }, storage, null, fileName)
+                : base(new SkinInfo { Name = "Test Skin", Creator = "Craftplacer" }, null, storage, fileName)
             {
             }
         }

osu.Game.Tests/Beatmaps/Formats/LegacyScoreDecoderTest.cs

@@ -8,6 +8,7 @@ using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Utils;
 using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Formats;
 using osu.Game.Replays;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Catch;
@@ -64,6 +65,62 @@ namespace osu.Game.Tests.Beatmaps.Formats
             }
         }
 
+        [TestCase(3, true)]
+        [TestCase(6, false)]
+        [TestCase(LegacyBeatmapDecoder.LATEST_VERSION, false)]
+        public void TestLegacyBeatmapReplayOffsetsDecode(int beatmapVersion, bool offsetApplied)
+        {
+            const double first_frame_time = 48;
+            const double second_frame_time = 65;
+
+            var decoder = new TestLegacyScoreDecoder(beatmapVersion);
+
+            using (var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr"))
+            {
+                var score = decoder.Parse(resourceStream);
+
+                Assert.That(score.Replay.Frames[0].Time, Is.EqualTo(first_frame_time + (offsetApplied ? LegacyBeatmapDecoder.EARLY_VERSION_TIMING_OFFSET : 0)));
+                Assert.That(score.Replay.Frames[1].Time, Is.EqualTo(second_frame_time + (offsetApplied ? LegacyBeatmapDecoder.EARLY_VERSION_TIMING_OFFSET : 0)));
+            }
+        }
+
+        [TestCase(3)]
+        [TestCase(6)]
+        [TestCase(LegacyBeatmapDecoder.LATEST_VERSION)]
+        public void TestLegacyBeatmapReplayOffsetsEncodeDecode(int beatmapVersion)
+        {
+            const double first_frame_time = 2000;
+            const double second_frame_time = 3000;
+
+            var ruleset = new OsuRuleset().RulesetInfo;
+            var scoreInfo = TestResources.CreateTestScoreInfo(ruleset);
+            var beatmap = new TestBeatmap(ruleset)
+            {
+                BeatmapInfo =
+                {
+                    BeatmapVersion = beatmapVersion
+                }
+            };
+
+            var score = new Score
+            {
+                ScoreInfo = scoreInfo,
+                Replay = new Replay
+                {
+                    Frames = new List<ReplayFrame>
+                    {
+                        new OsuReplayFrame(first_frame_time, OsuPlayfield.BASE_SIZE / 2, OsuAction.LeftButton),
+                        new OsuReplayFrame(second_frame_time, OsuPlayfield.BASE_SIZE / 2, OsuAction.LeftButton)
+                    }
+                }
+            };
+
+            var decodedAfterEncode = encodeThenDecode(beatmapVersion, score, beatmap);
+
+            Assert.That(decodedAfterEncode.Replay.Frames[0].Time, Is.EqualTo(first_frame_time));
+            Assert.That(decodedAfterEncode.Replay.Frames[1].Time, Is.EqualTo(second_frame_time));
+        }
+
         [Test]
         public void TestCultureInvariance()
         {
@@ -86,15 +143,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             // rather than the classic ASCII U+002D HYPHEN-MINUS.
             CultureInfo.CurrentCulture = new CultureInfo("se");
 
-            var encodeStream = new MemoryStream();
+            var decodedAfterEncode = encodeThenDecode(LegacyBeatmapDecoder.LATEST_VERSION, score, beatmap);
-
-            var encoder = new LegacyScoreEncoder(score, beatmap);
-            encoder.Encode(encodeStream);
-
-            var decodeStream = new MemoryStream(encodeStream.GetBuffer());
-
-            var decoder = new TestLegacyScoreDecoder();
-            var decodedAfterEncode = decoder.Parse(decodeStream);
 
             Assert.Multiple(() =>
             {
@@ -110,6 +159,20 @@ namespace osu.Game.Tests.Beatmaps.Formats
             });
         }
 
+        private static Score encodeThenDecode(int beatmapVersion, Score score, TestBeatmap beatmap)
+        {
+            var encodeStream = new MemoryStream();
+
+            var encoder = new LegacyScoreEncoder(score, beatmap);
+            encoder.Encode(encodeStream);
+
+            var decodeStream = new MemoryStream(encodeStream.GetBuffer());
+
+            var decoder = new TestLegacyScoreDecoder(beatmapVersion);
+            var decodedAfterEncode = decoder.Parse(decodeStream);
+            return decodedAfterEncode;
+        }
+
         [TearDown]
         public void TearDown()
         {
@@ -118,6 +181,8 @@ namespace osu.Game.Tests.Beatmaps.Formats
 
         private class TestLegacyScoreDecoder : LegacyScoreDecoder
         {
+            private readonly int beatmapVersion;
+
             private static readonly Dictionary<int, Ruleset> rulesets = new Ruleset[]
             {
                 new OsuRuleset(),
@@ -126,6 +191,11 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 new ManiaRuleset()
             }.ToDictionary(ruleset => ((ILegacyRuleset)ruleset).LegacyID);
 
+            public TestLegacyScoreDecoder(int beatmapVersion = LegacyBeatmapDecoder.LATEST_VERSION)
+            {
+                this.beatmapVersion = beatmapVersion;
+            }
+
             protected override Ruleset GetRuleset(int rulesetId) => rulesets[rulesetId];
 
             protected override WorkingBeatmap GetBeatmap(string md5Hash) => new TestWorkingBeatmap(new Beatmap
@@ -134,7 +204,8 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 {
                     MD5Hash = md5Hash,
                     Ruleset = new OsuRuleset().RulesetInfo,
-                    Difficulty = new BeatmapDifficulty()
+                    Difficulty = new BeatmapDifficulty(),
+                    BeatmapVersion = beatmapVersion,
                 }
             });
         }

osu.Game.Tests/Database/BeatmapImporterTests.cs

@@ -147,7 +147,10 @@ namespace osu.Game.Tests.Database
                     Live<BeatmapSetInfo>? imported;
 
                     using (var reader = new ZipArchiveReader(TestResources.GetTestBeatmapStream()))
+                    {
                         imported = await importer.Import(reader);
+                        EnsureLoaded(realm.Realm);
+                    }
 
                     Assert.AreEqual(1, realm.Realm.All<BeatmapSetInfo>().Count());
 
@@ -510,6 +513,8 @@ namespace osu.Game.Tests.Database
                     new ImportTask(zipStream, string.Empty)
                 );
 
+                realm.Run(r => r.Refresh());
+
                 checkBeatmapSetCount(realm.Realm, 0);
                 checkBeatmapCount(realm.Realm, 0);
 
@@ -565,6 +570,8 @@ namespace osu.Game.Tests.Database
                 {
                 }
 
+                EnsureLoaded(realm.Realm);
+
                 checkBeatmapSetCount(realm.Realm, 1);
                 checkBeatmapCount(realm.Realm, 12);
 
@@ -726,6 +733,8 @@ namespace osu.Game.Tests.Database
 
                 var imported = importer.Import(toImport);
 
+                realm.Run(r => r.Refresh());
+
                 Assert.NotNull(imported);
                 Debug.Assert(imported != null);
 
@@ -891,6 +900,8 @@ namespace osu.Game.Tests.Database
                 string? temp = TestResources.GetTestBeatmapForImport();
                 await importer.Import(temp);
 
+                EnsureLoaded(realm.Realm);
+
                 // Update via the beatmap, not the beatmap info, to ensure correct linking
                 BeatmapSetInfo setToUpdate = realm.Realm.All<BeatmapSetInfo>().First();
 

osu.Game.Tests/Gameplay/TestSceneStoryboardSamples.cs

@@ -148,7 +148,7 @@ namespace osu.Game.Tests.Gameplay
         private class TestSkin : LegacySkin
         {
             public TestSkin(string resourceName, IStorageResourceProvider resources)
-                : base(DefaultLegacySkin.CreateInfo(), new TestResourceStore(resourceName), resources, "skin.ini")
+                : base(DefaultLegacySkin.CreateInfo(), resources, new TestResourceStore(resourceName))
             {
             }
         }

osu.Game.Tests/NonVisual/Skinning/LegacySkinTextureFallbackTest.cs

@@ -1,12 +1,21 @@
 // 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.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using NUnit.Framework;
-using osu.Framework.Graphics.OpenGL.Textures;
+using osu.Framework.Audio;
 using osu.Framework.Graphics.Textures;
+using osu.Framework.IO.Stores;
+using osu.Game.Database;
+using osu.Game.IO;
 using osu.Game.Skinning;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
 
 namespace osu.Game.Tests.NonVisual.Skinning
 {
@@ -71,7 +80,7 @@ namespace osu.Game.Tests.NonVisual.Skinning
             var texture = legacySkin.GetTexture(requestedComponent);
 
             Assert.IsNotNull(texture);
-            Assert.AreEqual(textureStore.Textures[expectedTexture], texture);
+            Assert.AreEqual(textureStore.Textures[expectedTexture].Width, texture.Width);
             Assert.AreEqual(expectedScale, texture.ScaleAdjust);
         }
 
@@ -88,23 +97,50 @@ namespace osu.Game.Tests.NonVisual.Skinning
 
         private class TestLegacySkin : LegacySkin
         {
-            public TestLegacySkin(TextureStore textureStore)
+            public TestLegacySkin(IResourceStore<TextureUpload> textureStore)
-                : base(new SkinInfo(), null, null, string.Empty)
+                : base(new SkinInfo(), new TestResourceProvider(textureStore), null, string.Empty)
             {
-                Textures = textureStore;
+            }
+
+            private class TestResourceProvider : IStorageResourceProvider
+            {
+                private readonly IResourceStore<TextureUpload> textureStore;
+
+                public TestResourceProvider(IResourceStore<TextureUpload> textureStore)
+                {
+                    this.textureStore = textureStore;
+                }
+
+                public AudioManager AudioManager => null;
+                public IResourceStore<byte[]> Files => null;
+                public IResourceStore<byte[]> Resources => null;
+                public RealmAccess RealmAccess => null;
+                public IResourceStore<TextureUpload> CreateTextureLoaderStore(IResourceStore<byte[]> underlyingStore) => textureStore;
             }
         }
 
-        private class TestTextureStore : TextureStore
+        private class TestTextureStore : IResourceStore<TextureUpload>
         {
-            public readonly Dictionary<string, Texture> Textures;
+            public readonly Dictionary<string, TextureUpload> Textures;
 
             public TestTextureStore(params string[] fileNames)
             {
-                Textures = fileNames.ToDictionary(fileName => fileName, fileName => new Texture(1, 1));
+                // use an incrementing width to allow assertion matching on correct textures as they turn from uploads into actual textures.
+                int width = 1;
+                Textures = fileNames.ToDictionary(fileName => fileName, fileName => new TextureUpload(new Image<Rgba32>(width, width++)));
             }
 
-            public override Texture Get(string name, WrapMode wrapModeS, WrapMode wrapModeT) => Textures.GetValueOrDefault(name);
+            public TextureUpload Get(string name) => Textures.GetValueOrDefault(name);
+
+            public Task<TextureUpload> GetAsync(string name, CancellationToken cancellationToken = new CancellationToken()) => Task.FromResult(Get(name));
+
+            public Stream GetStream(string name) => throw new NotImplementedException();
+
+            public IEnumerable<string> GetAvailableResources() => throw new NotImplementedException();
+
+            public void Dispose()
+            {
+            }
         }
     }
 }

osu.Game.Tests/Skins/TestSceneBeatmapSkinLookupDisables.cs

@@ -77,7 +77,7 @@ namespace osu.Game.Tests.Skins
         public class BeatmapSkinSource : LegacyBeatmapSkin
         {
             public BeatmapSkinSource()
-                : base(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo, null, null)
+                : base(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo, null)
             {
             }
 

osu.Game.Tests/Skins/TestSceneSkinConfigurationLookup.cs

@@ -202,7 +202,7 @@ namespace osu.Game.Tests.Skins
         public class BeatmapSkinSource : LegacyBeatmapSkin
         {
             public BeatmapSkinSource()
-                : base(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo, null, null)
+                : base(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo, null)
             {
             }
         }

osu.Game.Tests/Visual/Gameplay/TestSceneBeatmapSkinFallbacks.cs

@@ -50,7 +50,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestEmptyLegacyBeatmapSkinFallsBack()
         {
-            CreateSkinTest(DefaultSkin.CreateInfo(), () => new LegacyBeatmapSkin(new BeatmapInfo(), null, null));
+            CreateSkinTest(DefaultSkin.CreateInfo(), () => new LegacyBeatmapSkin(new BeatmapInfo(), null));
             AddUntilStep("wait for hud load", () => Player.ChildrenOfType<SkinnableTargetContainer>().All(c => c.ComponentsLoaded));
             AddAssert("hud from default skin", () => AssertComponentsFromExpectedSource(SkinnableTarget.MainHUDComponents, skinManager.CurrentSkin.Value));
         }

osu.Game.Tests/Visual/Multiplayer/TestSceneMatchStartControl.cs

@@ -192,7 +192,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("local user became ready", () => MultiplayerClient.LocalUser?.State == MultiplayerUserState.Ready);
             AddUntilStep("countdown button visible", () => this.ChildrenOfType<MultiplayerCountdownButton>().Single().IsPresent);
 
-            AddStep("enable auto start", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { AutoStartDuration = TimeSpan.FromMinutes(1) }));
+            AddStep("enable auto start", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { AutoStartDuration = TimeSpan.FromMinutes(1) }).WaitSafely());
 
             ClickButtonWhenEnabled<MultiplayerReadyButton>();
             AddUntilStep("local user became ready", () => MultiplayerClient.LocalUser?.State == MultiplayerUserState.Ready);
@@ -202,7 +202,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestClickingReadyButtonUnReadiesDuringAutoStart()
         {
-            AddStep("enable auto start", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { AutoStartDuration = TimeSpan.FromMinutes(1) }));
+            AddStep("enable auto start", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { AutoStartDuration = TimeSpan.FromMinutes(1) }).WaitSafely());
             ClickButtonWhenEnabled<MultiplayerReadyButton>();
             AddUntilStep("local user became ready", () => MultiplayerClient.LocalUser?.State == MultiplayerUserState.Ready);
 

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerParticipantsList.cs

@@ -163,6 +163,25 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("second user crown visible", () => this.ChildrenOfType<ParticipantPanel>().ElementAt(1).ChildrenOfType<SpriteIcon>().First().Alpha == 1);
         }
 
+        [Test]
+        public void TestHostGetsPinnedToTop()
+        {
+            AddStep("add user", () => MultiplayerClient.AddUser(new APIUser
+            {
+                Id = 3,
+                Username = "Second",
+                CoverUrl = @"https://osu.ppy.sh/images/headers/profile-covers/c3.jpg",
+            }));
+
+            AddStep("make second user host", () => MultiplayerClient.TransferHost(3));
+            AddAssert("second user above first", () =>
+            {
+                var first = this.ChildrenOfType<ParticipantPanel>().ElementAt(0);
+                var second = this.ChildrenOfType<ParticipantPanel>().ElementAt(1);
+                return second.Y < first.Y;
+            });
+        }
+
         [Test]
         public void TestKickButtonOnlyPresentWhenHost()
         {
@@ -202,9 +221,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestManyUsers()
         {
+            const int users_count = 20;
+
             AddStep("add many users", () =>
             {
-                for (int i = 0; i < 20; i++)
+                for (int i = 0; i < users_count; i++)
                 {
                     MultiplayerClient.AddUser(new APIUser
                     {
@@ -243,6 +264,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     }
                 }
             });
+
+            AddRepeatStep("switch hosts", () => MultiplayerClient.TransferHost(RNG.Next(0, users_count)), 10);
+            AddStep("give host back", () => MultiplayerClient.TransferHost(API.LocalUser.Value.Id));
         }
 
         [Test]

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

@@ -0,0 +1,40 @@
+// 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 NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Overlays;
+using osu.Game.Overlays.Mods;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Mods;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    [TestFixture]
+    public class TestSceneModSettingsArea : OsuTestScene
+    {
+        [Cached]
+        private OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Green);
+
+        [Test]
+        public void TestModToggleArea()
+        {
+            ModSettingsArea modSettingsArea = null;
+
+            AddStep("create content", () => Child = new Container
+            {
+                RelativeSizeAxes = Axes.Both,
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Child = modSettingsArea = new ModSettingsArea()
+            });
+            AddStep("set DT", () => modSettingsArea.SelectedMods.Value = new[] { new OsuModDoubleTime() });
+            AddStep("set DA", () => modSettingsArea.SelectedMods.Value = new Mod[] { new OsuModDifficultyAdjust() });
+            AddStep("set FL+WU+DA+AD", () => modSettingsArea.SelectedMods.Value = new Mod[] { new OsuModFlashlight(), new ModWindUp(), new OsuModDifficultyAdjust(), new OsuModApproachDifferent() });
+            AddStep("set empty", () => modSettingsArea.SelectedMods.Value = Array.Empty<Mod>());
+        }
+    }
+}

osu.Game.Tournament/Screens/Setup/TournamentSwitcher.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Tournament.Screens.Setup
             dropdown.Current.BindValueChanged(v => Button.Enabled.Value = v.NewValue != startupTournament, true);
 
             Action = () => game.GracefullyExit();
-            folderButton.Action = storage.PresentExternally;
+            folderButton.Action = () => storage.PresentExternally();
 
             ButtonText = "Close osu!";
         }

osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -19,6 +19,11 @@ namespace osu.Game.Beatmaps.Formats
 {
     public class LegacyBeatmapDecoder : LegacyDecoder<Beatmap>
     {
+        /// <summary>
+        /// An offset which needs to be applied to old beatmaps (v4 and lower) to correct timing changes that were applied at a game client level.
+        /// </summary>
+        public const int EARLY_VERSION_TIMING_OFFSET = 24;
+
         internal static RulesetStore RulesetStore;
 
         private Beatmap beatmap;
@@ -50,8 +55,7 @@ namespace osu.Game.Beatmaps.Formats
                 RulesetStore = new AssemblyRulesetStore();
             }
 
-            // BeatmapVersion 4 and lower had an incorrect offset (stable has this set as 24ms off)
+            offset = FormatVersion < 5 ? EARLY_VERSION_TIMING_OFFSET : 0;
-            offset = FormatVersion < 5 ? 24 : 0;
         }
 
         protected override Beatmap CreateTemplateObject()

osu.Game/Beatmaps/WorkingBeatmapCache.cs

@@ -225,7 +225,7 @@ namespace osu.Game.Beatmaps
             {
                 try
                 {
-                    return new LegacyBeatmapSkin(BeatmapInfo, resources.Files, resources);
+                    return new LegacyBeatmapSkin(BeatmapInfo, resources);
                 }
                 catch (Exception e)
                 {

osu.Game/Database/RealmAccess.cs

@@ -1,6 +1,8 @@
 // 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.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
@@ -17,6 +19,7 @@ using osu.Framework.Input.Bindings;
 using osu.Framework.Logging;
 using osu.Framework.Platform;
 using osu.Framework.Statistics;
+using osu.Framework.Threading;
 using osu.Game.Beatmaps;
 using osu.Game.Configuration;
 using osu.Game.Input.Bindings;
@@ -28,8 +31,6 @@ using osu.Game.Stores;
 using Realms;
 using Realms.Exceptions;
 
-#nullable enable
-
 namespace osu.Game.Database
 {
     /// <summary>
@@ -46,6 +47,8 @@ namespace osu.Game.Database
 
         private readonly IDatabaseContextFactory? efContextFactory;
 
+        private readonly SynchronizationContext? updateThreadSyncContext;
+
         /// <summary>
         /// Version history:
         /// 6    ~2021-10-18   First tracked version.
@@ -143,12 +146,15 @@ namespace osu.Game.Database
         /// </summary>
         /// <param name="storage">The game storage which will be used to create the realm backing file.</param>
         /// <param name="filename">The filename to use for the realm backing file. A ".realm" extension will be added automatically if not specified.</param>
+        /// <param name="updateThread">The game update thread, used to post realm operations into a thread-safe context.</param>
         /// <param name="efContextFactory">An EF factory used only for migration purposes.</param>
-        public RealmAccess(Storage storage, string filename, IDatabaseContextFactory? efContextFactory = null)
+        public RealmAccess(Storage storage, string filename, GameThread? updateThread = null, IDatabaseContextFactory? efContextFactory = null)
         {
             this.storage = storage;
             this.efContextFactory = efContextFactory;
 
+            updateThreadSyncContext = updateThread?.SynchronizationContext ?? SynchronizationContext.Current;
+
             Filename = filename;
 
             if (!Filename.EndsWith(realm_extension, StringComparison.Ordinal))
@@ -379,9 +385,6 @@ namespace osu.Game.Database
         public IDisposable RegisterForNotifications<T>(Func<Realm, IQueryable<T>> query, NotificationCallbackDelegate<T> callback)
             where T : RealmObjectBase
         {
-            if (!ThreadSafety.IsUpdateThread)
-                throw new InvalidOperationException(@$"{nameof(RegisterForNotifications)} must be called from the update thread.");
-
             lock (realmLock)
             {
                 Func<Realm, IDisposable?> action = realm => query(realm).QueryAsyncWithNotifications(callback);
@@ -459,23 +462,24 @@ namespace osu.Game.Database
         /// <returns>An <see cref="IDisposable"/> which should be disposed to unsubscribe any inner subscription.</returns>
         public IDisposable RegisterCustomSubscription(Func<Realm, IDisposable?> action)
         {
-            if (!ThreadSafety.IsUpdateThread)
+            if (updateThreadSyncContext == null)
-                throw new InvalidOperationException(@$"{nameof(RegisterForNotifications)} must be called from the update thread.");
+                throw new InvalidOperationException("Attempted to register a realm subscription before update thread registration.");
-
-            var syncContext = SynchronizationContext.Current;
 
             total_subscriptions.Value++;
 
-            registerSubscription(action);
+            if (ThreadSafety.IsUpdateThread)
+                updateThreadSyncContext.Send(_ => registerSubscription(action), null);
+            else
+                updateThreadSyncContext.Post(_ => registerSubscription(action), null);
 
             // This token is returned to the consumer.
             // When disposed, it will cause the registration to be permanently ceased (unsubscribed with realm and unregistered by this class).
             return new InvokeOnDisposal(() =>
             {
                 if (ThreadSafety.IsUpdateThread)
-                    syncContext.Send(_ => unsubscribe(), null);
+                    updateThreadSyncContext.Send(_ => unsubscribe(), null);
                 else
-                    syncContext.Post(_ => unsubscribe(), null);
+                    updateThreadSyncContext.Post(_ => unsubscribe(), null);
 
                 void unsubscribe()
                 {

osu.Game/IO/WrappedStorage.cs

@@ -70,9 +70,9 @@ namespace osu.Game.IO
         public override Stream GetStream(string path, FileAccess access = FileAccess.Read, FileMode mode = FileMode.OpenOrCreate) =>
             UnderlyingStorage.GetStream(MutatePath(path), access, mode);
 
-        public override void OpenFileExternally(string filename) => UnderlyingStorage.OpenFileExternally(MutatePath(filename));
+        public override bool OpenFileExternally(string filename) => UnderlyingStorage.OpenFileExternally(MutatePath(filename));
 
-        public override void PresentFileExternally(string filename) => UnderlyingStorage.PresentFileExternally(MutatePath(filename));
+        public override bool PresentFileExternally(string filename) => UnderlyingStorage.PresentFileExternally(MutatePath(filename));
 
         public override Storage GetStorageForDirectory(string path)
         {

osu.Game/Online/Multiplayer/MultiplayerClient.cs

@@ -171,6 +171,8 @@ namespace osu.Game.Online.Multiplayer
                     Room = joinedRoom;
                     APIRoom = room;
 
+                    Debug.Assert(joinedRoom.Playlist.Count > 0);
+
                     APIRoom.Playlist.Clear();
                     APIRoom.Playlist.AddRange(joinedRoom.Playlist.Select(createPlaylistItem));
 
@@ -686,6 +688,8 @@ namespace osu.Game.Online.Multiplayer
                 Room.Playlist.Remove(Room.Playlist.Single(existing => existing.ID == playlistItemId));
                 APIRoom.Playlist.RemoveAll(existing => existing.ID == playlistItemId);
 
+                Debug.Assert(Room.Playlist.Count > 0);
+
                 ItemRemoved?.Invoke(playlistItemId);
                 RoomUpdated?.Invoke();
             });

osu.Game/OsuGameBase.cs

@@ -200,7 +200,7 @@ namespace osu.Game
             if (Storage.Exists(DatabaseContextFactory.DATABASE_NAME))
                 dependencies.Cache(EFContextFactory = new DatabaseContextFactory(Storage));
 
-            dependencies.Cache(realm = new RealmAccess(Storage, "client", EFContextFactory));
+            dependencies.Cache(realm = new RealmAccess(Storage, "client", Host.UpdateThread, EFContextFactory));
 
             dependencies.CacheAs<RulesetStore>(RulesetStore = new RealmRulesetStore(realm, Storage));
             dependencies.CacheAs<IRulesetStore>(RulesetStore);

osu.Game/Overlays/Mods/ModSettingsArea.cs

@@ -0,0 +1,176 @@
+// 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.Collections.Generic;
+using System.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Input.Events;
+using osu.Game.Configuration;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Containers;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.UI;
+using osuTK;
+
+namespace osu.Game.Overlays.Mods
+{
+    public class ModSettingsArea : CompositeDrawable
+    {
+        public Bindable<IReadOnlyList<Mod>> SelectedMods { get; } = new Bindable<IReadOnlyList<Mod>>();
+
+        private readonly Box background;
+        private readonly FillFlowContainer modSettingsFlow;
+
+        [Resolved]
+        private OverlayColourProvider colourProvider { get; set; }
+
+        public ModSettingsArea()
+        {
+            RelativeSizeAxes = Axes.X;
+            Height = 250;
+
+            Anchor = Anchor.BottomRight;
+            Origin = Anchor.BottomRight;
+
+            InternalChild = new Container
+            {
+                RelativeSizeAxes = Axes.Both,
+                Masking = true,
+                BorderThickness = 2,
+                Children = new Drawable[]
+                {
+                    background = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both
+                    },
+                    new OsuScrollContainer(Direction.Horizontal)
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        ScrollbarOverlapsContent = false,
+                        Child = modSettingsFlow = new FillFlowContainer
+                        {
+                            AutoSizeAxes = Axes.X,
+                            RelativeSizeAxes = Axes.Y,
+                            Padding = new MarginPadding { Vertical = 7, Horizontal = 70 },
+                            Spacing = new Vector2(7),
+                            Direction = FillDirection.Horizontal
+                        }
+                    }
+                }
+            };
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            background.Colour = colourProvider.Dark3;
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            SelectedMods.BindValueChanged(_ => updateMods());
+        }
+
+        private void updateMods()
+        {
+            modSettingsFlow.Clear();
+
+            foreach (var mod in SelectedMods.Value.OrderBy(mod => mod.Type).ThenBy(mod => mod.Acronym))
+            {
+                var settings = mod.CreateSettingsControls().ToList();
+
+                if (settings.Count > 0)
+                {
+                    if (modSettingsFlow.Any())
+                    {
+                        modSettingsFlow.Add(new Box
+                        {
+                            RelativeSizeAxes = Axes.Y,
+                            Width = 2,
+                            Colour = colourProvider.Dark4,
+                        });
+                    }
+
+                    modSettingsFlow.Add(new ModSettingsColumn(mod, settings));
+                }
+            }
+        }
+
+        protected override bool OnMouseDown(MouseDownEvent e) => true;
+        protected override bool OnHover(HoverEvent e) => true;
+
+        private class ModSettingsColumn : CompositeDrawable
+        {
+            public ModSettingsColumn(Mod mod, IEnumerable<Drawable> settingsControls)
+            {
+                Width = 250;
+                RelativeSizeAxes = Axes.Y;
+                Padding = new MarginPadding { Bottom = 7 };
+
+                InternalChild = new GridContainer
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    RowDimensions = new[]
+                    {
+                        new Dimension(GridSizeMode.AutoSize),
+                        new Dimension(GridSizeMode.Absolute, 10),
+                        new Dimension()
+                    },
+                    Content = new[]
+                    {
+                        new Drawable[]
+                        {
+                            new FillFlowContainer
+                            {
+                                RelativeSizeAxes = Axes.X,
+                                AutoSizeAxes = Axes.Y,
+                                Direction = FillDirection.Horizontal,
+                                Spacing = new Vector2(7),
+                                Children = new Drawable[]
+                                {
+                                    new ModSwitchTiny(mod)
+                                    {
+                                        Active = { Value = true },
+                                        Scale = new Vector2(0.6f),
+                                        Origin = Anchor.CentreLeft,
+                                        Anchor = Anchor.CentreLeft
+                                    },
+                                    new OsuSpriteText
+                                    {
+                                        Text = mod.Name,
+                                        Font = OsuFont.Default.With(size: 16, weight: FontWeight.SemiBold),
+                                        Origin = Anchor.CentreLeft,
+                                        Anchor = Anchor.CentreLeft,
+                                        Margin = new MarginPadding { Bottom = 2 }
+                                    }
+                                }
+                            }
+                        },
+                        new[] { Empty() },
+                        new Drawable[]
+                        {
+                            new OsuScrollContainer(Direction.Vertical)
+                            {
+                                RelativeSizeAxes = Axes.Both,
+                                Child = new FillFlowContainer
+                                {
+                                    RelativeSizeAxes = Axes.X,
+                                    AutoSizeAxes = Axes.Y,
+                                    Padding = new MarginPadding { Right = 7 },
+                                    ChildrenEnumerable = settingsControls,
+                                    Spacing = new Vector2(0, 7)
+                                }
+                            }
+                        }
+                    }
+                };
+            }
+        }
+    }
+}

osu.Game/Overlays/Settings/Sections/General/UpdateSettings.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Overlays.Settings.Sections.General
                 Add(new SettingsButton
                 {
                     Text = GeneralSettingsStrings.OpenOsuFolder,
-                    Action = storage.PresentExternally,
+                    Action = () => storage.PresentExternally(),
                 });
 
                 Add(new SettingsButton

osu.Game/Scoring/Legacy/LegacyScoreDecoder.cs

@@ -23,6 +23,8 @@ namespace osu.Game.Scoring.Legacy
         private IBeatmap currentBeatmap;
         private Ruleset currentRuleset;
 
+        private float beatmapOffset;
+
         public Score Parse(Stream stream)
         {
             var score = new Score
@@ -72,6 +74,9 @@ namespace osu.Game.Scoring.Legacy
                 currentBeatmap = workingBeatmap.GetPlayableBeatmap(currentRuleset.RulesetInfo, scoreInfo.Mods);
                 scoreInfo.BeatmapInfo = currentBeatmap.BeatmapInfo;
 
+                // As this is baked into hitobject timing (see `LegacyBeatmapDecoder`) we also need to apply this to replay frame timing.
+                beatmapOffset = currentBeatmap.BeatmapInfo.BeatmapVersion < 5 ? LegacyBeatmapDecoder.EARLY_VERSION_TIMING_OFFSET : 0;
+
                 /* score.HpGraphString = */
                 sr.ReadString();
 
@@ -229,7 +234,7 @@ namespace osu.Game.Scoring.Legacy
 
         private void readLegacyReplay(Replay replay, StreamReader reader)
         {
-            float lastTime = 0;
+            float lastTime = beatmapOffset;
             ReplayFrame currentFrame = null;
 
             string[] frames = reader.ReadToEnd().Split(',');

osu.Game/Scoring/Legacy/LegacyScoreEncoder.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.
 
+#nullable enable
+
 using System;
 using System.IO;
 using System.Linq;
 using System.Text;
 using osu.Framework.Extensions;
 using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Formats;
 using osu.Game.Extensions;
 using osu.Game.IO.Legacy;
 using osu.Game.Replays.Legacy;
@@ -14,8 +17,6 @@ using osu.Game.Rulesets.Replays;
 using osu.Game.Rulesets.Replays.Types;
 using SharpCompress.Compressors.LZMA;
 
-#nullable enable
-
 namespace osu.Game.Scoring.Legacy
 {
     public class LegacyScoreEncoder
@@ -111,6 +112,9 @@ namespace osu.Game.Scoring.Legacy
             {
                 StringBuilder replayData = new StringBuilder();
 
+                // As this is baked into hitobject timing (see `LegacyBeatmapDecoder`) we also need to apply this to replay frame timing.
+                double offset = beatmap?.BeatmapInfo.BeatmapVersion < 5 ? -LegacyBeatmapDecoder.EARLY_VERSION_TIMING_OFFSET : 0;
+
                 if (score.Replay != null)
                 {
                     int lastTime = 0;
@@ -120,7 +124,7 @@ namespace osu.Game.Scoring.Legacy
                         var legacyFrame = getLegacyFrame(f);
 
                         // Rounding because stable could only parse integral values
-                        int time = (int)Math.Round(legacyFrame.Time);
+                        int time = (int)Math.Round(legacyFrame.Time + offset);
                         replayData.Append(FormattableString.Invariant($"{time - lastTime}|{legacyFrame.MouseX ?? 0}|{legacyFrame.MouseY ?? 0}|{(int)legacyFrame.ButtonState},"));
                         lastTime = time;
                     }

osu.Game/Screens/Menu/ButtonSystem.cs

@@ -79,10 +79,10 @@ namespace osu.Game.Screens.Menu
 
         private readonly ButtonArea buttonArea;
 
-        private readonly Button backButton;
+        private readonly MainMenuButton backButton;
 
-        private readonly List<Button> buttonsTopLevel = new List<Button>();
+        private readonly List<MainMenuButton> buttonsTopLevel = new List<MainMenuButton>();
-        private readonly List<Button> buttonsPlay = new List<Button>();
+        private readonly List<MainMenuButton> buttonsPlay = new List<MainMenuButton>();
 
         private Sample sampleBack;
 
@@ -100,8 +100,8 @@ namespace osu.Game.Screens.Menu
 
             buttonArea.AddRange(new Drawable[]
             {
-                new Button(ButtonSystemStrings.Settings, string.Empty, FontAwesome.Solid.Cog, new Color4(85, 85, 85, 255), () => OnSettings?.Invoke(), -WEDGE_WIDTH, Key.O),
+                new MainMenuButton(ButtonSystemStrings.Settings, string.Empty, FontAwesome.Solid.Cog, new Color4(85, 85, 85, 255), () => OnSettings?.Invoke(), -WEDGE_WIDTH, Key.O),
-                backButton = new Button(ButtonSystemStrings.Back, @"button-back-select", OsuIcon.LeftCircle, new Color4(51, 58, 94, 255), () => State = ButtonSystemState.TopLevel, -WEDGE_WIDTH)
+                backButton = new MainMenuButton(ButtonSystemStrings.Back, @"button-back-select", OsuIcon.LeftCircle, new Color4(51, 58, 94, 255), () => State = ButtonSystemState.TopLevel, -WEDGE_WIDTH)
                 {
                     VisibleState = ButtonSystemState.Play,
                 },
@@ -126,24 +126,24 @@ namespace osu.Game.Screens.Menu
         [BackgroundDependencyLoader(true)]
         private void load(AudioManager audio, IdleTracker idleTracker, GameHost host)
         {
-            buttonsPlay.Add(new Button(ButtonSystemStrings.Solo, @"button-solo-select", FontAwesome.Solid.User, new Color4(102, 68, 204, 255), () => OnSolo?.Invoke(), WEDGE_WIDTH, Key.P));
+            buttonsPlay.Add(new MainMenuButton(ButtonSystemStrings.Solo, @"button-solo-select", FontAwesome.Solid.User, new Color4(102, 68, 204, 255), () => OnSolo?.Invoke(), WEDGE_WIDTH, Key.P));
-            buttonsPlay.Add(new Button(ButtonSystemStrings.Multi, @"button-generic-select", FontAwesome.Solid.Users, new Color4(94, 63, 186, 255), onMultiplayer, 0, Key.M));
+            buttonsPlay.Add(new MainMenuButton(ButtonSystemStrings.Multi, @"button-generic-select", FontAwesome.Solid.Users, new Color4(94, 63, 186, 255), onMultiplayer, 0, Key.M));
-            buttonsPlay.Add(new Button(ButtonSystemStrings.Playlists, @"button-generic-select", OsuIcon.Charts, new Color4(94, 63, 186, 255), onPlaylists, 0, Key.L));
+            buttonsPlay.Add(new MainMenuButton(ButtonSystemStrings.Playlists, @"button-generic-select", OsuIcon.Charts, new Color4(94, 63, 186, 255), onPlaylists, 0, Key.L));
             buttonsPlay.ForEach(b => b.VisibleState = ButtonSystemState.Play);
 
-            buttonsTopLevel.Add(new Button(ButtonSystemStrings.Play, @"button-play-select", OsuIcon.Logo, new Color4(102, 68, 204, 255), () => State = ButtonSystemState.Play, WEDGE_WIDTH, Key.P));
+            buttonsTopLevel.Add(new MainMenuButton(ButtonSystemStrings.Play, @"button-play-select", OsuIcon.Logo, new Color4(102, 68, 204, 255), () => State = ButtonSystemState.Play, WEDGE_WIDTH, Key.P));
-            buttonsTopLevel.Add(new Button(ButtonSystemStrings.Edit, @"button-edit-select", OsuIcon.EditCircle, new Color4(238, 170, 0, 255), () => OnEdit?.Invoke(), 0, Key.E));
+            buttonsTopLevel.Add(new MainMenuButton(ButtonSystemStrings.Edit, @"button-edit-select", OsuIcon.EditCircle, new Color4(238, 170, 0, 255), () => OnEdit?.Invoke(), 0, Key.E));
-            buttonsTopLevel.Add(new Button(ButtonSystemStrings.Browse, @"button-direct-select", OsuIcon.ChevronDownCircle, new Color4(165, 204, 0, 255), () => OnBeatmapListing?.Invoke(), 0, Key.D));
+            buttonsTopLevel.Add(new MainMenuButton(ButtonSystemStrings.Browse, @"button-direct-select", OsuIcon.ChevronDownCircle, new Color4(165, 204, 0, 255), () => OnBeatmapListing?.Invoke(), 0, Key.D));
 
             if (host.CanExit)
-                buttonsTopLevel.Add(new Button(ButtonSystemStrings.Exit, string.Empty, OsuIcon.CrossCircle, new Color4(238, 51, 153, 255), () => OnExit?.Invoke(), 0, Key.Q));
+                buttonsTopLevel.Add(new MainMenuButton(ButtonSystemStrings.Exit, string.Empty, OsuIcon.CrossCircle, new Color4(238, 51, 153, 255), () => OnExit?.Invoke(), 0, Key.Q));
 
             buttonArea.AddRange(buttonsPlay);
             buttonArea.AddRange(buttonsTopLevel);
 
             buttonArea.ForEach(b =>
             {
-                if (b is Button)
+                if (b is MainMenuButton)
                 {
                     b.Origin = Anchor.CentreLeft;
                     b.Anchor = Anchor.CentreLeft;
@@ -305,7 +305,7 @@ namespace osu.Game.Screens.Menu
                 {
                     buttonArea.ButtonSystemState = state;
 
-                    foreach (var b in buttonArea.Children.OfType<Button>())
+                    foreach (var b in buttonArea.Children.OfType<MainMenuButton>())
                         b.ButtonSystemState = state;
                 }
 

osu.Game/Screens/Menu/MainMenuButton.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Screens.Menu
     /// Button designed specifically for the osu!next main menu.
     /// In order to correctly flow, we have to use a negative margin on the parent container (due to the parallelogram shape).
     /// </summary>
-    public class Button : BeatSyncedContainer, IStateful<ButtonState>
+    public class MainMenuButton : BeatSyncedContainer, IStateful<ButtonState>
     {
         public event Action<ButtonState> StateChanged;
 
@@ -51,7 +51,7 @@ namespace osu.Game.Screens.Menu
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => box.ReceivePositionalInputAt(screenSpacePos);
 
-        public Button(LocalisableString text, string sampleName, IconUsage symbol, Color4 colour, Action clickAction = null, float extraWidth = 0, Key triggerKey = Key.Unknown)
+        public MainMenuButton(LocalisableString text, string sampleName, IconUsage symbol, Color4 colour, Action clickAction = null, float extraWidth = 0, Key triggerKey = Key.Unknown)
         {
             this.sampleName = sampleName;
             this.clickAction = clickAction;
@@ -209,7 +209,7 @@ namespace osu.Game.Screens.Menu
 
         protected override bool OnKeyDown(KeyDownEvent e)
         {
-            if (e.Repeat || e.ControlPressed || e.ShiftPressed || e.AltPressed)
+            if (e.Repeat || e.ControlPressed || e.ShiftPressed || e.AltPressed || e.SuperPressed)
                 return false;
 
             if (TriggerKey == e.Key && TriggerKey != Key.Unknown)

osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerCountdownButton.cs

@@ -42,8 +42,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
 
         public MultiplayerCountdownButton()
         {
-            Icon = FontAwesome.Solid.CaretDown;
+            Icon = FontAwesome.Regular.Clock;
-            IconScale = new Vector2(0.6f);
 
             Add(background = new Box
             {
@@ -52,6 +51,8 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
             });
 
             base.Action = this.ShowPopover;
+
+            TooltipText = "Countdown settings";
         }
 
         [BackgroundDependencyLoader]

osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerMatchSettingsOverlay.cs

@@ -165,6 +165,14 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
                                                                         LengthLimit = 100,
                                                                     },
                                                                 },
+                                                                // new Section("Room visibility")
+                                                                // {
+                                                                //     Alpha = disabled_alpha,
+                                                                //     Child = AvailabilityPicker = new RoomAvailabilityPicker
+                                                                //     {
+                                                                //         Enabled = { Value = false }
+                                                                //     },
+                                                                // },
                                                                 new Section("Game type")
                                                                 {
                                                                     Child = new FillFlowContainer

osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerReadyButton.cs

@@ -47,7 +47,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
             countdown = room?.Countdown;
 
             if (room?.Countdown != null)
-                countdownUpdateDelegate ??= Scheduler.AddDelayed(updateButtonText, 1000, true);
+                countdownUpdateDelegate ??= Scheduler.AddDelayed(updateButtonText, 100, true);
             else
             {
                 countdownUpdateDelegate?.Cancel();

osu.Game/Screens/OnlinePlay/Multiplayer/Participants/ParticipantPanel.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.Color4Extensions;
@@ -187,9 +186,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
             const double fade_time = 50;
 
             var currentItem = Playlist.GetCurrentItem();
-            Debug.Assert(currentItem != null);
+            var ruleset = currentItem != null ? rulesets.GetRuleset(currentItem.RulesetID)?.CreateInstance() : null;
-
-            var ruleset = rulesets.GetRuleset(currentItem.RulesetID)?.CreateInstance();
 
             int? currentModeRank = ruleset != null ? User.User?.RulesetsStatistics?.GetValueOrDefault(ruleset.ShortName)?.GlobalRank : null;
             userRankText.Text = currentModeRank != null ? $"#{currentModeRank.Value:N0}" : string.Empty;
@@ -201,15 +198,8 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
             else
                 userModsDisplay.FadeOut(fade_time);
 
-            if (Client.IsHost && !User.Equals(Client.LocalUser))
+            kickButton.Alpha = Client.IsHost && !User.Equals(Client.LocalUser) ? 1 : 0;
-                kickButton.FadeIn(fade_time);
+            crown.Alpha = Room.Host?.Equals(User) == true ? 1 : 0;
-            else
-                kickButton.FadeOut(fade_time);
-
-            if (Room.Host?.Equals(User) == true)
-                crown.FadeIn(fade_time);
-            else
-                crown.FadeOut(fade_time);
 
             // If the mods are updated at the end of the frame, the flow container will skip a reflow cycle: https://github.com/ppy/osu-framework/issues/4187
             // This looks particularly jarring here, so re-schedule the update to that start of our frame as a fix.

osu.Game/Screens/OnlinePlay/Multiplayer/Participants/ParticipantsList.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Linq;
+using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -15,6 +16,9 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
     {
         private FillFlowContainer<ParticipantPanel> panels;
 
+        [CanBeNull]
+        private ParticipantPanel currentHostPanel;
+
         [BackgroundDependencyLoader]
         private void load()
         {
@@ -55,6 +59,24 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
                 // Add panels for all users new to the room.
                 foreach (var user in Room.Users.Except(panels.Select(p => p.User)))
                     panels.Add(new ParticipantPanel(user));
+
+                if (currentHostPanel == null || !currentHostPanel.User.Equals(Room.Host))
+                {
+                    // Reset position of previous host back to normal, if one existing.
+                    if (currentHostPanel != null && panels.Contains(currentHostPanel))
+                        panels.SetLayoutPosition(currentHostPanel, 0);
+
+                    currentHostPanel = null;
+
+                    // Change position of new host to display above all participants.
+                    if (Room.Host != null)
+                    {
+                        currentHostPanel = panels.SingleOrDefault(u => u.User.Equals(Room.Host));
+
+                        if (currentHostPanel != null)
+                            panels.SetLayoutPosition(currentHostPanel, -1);
+                    }
+                }
             }
         }
     }

osu.Game/Skinning/DefaultLegacySkin.cs

@@ -30,11 +30,9 @@ namespace osu.Game.Skinning
         public DefaultLegacySkin(SkinInfo skin, IStorageResourceProvider resources)
             : base(
                 skin,
-                new NamespacedResourceStore<byte[]>(resources.Resources, "Skins/Legacy"),
                 resources,
-                // A default legacy skin may still have a skin.ini if it is modified by the user.
+                // In the case of the actual default legacy skin (ie. the fallback one, which a user hasn't applied any modifications to) we want to use the game provided resources.
-                // We must specify the stream directly as we are redirecting storage to the osu-resources location for other files.
+                skin.Protected ? new NamespacedResourceStore<byte[]>(resources.Resources, "Skins/Legacy") : null
-                new LegacyDatabasedSkinResourceStore(skin, resources.Files).GetStream("skin.ini")
             )
         {
             Configuration.CustomColours["SliderBall"] = new Color4(2, 170, 255, 255);

osu.Game/Skinning/ISkin.cs

@@ -1,7 +1,8 @@
 // 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 JetBrains.Annotations;
+#nullable enable
+
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -21,16 +22,14 @@ namespace osu.Game.Skinning
         /// </summary>
         /// <param name="component">The requested component.</param>
         /// <returns>A drawable representation for the requested component, or null if unavailable.</returns>
-        [CanBeNull]
+        Drawable? GetDrawableComponent(ISkinComponent component);
-        Drawable GetDrawableComponent(ISkinComponent component);
 
         /// <summary>
         /// Retrieve a <see cref="Texture"/>.
         /// </summary>
         /// <param name="componentName">The requested texture.</param>
         /// <returns>A matching texture, or null if unavailable.</returns>
-        [CanBeNull]
+        Texture? GetTexture(string componentName) => GetTexture(componentName, default, default);
-        Texture GetTexture(string componentName) => GetTexture(componentName, default, default);
 
         /// <summary>
         /// Retrieve a <see cref="Texture"/>.
@@ -39,23 +38,22 @@ namespace osu.Game.Skinning
         /// <param name="wrapModeS">The texture wrap mode in horizontal direction.</param>
         /// <param name="wrapModeT">The texture wrap mode in vertical direction.</param>
         /// <returns>A matching texture, or null if unavailable.</returns>
-        [CanBeNull]
+        Texture? GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);
-        Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);
 
         /// <summary>
         /// Retrieve a <see cref="SampleChannel"/>.
         /// </summary>
         /// <param name="sampleInfo">The requested sample.</param>
         /// <returns>A matching sample channel, or null if unavailable.</returns>
-        [CanBeNull]
+        ISample? GetSample(ISampleInfo sampleInfo);
-        ISample GetSample(ISampleInfo sampleInfo);
 
         /// <summary>
         /// Retrieve a configuration value.
         /// </summary>
         /// <param name="lookup">The requested configuration value.</param>
         /// <returns>A matching value boxed in an <see cref="IBindable{TValue}"/>, or null if unavailable.</returns>
-        [CanBeNull]
+        IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
-        IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup);
+            where TLookup : notnull
+            where TValue : notnull;
     }
 }

osu.Game/Skinning/LegacyBeatmapSkin.cs

@@ -1,8 +1,11 @@
 // 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.
 
+#nullable enable
+
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.IO.Stores;
 using osu.Game.Audio;
@@ -20,14 +23,28 @@ namespace osu.Game.Skinning
         protected override bool AllowManiaSkin => false;
         protected override bool UseCustomSampleBanks => true;
 
-        public LegacyBeatmapSkin(BeatmapInfo beatmapInfo, IResourceStore<byte[]> storage, IStorageResourceProvider resources)
+        /// <summary>
-            : base(createSkinInfo(beatmapInfo), new LegacySkinResourceStore(beatmapInfo.BeatmapSet, storage), resources, beatmapInfo.Path)
+        /// Construct a new legacy beatmap skin instance.
+        /// </summary>
+        /// <param name="beatmapInfo">The model for this beatmap.</param>
+        /// <param name="resources">Access to raw game resources.</param>
+        public LegacyBeatmapSkin(BeatmapInfo beatmapInfo, IStorageResourceProvider? resources)
+            : base(createSkinInfo(beatmapInfo), resources, createRealmBackedStore(beatmapInfo, resources), beatmapInfo.Path.AsNonNull())
         {
             // Disallow default colours fallback on beatmap skins to allow using parent skin combo colours. (via SkinProvidingContainer)
             Configuration.AllowDefaultComboColoursFallback = false;
         }
 
-        public override Drawable GetDrawableComponent(ISkinComponent component)
+        private static IResourceStore<byte[]> createRealmBackedStore(BeatmapInfo beatmapInfo, IStorageResourceProvider? resources)
+        {
+            if (resources == null)
+                // should only ever be used in tests.
+                return new ResourceStore<byte[]>();
+
+            return new RealmBackedResourceStore(beatmapInfo.BeatmapSet, resources.Files, new[] { @"ogg" });
+        }
+
+        public override Drawable? GetDrawableComponent(ISkinComponent component)
         {
             if (component is SkinnableTargetComponent targetComponent)
             {
@@ -46,7 +63,7 @@ namespace osu.Game.Skinning
             return base.GetDrawableComponent(component);
         }
 
-        public override IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup)
+        public override IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
         {
             switch (lookup)
             {
@@ -62,10 +79,10 @@ namespace osu.Game.Skinning
             return base.GetConfig<TLookup, TValue>(lookup);
         }
 
-        protected override IBindable<Color4> GetComboColour(IHasComboColours source, int comboIndex, IHasComboInformation combo)
+        protected override IBindable<Color4>? GetComboColour(IHasComboColours source, int comboIndex, IHasComboInformation combo)
             => base.GetComboColour(source, combo.ComboIndexWithOffsets, combo);
 
-        public override ISample GetSample(ISampleInfo sampleInfo)
+        public override ISample? GetSample(ISampleInfo sampleInfo)
         {
             if (sampleInfo is ConvertHitObjectParser.LegacyHitSampleInfo legacy && legacy.CustomSampleBank == 0)
             {
@@ -77,6 +94,10 @@ namespace osu.Game.Skinning
         }
 
         private static SkinInfo createSkinInfo(BeatmapInfo beatmapInfo) =>
-            new SkinInfo { Name = beatmapInfo.ToString(), Creator = beatmapInfo.Metadata.Author.Username ?? string.Empty };
+            new SkinInfo
+            {
+                Name = beatmapInfo.ToString(),
+                Creator = beatmapInfo.Metadata.Author.Username ?? string.Empty
+            };
     }
 }

osu.Game/Skinning/LegacySkin.cs

@@ -1,6 +1,8 @@
 // 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.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -15,6 +17,7 @@ using osu.Framework.Graphics.Textures;
 using osu.Framework.IO.Stores;
 using osu.Game.Audio;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.Database;
 using osu.Game.IO;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Scoring;
@@ -27,12 +30,6 @@ namespace osu.Game.Skinning
 {
     public class LegacySkin : Skin
     {
-        [CanBeNull]
-        protected TextureStore Textures;
-
-        [CanBeNull]
-        protected ISampleStore Samples;
-
         /// <summary>
         /// Whether texture for the keys exists.
         /// Used to determine if the mania ruleset is skinned.
@@ -51,7 +48,7 @@ namespace osu.Game.Skinning
 
         [UsedImplicitly(ImplicitUseKindFlags.InstantiatedWithFixedConstructorSignature)]
         public LegacySkin(SkinInfo skin, IStorageResourceProvider resources)
-            : this(skin, new LegacyDatabasedSkinResourceStore(skin, resources.Files), resources, "skin.ini")
+            : this(skin, resources, null)
         {
         }
 
@@ -59,36 +56,12 @@ namespace osu.Game.Skinning
         /// Construct a new legacy skin instance.
         /// </summary>
         /// <param name="skin">The model for this skin.</param>
-        /// <param name="storage">A storage for looking up files within this skin using user-facing filenames.</param>
         /// <param name="resources">Access to raw game resources.</param>
+        /// <param name="storage">An optional store which will be used for looking up skin resources. If null, one will be created from realm <see cref="IHasRealmFiles"/> pattern.</param>
         /// <param name="configurationFilename">The user-facing filename of the configuration file to be parsed. Can accept an .osu or skin.ini file.</param>
-        protected LegacySkin(SkinInfo skin, [CanBeNull] IResourceStore<byte[]> storage, [CanBeNull] IStorageResourceProvider resources, string configurationFilename)
+        protected LegacySkin(SkinInfo skin, IStorageResourceProvider? resources, IResourceStore<byte[]>? storage, string configurationFilename = @"skin.ini")
-            : this(skin, storage, resources, string.IsNullOrEmpty(configurationFilename) ? null : storage?.GetStream(configurationFilename))
+            : base(skin, resources, storage, configurationFilename)
         {
-        }
-
-        /// <summary>
-        /// Construct a new legacy skin instance.
-        /// </summary>
-        /// <param name="skin">The model for this skin.</param>
-        /// <param name="storage">A storage for looking up files within this skin using user-facing filenames.</param>
-        /// <param name="resources">Access to raw game resources.</param>
-        /// <param name="configurationStream">An optional stream containing the contents of a skin.ini file.</param>
-        protected LegacySkin(SkinInfo skin, [CanBeNull] IResourceStore<byte[]> storage, [CanBeNull] IStorageResourceProvider resources, [CanBeNull] Stream configurationStream)
-            : base(skin, resources, configurationStream)
-        {
-            if (storage != null)
-            {
-                var samples = resources?.AudioManager?.GetSampleStore(storage);
-                if (samples != null)
-                    samples.PlaybackConcurrency = OsuGameBase.SAMPLE_CONCURRENCY;
-
-                Samples = samples;
-                Textures = new TextureStore(resources?.CreateTextureLoaderStore(storage));
-
-                (storage as ResourceStore<byte[]>)?.AddExtension("ogg");
-            }
-
             // todo: this shouldn't really be duplicated here (from ManiaLegacySkinTransformer). we need to come up with a better solution.
             hasKeyTexture = new Lazy<bool>(() => this.GetAnimation(
                 lookupForMania<string>(new LegacyManiaSkinConfigurationLookup(4, LegacyManiaSkinConfigurationLookups.KeyImage, 0))?.Value ?? "mania-key1", true,
@@ -110,7 +83,7 @@ namespace osu.Game.Skinning
             }
         }
 
-        public override IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup)
+        public override IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
         {
             switch (lookup)
             {
@@ -156,7 +129,7 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        private IBindable<TValue> lookupForMania<TValue>(LegacyManiaSkinConfigurationLookup maniaLookup)
+        private IBindable<TValue>? lookupForMania<TValue>(LegacyManiaSkinConfigurationLookup maniaLookup)
         {
             if (!maniaConfigurations.TryGetValue(maniaLookup.Keys, out var existing))
                 maniaConfigurations[maniaLookup.Keys] = existing = new LegacyManiaSkinConfiguration(maniaLookup.Keys);
@@ -296,20 +269,20 @@ namespace osu.Game.Skinning
         /// <param name="source">The source to retrieve the combo colours from.</param>
         /// <param name="colourIndex">The preferred index for retrieving the combo colour with.</param>
         /// <param name="combo">Information on the combo whose using the returned colour.</param>
-        protected virtual IBindable<Color4> GetComboColour(IHasComboColours source, int colourIndex, IHasComboInformation combo)
+        protected virtual IBindable<Color4>? GetComboColour(IHasComboColours source, int colourIndex, IHasComboInformation combo)
         {
             var colour = source.ComboColours?[colourIndex % source.ComboColours.Count];
             return colour.HasValue ? new Bindable<Color4>(colour.Value) : null;
         }
 
-        private IBindable<Color4> getCustomColour(IHasCustomColours source, string lookup)
+        private IBindable<Color4>? getCustomColour(IHasCustomColours source, string lookup)
             => source.CustomColours.TryGetValue(lookup, out var col) ? new Bindable<Color4>(col) : null;
 
-        private IBindable<string> getManiaImage(LegacyManiaSkinConfiguration source, string lookup)
+        private IBindable<string>? getManiaImage(LegacyManiaSkinConfiguration source, string lookup)
             => source.ImageLookups.TryGetValue(lookup, out string image) ? new Bindable<string>(image) : null;
 
-        [CanBeNull]
+        private IBindable<TValue>? legacySettingLookup<TValue>(SkinConfiguration.LegacySetting legacySetting)
-        private IBindable<TValue> legacySettingLookup<TValue>(SkinConfiguration.LegacySetting legacySetting)
+            where TValue : notnull
         {
             switch (legacySetting)
             {
@@ -321,8 +294,9 @@ namespace osu.Game.Skinning
             }
         }
 
-        [CanBeNull]
+        private IBindable<TValue>? genericLookup<TLookup, TValue>(TLookup lookup)
-        private IBindable<TValue> genericLookup<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull
         {
             try
             {
@@ -345,7 +319,7 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        public override Drawable GetDrawableComponent(ISkinComponent component)
+        public override Drawable? GetDrawableComponent(ISkinComponent component)
         {
             if (base.GetDrawableComponent(component) is Drawable c)
                 return c;
@@ -385,26 +359,15 @@ namespace osu.Game.Skinning
                                 }
                             })
                             {
-                                Children = this.HasFont(LegacyFont.Score)
+                                Children = new Drawable[]
-                                    ? new Drawable[]
+                                {
-                                    {
+                                    new LegacyComboCounter(),
-                                        new LegacyComboCounter(),
+                                    new LegacyScoreCounter(),
-                                        new LegacyScoreCounter(),
+                                    new LegacyAccuracyCounter(),
-                                        new LegacyAccuracyCounter(),
+                                    new LegacyHealthDisplay(),
-                                        new LegacyHealthDisplay(),
+                                    new SongProgress(),
-                                        new SongProgress(),
+                                    new BarHitErrorMeter(),
-                                        new BarHitErrorMeter(),
+                                }
-                                    }
-                                    : new Drawable[]
-                                    {
-                                        // TODO: these should fallback to using osu!classic skin textures, rather than doing this.
-                                        new DefaultComboCounter(),
-                                        new DefaultScoreCounter(),
-                                        new DefaultAccuracyCounter(),
-                                        new DefaultHealthDisplay(),
-                                        new SongProgress(),
-                                        new BarHitErrorMeter(),
-                                    }
                             };
 
                             return skinnableTargetWrapper;
@@ -414,7 +377,7 @@ namespace osu.Game.Skinning
 
                 case GameplaySkinComponent<HitResult> resultComponent:
                     // TODO: this should be inside the judgement pieces.
-                    Func<Drawable> createDrawable = () => getJudgementAnimation(resultComponent.Component);
+                    Func<Drawable?> createDrawable = () => getJudgementAnimation(resultComponent.Component);
 
                     // kind of wasteful that we throw this away, but should do for now.
                     if (createDrawable() != null)
@@ -433,7 +396,7 @@ namespace osu.Game.Skinning
             return this.GetAnimation(component.LookupName, false, false);
         }
 
-        private Texture getParticleTexture(HitResult result)
+        private Texture? getParticleTexture(HitResult result)
         {
             switch (result)
             {
@@ -450,7 +413,7 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        private Drawable getJudgementAnimation(HitResult result)
+        private Drawable? getJudgementAnimation(HitResult result)
         {
             switch (result)
             {
@@ -470,7 +433,7 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        public override Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT)
+        public override Texture? GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT)
         {
             foreach (string name in getFallbackNames(componentName))
             {
@@ -498,7 +461,7 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        public override ISample GetSample(ISampleInfo sampleInfo)
+        public override ISample? GetSample(ISampleInfo sampleInfo)
         {
             IEnumerable<string> lookupNames;
 
@@ -551,12 +514,5 @@ namespace osu.Game.Skinning
             // Fall back to using the last piece for components coming from lazer (e.g. "Gameplay/osu/approachcircle" -> "approachcircle").
             yield return componentName.Split('/').Last();
         }
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-            Textures?.Dispose();
-            Samples?.Dispose();
-        }
     }
 }

osu.Game/Skinning/LegacySkinResourceStore.cs

@@ -1,39 +0,0 @@
-// 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.Collections.Generic;
-using System.Linq;
-using osu.Framework.Extensions;
-using osu.Framework.IO.Stores;
-using osu.Game.Database;
-using osu.Game.Extensions;
-
-namespace osu.Game.Skinning
-{
-    public class LegacySkinResourceStore : ResourceStore<byte[]>
-    {
-        private readonly IHasNamedFiles source;
-
-        public LegacySkinResourceStore(IHasNamedFiles source, IResourceStore<byte[]> underlyingStore)
-            : base(underlyingStore)
-        {
-            this.source = source;
-        }
-
-        protected override IEnumerable<string> GetFilenames(string name)
-        {
-            foreach (string filename in base.GetFilenames(name))
-            {
-                string path = getPathForFile(filename.ToStandardisedPath());
-                if (path != null)
-                    yield return path;
-            }
-        }
-
-        private string getPathForFile(string filename) =>
-            source.Files.FirstOrDefault(f => string.Equals(f.Filename, filename, StringComparison.OrdinalIgnoreCase))?.File.GetStoragePath();
-
-        public override IEnumerable<string> GetAvailableResources() => source.Files.Select(f => f.Filename);
-    }
-}

osu.Game/Skinning/RealmBackedResourceStore.cs

@@ -4,21 +4,29 @@
 using System.Collections.Generic;
 using osu.Framework.Extensions;
 using osu.Framework.IO.Stores;
+using osu.Game.Database;
 using osu.Game.Extensions;
 
 namespace osu.Game.Skinning
 {
-    public class LegacyDatabasedSkinResourceStore : ResourceStore<byte[]>
+    public class RealmBackedResourceStore : ResourceStore<byte[]>
     {
         private readonly Dictionary<string, string> fileToStoragePathMapping = new Dictionary<string, string>();
 
-        public LegacyDatabasedSkinResourceStore(SkinInfo source, IResourceStore<byte[]> underlyingStore)
+        public RealmBackedResourceStore(IHasRealmFiles source, IResourceStore<byte[]> underlyingStore, string[] extensions = null)
             : base(underlyingStore)
         {
+            // Must be initialised before the file cache.
+            if (extensions != null)
+            {
+                foreach (string extension in extensions)
+                    AddExtension(extension);
+            }
+
             initialiseFileCache(source);
         }
 
-        private void initialiseFileCache(SkinInfo source)
+        private void initialiseFileCache(IHasRealmFiles source)
         {
             fileToStoragePathMapping.Clear();
             foreach (var f in source.Files)

osu.Game/Skinning/ResourceStoreBackedSkin.cs

@@ -46,7 +46,10 @@ namespace osu.Game.Skinning
             return null;
         }
 
-        public IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup) => null;
+        public IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull
+            => null;
 
         public void Dispose()
         {

osu.Game/Skinning/Skin.cs

@@ -1,22 +1,24 @@
 // 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.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Text;
-using JetBrains.Annotations;
 using Newtonsoft.Json;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.OpenGL.Textures;
 using osu.Framework.Graphics.Textures;
+using osu.Framework.IO.Stores;
 using osu.Framework.Logging;
 using osu.Game.Audio;
 using osu.Game.Database;
-using osu.Game.Extensions;
 using osu.Game.IO;
 using osu.Game.Screens.Play.HUD;
 
@@ -24,8 +26,17 @@ namespace osu.Game.Skinning
 {
     public abstract class Skin : IDisposable, ISkin
     {
+        /// <summary>
+        /// A texture store which can be used to perform user file lookups for this skin.
+        /// </summary>
+        protected TextureStore? Textures { get; }
+
+        /// <summary>
+        /// A sample store which can be used to perform user file lookups for this skin.
+        /// </summary>
+        protected ISampleStore? Samples { get; }
+
         public readonly Live<SkinInfo> SkinInfo;
-        private readonly IStorageResourceProvider resources;
 
         public SkinConfiguration Configuration { get; set; }
 
@@ -33,66 +44,80 @@ namespace osu.Game.Skinning
 
         private readonly Dictionary<SkinnableTarget, SkinnableInfo[]> drawableComponentInfo = new Dictionary<SkinnableTarget, SkinnableInfo[]>();
 
-        public abstract ISample GetSample(ISampleInfo sampleInfo);
+        public abstract ISample? GetSample(ISampleInfo sampleInfo);
 
-        public Texture GetTexture(string componentName) => GetTexture(componentName, default, default);
+        public Texture? GetTexture(string componentName) => GetTexture(componentName, default, default);
 
-        public abstract Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);
+        public abstract Texture? GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);
 
-        public abstract IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup);
+        public abstract IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull;
 
-        protected Skin(SkinInfo skin, IStorageResourceProvider resources, [CanBeNull] Stream configurationStream = null)
+        /// <summary>
+        /// Construct a new skin.
+        /// </summary>
+        /// <param name="skin">The skin's metadata. Usually a live realm object.</param>
+        /// <param name="resources">Access to game-wide resources.</param>
+        /// <param name="storage">An optional store which will *replace* all file lookups that are usually sourced from <paramref name="skin"/>.</param>
+        /// <param name="configurationFilename">An optional filename to read the skin configuration from. If not provided, the configuration will be retrieved from the storage using "skin.ini".</param>
+        protected Skin(SkinInfo skin, IStorageResourceProvider? resources, IResourceStore<byte[]>? storage = null, string configurationFilename = @"skin.ini")
         {
-            SkinInfo = resources?.RealmAccess != null
+            if (resources != null)
-                ? skin.ToLive(resources.RealmAccess)
+            {
-                // This path should only be used in some tests.
+                SkinInfo = skin.ToLive(resources.RealmAccess);
-                : skin.ToLiveUnmanaged();
 
-            this.resources = resources;
+                storage ??= new RealmBackedResourceStore(skin, resources.Files, new[] { @"ogg" });
 
-            configurationStream ??= getConfigurationStream();
+                var samples = resources.AudioManager?.GetSampleStore(storage);
+                if (samples != null)
+                    samples.PlaybackConcurrency = OsuGameBase.SAMPLE_CONCURRENCY;
+
+                Samples = samples;
+                Textures = new TextureStore(resources.CreateTextureLoaderStore(storage));
+            }
+            else
+            {
+                // Generally only used for tests.
+                SkinInfo = skin.ToLiveUnmanaged();
+            }
+
+            var configurationStream = storage?.GetStream(configurationFilename);
 
             if (configurationStream != null)
+            {
                 // stream will be closed after use by LineBufferedReader.
                 ParseConfigurationStream(configurationStream);
+                Debug.Assert(Configuration != null);
+            }
             else
                 Configuration = new SkinConfiguration();
 
             // skininfo files may be null for default skin.
-            SkinInfo.PerformRead(s =>
+            foreach (SkinnableTarget skinnableTarget in Enum.GetValues(typeof(SkinnableTarget)))
             {
-                // we may want to move this to some kind of async operation in the future.
+                string filename = $"{skinnableTarget}.json";
-                foreach (SkinnableTarget skinnableTarget in Enum.GetValues(typeof(SkinnableTarget)))
+
+                byte[]? bytes = storage?.Get(filename);
+
+                if (bytes == null)
+                    continue;
+
+                try
                 {
-                    string filename = $"{skinnableTarget}.json";
+                    string jsonContent = Encoding.UTF8.GetString(bytes);
+                    var deserializedContent = JsonConvert.DeserializeObject<IEnumerable<SkinnableInfo>>(jsonContent);
 
-                    // skininfo files may be null for default skin.
+                    if (deserializedContent == null)
-                    var fileInfo = s.Files.FirstOrDefault(f => f.Filename == filename);
-
-                    if (fileInfo == null)
                         continue;
 
-                    byte[] bytes = resources?.Files.Get(fileInfo.File.GetStoragePath());
+                    DrawableComponentInfo[skinnableTarget] = deserializedContent.ToArray();
-
-                    if (bytes == null)
-                        continue;
-
-                    try
-                    {
-                        string jsonContent = Encoding.UTF8.GetString(bytes);
-                        var deserializedContent = JsonConvert.DeserializeObject<IEnumerable<SkinnableInfo>>(jsonContent);
-
-                        if (deserializedContent == null)
-                            continue;
-
-                        DrawableComponentInfo[skinnableTarget] = deserializedContent.ToArray();
-                    }
-                    catch (Exception ex)
-                    {
-                        Logger.Error(ex, "Failed to load skin configuration.");
-                    }
                 }
-            });
+                catch (Exception ex)
+                {
+                    Logger.Error(ex, "Failed to load skin configuration.");
+                }
+            }
         }
 
         protected virtual void ParseConfigurationStream(Stream stream)
@@ -101,16 +126,6 @@ namespace osu.Game.Skinning
                 Configuration = new LegacySkinDecoder().Decode(reader);
         }
 
-        private Stream getConfigurationStream()
-        {
-            string path = SkinInfo.PerformRead(s => s.Files.SingleOrDefault(f => f.Filename.Equals(@"skin.ini", StringComparison.OrdinalIgnoreCase))?.File.GetStoragePath());
-
-            if (string.IsNullOrEmpty(path))
-                return null;
-
-            return resources?.Files.GetStream(path);
-        }
-
         /// <summary>
         /// Remove all stored customisations for the provided target.
         /// </summary>
@@ -129,7 +144,7 @@ namespace osu.Game.Skinning
             DrawableComponentInfo[targetContainer.Target] = targetContainer.CreateSkinnableInfo().ToArray();
         }
 
-        public virtual Drawable GetDrawableComponent(ISkinComponent component)
+        public virtual Drawable? GetDrawableComponent(ISkinComponent component)
         {
             switch (component)
             {
@@ -137,9 +152,23 @@ namespace osu.Game.Skinning
                     if (!DrawableComponentInfo.TryGetValue(target.Target, out var skinnableInfo))
                         return null;
 
+                    var components = new List<Drawable>();
+
+                    foreach (var i in skinnableInfo)
+                    {
+                        try
+                        {
+                            components.Add(i.CreateInstance());
+                        }
+                        catch (Exception e)
+                        {
+                            Logger.Error(e, $"Unable to create skin component {i.Type.Name}");
+                        }
+                    }
+
                     return new SkinnableTargetComponentsContainer
                     {
-                        ChildrenEnumerable = skinnableInfo.Select(i => i.CreateInstance())
+                        Children = components,
                     };
             }
 
@@ -168,6 +197,9 @@ namespace osu.Game.Skinning
                 return;
 
             isDisposed = true;
+
+            Textures?.Dispose();
+            Samples?.Dispose();
         }
 
         #endregion

osu.Game/Tests/Beatmaps/HitObjectSampleTest.cs

@@ -96,12 +96,14 @@ namespace osu.Game.Tests.Beatmaps
             AddStep("setup skins", () =>
             {
                 userSkinInfo.Files.Clear();
-                userSkinInfo.Files.Add(new RealmNamedFileUsage(new RealmFile { Hash = userFile }, userFile));
+                if (!string.IsNullOrEmpty(userFile))
+                    userSkinInfo.Files.Add(new RealmNamedFileUsage(new RealmFile { Hash = userFile }, userFile));
 
                 Debug.Assert(beatmapInfo.BeatmapSet != null);
 
                 beatmapInfo.BeatmapSet.Files.Clear();
-                beatmapInfo.BeatmapSet.Files.Add(new RealmNamedFileUsage(new RealmFile { Hash = beatmapFile }, beatmapFile));
+                if (!string.IsNullOrEmpty(beatmapFile))
+                    beatmapInfo.BeatmapSet.Files.Add(new RealmNamedFileUsage(new RealmFile { Hash = beatmapFile }, beatmapFile));
 
                 // Need to refresh the cached skin source to refresh the skin resource store.
                 dependencies.SkinSource = new SkinProvidingContainer(Skin = new LegacySkin(userSkinInfo, this));
@@ -191,22 +193,32 @@ namespace osu.Game.Tests.Beatmaps
             }
         }
 
-        private class TestWorkingBeatmap : ClockBackedTestWorkingBeatmap
+        private class TestWorkingBeatmap : ClockBackedTestWorkingBeatmap, IStorageResourceProvider
         {
             private readonly BeatmapInfo skinBeatmapInfo;
-            private readonly IResourceStore<byte[]> resourceStore;
 
             private readonly IStorageResourceProvider resources;
 
-            public TestWorkingBeatmap(BeatmapInfo skinBeatmapInfo, IResourceStore<byte[]> resourceStore, IBeatmap beatmap, Storyboard storyboard, IFrameBasedClock referenceClock, IStorageResourceProvider resources)
+            public TestWorkingBeatmap(BeatmapInfo skinBeatmapInfo, IResourceStore<byte[]> accessMarkingResourceStore, IBeatmap beatmap, Storyboard storyboard, IFrameBasedClock referenceClock,
+                                      IStorageResourceProvider resources)
                 : base(beatmap, storyboard, referenceClock, resources.AudioManager)
             {
                 this.skinBeatmapInfo = skinBeatmapInfo;
-                this.resourceStore = resourceStore;
+                Files = accessMarkingResourceStore;
                 this.resources = resources;
             }
 
-            protected internal override ISkin GetSkin() => new LegacyBeatmapSkin(skinBeatmapInfo, resourceStore, resources);
+            protected internal override ISkin GetSkin() => new LegacyBeatmapSkin(skinBeatmapInfo, this);
+
+            public AudioManager AudioManager => resources.AudioManager;
+
+            public IResourceStore<byte[]> Files { get; }
+
+            public IResourceStore<byte[]> Resources => resources.Resources;
+
+            public RealmAccess RealmAccess => resources.RealmAccess;
+
+            public IResourceStore<TextureUpload> CreateTextureLoaderStore(IResourceStore<byte[]> underlyingStore) => resources.CreateTextureLoaderStore(underlyingStore);
         }
     }
 }

osu.Game/Tests/Beatmaps/LegacyBeatmapSkinColourTest.cs

@@ -7,7 +7,6 @@ using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Bindables;
-using osu.Framework.IO.Stores;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps;
 using osu.Game.Skinning;
@@ -112,7 +111,7 @@ namespace osu.Game.Tests.Beatmaps
             public static readonly Color4 HYPER_DASH_FRUIT_COLOUR = Color4.DarkGoldenrod;
 
             public TestBeatmapSkin(BeatmapInfo beatmapInfo, bool hasColours)
-                : base(beatmapInfo, new ResourceStore<byte[]>(), null)
+                : base(beatmapInfo, null)
             {
                 if (hasColours)
                 {
@@ -141,7 +140,7 @@ namespace osu.Game.Tests.Beatmaps
             public static readonly Color4 HYPER_DASH_FRUIT_COLOUR = Color4.LightCyan;
 
             public TestSkin(bool hasCustomColours)
-                : base(new SkinInfo(), new ResourceStore<byte[]>(), null, string.Empty)
+                : base(new SkinInfo(), null, null)
             {
                 if (hasCustomColours)
                 {

osu.Game/Tests/Visual/OsuTestScene.cs

@@ -115,11 +115,13 @@ namespace osu.Game.Tests.Visual
 
         protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
         {
-            headlessHostStorage = (parent.Get<GameHost>() as HeadlessGameHost)?.Storage;
+            var host = parent.Get<GameHost>();
+
+            headlessHostStorage = (host as HeadlessGameHost)?.Storage;
 
             Resources = parent.Get<OsuGameBase>().Resources;
 
-            realm = new Lazy<RealmAccess>(() => new RealmAccess(LocalStorage, "client"));
+            realm = new Lazy<RealmAccess>(() => new RealmAccess(LocalStorage, "client", host.UpdateThread));
 
             RecycleLocalStorage(false);
 

osu.Game/Tests/Visual/SkinnableTestScene.cs

@@ -96,7 +96,7 @@ namespace osu.Game.Tests.Visual
                     },
                     new OsuSpriteText
                     {
-                        Text = skin?.SkinInfo?.Value.Name ?? "none",
+                        Text = skin?.SkinInfo.Value.Name ?? "none",
                         Scale = new Vector2(1.5f),
                         Padding = new MarginPadding(5),
                     },
@@ -187,7 +187,7 @@ namespace osu.Game.Tests.Visual
             private readonly bool extrapolateAnimations;
 
             public TestLegacySkin(SkinInfo skin, IResourceStore<byte[]> storage, IStorageResourceProvider resources, bool extrapolateAnimations)
-                : base(skin, storage, resources, "skin.ini")
+                : base(skin, resources, storage)
             {
                 this.extrapolateAnimations = extrapolateAnimations;
             }

osu.Game/osu.Game.csproj

@@ -36,8 +36,8 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Realm" Version="10.10.0" />
-    <PackageReference Include="ppy.osu.Framework" Version="2022.314.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2022.325.0" />
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.304.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.325.0" />
     <PackageReference Include="Sentry" Version="3.14.1" />
     <PackageReference Include="SharpCompress" Version="0.30.1" />
     <PackageReference Include="NUnit" Version="3.13.2" />

osu.iOS.props

@@ -61,8 +61,8 @@
     <Reference Include="System.Net.Http" />
   </ItemGroup>
   <ItemGroup Label="Package References">
-    <PackageReference Include="ppy.osu.Framework.iOS" Version="2022.314.0" />
+    <PackageReference Include="ppy.osu.Framework.iOS" Version="2022.325.0" />
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.304.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.325.0" />
   </ItemGroup>
   <!-- See https://github.com/dotnet/runtime/issues/35988 (can be removed after Xamarin uses net6.0) -->
   <PropertyGroup>
@@ -84,7 +84,7 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="5.0.14" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="5.0.14" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
-    <PackageReference Include="ppy.osu.Framework" Version="2022.314.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2022.325.0" />
     <PackageReference Include="SharpCompress" Version="0.30.1" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />