Merge branch 'master' into fix-leave-room-race-2

osu.Android.props

@@ -52,6 +52,6 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="ppy.osu.Game.Resources" Version="2020.1202.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.118.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.128.0" />
   </ItemGroup>
 </Project>

osu.Desktop/osu.Desktop.csproj

@@ -24,16 +24,13 @@
     <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
   </ItemGroup>
   <ItemGroup Label="Package References">
+    <PackageReference Include="Microsoft.NETCore.Targets" Version="5.0.0" />
     <PackageReference Include="System.IO.Packaging" Version="5.0.0" />
-    <PackageReference Include="ppy.squirrel.windows" Version="1.9.0.4" />
+    <PackageReference Include="ppy.squirrel.windows" Version="1.9.0.5" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.2.6" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.2.6" />
     <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />
     <PackageReference Include="DiscordRichPresence" Version="1.0.169" />
-    <!-- .NET 3.1 SDK seems to cause issues with a runtime specification. This will likely be resolved in .NET 5. -->
-    <PackageReference Include="System.IO.FileSystem.Primitives" Version="4.3.0" />
-    <PackageReference Include="System.Runtime.Handles" Version="4.3.0" />
-    <PackageReference Include="System.Runtime.InteropServices" Version="4.3.0" />
   </ItemGroup>
   <ItemGroup Label="Resources">
     <EmbeddedResource Include="lazer.ico" />

osu.Game.Rulesets.Catch/Replays/CatchAutoGenerator.cs

@@ -45,6 +45,11 @@ namespace osu.Game.Rulesets.Catch.Replays
                 float positionChange = Math.Abs(lastPosition - h.EffectiveX);
                 double timeAvailable = h.StartTime - lastTime;
 
+                if (timeAvailable < 0)
+                {
+                    return;
+                }
+
                 // So we can either make it there without a dash or not.
                 // If positionChange is 0, we don't need to move, so speedRequired should also be 0 (could be NaN if timeAvailable is 0 too)
                 // The case where positionChange > 0 and timeAvailable == 0 results in PositiveInfinity which provides expected beheaviour.

osu.Game.Rulesets.Taiko/Mods/TaikoModDifficultyAdjust.cs

@@ -1,11 +1,45 @@
 // 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.Linq;
+using osu.Framework.Bindables;
+using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods
 {
     public class TaikoModDifficultyAdjust : ModDifficultyAdjust
     {
+        [SettingSource("Scroll Speed", "Adjust a beatmap's set scroll speed", LAST_SETTING_ORDER + 1)]
+        public BindableNumber<float> ScrollSpeed { get; } = new BindableFloat
+        {
+            Precision = 0.05f,
+            MinValue = 0.25f,
+            MaxValue = 4,
+            Default = 1,
+            Value = 1,
+        };
+
+        public override string SettingDescription
+        {
+            get
+            {
+                string scrollSpeed = ScrollSpeed.IsDefault ? string.Empty : $"Scroll x{ScrollSpeed.Value:N1}";
+
+                return string.Join(", ", new[]
+                {
+                    base.SettingDescription,
+                    scrollSpeed
+                }.Where(s => !string.IsNullOrEmpty(s)));
+            }
+        }
+
+        protected override void ApplySettings(BeatmapDifficulty difficulty)
+        {
+            base.ApplySettings(difficulty);
+
+            ApplySetting(ScrollSpeed, scroll => difficulty.SliderMultiplier *= scroll);
+        }
     }
 }

osu.Game.Rulesets.Taiko/Mods/TaikoModEasy.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods
@@ -8,5 +9,16 @@ namespace osu.Game.Rulesets.Taiko.Mods
     public class TaikoModEasy : ModEasy
     {
         public override string Description => @"Beats move slower, and less accuracy required!";
+
+        /// <summary>
+        /// Multiplier factor added to the scrolling speed.
+        /// </summary>
+        private const double slider_multiplier = 0.8;
+
+        public override void ApplyToDifficulty(BeatmapDifficulty difficulty)
+        {
+            base.ApplyToDifficulty(difficulty);
+            difficulty.SliderMultiplier *= slider_multiplier;
+        }
     }
 }

osu.Game.Rulesets.Taiko/Mods/TaikoModHardRock.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods
@@ -9,5 +10,21 @@ namespace osu.Game.Rulesets.Taiko.Mods
     {
         public override double ScoreMultiplier => 1.06;
         public override bool Ranked => true;
+
+        /// <summary>
+        /// Multiplier factor added to the scrolling speed.
+        /// </summary>
+        /// <remarks>
+        /// This factor is made up of two parts: the base part (1.4) and the aspect ratio adjustment (4/3).
+        /// Stable applies the latter by dividing the width of the user's display by the width of a display with the same height, but 4:3 aspect ratio.
+        /// TODO: Revisit if taiko playfield ever changes away from a hard-coded 16:9 (see https://github.com/ppy/osu/issues/5685).
+        /// </remarks>
+        private const double slider_multiplier = 1.4 * 4 / 3;
+
+        public override void ApplyToDifficulty(BeatmapDifficulty difficulty)
+        {
+            base.ApplyToDifficulty(difficulty);
+            difficulty.SliderMultiplier *= slider_multiplier;
+        }
     }
 }

osu.Game.Tests/NonVisual/OngoingOperationTrackerTest.cs

@@ -0,0 +1,62 @@
+// 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.Bindables;
+using osu.Framework.Testing;
+using osu.Game.Screens.OnlinePlay;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.NonVisual
+{
+    [HeadlessTest]
+    public class OngoingOperationTrackerTest : OsuTestScene
+    {
+        private OngoingOperationTracker tracker;
+        private IBindable<bool> operationInProgress;
+
+        [SetUpSteps]
+        public void SetUp()
+        {
+            AddStep("create tracker", () => Child = tracker = new OngoingOperationTracker());
+            AddStep("bind to operation status", () => operationInProgress = tracker.InProgress.GetBoundCopy());
+        }
+
+        [Test]
+        public void TestOperationTracking()
+        {
+            IDisposable firstOperation = null;
+            IDisposable secondOperation = null;
+
+            AddStep("begin first operation", () => firstOperation = tracker.BeginOperation());
+            AddAssert("first operation in progress", () => operationInProgress.Value);
+
+            AddStep("cannot start another operation",
+                () => Assert.Throws<InvalidOperationException>(() => tracker.BeginOperation()));
+
+            AddStep("end first operation", () => firstOperation.Dispose());
+            AddAssert("first operation is ended", () => !operationInProgress.Value);
+
+            AddStep("start second operation", () => secondOperation = tracker.BeginOperation());
+            AddAssert("second operation in progress", () => operationInProgress.Value);
+
+            AddStep("dispose first operation again", () => firstOperation.Dispose());
+            AddAssert("second operation still in progress", () => operationInProgress.Value);
+
+            AddStep("dispose second operation", () => secondOperation.Dispose());
+            AddAssert("second operation is ended", () => !operationInProgress.Value);
+        }
+
+        [Test]
+        public void TestOperationDisposalAfterTracker()
+        {
+            IDisposable operation = null;
+
+            AddStep("begin operation", () => operation = tracker.BeginOperation());
+            AddStep("dispose tracker", () => tracker.Expire());
+            AddStep("end operation", () => operation.Dispose());
+            AddAssert("operation is ended", () => !operationInProgress.Value);
+        }
+    }
+}

osu.Game.Tests/Visual/Editing/TestSceneEditorSummaryTimeline.cs

@@ -5,6 +5,8 @@ using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Osu.Beatmaps;
+using osu.Game.Screens.Edit;
 using osu.Game.Screens.Edit.Components.Timelines.Summary;
 using osuTK;
 
@@ -13,6 +15,9 @@ namespace osu.Game.Tests.Visual.Editing
     [TestFixture]
     public class TestSceneEditorSummaryTimeline : EditorClockTestScene
     {
+        [Cached(typeof(EditorBeatmap))]
+        private readonly EditorBeatmap editorBeatmap = new EditorBeatmap(new OsuBeatmap());
+
         [BackgroundDependencyLoader]
         private void load()
         {

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

@@ -17,10 +17,12 @@ using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Difficulty;
+using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Objects.Legacy;
+using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.UI;
 using osuTK;
 using osuTK.Graphics;
@@ -129,6 +131,31 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddUntilStep("no DHOs shown", () => !this.ChildrenOfType<DrawableTestHitObject>().Any());
         }
 
+        [Test]
+        public void TestApplyHitResultOnKilled()
+        {
+            ManualClock clock = null;
+            bool anyJudged = false;
+
+            void onNewResult(JudgementResult _) => anyJudged = true;
+
+            var beatmap = new Beatmap();
+            beatmap.HitObjects.Add(new TestKilledHitObject { Duration = 20 });
+
+            createTest(beatmap, 10, () => new FramedClock(clock = new ManualClock()));
+
+            AddStep("subscribe to new result", () =>
+            {
+                anyJudged = false;
+                drawableRuleset.NewResult += onNewResult;
+            });
+            AddStep("skip past object", () => clock.CurrentTime = beatmap.HitObjects[0].GetEndTime() + 1000);
+
+            AddAssert("object judged", () => anyJudged);
+
+            AddStep("clean up", () => drawableRuleset.NewResult -= onNewResult);
+        }
+
         private void createTest(IBeatmap beatmap, int poolSize, Func<IFrameBasedClock> createClock = null) => AddStep("create test", () =>
         {
             var ruleset = new TestPoolingRuleset();
@@ -192,6 +219,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             private void load()
             {
                 RegisterPool<TestHitObject, DrawableTestHitObject>(poolSize);
+                RegisterPool<TestKilledHitObject, DrawableTestKilledHitObject>(poolSize);
             }
 
             protected override HitObjectLifetimeEntry CreateLifetimeEntry(HitObject hitObject) => new TestHitObjectLifetimeEntry(hitObject);
@@ -220,19 +248,30 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             protected override IEnumerable<TestHitObject> ConvertHitObject(HitObject original, IBeatmap beatmap, CancellationToken cancellationToken)
             {
+                switch (original)
+                {
+                    case TestKilledHitObject h:
+                        yield return h;
+
+                        break;
+
+                    default:
                         yield return new TestHitObject
                         {
                             StartTime = original.StartTime,
                             Duration = 250
                         };
+
+                        break;
+                }
             }
         }
 
         #endregion
 
-        #region HitObject
+        #region HitObjects
 
-        private class TestHitObject : ConvertHitObject
+        private class TestHitObject : ConvertHitObject, IHasDuration
         {
             public double EndTime => StartTime + Duration;
 
@@ -287,6 +326,30 @@ namespace osu.Game.Tests.Visual.Gameplay
             }
         }
 
+        private class TestKilledHitObject : TestHitObject
+        {
+        }
+
+        private class DrawableTestKilledHitObject : DrawableHitObject<TestKilledHitObject>
+        {
+            public DrawableTestKilledHitObject()
+                : base(null)
+            {
+            }
+
+            protected override void UpdateHitStateTransforms(ArmedState state)
+            {
+                base.UpdateHitStateTransforms(state);
+                Expire();
+            }
+
+            public override void OnKilled()
+            {
+                base.OnKilled();
+                ApplyResult(r => r.Type = r.Judgement.MinResult);
+            }
+        }
+
         #endregion
     }
 }

osu.Game.Tests/Visual/Online/TestSceneBeatmapListingOverlay.cs

@@ -1,32 +1,81 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Game.Overlays;
+using System.Collections.Generic;
+using System.Linq;
 using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Testing;
+using osu.Game.Beatmaps;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Overlays;
+using osu.Game.Overlays.BeatmapListing;
+using osu.Game.Rulesets;
 
 namespace osu.Game.Tests.Visual.Online
 {
     public class TestSceneBeatmapListingOverlay : OsuTestScene
     {
-        protected override bool UseOnlineAPI => true;
+        private readonly List<APIBeatmapSet> setsForResponse = new List<APIBeatmapSet>();
 
-        private readonly BeatmapListingOverlay overlay;
+        private BeatmapListingOverlay overlay;
 
-        public TestSceneBeatmapListingOverlay()
+        [BackgroundDependencyLoader]
+        private void load()
         {
-            Add(overlay = new BeatmapListingOverlay());
+            Child = overlay = new BeatmapListingOverlay { State = { Value = Visibility.Visible } };
+
+            ((DummyAPIAccess)API).HandleRequest = req =>
+            {
+                if (req is SearchBeatmapSetsRequest searchBeatmapSetsRequest)
+                {
+                    searchBeatmapSetsRequest.TriggerSuccess(new SearchBeatmapSetsResponse
+                    {
+                        BeatmapSets = setsForResponse,
+                    });
+                }
+            };
         }
 
         [Test]
-        public void TestShow()
+        public void TestNoBeatmapsPlaceholder()
         {
-            AddStep("Show", overlay.Show);
+            AddStep("fetch for 0 beatmaps", () => fetchFor());
+            AddUntilStep("placeholder shown", () => overlay.ChildrenOfType<BeatmapListingOverlay.NotFoundDrawable>().SingleOrDefault()?.IsPresent == true);
+
+            AddStep("fetch for 1 beatmap", () => fetchFor(CreateBeatmap(Ruleset.Value).BeatmapInfo.BeatmapSet));
+            AddUntilStep("placeholder hidden", () => !overlay.ChildrenOfType<BeatmapListingOverlay.NotFoundDrawable>().Any());
+
+            AddStep("fetch for 0 beatmaps", () => fetchFor());
+            AddUntilStep("placeholder shown", () => overlay.ChildrenOfType<BeatmapListingOverlay.NotFoundDrawable>().SingleOrDefault()?.IsPresent == true);
+
+            // fetch once more to ensure nothing happens in displaying placeholder again when it already is present.
+            AddStep("fetch for 0 beatmaps again", () => fetchFor());
+            AddUntilStep("placeholder shown", () => overlay.ChildrenOfType<BeatmapListingOverlay.NotFoundDrawable>().SingleOrDefault()?.IsPresent == true);
         }
 
-        [Test]
+        private void fetchFor(params BeatmapSetInfo[] beatmaps)
-        public void TestHide()
         {
-            AddStep("Hide", overlay.Hide);
+            setsForResponse.Clear();
+            setsForResponse.AddRange(beatmaps.Select(b => new TestAPIBeatmapSet(b)));
+
+            // trigger arbitrary change for fetching.
+            overlay.ChildrenOfType<BeatmapListingSearchControl>().Single().Query.TriggerChange();
+        }
+
+        private class TestAPIBeatmapSet : APIBeatmapSet
+        {
+            private readonly BeatmapSetInfo beatmapSet;
+
+            public TestAPIBeatmapSet(BeatmapSetInfo beatmapSet)
+            {
+                this.beatmapSet = beatmapSet;
+            }
+
+            public override BeatmapSetInfo ToBeatmapSet(RulesetStore rulesets) => beatmapSet;
         }
     }
 }

osu.Game.Tests/Visual/Online/TestSceneBeatmapSetOverlay.cs

@@ -231,8 +231,8 @@ namespace osu.Game.Tests.Visual.Online
                 });
             });
 
-            AddAssert("shown beatmaps of current ruleset", () => overlay.Header.Picker.Difficulties.All(b => b.Beatmap.Ruleset.Equals(overlay.Header.RulesetSelector.Current.Value)));
+            AddAssert("shown beatmaps of current ruleset", () => overlay.Header.HeaderContent.Picker.Difficulties.All(b => b.Beatmap.Ruleset.Equals(overlay.Header.RulesetSelector.Current.Value)));
-            AddAssert("left-most beatmap selected", () => overlay.Header.Picker.Difficulties.First().State == BeatmapPicker.DifficultySelectorState.Selected);
+            AddAssert("left-most beatmap selected", () => overlay.Header.HeaderContent.Picker.Difficulties.First().State == BeatmapPicker.DifficultySelectorState.Selected);
         }
 
         [Test]
@@ -310,12 +310,12 @@ namespace osu.Game.Tests.Visual.Online
 
         private void downloadAssert(bool shown)
         {
-            AddAssert($"is download button {(shown ? "shown" : "hidden")}", () => overlay.Header.DownloadButtonsVisible == shown);
+            AddAssert($"is download button {(shown ? "shown" : "hidden")}", () => overlay.Header.HeaderContent.DownloadButtonsVisible == shown);
         }
 
         private class TestBeatmapSetOverlay : BeatmapSetOverlay
         {
-            public new Header Header => base.Header;
+            public new BeatmapSetHeader Header => base.Header;
         }
     }
 }

osu.Game.Tests/Visual/Online/TestSceneOnlineBeatmapListingOverlay.cs

@@ -0,0 +1,33 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Overlays;
+using NUnit.Framework;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    [Description("uses online API")]
+    public class TestSceneOnlineBeatmapListingOverlay : OsuTestScene
+    {
+        protected override bool UseOnlineAPI => true;
+
+        private readonly BeatmapListingOverlay overlay;
+
+        public TestSceneOnlineBeatmapListingOverlay()
+        {
+            Add(overlay = new BeatmapListingOverlay());
+        }
+
+        [Test]
+        public void TestShow()
+        {
+            AddStep("Show", overlay.Show);
+        }
+
+        [Test]
+        public void TestHide()
+        {
+            AddStep("Hide", overlay.Hide);
+        }
+    }
+}

osu.Game.Tests/Visual/Online/TestSceneVotePill.cs

@@ -7,6 +7,8 @@ using osu.Game.Overlays.Comments;
 using osu.Game.Online.API.Requests.Responses;
 using osu.Framework.Allocation;
 using osu.Game.Overlays;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Containers;
 
 namespace osu.Game.Tests.Visual.Online
 {
@@ -16,13 +18,33 @@ namespace osu.Game.Tests.Visual.Online
         [Cached]
         private readonly OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Blue);
 
-        private VotePill votePill;
+        [Cached]
+        private LoginOverlay login;
+
+        private TestPill votePill;
+        private readonly Container pillContainer;
+
+        public TestSceneVotePill()
+        {
+            AddRange(new Drawable[]
+            {
+                pillContainer = new Container
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    AutoSizeAxes = Axes.Both
+                },
+                login = new LoginOverlay()
+            });
+        }
 
         [Test]
         public void TestUserCommentPill()
         {
+            AddStep("Hide login overlay", () => login.Hide());
             AddStep("Log in", logIn);
             AddStep("User comment", () => addVotePill(getUserComment()));
+            AddAssert("Background is transparent", () => votePill.Background.Alpha == 0);
             AddStep("Click", () => votePill.Click());
             AddAssert("Not loading", () => !votePill.IsLoading);
         }
@@ -30,8 +52,10 @@ namespace osu.Game.Tests.Visual.Online
         [Test]
         public void TestRandomCommentPill()
         {
+            AddStep("Hide login overlay", () => login.Hide());
             AddStep("Log in", logIn);
             AddStep("Random comment", () => addVotePill(getRandomComment()));
+            AddAssert("Background is visible", () => votePill.Background.Alpha == 1);
             AddStep("Click", () => votePill.Click());
             AddAssert("Loading", () => votePill.IsLoading);
         }
@@ -39,10 +63,11 @@ namespace osu.Game.Tests.Visual.Online
         [Test]
         public void TestOfflineRandomCommentPill()
         {
+            AddStep("Hide login overlay", () => login.Hide());
             AddStep("Log out", API.Logout);
             AddStep("Random comment", () => addVotePill(getRandomComment()));
             AddStep("Click", () => votePill.Click());
-            AddAssert("Not loading", () => !votePill.IsLoading);
+            AddAssert("Login overlay is visible", () => login.State.Value == Visibility.Visible);
         }
 
         private void logIn() => API.Login("localUser", "password");
@@ -63,12 +88,22 @@ namespace osu.Game.Tests.Visual.Online
 
         private void addVotePill(Comment comment)
         {
-            Clear();
+            pillContainer.Clear();
-            Add(votePill = new VotePill(comment)
+            pillContainer.Child = votePill = new TestPill(comment)
             {
                 Anchor = Anchor.Centre,
                 Origin = Anchor.Centre,
-            });
+            };
+        }
+
+        private class TestPill : VotePill
+        {
+            public new Box Background => base.Background;
+
+            public TestPill(Comment comment)
+                : base(comment)
+            {
+            }
         }
     }
 }

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsRoomSubScreen.cs

@@ -11,12 +11,10 @@ using osu.Framework.Platform;
 using osu.Framework.Screens;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps;
-using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.Rooms;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Screens.OnlinePlay;
-using osu.Game.Screens.OnlinePlay.Match.Components;
 using osu.Game.Screens.OnlinePlay.Playlists;
 using osu.Game.Tests.Beatmaps;
 using osu.Game.Users;
@@ -85,8 +83,7 @@ namespace osu.Game.Tests.Visual.Playlists
 
             AddStep("move mouse to create button", () =>
             {
-                var footer = match.ChildrenOfType<Footer>().Single();
+                InputManager.MoveMouseTo(this.ChildrenOfType<PlaylistsMatchSettingsOverlay.CreateRoomButton>().Single());
-                InputManager.MoveMouseTo(footer.ChildrenOfType<OsuButton>().Single());
             });
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));

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

@@ -40,6 +40,7 @@ namespace osu.Game.Tests.Visual.UserInterface
         [SetUp]
         public void SetUp() => Schedule(() =>
         {
+            SelectedMods.Value = Array.Empty<Mod>();
             Children = new Drawable[]
             {
                 modSelect = new TestModSelectOverlay
@@ -134,6 +135,8 @@ namespace osu.Game.Tests.Visual.UserInterface
         [Test]
         public void TestExternallySetCustomizedMod()
         {
+            changeRuleset(0);
+
             AddStep("set customized mod externally", () => SelectedMods.Value = new[] { new OsuModDoubleTime { SpeedChange = { Value = 1.01 } } });
 
             AddAssert("ensure button is selected and customized accordingly", () =>

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

@@ -0,0 +1,122 @@
+// 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.Linq;
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Colour;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Graphics.Containers;
+using osuTK.Graphics;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    public class TestSceneSectionsContainer : OsuManualInputManagerTestScene
+    {
+        private readonly SectionsContainer<TestSection> container;
+        private float custom;
+        private const float header_height = 100;
+
+        public TestSceneSectionsContainer()
+        {
+            container = new SectionsContainer<TestSection>
+            {
+                RelativeSizeAxes = Axes.Y,
+                Width = 300,
+                Origin = Anchor.Centre,
+                Anchor = Anchor.Centre,
+                FixedHeader = new Box
+                {
+                    Alpha = 0.5f,
+                    Width = 300,
+                    Height = header_height,
+                    Colour = Color4.Red
+                }
+            };
+            container.SelectedSection.ValueChanged += section =>
+            {
+                if (section.OldValue != null)
+                    section.OldValue.Selected = false;
+                if (section.NewValue != null)
+                    section.NewValue.Selected = true;
+            };
+            Add(container);
+        }
+
+        [Test]
+        public void TestSelection()
+        {
+            AddStep("clear", () => container.Clear());
+            AddStep("add 1/8th", () => append(1 / 8.0f));
+            AddStep("add third", () => append(1 / 3.0f));
+            AddStep("add half", () => append(1 / 2.0f));
+            AddStep("add full", () => append(1));
+            AddSliderStep("set custom", 0.1f, 1.1f, 0.5f, i => custom = i);
+            AddStep("add custom", () => append(custom));
+            AddStep("scroll to previous", () => container.ScrollTo(
+                container.Children.Reverse().SkipWhile(s => s != container.SelectedSection.Value).Skip(1).FirstOrDefault() ?? container.Children.First()
+            ));
+            AddStep("scroll to next", () => container.ScrollTo(
+                container.Children.SkipWhile(s => s != container.SelectedSection.Value).Skip(1).FirstOrDefault() ?? container.Children.Last()
+            ));
+            AddStep("scroll up", () => triggerUserScroll(1));
+            AddStep("scroll down", () => triggerUserScroll(-1));
+        }
+
+        [Test]
+        public void TestCorrectSectionSelected()
+        {
+            const int sections_count = 11;
+            float[] alternating = { 0.07f, 0.33f, 0.16f, 0.33f };
+            AddStep("clear", () => container.Clear());
+            AddStep("fill with sections", () =>
+            {
+                for (int i = 0; i < sections_count; i++)
+                    append(alternating[i % alternating.Length]);
+            });
+
+            void step(int scrollIndex)
+            {
+                AddStep($"scroll to section {scrollIndex + 1}", () => container.ScrollTo(container.Children[scrollIndex]));
+                AddUntilStep("correct section selected", () => container.SelectedSection.Value == container.Children[scrollIndex]);
+            }
+
+            for (int i = 1; i < sections_count; i++)
+                step(i);
+            for (int i = sections_count - 2; i >= 0; i--)
+                step(i);
+
+            AddStep("scroll almost to end", () => container.ScrollTo(container.Children[sections_count - 2]));
+            AddUntilStep("correct section selected", () => container.SelectedSection.Value == container.Children[sections_count - 2]);
+            AddStep("scroll down", () => triggerUserScroll(-1));
+            AddUntilStep("correct section selected", () => container.SelectedSection.Value == container.Children[sections_count - 1]);
+        }
+
+        private static readonly ColourInfo selected_colour = ColourInfo.GradientVertical(Color4.Yellow, Color4.Gold);
+        private static readonly ColourInfo default_colour = ColourInfo.GradientVertical(Color4.White, Color4.DarkGray);
+
+        private void append(float multiplier)
+        {
+            container.Add(new TestSection
+            {
+                Width = 300,
+                Height = (container.ChildSize.Y - header_height) * multiplier,
+                Colour = default_colour
+            });
+        }
+
+        private void triggerUserScroll(float direction)
+        {
+            InputManager.MoveMouseTo(container);
+            InputManager.ScrollVerticalBy(direction);
+        }
+
+        private class TestSection : Box
+        {
+            public bool Selected
+            {
+                set => Colour = value ? selected_colour : default_colour;
+            }
+        }
+    }
+}

osu.Game.Tournament.Tests/Components/TestSceneTournamentModDisplay.cs

@@ -0,0 +1,60 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Rulesets;
+using osu.Game.Tournament.Components;
+
+namespace osu.Game.Tournament.Tests.Components
+{
+    public class TestSceneTournamentModDisplay : TournamentTestScene
+    {
+        [Resolved]
+        private IAPIProvider api { get; set; }
+
+        [Resolved]
+        private RulesetStore rulesets { get; set; }
+
+        private FillFlowContainer<TournamentBeatmapPanel> fillFlow;
+
+        private BeatmapInfo beatmap;
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            var req = new GetBeatmapRequest(new BeatmapInfo { OnlineBeatmapID = 490154 });
+            req.Success += success;
+            api.Queue(req);
+
+            Add(fillFlow = new FillFlowContainer<TournamentBeatmapPanel>
+            {
+                RelativeSizeAxes = Axes.Both,
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Direction = FillDirection.Full,
+                Spacing = new osuTK.Vector2(10)
+            });
+        }
+
+        private void success(APIBeatmap apiBeatmap)
+        {
+            beatmap = apiBeatmap.ToBeatmap(rulesets);
+            var mods = rulesets.GetRuleset(Ladder.Ruleset.Value.ID ?? 0).CreateInstance().GetAllMods();
+
+            foreach (var mod in mods)
+            {
+                fillFlow.Add(new TournamentBeatmapPanel(beatmap, mod.Acronym)
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre
+                });
+            }
+        }
+    }
+}

osu.Game.Tournament.Tests/Screens/TestSceneScheduleScreen.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.
 
+using System;
+using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Tournament.Components;
@@ -16,5 +18,23 @@ namespace osu.Game.Tournament.Tests.Screens
             Add(new TourneyVideo("main") { RelativeSizeAxes = Axes.Both });
             Add(new ScheduleScreen());
         }
+
+        [Test]
+        public void TestCurrentMatchTime()
+        {
+            setMatchDate(TimeSpan.FromDays(-1));
+            setMatchDate(TimeSpan.FromSeconds(5));
+            setMatchDate(TimeSpan.FromMinutes(4));
+            setMatchDate(TimeSpan.FromHours(3));
+        }
+
+        private void setMatchDate(TimeSpan relativeTime)
+            // Humanizer cannot handle negative timespans.
+            => AddStep($"start time is {relativeTime}", () =>
+            {
+                var match = CreateSampleMatch();
+                match.Date.Value = DateTimeOffset.Now + relativeTime;
+                Ladder.CurrentMatch.Value = match;
+            });
     }
 }

osu.Game.Tournament/Components/TournamentBeatmapPanel.cs

@@ -9,7 +9,6 @@ using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
-using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Localisation;
 using osu.Game.Beatmaps;
@@ -23,7 +22,7 @@ namespace osu.Game.Tournament.Components
     public class TournamentBeatmapPanel : CompositeDrawable
     {
         public readonly BeatmapInfo Beatmap;
-        private readonly string mods;
+        private readonly string mod;
 
         private const float horizontal_padding = 10;
         private const float vertical_padding = 10;
@@ -33,12 +32,12 @@ namespace osu.Game.Tournament.Components
         private readonly Bindable<TournamentMatch> currentMatch = new Bindable<TournamentMatch>();
         private Box flash;
 
-        public TournamentBeatmapPanel(BeatmapInfo beatmap, string mods = null)
+        public TournamentBeatmapPanel(BeatmapInfo beatmap, string mod = null)
         {
             if (beatmap == null) throw new ArgumentNullException(nameof(beatmap));
 
             Beatmap = beatmap;
-            this.mods = mods;
+            this.mod = mod;
             Width = 400;
             Height = HEIGHT;
         }
@@ -122,23 +121,15 @@ namespace osu.Game.Tournament.Components
                 },
             });
 
-            if (!string.IsNullOrEmpty(mods))
+            if (!string.IsNullOrEmpty(mod))
             {
-                AddInternal(new Container
+                AddInternal(new TournamentModIcon(mod)
                 {
-                    RelativeSizeAxes = Axes.Y,
-                    Width = 60,
                     Anchor = Anchor.CentreRight,
                     Origin = Anchor.CentreRight,
                     Margin = new MarginPadding(10),
-                    Child = new Sprite
+                    Width = 60,
-                    {
+                    RelativeSizeAxes = Axes.Y,
-                        FillMode = FillMode.Fit,
-                        RelativeSizeAxes = Axes.Both,
-                        Anchor = Anchor.CentreRight,
-                        Origin = Anchor.CentreRight,
-                        Texture = textures.Get($"mods/{mods}"),
-                    }
                 });
             }
         }

osu.Game.Tournament/Components/TournamentModIcon.cs

@@ -0,0 +1,65 @@
+// 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.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Textures;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.UI;
+using osu.Game.Tournament.Models;
+using osuTK;
+
+namespace osu.Game.Tournament.Components
+{
+    /// <summary>
+    /// Mod icon displayed in tournament usages, allowing user overridden graphics.
+    /// </summary>
+    public class TournamentModIcon : CompositeDrawable
+    {
+        private readonly string modAcronym;
+
+        [Resolved]
+        private RulesetStore rulesets { get; set; }
+
+        public TournamentModIcon(string modAcronym)
+        {
+            this.modAcronym = modAcronym;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(TextureStore textures, LadderInfo ladderInfo)
+        {
+            var customTexture = textures.Get($"mods/{modAcronym}");
+
+            if (customTexture != null)
+            {
+                AddInternal(new Sprite
+                {
+                    FillMode = FillMode.Fit,
+                    RelativeSizeAxes = Axes.Both,
+                    Anchor = Anchor.CentreRight,
+                    Origin = Anchor.CentreRight,
+                    Texture = customTexture
+                });
+
+                return;
+            }
+
+            var ruleset = rulesets.GetRuleset(ladderInfo.Ruleset.Value?.ID ?? 0);
+            var modIcon = ruleset?.CreateInstance().GetAllMods().FirstOrDefault(mod => mod.Acronym == modAcronym);
+
+            if (modIcon == null)
+                return;
+
+            AddInternal(new ModIcon(modIcon, false)
+            {
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Scale = new Vector2(0.5f)
+            });
+        }
+    }
+}

osu.Game.Tournament/Screens/Schedule/ScheduleScreen.cs

@@ -192,12 +192,7 @@ namespace osu.Game.Tournament.Screens.Schedule
                                         Origin = Anchor.CentreLeft,
                                         Children = new Drawable[]
                                         {
-                                            new TournamentSpriteText
+                                            new ScheduleMatchDate(match.NewValue.Date.Value)
-                                            {
-                                                Text = "Starting ",
-                                                Font = OsuFont.Torus.With(size: 24, weight: FontWeight.Regular)
-                                            },
-                                            new DrawableDate(match.NewValue.Date.Value)
                                             {
                                                 Font = OsuFont.Torus.With(size: 24, weight: FontWeight.Regular)
                                             }
@@ -251,6 +246,18 @@ namespace osu.Game.Tournament.Screens.Schedule
             }
         }
 
+        public class ScheduleMatchDate : DrawableDate
+        {
+            public ScheduleMatchDate(DateTimeOffset date, float textSize = OsuFont.DEFAULT_FONT_SIZE, bool italic = true)
+                : base(date, textSize, italic)
+            {
+            }
+
+            protected override string Format() => Date < DateTimeOffset.Now
+                ? $"Started {base.Format()}"
+                : $"Starting {base.Format()}";
+        }
+
         public class ScheduleContainer : Container
         {
             protected override Container<Drawable> Content => content;

osu.Game/Beatmaps/Beatmap.cs

@@ -50,15 +50,7 @@ namespace osu.Game.Beatmaps
 
         IBeatmap IBeatmap.Clone() => Clone();
 
-        public Beatmap<T> Clone()
+        public Beatmap<T> Clone() => (Beatmap<T>)MemberwiseClone();
-        {
-            var clone = (Beatmap<T>)MemberwiseClone();
-
-            clone.ControlPointInfo = ControlPointInfo.CreateCopy();
-            // todo: deep clone other elements as required.
-
-            return clone;
-        }
     }
 
     public class Beatmap : Beatmap<HitObject>

osu.Game/Beatmaps/BeatmapManager_BeatmapOnlineLookupQueue.cs

@@ -7,7 +7,6 @@ using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using Dapper;
 using Microsoft.Data.Sqlite;
 using osu.Framework.Development;
 using osu.Framework.IO.Network;
@@ -154,23 +153,34 @@ namespace osu.Game.Beatmaps
                 {
                     using (var db = new SqliteConnection(storage.GetDatabaseConnectionString("online")))
                     {
-                        var found = db.QuerySingleOrDefault<CachedOnlineBeatmapLookup>(
+                        db.Open();
-                            "SELECT * FROM osu_beatmaps WHERE checksum = @MD5Hash OR beatmap_id = @OnlineBeatmapID OR filename = @Path", beatmap);
 
-                        if (found != null)
+                        using (var cmd = db.CreateCommand())
                         {
-                            var status = (BeatmapSetOnlineStatus)found.approved;
+                            cmd.CommandText = "SELECT beatmapset_id, beatmap_id, approved FROM osu_beatmaps WHERE checksum = @MD5Hash OR beatmap_id = @OnlineBeatmapID OR filename = @Path";
+
+                            cmd.Parameters.Add(new SqliteParameter("@MD5Hash", beatmap.MD5Hash));
+                            cmd.Parameters.Add(new SqliteParameter("@OnlineBeatmapID", beatmap.OnlineBeatmapID ?? (object)DBNull.Value));
+                            cmd.Parameters.Add(new SqliteParameter("@Path", beatmap.Path));
+
+                            using (var reader = cmd.ExecuteReader())
+                            {
+                                if (reader.Read())
+                                {
+                                    var status = (BeatmapSetOnlineStatus)reader.GetByte(2);
 
                                     beatmap.Status = status;
                                     beatmap.BeatmapSet.Status = status;
-                            beatmap.BeatmapSet.OnlineBeatmapSetID = found.beatmapset_id;
+                                    beatmap.BeatmapSet.OnlineBeatmapSetID = reader.GetInt32(0);
-                            beatmap.OnlineBeatmapID = found.beatmap_id;
+                                    beatmap.OnlineBeatmapID = reader.GetInt32(1);
 
                                     LogForModel(set, $"Cached local retrieval for {beatmap}.");
                                     return true;
                                 }
                             }
                         }
+                    }
+                }
                 catch (Exception ex)
                 {
                     LogForModel(set, $"Cached local retrieval for {beatmap} failed with {ex}.");

osu.Game/Beatmaps/IBeatmap.cs

@@ -24,7 +24,7 @@ namespace osu.Game.Beatmaps
         /// <summary>
         /// The control points in this beatmap.
         /// </summary>
-        ControlPointInfo ControlPointInfo { get; }
+        ControlPointInfo ControlPointInfo { get; set; }
 
         /// <summary>
         /// The breaks in this beatmap.

osu.Game/Extensions/TaskExtensions.cs

@@ -6,34 +6,11 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
-using osu.Framework.Extensions.ExceptionExtensions;
-using osu.Framework.Logging;
 
 namespace osu.Game.Extensions
 {
     public static class TaskExtensions
     {
-        /// <summary>
-        /// Denote a task which is to be run without local error handling logic, where failure is not catastrophic.
-        /// Avoids unobserved exceptions from being fired.
-        /// </summary>
-        /// <param name="task">The task.</param>
-        /// <param name="logAsError">
-        /// Whether errors should be logged as errors visible to users, or as debug messages.
-        /// Logging as debug will essentially silence the errors on non-release builds.
-        /// </param>
-        public static Task CatchUnobservedExceptions(this Task task, bool logAsError = false)
-        {
-            return task.ContinueWith(t =>
-            {
-                Exception? exception = t.Exception?.AsSingular();
-                if (logAsError)
-                    Logger.Error(exception, $"Error running task: {exception?.Message ?? "(unknown)"}", LoggingTarget.Runtime, true);
-                else
-                    Logger.Log($"Error running task: {exception}", LoggingTarget.Runtime, LogLevel.Debug);
-            }, TaskContinuationOptions.NotOnRanToCompletion);
-        }
-
         /// <summary>
         /// Add a continuation to be performed only after the attached task has completed.
         /// </summary>

osu.Game/Graphics/Containers/ParallaxContainer.cs

@@ -24,6 +24,10 @@ namespace osu.Game.Graphics.Containers
 
         private Bindable<bool> parallaxEnabled;
 
+        private const float parallax_duration = 100;
+
+        private bool firstUpdate = true;
+
         public ParallaxContainer()
         {
             RelativeSizeAxes = Axes.Both;
@@ -60,17 +64,27 @@ namespace osu.Game.Graphics.Containers
             input = GetContainingInputManager();
         }
 
-        private bool firstUpdate = true;
-
         protected override void Update()
         {
             base.Update();
 
             if (parallaxEnabled.Value)
             {
-                Vector2 offset = (input.CurrentState.Mouse == null ? Vector2.Zero : ToLocalSpace(input.CurrentState.Mouse.Position) - DrawSize / 2) * ParallaxAmount;
+                Vector2 offset = Vector2.Zero;
 
-                const float parallax_duration = 100;
+                if (input.CurrentState.Mouse != null)
+                {
+                    var sizeDiv2 = DrawSize / 2;
+
+                    Vector2 relativeAmount = ToLocalSpace(input.CurrentState.Mouse.Position) - sizeDiv2;
+
+                    const float base_factor = 0.999f;
+
+                    relativeAmount.X = (float)(Math.Sign(relativeAmount.X) * Interpolation.Damp(0, 1, base_factor, Math.Abs(relativeAmount.X)));
+                    relativeAmount.Y = (float)(Math.Sign(relativeAmount.Y) * Interpolation.Damp(0, 1, base_factor, Math.Abs(relativeAmount.Y)));
+
+                    offset = relativeAmount * sizeDiv2 * ParallaxAmount;
+                }
 
                 double elapsed = Math.Clamp(Clock.ElapsedFrameTime, 0, parallax_duration);
 

osu.Game/Graphics/Containers/SectionsContainer.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Diagnostics;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
@@ -9,6 +10,7 @@ using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Layout;
+using osu.Framework.Utils;
 
 namespace osu.Game.Graphics.Containers
 {
@@ -20,6 +22,7 @@ namespace osu.Game.Graphics.Containers
         where T : Drawable
     {
         public Bindable<T> SelectedSection { get; } = new Bindable<T>();
+        private Drawable lastClickedSection;
 
         public Drawable ExpandableHeader
         {
@@ -36,7 +39,7 @@ namespace osu.Game.Graphics.Containers
                 if (value == null) return;
 
                 AddInternal(expandableHeader);
-                lastKnownScroll = float.NaN;
+                lastKnownScroll = null;
             }
         }
 
@@ -52,7 +55,7 @@ namespace osu.Game.Graphics.Containers
                 if (value == null) return;
 
                 AddInternal(fixedHeader);
-                lastKnownScroll = float.NaN;
+                lastKnownScroll = null;
             }
         }
 
@@ -71,7 +74,7 @@ namespace osu.Game.Graphics.Containers
                 footer.Anchor |= Anchor.y2;
                 footer.Origin |= Anchor.y2;
                 scrollContainer.Add(footer);
-                lastKnownScroll = float.NaN;
+                lastKnownScroll = null;
             }
         }
 
@@ -89,21 +92,26 @@ namespace osu.Game.Graphics.Containers
 
                 headerBackgroundContainer.Add(headerBackground);
 
-                lastKnownScroll = float.NaN;
+                lastKnownScroll = null;
             }
         }
 
         protected override Container<T> Content => scrollContentContainer;
 
-        private readonly OsuScrollContainer scrollContainer;
+        private readonly UserTrackingScrollContainer scrollContainer;
         private readonly Container headerBackgroundContainer;
         private readonly MarginPadding originalSectionsMargin;
         private Drawable expandableHeader, fixedHeader, footer, headerBackground;
         private FlowContainer<T> scrollContentContainer;
 
-        private float headerHeight, footerHeight;
+        private float? headerHeight, footerHeight;
 
-        private float lastKnownScroll;
+        private float? lastKnownScroll;
+
+        /// <summary>
+        /// The percentage of the container to consider the centre-point for deciding the active section (and scrolling to a requested section).
+        /// </summary>
+        private const float scroll_y_centre = 0.1f;
 
         public SectionsContainer()
         {
@@ -128,18 +136,24 @@ namespace osu.Game.Graphics.Containers
         public override void Add(T drawable)
         {
             base.Add(drawable);
-            lastKnownScroll = float.NaN;
+
-            headerHeight = float.NaN;
+            Debug.Assert(drawable != null);
-            footerHeight = float.NaN;
+
+            lastKnownScroll = null;
+            headerHeight = null;
+            footerHeight = null;
         }
 
-        public void ScrollTo(Drawable section) =>
+        public void ScrollTo(Drawable section)
-            scrollContainer.ScrollTo(scrollContainer.GetChildPosInContent(section) - (FixedHeader?.BoundingBox.Height ?? 0));
+        {
+            lastClickedSection = section;
+            scrollContainer.ScrollTo(scrollContainer.GetChildPosInContent(section) - scrollContainer.DisplayableContent * scroll_y_centre - (FixedHeader?.BoundingBox.Height ?? 0));
+        }
 
         public void ScrollToTop() => scrollContainer.ScrollTo(0);
 
         [NotNull]
-        protected virtual OsuScrollContainer CreateScrollContainer() => new OsuScrollContainer();
+        protected virtual UserTrackingScrollContainer CreateScrollContainer() => new UserTrackingScrollContainer();
 
         [NotNull]
         protected virtual FlowContainer<T> CreateScrollContentContainer() =>
@@ -156,7 +170,7 @@ namespace osu.Game.Graphics.Containers
 
             if (source == InvalidationSource.Child && (invalidation & Invalidation.DrawSize) != 0)
             {
-                lastKnownScroll = -1;
+                lastKnownScroll = null;
                 result = true;
             }
 
@@ -167,7 +181,10 @@ namespace osu.Game.Graphics.Containers
         {
             base.UpdateAfterChildren();
 
-            float headerH = (ExpandableHeader?.LayoutSize.Y ?? 0) + (FixedHeader?.LayoutSize.Y ?? 0);
+            float fixedHeaderSize = FixedHeader?.LayoutSize.Y ?? 0;
+            float expandableHeaderSize = ExpandableHeader?.LayoutSize.Y ?? 0;
+
+            float headerH = expandableHeaderSize + fixedHeaderSize;
             float footerH = Footer?.LayoutSize.Y ?? 0;
 
             if (headerH != headerHeight || footerH != footerHeight)
@@ -183,28 +200,39 @@ namespace osu.Game.Graphics.Containers
             {
                 lastKnownScroll = currentScroll;
 
+                // reset last clicked section because user started scrolling themselves
+                if (scrollContainer.UserScrolling)
+                    lastClickedSection = null;
+
                 if (ExpandableHeader != null && FixedHeader != null)
                 {
-                    float offset = Math.Min(ExpandableHeader.LayoutSize.Y, currentScroll);
+                    float offset = Math.Min(expandableHeaderSize, currentScroll);
 
                     ExpandableHeader.Y = -offset;
-                    FixedHeader.Y = -offset + ExpandableHeader.LayoutSize.Y;
+                    FixedHeader.Y = -offset + expandableHeaderSize;
                 }
 
-                headerBackgroundContainer.Height = (ExpandableHeader?.LayoutSize.Y ?? 0) + (FixedHeader?.LayoutSize.Y ?? 0);
+                headerBackgroundContainer.Height = expandableHeaderSize + fixedHeaderSize;
                 headerBackgroundContainer.Y = ExpandableHeader?.Y ?? 0;
 
-                float scrollOffset = FixedHeader?.LayoutSize.Y ?? 0;
+                var smallestSectionHeight = Children.Count > 0 ? Children.Min(d => d.Height) : 0;
-                Func<T, float> diff = section => scrollContainer.GetChildPosInContent(section) - currentScroll - scrollOffset;
 
-                if (scrollContainer.IsScrolledToEnd())
+                // scroll offset is our fixed header height if we have it plus 10% of content height
-                {
+                // plus 5% to fix floating point errors and to not have a section instantly unselect when scrolling upwards
-                    SelectedSection.Value = Children.LastOrDefault();
+                // but the 5% can't be bigger than our smallest section height, otherwise it won't get selected correctly
-                }
+                float selectionLenienceAboveSection = Math.Min(smallestSectionHeight / 2.0f, scrollContainer.DisplayableContent * 0.05f);
+
+                float scrollCentre = fixedHeaderSize + scrollContainer.DisplayableContent * scroll_y_centre + selectionLenienceAboveSection;
+
+                if (Precision.AlmostBigger(0, scrollContainer.Current))
+                    SelectedSection.Value = lastClickedSection as T ?? Children.FirstOrDefault();
+                else if (Precision.AlmostBigger(scrollContainer.Current, scrollContainer.ScrollableExtent))
+                    SelectedSection.Value = lastClickedSection as T ?? Children.LastOrDefault();
                 else
                 {
-                    SelectedSection.Value = Children.TakeWhile(section => diff(section) <= 0).LastOrDefault()
+                    SelectedSection.Value = Children
-                                            ?? Children.FirstOrDefault();
+                                            .TakeWhile(section => scrollContainer.GetChildPosInContent(section) - currentScroll - scrollCentre <= 0)
+                                            .LastOrDefault() ?? Children.FirstOrDefault();
                 }
             }
         }
@@ -214,8 +242,9 @@ namespace osu.Game.Graphics.Containers
             if (!Children.Any()) return;
 
             var newMargin = originalSectionsMargin;
-            newMargin.Top += headerHeight;
+
-            newMargin.Bottom += footerHeight;
+            newMargin.Top += (headerHeight ?? 0);
+            newMargin.Bottom += (footerHeight ?? 0);
 
             scrollContentContainer.Margin = newMargin;
         }

osu.Game/Graphics/Containers/UserTrackingScrollContainer.cs

@@ -0,0 +1,49 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+
+namespace osu.Game.Graphics.Containers
+{
+    public class UserTrackingScrollContainer : UserTrackingScrollContainer<Drawable>
+    {
+        public UserTrackingScrollContainer()
+        {
+        }
+
+        public UserTrackingScrollContainer(Direction direction)
+            : base(direction)
+        {
+        }
+    }
+
+    public class UserTrackingScrollContainer<T> : OsuScrollContainer<T>
+        where T : Drawable
+    {
+        /// <summary>
+        /// Whether the last scroll event was user triggered, directly on the scroll container.
+        /// </summary>
+        public bool UserScrolling { get; private set; }
+
+        public UserTrackingScrollContainer()
+        {
+        }
+
+        public UserTrackingScrollContainer(Direction direction)
+            : base(direction)
+        {
+        }
+
+        protected override void OnUserScroll(float value, bool animated = true, double? distanceDecay = default)
+        {
+            UserScrolling = true;
+            base.OnUserScroll(value, animated, distanceDecay);
+        }
+
+        public new void ScrollTo(float value, bool animated = true, double? distanceDecay = null)
+        {
+            UserScrolling = false;
+            base.ScrollTo(value, animated, distanceDecay);
+        }
+    }
+}

osu.Game/Online/API/APIMod.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using Humanizer;
+using MessagePack;
 using Newtonsoft.Json;
 using osu.Framework.Bindables;
 using osu.Game.Configuration;
@@ -13,16 +14,20 @@ using osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Online.API
 {
+    [MessagePackObject]
     public class APIMod : IMod
     {
         [JsonProperty("acronym")]
+        [Key(0)]
         public string Acronym { get; set; }
 
         [JsonProperty("settings")]
+        [Key(1)]
         public Dictionary<string, object> Settings { get; set; } = new Dictionary<string, object>();
 
         [JsonConstructor]
-        private APIMod()
+        [SerializationConstructor]
+        public APIMod()
         {
         }
 

osu.Game/Online/API/Requests/Responses/APIBeatmapSet.cs

@@ -81,7 +81,7 @@ namespace osu.Game.Online.API.Requests.Responses
         [JsonProperty(@"beatmaps")]
         private IEnumerable<APIBeatmap> beatmaps { get; set; }
 
-        public BeatmapSetInfo ToBeatmapSet(RulesetStore rulesets)
+        public virtual BeatmapSetInfo ToBeatmapSet(RulesetStore rulesets)
         {
             var beatmapSet = new BeatmapSetInfo
             {

osu.Game/Online/Chat/ChannelManager.cs

@@ -339,7 +339,7 @@ namespace osu.Game.Online.Chat
         }
 
         /// <summary>
-        /// Joins a channel if it has not already been joined.
+        /// Joins a channel if it has not already been joined. Must be called from the update thread.
         /// </summary>
         /// <param name="channel">The channel to join.</param>
         /// <returns>The joined channel. Note that this may not match the parameter channel as it is a backed object.</returns>
@@ -399,7 +399,11 @@ namespace osu.Game.Online.Chat
             return channel;
         }
 
-        public void LeaveChannel(Channel channel)
+        /// <summary>
+        /// Leave the specified channel. Can be called from any thread.
+        /// </summary>
+        /// <param name="channel">The channel to leave.</param>
+        public void LeaveChannel(Channel channel) => Schedule(() =>
         {
             if (channel == null) return;
 
@@ -413,7 +417,7 @@ namespace osu.Game.Online.Chat
                 api.Queue(new LeaveChannelRequest(channel));
                 channel.Joined.Value = false;
             }
-        }
+        });
 
         private long lastMessageId;
 

osu.Game/Online/Multiplayer/MultiplayerClient.cs

@@ -10,6 +10,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.SignalR.Client;
 using Microsoft.Extensions.DependencyInjection;
 using Newtonsoft.Json;
+using osu.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Logging;
@@ -65,13 +66,19 @@ namespace osu.Game.Online.Multiplayer
             if (connection != null)
                 return;
 
-            connection = new HubConnectionBuilder()
+            var builder = new HubConnectionBuilder()
-                         .WithUrl(endpoint, options =>
+                .WithUrl(endpoint, options => { options.Headers.Add("Authorization", $"Bearer {api.AccessToken}"); });
+
+            if (RuntimeInfo.SupportsJIT)
+                builder.AddMessagePackProtocol();
+            else
             {
-                             options.Headers.Add("Authorization", $"Bearer {api.AccessToken}");
+                // eventually we will precompile resolvers for messagepack, but this isn't working currently
-                         })
+                // see https://github.com/neuecc/MessagePack-CSharp/issues/780#issuecomment-768794308.
-                         .AddNewtonsoftJsonProtocol(options => { options.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; })
+                builder.AddNewtonsoftJsonProtocol(options => { options.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; });
-                         .Build();
+            }
+
+            connection = builder.Build();
 
             // this is kind of SILLY
             // https://github.com/dotnet/aspnetcore/issues/15198

osu.Game/Online/Multiplayer/MultiplayerRoom.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using MessagePack;
 using Newtonsoft.Json;
 
 namespace osu.Game.Online.Multiplayer
@@ -13,35 +14,42 @@ namespace osu.Game.Online.Multiplayer
     /// A multiplayer room.
     /// </summary>
     [Serializable]
+    [MessagePackObject]
     public class MultiplayerRoom
     {
         /// <summary>
         /// The ID of the room, used for database persistence.
         /// </summary>
+        [Key(0)]
         public readonly long RoomID;
 
         /// <summary>
         /// The current state of the room (ie. whether it is in progress or otherwise).
         /// </summary>
+        [Key(1)]
         public MultiplayerRoomState State { get; set; }
 
         /// <summary>
         /// All currently enforced game settings for this room.
         /// </summary>
+        [Key(2)]
         public MultiplayerRoomSettings Settings { get; set; } = new MultiplayerRoomSettings();
 
         /// <summary>
         /// All users currently in this room.
         /// </summary>
+        [Key(3)]
         public List<MultiplayerRoomUser> Users { get; set; } = new List<MultiplayerRoomUser>();
 
         /// <summary>
         /// The host of this room, in control of changing room settings.
         /// </summary>
+        [Key(4)]
         public MultiplayerRoomUser? Host { get; set; }
 
         [JsonConstructor]
-        public MultiplayerRoom(in long roomId)
+        [SerializationConstructor]
+        public MultiplayerRoom(long roomId)
         {
             RoomID = roomId;
         }

osu.Game/Online/Multiplayer/MultiplayerRoomSettings.cs

@@ -7,22 +7,29 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using JetBrains.Annotations;
+using MessagePack;
 using osu.Game.Online.API;
 
 namespace osu.Game.Online.Multiplayer
 {
     [Serializable]
+    [MessagePackObject]
     public class MultiplayerRoomSettings : IEquatable<MultiplayerRoomSettings>
     {
+        [Key(0)]
         public int BeatmapID { get; set; }
 
+        [Key(1)]
         public int RulesetID { get; set; }
 
+        [Key(2)]
         public string BeatmapChecksum { get; set; } = string.Empty;
 
+        [Key(3)]
         public string Name { get; set; } = "Unnamed room";
 
         [NotNull]
+        [Key(4)]
         public IEnumerable<APIMod> Mods { get; set; } = Enumerable.Empty<APIMod>();
 
         public bool Equals(MultiplayerRoomSettings other)

osu.Game/Online/Multiplayer/MultiplayerRoomUser.cs

@@ -4,6 +4,7 @@
 #nullable enable
 
 using System;
+using MessagePack;
 using Newtonsoft.Json;
 using osu.Game.Online.Rooms;
 using osu.Game.Users;
@@ -11,21 +12,26 @@ using osu.Game.Users;
 namespace osu.Game.Online.Multiplayer
 {
     [Serializable]
+    [MessagePackObject]
     public class MultiplayerRoomUser : IEquatable<MultiplayerRoomUser>
     {
+        [Key(0)]
         public readonly int UserID;
 
+        [Key(1)]
         public MultiplayerUserState State { get; set; } = MultiplayerUserState.Idle;
 
         /// <summary>
         /// The availability state of the current beatmap.
         /// </summary>
+        [Key(2)]
         public BeatmapAvailability BeatmapAvailability { get; set; } = BeatmapAvailability.LocallyAvailable();
 
+        [IgnoreMember]
         public User? User { get; set; }
 
         [JsonConstructor]
-        public MultiplayerRoomUser(in int userId)
+        public MultiplayerRoomUser(int userId)
         {
             UserID = userId;
         }

osu.Game/Online/Multiplayer/StatefulMultiplayerClient.cs

@@ -15,7 +15,6 @@ using osu.Framework.Graphics;
 using osu.Framework.Logging;
 using osu.Game.Beatmaps;
 using osu.Game.Database;
-using osu.Game.Extensions;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
 using osu.Game.Online.API.Requests.Responses;
@@ -104,7 +103,7 @@ namespace osu.Game.Online.Multiplayer
                 if (!connected.NewValue && Room != null)
                 {
                     Logger.Log("Connection to multiplayer server was lost.", LoggingTarget.Runtime, LogLevel.Important);
-                    LeaveRoom().CatchUnobservedExceptions();
+                    LeaveRoom();
                 }
             });
         }

osu.Game/Online/Rooms/BeatmapAvailability.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using MessagePack;
 using Newtonsoft.Json;
 
 namespace osu.Game.Online.Rooms
@@ -9,20 +10,23 @@ namespace osu.Game.Online.Rooms
     /// <summary>
     /// The local availability information about a certain beatmap for the client.
     /// </summary>
+    [MessagePackObject]
     public class BeatmapAvailability : IEquatable<BeatmapAvailability>
     {
         /// <summary>
         /// The beatmap's availability state.
         /// </summary>
+        [Key(0)]
         public readonly DownloadState State;
 
         /// <summary>
         /// The beatmap's downloading progress, null when not in <see cref="DownloadState.Downloading"/> state.
         /// </summary>
+        [Key(1)]
         public readonly double? DownloadProgress;
 
         [JsonConstructor]
-        private BeatmapAvailability(DownloadState state, double? downloadProgress = null)
+        public BeatmapAvailability(DownloadState state, double? downloadProgress = null)
         {
             State = state;
             DownloadProgress = downloadProgress;

osu.Game/Online/Spectator/FrameDataBundle.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using MessagePack;
 using Newtonsoft.Json;
 using osu.Game.Replays.Legacy;
 using osu.Game.Scoring;
@@ -12,10 +13,13 @@ using osu.Game.Scoring;
 namespace osu.Game.Online.Spectator
 {
     [Serializable]
+    [MessagePackObject]
     public class FrameDataBundle
     {
+        [Key(0)]
         public FrameHeader Header { get; set; }
 
+        [Key(1)]
         public IEnumerable<LegacyReplayFrame> Frames { get; set; }
 
         public FrameDataBundle(ScoreInfo score, IEnumerable<LegacyReplayFrame> frames)

osu.Game/Online/Spectator/FrameHeader.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using MessagePack;
 using Newtonsoft.Json;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Scoring;
@@ -12,31 +13,37 @@ using osu.Game.Scoring;
 namespace osu.Game.Online.Spectator
 {
     [Serializable]
+    [MessagePackObject]
     public class FrameHeader
     {
         /// <summary>
         /// The current accuracy of the score.
         /// </summary>
+        [Key(0)]
         public double Accuracy { get; set; }
 
         /// <summary>
         /// The current combo of the score.
         /// </summary>
+        [Key(1)]
         public int Combo { get; set; }
 
         /// <summary>
         /// The maximum combo achieved up to the current point in time.
         /// </summary>
+        [Key(2)]
         public int MaxCombo { get; set; }
 
         /// <summary>
         /// Cumulative hit statistics.
         /// </summary>
+        [Key(3)]
         public Dictionary<HitResult, int> Statistics { get; set; }
 
         /// <summary>
         /// The time at which this frame was received by the server.
         /// </summary>
+        [Key(4)]
         public DateTimeOffset ReceivedTime { get; set; }
 
         /// <summary>
@@ -54,7 +61,8 @@ namespace osu.Game.Online.Spectator
         }
 
         [JsonConstructor]
-        public FrameHeader(int combo, int maxCombo, double accuracy, Dictionary<HitResult, int> statistics, DateTimeOffset receivedTime)
+        [SerializationConstructor]
+        public FrameHeader(double accuracy, int combo, int maxCombo, Dictionary<HitResult, int> statistics, DateTimeOffset receivedTime)
         {
             Combo = combo;
             MaxCombo = maxCombo;

osu.Game/Online/Spectator/SpectatorState.cs

@@ -5,18 +5,23 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using MessagePack;
 using osu.Game.Online.API;
 
 namespace osu.Game.Online.Spectator
 {
     [Serializable]
+    [MessagePackObject]
     public class SpectatorState : IEquatable<SpectatorState>
     {
+        [Key(0)]
         public int? BeatmapID { get; set; }
 
+        [Key(1)]
         public int? RulesetID { get; set; }
 
         [NotNull]
+        [Key(2)]
         public IEnumerable<APIMod> Mods { get; set; } = Enumerable.Empty<APIMod>();
 
         public bool Equals(SpectatorState other) => BeatmapID == other?.BeatmapID && Mods.SequenceEqual(other?.Mods) && RulesetID == other?.RulesetID;

osu.Game/Online/Spectator/SpectatorStreamingClient.cs

@@ -10,6 +10,7 @@ using JetBrains.Annotations;
 using Microsoft.AspNetCore.SignalR.Client;
 using Microsoft.Extensions.DependencyInjection;
 using Newtonsoft.Json;
+using osu.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -116,14 +117,19 @@ namespace osu.Game.Online.Spectator
             if (connection != null)
                 return;
 
-            connection = new HubConnectionBuilder()
+            var builder = new HubConnectionBuilder()
-                         .WithUrl(endpoint, options =>
+                .WithUrl(endpoint, options => { options.Headers.Add("Authorization", $"Bearer {api.AccessToken}"); });
-                         {
-                             options.Headers.Add("Authorization", $"Bearer {api.AccessToken}");
-                         })
-                         .AddNewtonsoftJsonProtocol(options => { options.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; })
-                         .Build();
 
+            if (RuntimeInfo.SupportsJIT)
+                builder.AddMessagePackProtocol();
+            else
+            {
+                // eventually we will precompile resolvers for messagepack, but this isn't working currently
+                // see https://github.com/neuecc/MessagePack-CSharp/issues/780#issuecomment-768794308.
+                builder.AddNewtonsoftJsonProtocol(options => { options.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; });
+            }
+
+            connection = builder.Build();
             // until strong typed client support is added, each method must be manually bound (see https://github.com/dotnet/aspnetcore/issues/15198)
             connection.On<int, SpectatorState>(nameof(ISpectatorClient.UserBeganPlaying), ((ISpectatorClient)this).UserBeganPlaying);
             connection.On<int, FrameDataBundle>(nameof(ISpectatorClient.UserSentFrames), ((ISpectatorClient)this).UserSentFrames);

osu.Game/OsuGameBase.cs

@@ -327,6 +327,7 @@ namespace osu.Game
 
             if (!SelectedMods.Disabled)
                 SelectedMods.Value = Array.Empty<Mod>();
+
             AvailableMods.Value = dict;
         }
 

osu.Game/Overlays/BeatmapListing/BeatmapSearchFilterRow.cs

@@ -12,7 +12,7 @@ using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
 using osuTK;
 using Humanizer;
-using osu.Game.Utils;
+using osu.Framework.Extensions.EnumExtensions;
 
 namespace osu.Game.Overlays.BeatmapListing
 {
@@ -80,7 +80,7 @@ namespace osu.Game.Overlays.BeatmapListing
 
                 if (typeof(T).IsEnum)
                 {
-                    foreach (var val in OrderAttributeUtils.GetValuesInOrder<T>())
+                    foreach (var val in EnumExtensions.GetValuesInOrder<T>())
                         AddItem(val);
                 }
             }

osu.Game/Overlays/BeatmapListing/SearchLanguage.cs

@@ -1,7 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Game.Utils;
+using osu.Framework.Utils;
 
 namespace osu.Game.Overlays.BeatmapListing
 {

osu.Game/Overlays/BeatmapListingOverlay.cs

@@ -176,23 +176,34 @@ namespace osu.Game.Overlays
             loadingLayer.Hide();
             lastFetchDisplayedTime = Time.Current;
 
+            if (content == currentContent)
+                return;
+
             var lastContent = currentContent;
 
             if (lastContent != null)
             {
-                lastContent.FadeOut(100, Easing.OutQuint).Expire();
+                var transform = lastContent.FadeOut(100, Easing.OutQuint);
 
+                if (lastContent == notFoundContent)
+                {
+                    // not found display may be used multiple times, so don't expire/dispose it.
+                    transform.Schedule(() => panelTarget.Remove(lastContent));
+                }
+                else
+                {
                     // Consider the case when the new content is smaller than the last content.
                     // If the auto-size computation is delayed until fade out completes, the background remain high for too long making the resulting transition to the smaller height look weird.
                     // At the same time, if the last content's height is bypassed immediately, there is a period where the new content is at Alpha = 0 when the auto-sized height will be 0.
                     // To resolve both of these issues, the bypass is delayed until a point when the content transitions (fade-in and fade-out) overlap and it looks good to do so.
-                lastContent.Delay(25).Schedule(() => lastContent.BypassAutoSizeAxes = Axes.Y).Then().Schedule(() => panelTarget.Remove(lastContent));
+                    lastContent.Delay(25).Schedule(() => lastContent.BypassAutoSizeAxes = Axes.Y).Then().Schedule(() => lastContent.Expire());
+                }
             }
 
             if (!content.IsAlive)
                 panelTarget.Add(content);
-            content.FadeIn(200, Easing.OutQuint);
 
+            content.FadeInFromZero(200, Easing.OutQuint);
             currentContent = content;
         }
 
@@ -202,7 +213,7 @@ namespace osu.Game.Overlays
             base.Dispose(isDisposing);
         }
 
-        private class NotFoundDrawable : CompositeDrawable
+        public class NotFoundDrawable : CompositeDrawable
         {
             public NotFoundDrawable()
             {

osu.Game/Overlays/BeatmapSet/BeatmapSetHeader.cs

@@ -1,25 +1,55 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Effects;
+using osu.Game.Beatmaps;
 using osu.Game.Rulesets;
+using osuTK;
+using osuTK.Graphics;
 
 namespace osu.Game.Overlays.BeatmapSet
 {
     public class BeatmapSetHeader : OverlayHeader
     {
-        public readonly Bindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
+        public readonly Bindable<BeatmapSetInfo> BeatmapSet = new Bindable<BeatmapSetInfo>();
 
+        public BeatmapSetHeaderContent HeaderContent { get; private set; }
+
+        [Cached]
         public BeatmapRulesetSelector RulesetSelector { get; private set; }
 
-        protected override OverlayTitle CreateTitle() => new BeatmapHeaderTitle();
+        [Cached(typeof(IBindable<RulesetInfo>))]
+        private readonly Bindable<RulesetInfo> ruleset = new Bindable<RulesetInfo>();
+
+        public BeatmapSetHeader()
+        {
+            Masking = true;
+
+            EdgeEffect = new EdgeEffectParameters
+            {
+                Colour = Color4.Black.Opacity(0.25f),
+                Type = EdgeEffectType.Shadow,
+                Radius = 3,
+                Offset = new Vector2(0f, 1f),
+            };
+        }
+
+        protected override Drawable CreateContent() => HeaderContent = new BeatmapSetHeaderContent
+        {
+            BeatmapSet = { BindTarget = BeatmapSet }
+        };
 
         protected override Drawable CreateTitleContent() => RulesetSelector = new BeatmapRulesetSelector
         {
-            Current = Ruleset
+            Current = ruleset
         };
 
+        protected override OverlayTitle CreateTitle() => new BeatmapHeaderTitle();
+
         private class BeatmapHeaderTitle : OverlayTitle
         {
             public BeatmapHeaderTitle()

osu.Game/Overlays/BeatmapSet/BeatmapSetHeaderContent.cs

@@ -3,12 +3,10 @@
 
 using System.Linq;
 using osu.Framework.Allocation;
-using osu.Framework.Bindables;
 using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Effects;
 using osu.Framework.Graphics.Shapes;
 using osu.Game.Beatmaps.Drawables;
 using osu.Game.Graphics;
@@ -18,18 +16,21 @@ using osu.Game.Online;
 using osu.Game.Online.API;
 using osu.Game.Overlays.BeatmapListing.Panels;
 using osu.Game.Overlays.BeatmapSet.Buttons;
-using osu.Game.Rulesets;
 using osuTK;
-using osuTK.Graphics;
 
 namespace osu.Game.Overlays.BeatmapSet
 {
-    public class Header : BeatmapDownloadTrackingComposite
+    public class BeatmapSetHeaderContent : BeatmapDownloadTrackingComposite
     {
         private const float transition_duration = 200;
         private const float buttons_height = 45;
         private const float buttons_spacing = 5;
 
+        public bool DownloadButtonsVisible => downloadButtonsContainer.Any();
+
+        public readonly Details Details;
+        public readonly BeatmapPicker Picker;
+
         private readonly UpdateableBeatmapSetCover cover;
         private readonly Box coverGradient;
         private readonly OsuSpriteText title, artist;
@@ -38,52 +39,23 @@ namespace osu.Game.Overlays.BeatmapSet
         private readonly FillFlowContainer downloadButtonsContainer;
         private readonly BeatmapAvailability beatmapAvailability;
         private readonly BeatmapSetOnlineStatusPill onlineStatusPill;
-        public Details Details;
+        private readonly FavouriteButton favouriteButton;
-
+        private readonly FillFlowContainer fadeContent;
-        public bool DownloadButtonsVisible => downloadButtonsContainer.Any();
+        private readonly LoadingSpinner loading;
 
         [Resolved]
         private IAPIProvider api { get; set; }
 
-        public BeatmapRulesetSelector RulesetSelector => beatmapSetHeader.RulesetSelector;
+        [Resolved]
-        public readonly BeatmapPicker Picker;
+        private BeatmapRulesetSelector rulesetSelector { get; set; }
 
-        private readonly FavouriteButton favouriteButton;
+        public BeatmapSetHeaderContent()
-        private readonly FillFlowContainer fadeContent;
-        private readonly LoadingSpinner loading;
-        private readonly BeatmapSetHeader beatmapSetHeader;
-
-        [Cached(typeof(IBindable<RulesetInfo>))]
-        private readonly Bindable<RulesetInfo> ruleset = new Bindable<RulesetInfo>();
-
-        public Header()
         {
             ExternalLinkButton externalLink;
 
             RelativeSizeAxes = Axes.X;
             AutoSizeAxes = Axes.Y;
-            Masking = true;
+            InternalChild = new Container
-
-            EdgeEffect = new EdgeEffectParameters
-            {
-                Colour = Color4.Black.Opacity(0.25f),
-                Type = EdgeEffectType.Shadow,
-                Radius = 3,
-                Offset = new Vector2(0f, 1f),
-            };
-
-            InternalChild = new FillFlowContainer
-            {
-                RelativeSizeAxes = Axes.X,
-                AutoSizeAxes = Axes.Y,
-                Direction = FillDirection.Vertical,
-                Children = new Drawable[]
-                {
-                    beatmapSetHeader = new BeatmapSetHeader
-                    {
-                        Ruleset = { BindTarget = ruleset },
-                    },
-                    new Container
             {
                 RelativeSizeAxes = Axes.X,
                 AutoSizeAxes = Axes.Y,
@@ -217,8 +189,6 @@ namespace osu.Game.Overlays.BeatmapSet
                             Details = new Details(),
                         },
                     },
-                        },
-                    },
                 }
             };
 
@@ -239,7 +209,7 @@ namespace osu.Game.Overlays.BeatmapSet
 
             BeatmapSet.BindValueChanged(setInfo =>
             {
-                Picker.BeatmapSet = RulesetSelector.BeatmapSet = author.BeatmapSet = beatmapAvailability.BeatmapSet = Details.BeatmapSet = setInfo.NewValue;
+                Picker.BeatmapSet = rulesetSelector.BeatmapSet = author.BeatmapSet = beatmapAvailability.BeatmapSet = Details.BeatmapSet = setInfo.NewValue;
                 cover.BeatmapSet = setInfo.NewValue;
 
                 if (setInfo.NewValue == null)

osu.Game/Overlays/BeatmapSet/Scores/ScoreTable.cs

@@ -7,6 +7,7 @@ using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions;
+using osu.Framework.Extensions.EnumExtensions;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.Sprites;
@@ -15,7 +16,6 @@ using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI;
 using osu.Game.Scoring;
 using osu.Game.Users.Drawables;
-using osu.Game.Utils;
 using osuTK;
 using osuTK.Graphics;
 
@@ -105,7 +105,7 @@ namespace osu.Game.Overlays.BeatmapSet.Scores
 
             var ruleset = scores.First().Ruleset.CreateInstance();
 
-            foreach (var result in OrderAttributeUtils.GetValuesInOrder<HitResult>())
+            foreach (var result in EnumExtensions.GetValuesInOrder<HitResult>())
             {
                 if (!allScoreStatistics.Contains(result))
                     continue;

osu.Game/Overlays/BeatmapSetOverlay.cs

@@ -19,15 +19,12 @@ using osuTK;
 
 namespace osu.Game.Overlays
 {
-    public class BeatmapSetOverlay : FullscreenOverlay<OverlayHeader> // we don't provide a standard header for now.
+    public class BeatmapSetOverlay : FullscreenOverlay<BeatmapSetHeader>
     {
         public const float X_PADDING = 40;
         public const float Y_PADDING = 25;
         public const float RIGHT_WIDTH = 275;
 
-        //todo: should be an OverlayHeader? or maybe not?
-        protected new readonly Header Header;
-
         [Resolved]
         private RulesetStore rulesets { get; set; }
 
@@ -39,7 +36,7 @@ namespace osu.Game.Overlays
         private readonly Box background;
 
         public BeatmapSetOverlay()
-            : base(OverlayColourScheme.Blue, null)
+            : base(OverlayColourScheme.Blue, new BeatmapSetHeader())
         {
             OverlayScrollContainer scroll;
             Info info;
@@ -72,14 +69,14 @@ namespace osu.Game.Overlays
                                     Direction = FillDirection.Vertical,
                                     Children = new Drawable[]
                                     {
-                                        Header = new Header(),
+                                        Header,
                                         info = new Info()
                                     }
                                 },
                             },
                             new ScoresContainer
                             {
-                                Beatmap = { BindTarget = Header.Picker.Beatmap }
+                                Beatmap = { BindTarget = Header.HeaderContent.Picker.Beatmap }
                             },
                             comments = new CommentsSection()
                         },
@@ -91,7 +88,7 @@ namespace osu.Game.Overlays
             info.BeatmapSet.BindTo(beatmapSet);
             comments.BeatmapSet.BindTo(beatmapSet);
 
-            Header.Picker.Beatmap.ValueChanged += b =>
+            Header.HeaderContent.Picker.Beatmap.ValueChanged += b =>
             {
                 info.Beatmap = b.NewValue;
 
@@ -125,7 +122,7 @@ namespace osu.Game.Overlays
             req.Success += res =>
             {
                 beatmapSet.Value = res.ToBeatmapSet(rulesets);
-                Header.Picker.Beatmap.Value = Header.BeatmapSet.Value.Beatmaps.First(b => b.OnlineBeatmapID == beatmapId);
+                Header.HeaderContent.Picker.Beatmap.Value = Header.BeatmapSet.Value.Beatmaps.First(b => b.OnlineBeatmapID == beatmapId);
             };
             API.Queue(req);
 

osu.Game/Overlays/Chat/ChatLine.cs

@@ -190,13 +190,13 @@ namespace osu.Game.Overlays.Chat
                     }
                 }
             };
-
-            updateMessageContent();
         }
 
         protected override void LoadComplete()
         {
             base.LoadComplete();
+
+            updateMessageContent();
             FinishTransforms(true);
         }
 

osu.Game/Overlays/Comments/VotePill.cs

@@ -33,11 +33,16 @@ namespace osu.Game.Overlays.Comments
         [Resolved]
         private IAPIProvider api { get; set; }
 
+        [Resolved(canBeNull: true)]
+        private LoginOverlay login { get; set; }
+
         [Resolved]
         private OverlayColourProvider colourProvider { get; set; }
 
+        protected Box Background { get; private set; }
+
         private readonly Comment comment;
-        private Box background;
+
         private Box hoverLayer;
         private CircularContainer borderContainer;
         private SpriteText sideNumber;
@@ -62,8 +67,12 @@ namespace osu.Game.Overlays.Comments
             AccentColour = borderContainer.BorderColour = sideNumber.Colour = colours.GreenLight;
             hoverLayer.Colour = Color4.Black.Opacity(0.5f);
 
-            if (api.IsLoggedIn && api.LocalUser.Value.Id != comment.UserId)
+            var ownComment = api.LocalUser.Value.Id == comment.UserId;
+
+            if (!ownComment)
                 Action = onAction;
+
+            Background.Alpha = ownComment ? 0 : 1;
         }
 
         protected override void LoadComplete()
@@ -71,12 +80,18 @@ namespace osu.Game.Overlays.Comments
             base.LoadComplete();
             isVoted.Value = comment.IsVoted;
             votesCount.Value = comment.VotesCount;
-            isVoted.BindValueChanged(voted => background.Colour = voted.NewValue ? AccentColour : colourProvider.Background6, true);
+            isVoted.BindValueChanged(voted => Background.Colour = voted.NewValue ? AccentColour : colourProvider.Background6, true);
             votesCount.BindValueChanged(count => votesCounter.Text = $"+{count.NewValue}", true);
         }
 
         private void onAction()
         {
+            if (!api.IsLoggedIn)
+            {
+                login?.Show();
+                return;
+            }
+
             request = new CommentVoteRequest(comment.Id, isVoted.Value ? CommentVoteAction.UnVote : CommentVoteAction.Vote);
             request.Success += onSuccess;
             api.Queue(request);
@@ -102,7 +117,7 @@ namespace osu.Game.Overlays.Comments
                     Masking = true,
                     Children = new Drawable[]
                     {
-                        background = new Box
+                        Background = new Box
                         {
                             RelativeSizeAxes = Axes.Both
                         },

osu.Game/Overlays/Mods/ModButton.cs

@@ -236,13 +236,13 @@ namespace osu.Game.Overlays.Mods
             {
                 iconsContainer.AddRange(new[]
                 {
-                    backgroundIcon = new PassThroughTooltipModIcon(Mods[1])
+                    backgroundIcon = new ModIcon(Mods[1], false)
                     {
                         Origin = Anchor.BottomRight,
                         Anchor = Anchor.BottomRight,
                         Position = new Vector2(1.5f),
                     },
-                    foregroundIcon = new PassThroughTooltipModIcon(Mods[0])
+                    foregroundIcon = new ModIcon(Mods[0], false)
                     {
                         Origin = Anchor.BottomRight,
                         Anchor = Anchor.BottomRight,
@@ -252,7 +252,7 @@ namespace osu.Game.Overlays.Mods
             }
             else
             {
-                iconsContainer.Add(foregroundIcon = new PassThroughTooltipModIcon(Mod)
+                iconsContainer.Add(foregroundIcon = new ModIcon(Mod, false)
                 {
                     Origin = Anchor.Centre,
                     Anchor = Anchor.Centre,
@@ -297,15 +297,5 @@ namespace osu.Game.Overlays.Mods
 
             Mod = mod;
         }
-
-        private class PassThroughTooltipModIcon : ModIcon
-        {
-            public override string TooltipText => null;
-
-            public PassThroughTooltipModIcon(Mod mod)
-                : base(mod)
-            {
-            }
-        }
     }
 }

osu.Game/Overlays/Mods/ModSelectOverlay.cs

@@ -30,6 +30,7 @@ namespace osu.Game.Overlays.Mods
 {
     public class ModSelectOverlay : WaveOverlayContainer
     {
+        private readonly Func<Mod, bool> isValidMod;
         public const float HEIGHT = 510;
 
         protected readonly TriangleButton DeselectAllButton;
@@ -60,8 +61,10 @@ namespace osu.Game.Overlays.Mods
 
         private SampleChannel sampleOn, sampleOff;
 
-        public ModSelectOverlay()
+        public ModSelectOverlay(Func<Mod, bool> isValidMod = null)
         {
+            this.isValidMod = isValidMod ?? (m => true);
+
             Waves.FirstWaveColour = Color4Extensions.FromHex(@"19b0e2");
             Waves.SecondWaveColour = Color4Extensions.FromHex(@"2280a2");
             Waves.ThirdWaveColour = Color4Extensions.FromHex(@"005774");
@@ -213,9 +216,9 @@ namespace osu.Game.Overlays.Mods
                         },
                         new Drawable[]
                         {
-                            // Footer
                             new Container
                             {
+                                Name = "Footer content",
                                 RelativeSizeAxes = Axes.X,
                                 AutoSizeAxes = Axes.Y,
                                 Origin = Anchor.TopCentre,
@@ -234,10 +237,9 @@ namespace osu.Game.Overlays.Mods
                                         Anchor = Anchor.BottomCentre,
                                         AutoSizeAxes = Axes.Y,
                                         RelativeSizeAxes = Axes.X,
+                                        RelativePositionAxes = Axes.X,
                                         Width = content_width,
                                         Spacing = new Vector2(footer_button_spacing, footer_button_spacing / 2),
-                                        LayoutDuration = 100,
-                                        LayoutEasing = Easing.OutQuint,
                                         Padding = new MarginPadding
                                         {
                                             Vertical = 15,
@@ -351,7 +353,7 @@ namespace osu.Game.Overlays.Mods
         {
             base.PopOut();
 
-            footerContainer.MoveToX(footerContainer.DrawSize.X, WaveContainer.DISAPPEAR_DURATION, Easing.InSine);
+            footerContainer.MoveToX(content_width, WaveContainer.DISAPPEAR_DURATION, Easing.InSine);
             footerContainer.FadeOut(WaveContainer.DISAPPEAR_DURATION, Easing.InSine);
 
             foreach (var section in ModSectionsContainer.Children)
@@ -403,7 +405,7 @@ namespace osu.Game.Overlays.Mods
             if (mods.NewValue == null) return;
 
             foreach (var section in ModSectionsContainer.Children)
-                section.Mods = mods.NewValue[section.ModType];
+                section.Mods = mods.NewValue[section.ModType].Where(isValidMod);
         }
 
         private void selectedModsChanged(ValueChangedEvent<IReadOnlyList<Mod>> mods)

osu.Game/Overlays/OverlayScrollContainer.cs

@@ -17,9 +17,9 @@ using osuTK.Graphics;
 namespace osu.Game.Overlays
 {
     /// <summary>
-    /// <see cref="OsuScrollContainer"/> which provides <see cref="ScrollToTopButton"/>. Mostly used in <see cref="FullscreenOverlay{T}"/>.
+    /// <see cref="UserTrackingScrollContainer"/> which provides <see cref="ScrollToTopButton"/>. Mostly used in <see cref="FullscreenOverlay{T}"/>.
     /// </summary>
-    public class OverlayScrollContainer : OsuScrollContainer
+    public class OverlayScrollContainer : UserTrackingScrollContainer
     {
         /// <summary>
         /// Scroll position at which the <see cref="ScrollToTopButton"/> will be shown.

osu.Game/Overlays/Profile/Header/CentreHeaderContainer.cs

@@ -49,9 +49,12 @@ namespace osu.Game.Overlays.Profile.Header
                     Spacing = new Vector2(10, 0),
                     Children = new Drawable[]
                     {
-                        new AddFriendButton
+                        new FollowersButton
+                        {
+                            User = { BindTarget = User }
+                        },
+                        new MappingSubscribersButton
                         {
-                            RelativeSizeAxes = Axes.Y,
                             User = { BindTarget = User }
                         },
                         new MessageUserButton
@@ -69,7 +72,6 @@ namespace osu.Game.Overlays.Profile.Header
                     Width = UserProfileOverlay.CONTENT_X_MARGIN,
                     Child = new ExpandDetailsButton
                     {
-                        RelativeSizeAxes = Axes.Y,
                         Anchor = Anchor.Centre,
                         Origin = Anchor.Centre,
                         DetailsVisible = { BindTarget = DetailsVisible }

osu.Game/Overlays/Profile/Header/Components/AddFriendButton.cs

@@ -1,60 +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 osu.Framework.Allocation;
-using osu.Framework.Bindables;
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Sprites;
-using osu.Game.Graphics;
-using osu.Game.Graphics.Sprites;
-using osu.Game.Users;
-using osuTK;
-
-namespace osu.Game.Overlays.Profile.Header.Components
-{
-    public class AddFriendButton : ProfileHeaderButton
-    {
-        public readonly Bindable<User> User = new Bindable<User>();
-
-        public override string TooltipText => "friends";
-
-        private OsuSpriteText followerText;
-
-        [BackgroundDependencyLoader]
-        private void load()
-        {
-            Child = new FillFlowContainer
-            {
-                AutoSizeAxes = Axes.Both,
-                Anchor = Anchor.CentreLeft,
-                Origin = Anchor.CentreLeft,
-                Direction = FillDirection.Horizontal,
-                Padding = new MarginPadding { Right = 10 },
-                Children = new Drawable[]
-                {
-                    new SpriteIcon
-                    {
-                        Anchor = Anchor.CentreLeft,
-                        Origin = Anchor.CentreLeft,
-                        Icon = FontAwesome.Solid.User,
-                        FillMode = FillMode.Fit,
-                        Size = new Vector2(50, 14)
-                    },
-                    followerText = new OsuSpriteText
-                    {
-                        Anchor = Anchor.CentreLeft,
-                        Origin = Anchor.CentreLeft,
-                        Font = OsuFont.GetFont(weight: FontWeight.Bold)
-                    }
-                }
-            };
-
-            // todo: when friending/unfriending is implemented, the APIAccess.Friends list should be updated accordingly.
-
-            User.BindValueChanged(user => updateFollowers(user.NewValue), true);
-        }
-
-        private void updateFollowers(User user) => followerText.Text = user?.FollowerCount.ToString("#,##0");
-    }
-}

osu.Game/Overlays/Profile/Header/Components/FollowersButton.cs

@@ -0,0 +1,26 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Users;
+
+namespace osu.Game.Overlays.Profile.Header.Components
+{
+    public class FollowersButton : ProfileHeaderStatisticsButton
+    {
+        public readonly Bindable<User> User = new Bindable<User>();
+
+        public override string TooltipText => "followers";
+
+        protected override IconUsage Icon => FontAwesome.Solid.User;
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            // todo: when friending/unfriending is implemented, the APIAccess.Friends list should be updated accordingly.
+            User.BindValueChanged(user => SetValue(user.NewValue?.FollowerCount ?? 0), true);
+        }
+    }
+}

osu.Game/Overlays/Profile/Header/Components/MappingSubscribersButton.cs

@@ -0,0 +1,25 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Users;
+
+namespace osu.Game.Overlays.Profile.Header.Components
+{
+    public class MappingSubscribersButton : ProfileHeaderStatisticsButton
+    {
+        public readonly Bindable<User> User = new Bindable<User>();
+
+        public override string TooltipText => "mapping subscribers";
+
+        protected override IconUsage Icon => FontAwesome.Solid.Bell;
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            User.BindValueChanged(user => SetValue(user.NewValue?.MappingFollowerCount ?? 0), true);
+        }
+    }
+}

osu.Game/Overlays/Profile/Header/Components/MessageUserButton.cs

@@ -33,7 +33,6 @@ namespace osu.Game.Overlays.Profile.Header.Components
         public MessageUserButton()
         {
             Content.Alpha = 0;
-            RelativeSizeAxes = Axes.Y;
 
             Child = new SpriteIcon
             {

osu.Game/Overlays/Profile/Header/Components/ProfileHeaderButton.cs

@@ -22,6 +22,7 @@ namespace osu.Game.Overlays.Profile.Header.Components
         protected ProfileHeaderButton()
         {
             AutoSizeAxes = Axes.X;
+            Height = 40;
 
             base.Content.Add(new CircularContainer
             {

osu.Game/Overlays/Profile/Header/Components/ProfileHeaderStatisticsButton.cs

@@ -0,0 +1,51 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osuTK;
+
+namespace osu.Game.Overlays.Profile.Header.Components
+{
+    public abstract class ProfileHeaderStatisticsButton : ProfileHeaderButton
+    {
+        private readonly OsuSpriteText drawableText;
+
+        protected ProfileHeaderStatisticsButton()
+        {
+            Child = new FillFlowContainer
+            {
+                AutoSizeAxes = Axes.X,
+                RelativeSizeAxes = Axes.Y,
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Direction = FillDirection.Horizontal,
+                Children = new Drawable[]
+                {
+                    new SpriteIcon
+                    {
+                        Anchor = Anchor.CentreLeft,
+                        Origin = Anchor.CentreLeft,
+                        Icon = Icon,
+                        FillMode = FillMode.Fit,
+                        Size = new Vector2(50, 14)
+                    },
+                    drawableText = new OsuSpriteText
+                    {
+                        Anchor = Anchor.CentreLeft,
+                        Origin = Anchor.CentreLeft,
+                        Margin = new MarginPadding { Right = 10 },
+                        Font = OsuFont.GetFont(size: 14, weight: FontWeight.Bold)
+                    }
+                }
+            };
+        }
+
+        protected abstract IconUsage Icon { get; }
+
+        protected void SetValue(int value) => drawableText.Text = value.ToString("#,##0");
+    }
+}

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

@@ -38,6 +38,18 @@ namespace osu.Game.Overlays.Settings.Sections
 
         private List<SkinInfo> skinItems;
 
+        private int firstNonDefaultSkinIndex
+        {
+            get
+            {
+                var index = skinItems.FindIndex(s => s.ID > 0);
+                if (index < 0)
+                    index = skinItems.Count;
+
+                return index;
+            }
+        }
+
         [Resolved]
         private SkinManager skins { get; set; }
 
@@ -96,7 +108,7 @@ namespace osu.Game.Overlays.Settings.Sections
             if (skinDropdown.Items.All(s => s.ID != configBindable.Value))
                 configBindable.Value = 0;
 
-            configBindable.BindValueChanged(id => dropdownBindable.Value = skinDropdown.Items.Single(s => s.ID == id.NewValue), true);
+            configBindable.BindValueChanged(id => Scheduler.AddOnce(updateSelectedSkinFromConfig), true);
             dropdownBindable.BindValueChanged(skin =>
             {
                 if (skin.NewValue == random_skin_info)
@@ -109,24 +121,42 @@ namespace osu.Game.Overlays.Settings.Sections
             });
         }
 
+        private void updateSelectedSkinFromConfig()
+        {
+            int id = configBindable.Value;
+
+            var skin = skinDropdown.Items.FirstOrDefault(s => s.ID == id);
+
+            if (skin == null)
+            {
+                // there may be a thread race condition where an item is selected that hasn't yet been added to the dropdown.
+                // to avoid adding complexity, let's just ensure the item is added so we can perform the selection.
+                skin = skins.Query(s => s.ID == id);
+                addItem(skin);
+            }
+
+            dropdownBindable.Value = skin;
+        }
+
         private void updateItems()
         {
             skinItems = skins.GetAllUsableSkins();
-
+            skinItems.Insert(firstNonDefaultSkinIndex, random_skin_info);
-            // insert after lazer built-in skins
+            sortUserSkins(skinItems);
-            int firstNonDefault = skinItems.FindIndex(s => s.ID > 0);
-            if (firstNonDefault < 0)
-                firstNonDefault = skinItems.Count;
-
-            skinItems.Insert(firstNonDefault, random_skin_info);
-
             skinDropdown.Items = skinItems;
         }
 
         private void itemUpdated(ValueChangedEvent<WeakReference<SkinInfo>> weakItem)
         {
             if (weakItem.NewValue.TryGetTarget(out var item))
-                Schedule(() => skinDropdown.Items = skinDropdown.Items.Where(i => !i.Equals(item)).Append(item).ToArray());
+                Schedule(() => addItem(item));
+        }
+
+        private void addItem(SkinInfo item)
+        {
+            List<SkinInfo> newDropdownItems = skinDropdown.Items.Where(i => !i.Equals(item)).Append(item).ToList();
+            sortUserSkins(newDropdownItems);
+            skinDropdown.Items = newDropdownItems;
         }
 
         private void itemRemoved(ValueChangedEvent<WeakReference<SkinInfo>> weakItem)
@@ -135,6 +165,13 @@ namespace osu.Game.Overlays.Settings.Sections
                 Schedule(() => skinDropdown.Items = skinDropdown.Items.Where(i => i.ID != item.ID).ToArray());
         }
 
+        private void sortUserSkins(List<SkinInfo> skinsList)
+        {
+            // Sort user skins separately from built-in skins
+            skinsList.Sort(firstNonDefaultSkinIndex, skinsList.Count - firstNonDefaultSkinIndex,
+                Comparer<SkinInfo>.Create((a, b) => string.Compare(a.Name, b.Name, StringComparison.OrdinalIgnoreCase)));
+        }
+
         private class SkinSettingsDropdown : SettingsDropdown<SkinInfo>
         {
             protected override OsuDropdown<SkinInfo> CreateDropdown() => new SkinDropdownControl();

osu.Game/Overlays/UserProfileOverlay.cs

@@ -202,7 +202,7 @@ namespace osu.Game.Overlays
                 RelativeSizeAxes = Axes.Both;
             }
 
-            protected override OsuScrollContainer CreateScrollContainer() => new OverlayScrollContainer();
+            protected override UserTrackingScrollContainer CreateScrollContainer() => new OverlayScrollContainer();
 
             protected override FlowContainer<ProfileSection> CreateScrollContentContainer() => new FillFlowContainer<ProfileSection>
             {

osu.Game/Replays/Legacy/LegacyReplayFrame.cs

@@ -1,38 +1,51 @@
 // 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 MessagePack;
 using Newtonsoft.Json;
 using osu.Game.Rulesets.Replays;
 using osuTK;
 
 namespace osu.Game.Replays.Legacy
 {
+    [MessagePackObject]
     public class LegacyReplayFrame : ReplayFrame
     {
         [JsonIgnore]
+        [IgnoreMember]
         public Vector2 Position => new Vector2(MouseX ?? 0, MouseY ?? 0);
 
+        [Key(1)]
         public float? MouseX;
+
+        [Key(2)]
         public float? MouseY;
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseLeft => MouseLeft1 || MouseLeft2;
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseRight => MouseRight1 || MouseRight2;
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseLeft1 => ButtonState.HasFlag(ReplayButtonState.Left1);
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseRight1 => ButtonState.HasFlag(ReplayButtonState.Right1);
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseLeft2 => ButtonState.HasFlag(ReplayButtonState.Left2);
 
         [JsonIgnore]
+        [IgnoreMember]
         public bool MouseRight2 => ButtonState.HasFlag(ReplayButtonState.Right2);
 
+        [Key(3)]
         public ReplayButtonState ButtonState;
 
         public LegacyReplayFrame(double time, float? mouseX, float? mouseY, ReplayButtonState buttonState)

osu.Game/Rulesets/Edit/HitObjectComposer.cs

@@ -332,7 +332,7 @@ namespace osu.Game.Rulesets.Edit
                 EditorBeatmap.Add(hitObject);
 
                 if (EditorClock.CurrentTime < hitObject.StartTime)
-                    EditorClock.SeekTo(hitObject.StartTime);
+                    EditorClock.SeekSmoothlyTo(hitObject.StartTime);
             }
         }
 

osu.Game/Rulesets/Mods/ModHardRock.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Mods
         {
         }
 
-        public void ApplyToDifficulty(BeatmapDifficulty difficulty)
+        public virtual void ApplyToDifficulty(BeatmapDifficulty difficulty)
         {
             const float ratio = 1.4f;
             difficulty.CircleSize = Math.Min(difficulty.CircleSize * 1.3f, 10.0f); // CS uses a custom 1.3 ratio.

osu.Game/Rulesets/Replays/ReplayFrame.cs

@@ -1,10 +1,14 @@
 // 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 MessagePack;
+
 namespace osu.Game.Rulesets.Replays
 {
+    [MessagePackObject]
     public class ReplayFrame
     {
+        [Key(0)]
         public double Time;
 
         public ReplayFrame()

osu.Game/Rulesets/Ruleset.cs

@@ -24,9 +24,9 @@ using osu.Game.Skinning;
 using osu.Game.Users;
 using JetBrains.Annotations;
 using osu.Framework.Extensions;
+using osu.Framework.Extensions.EnumExtensions;
 using osu.Framework.Testing;
 using osu.Game.Screens.Ranking.Statistics;
-using osu.Game.Utils;
 
 namespace osu.Game.Rulesets
 {
@@ -272,7 +272,7 @@ namespace osu.Game.Rulesets
             var validResults = GetValidHitResults();
 
             // enumerate over ordered list to guarantee return order is stable.
-            foreach (var result in OrderAttributeUtils.GetValuesInOrder<HitResult>())
+            foreach (var result in EnumExtensions.GetValuesInOrder<HitResult>())
             {
                 switch (result)
                 {
@@ -298,7 +298,7 @@ namespace osu.Game.Rulesets
         /// <remarks>
         /// <see cref="HitResult.Miss"/> is implicitly included. Special types like <see cref="HitResult.IgnoreHit"/> are ignored even when specified.
         /// </remarks>
-        protected virtual IEnumerable<HitResult> GetValidHitResults() => OrderAttributeUtils.GetValuesInOrder<HitResult>();
+        protected virtual IEnumerable<HitResult> GetValidHitResults() => EnumExtensions.GetValuesInOrder<HitResult>();
 
         /// <summary>
         /// Get a display friendly name for the specified result type.

osu.Game/Rulesets/Scoring/HitResult.cs

@@ -3,7 +3,7 @@
 
 using System.ComponentModel;
 using System.Diagnostics;
-using osu.Game.Utils;
+using osu.Framework.Utils;
 
 namespace osu.Game.Rulesets.Scoring
 {

osu.Game/Rulesets/UI/HitObjectContainer.cs

@@ -124,9 +124,11 @@ namespace osu.Game.Rulesets.UI
             Debug.Assert(drawableMap.ContainsKey(entry));
 
             var drawable = drawableMap[entry];
+
+            // OnKilled can potentially change the hitobject's result, so it needs to run first before unbinding.
+            drawable.OnKilled();
             drawable.OnNewResult -= onNewResult;
             drawable.OnRevertResult -= onRevertResult;
-            drawable.OnKilled();
 
             drawableMap.Remove(entry);
 

osu.Game/Rulesets/UI/ModIcon.cs

@@ -16,6 +16,9 @@ using osu.Framework.Bindables;
 
 namespace osu.Game.Rulesets.UI
 {
+    /// <summary>
+    /// Display the specified mod at a fixed size.
+    /// </summary>
     public class ModIcon : Container, IHasTooltip
     {
         public readonly BindableBool Selected = new BindableBool();
@@ -28,9 +31,10 @@ namespace osu.Game.Rulesets.UI
 
         private readonly ModType type;
 
-        public virtual string TooltipText => mod.IconTooltip;
+        public virtual string TooltipText => showTooltip ? mod.IconTooltip : null;
 
         private Mod mod;
+        private readonly bool showTooltip;
 
         public Mod Mod
         {
@@ -42,9 +46,15 @@ namespace osu.Game.Rulesets.UI
             }
         }
 
-        public ModIcon(Mod mod)
+        /// <summary>
+        /// Construct a new instance.
+        /// </summary>
+        /// <param name="mod">The mod to be displayed</param>
+        /// <param name="showTooltip">Whether a tooltip describing the mod should display on hover.</param>
+        public ModIcon(Mod mod, bool showTooltip = true)
         {
             this.mod = mod ?? throw new ArgumentNullException(nameof(mod));
+            this.showTooltip = showTooltip;
 
             type = mod.Type;
 

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/BookmarkPart.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Framework.Allocation;
-using osu.Game.Beatmaps;
 using osu.Game.Graphics;
 using osu.Game.Screens.Edit.Components.Timelines.Summary.Visualisations;
 
@@ -13,7 +12,7 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     /// </summary>
     public class BookmarkPart : TimelinePart
     {
-        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        protected override void LoadBeatmap(EditorBeatmap beatmap)
         {
             base.LoadBeatmap(beatmap);
             foreach (int bookmark in beatmap.BeatmapInfo.Bookmarks)

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/BreakPart.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Framework.Allocation;
-using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Timing;
 using osu.Game.Graphics;
 using osu.Game.Screens.Edit.Components.Timelines.Summary.Visualisations;
@@ -14,10 +13,10 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     /// </summary>
     public class BreakPart : TimelinePart
     {
-        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        protected override void LoadBeatmap(EditorBeatmap beatmap)
         {
             base.LoadBeatmap(beatmap);
-            foreach (var breakPeriod in beatmap.Beatmap.Breaks)
+            foreach (var breakPeriod in beatmap.Breaks)
                 Add(new BreakVisualisation(breakPeriod));
         }
 

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/ControlPointPart.cs

@@ -4,7 +4,6 @@
 using System.Collections.Specialized;
 using System.Linq;
 using osu.Framework.Bindables;
-using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
 
 namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
@@ -16,12 +15,12 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     {
         private readonly IBindableList<ControlPointGroup> controlPointGroups = new BindableList<ControlPointGroup>();
 
-        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        protected override void LoadBeatmap(EditorBeatmap beatmap)
         {
             base.LoadBeatmap(beatmap);
 
             controlPointGroups.UnbindAll();
-            controlPointGroups.BindTo(beatmap.Beatmap.ControlPointInfo.Groups);
+            controlPointGroups.BindTo(beatmap.ControlPointInfo.Groups);
             controlPointGroups.BindCollectionChanged((sender, args) =>
             {
                 switch (args.Action)

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/MarkerPart.cs

@@ -2,15 +2,14 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using osuTK;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Input.Events;
 using osu.Framework.Threading;
-using osu.Game.Beatmaps;
 using osu.Game.Graphics;
+using osuTK;
 
 namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
 {
@@ -54,11 +53,8 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
             scheduledSeek?.Cancel();
             scheduledSeek = Schedule(() =>
             {
-                if (Beatmap.Value == null)
-                    return;
-
                 float markerPos = Math.Clamp(ToLocalSpace(screenPosition).X, 0, DrawWidth);
-                editorClock.SeekTo(markerPos / DrawWidth * editorClock.TrackLength);
+                editorClock.SeekSmoothlyTo(markerPos / DrawWidth * editorClock.TrackLength);
             });
         }
 
@@ -68,7 +64,7 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
             marker.X = (float)editorClock.CurrentTime;
         }
 
-        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        protected override void LoadBeatmap(EditorBeatmap beatmap)
         {
             // block base call so we don't clear our marker (can be reused on beatmap change).
         }

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/TimelinePart.cs

@@ -21,7 +21,10 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     /// </summary>
     public class TimelinePart<T> : Container<T> where T : Drawable
     {
-        protected readonly IBindable<WorkingBeatmap> Beatmap = new Bindable<WorkingBeatmap>();
+        private readonly IBindable<WorkingBeatmap> beatmap = new Bindable<WorkingBeatmap>();
+
+        [Resolved]
+        protected EditorBeatmap EditorBeatmap { get; private set; }
 
         protected readonly IBindable<Track> Track = new Bindable<Track>();
 
@@ -33,10 +36,9 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
         {
             AddInternal(this.content = content ?? new Container<T> { RelativeSizeAxes = Axes.Both });
 
-            Beatmap.ValueChanged += b =>
+            beatmap.ValueChanged += b =>
             {
                 updateRelativeChildSize();
-                LoadBeatmap(b.NewValue);
             };
 
             Track.ValueChanged += _ => updateRelativeChildSize();
@@ -45,24 +47,26 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
         [BackgroundDependencyLoader]
         private void load(IBindable<WorkingBeatmap> beatmap, EditorClock clock)
         {
-            Beatmap.BindTo(beatmap);
+            this.beatmap.BindTo(beatmap);
+            LoadBeatmap(EditorBeatmap);
+
             Track.BindTo(clock.Track);
         }
 
         private void updateRelativeChildSize()
         {
             // the track may not be loaded completely (only has a length once it is).
-            if (!Beatmap.Value.Track.IsLoaded)
+            if (!beatmap.Value.Track.IsLoaded)
             {
                 content.RelativeChildSize = Vector2.One;
                 Schedule(updateRelativeChildSize);
                 return;
             }
 
-            content.RelativeChildSize = new Vector2((float)Math.Max(1, Beatmap.Value.Track.Length), 1);
+            content.RelativeChildSize = new Vector2((float)Math.Max(1, beatmap.Value.Track.Length), 1);
         }
 
-        protected virtual void LoadBeatmap(WorkingBeatmap beatmap)
+        protected virtual void LoadBeatmap(EditorBeatmap beatmap)
         {
             content.Clear();
         }

osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs

@@ -170,7 +170,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             if (clickedBlueprint == null || SelectionHandler.SelectedBlueprints.FirstOrDefault(b => b.IsHovered) != clickedBlueprint)
                 return false;
 
-            EditorClock?.SeekTo(clickedBlueprint.HitObject.StartTime);
+            EditorClock?.SeekSmoothlyTo(clickedBlueprint.HitObject.StartTime);
             return true;
         }
 

osu.Game/Screens/Edit/Compose/Components/Timeline/Timeline.cs

@@ -155,12 +155,14 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 seekTrackToCurrent();
             else if (!editorClock.IsRunning)
             {
-                // The track isn't running. There are two cases we have to be wary of:
+                // The track isn't running. There are three cases we have to be wary of:
-                // 1) The user flick-drags on this timeline: We want the track to follow us
+                // 1) The user flick-drags on this timeline and we are applying an interpolated seek on the clock, until interrupted by 2 or 3.
-                // 2) The user changes the track time through some other means (scrolling in the editor or overview timeline): We want to follow the track time
+                // 2) The user changes the track time through some other means (scrolling in the editor or overview timeline; clicking a hitobject etc.). We want the timeline to track the clock's time.
+                // 3) An ongoing seek transform is running from an external seek. We want the timeline to track the clock's time.
 
-                // The simplest way to cover both cases is by checking whether the scroll position has changed and the audio hasn't been changed externally
+                // The simplest way to cover the first two cases is by checking whether the scroll position has changed and the audio hasn't been changed externally
-                if (Current != lastScrollPosition && editorClock.CurrentTime == lastTrackTime)
+                // Checking IsSeeking covers the third case, where the transform may not have been applied yet.
+                if (Current != lastScrollPosition && editorClock.CurrentTime == lastTrackTime && !editorClock.IsSeeking)
                     seekTrackToCurrent();
                 else
                     scrollToTrackTime();

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineControlPointDisplay.cs

@@ -5,7 +5,6 @@ using System.Collections.Specialized;
 using System.Linq;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
-using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Screens.Edit.Components.Timelines.Summary.Parts;
 
@@ -23,12 +22,12 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             RelativeSizeAxes = Axes.Both;
         }
 
-        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        protected override void LoadBeatmap(EditorBeatmap beatmap)
         {
             base.LoadBeatmap(beatmap);
 
             controlPointGroups.UnbindAll();
-            controlPointGroups.BindTo(beatmap.Beatmap.ControlPointInfo.Groups);
+            controlPointGroups.BindTo(beatmap.ControlPointInfo.Groups);
             controlPointGroups.BindCollectionChanged((sender, args) =>
             {
                 switch (args.Action)

osu.Game/Screens/Edit/Editor.cs

@@ -131,6 +131,10 @@ namespace osu.Game.Screens.Edit
             try
             {
                 playableBeatmap = Beatmap.Value.GetPlayableBeatmap(Beatmap.Value.BeatmapInfo.Ruleset);
+
+                // clone these locally for now to avoid incurring overhead on GetPlayableBeatmap usages.
+                // eventually we will want to improve how/where this is done as there are issues with *not* cloning it in all cases.
+                playableBeatmap.ControlPointInfo = playableBeatmap.ControlPointInfo.CreateCopy();
             }
             catch (Exception e)
             {

osu.Game/Screens/Edit/EditorBeatmap.cs

@@ -74,7 +74,11 @@ namespace osu.Game.Screens.Edit
 
         public BeatmapMetadata Metadata => PlayableBeatmap.Metadata;
 
-        public ControlPointInfo ControlPointInfo => PlayableBeatmap.ControlPointInfo;
+        public ControlPointInfo ControlPointInfo
+        {
+            get => PlayableBeatmap.ControlPointInfo;
+            set => PlayableBeatmap.ControlPointInfo = value;
+        }
 
         public List<BreakPeriod> Breaks => PlayableBeatmap.Breaks;
 

osu.Game/Screens/Edit/EditorClock.cs

@@ -35,6 +35,11 @@ namespace osu.Game.Screens.Edit
 
         private readonly Bindable<bool> seekingOrStopped = new Bindable<bool>(true);
 
+        /// <summary>
+        /// Whether a seek is currently in progress. True for the duration of a seek performed via <see cref="SeekSmoothlyTo"/>.
+        /// </summary>
+        public bool IsSeeking { get; private set; }
+
         public EditorClock(WorkingBeatmap beatmap, BindableBeatDivisor beatDivisor)
             : this(beatmap.Beatmap.ControlPointInfo, beatmap.Track.Length, beatDivisor)
         {
@@ -111,7 +116,7 @@ namespace osu.Game.Screens.Edit
 
             if (!snapped || ControlPointInfo.TimingPoints.Count == 0)
             {
-                SeekTo(seekTime);
+                SeekSmoothlyTo(seekTime);
                 return;
             }
 
@@ -145,11 +150,11 @@ namespace osu.Game.Screens.Edit
 
             // Ensure the sought point is within the boundaries
             seekTime = Math.Clamp(seekTime, 0, TrackLength);
-            SeekTo(seekTime);
+            SeekSmoothlyTo(seekTime);
         }
 
         /// <summary>
-        /// The current time of this clock, include any active transform seeks performed via <see cref="SeekTo"/>.
+        /// The current time of this clock, include any active transform seeks performed via <see cref="SeekSmoothlyTo"/>.
         /// </summary>
         public double CurrentTimeAccurate =>
             Transforms.OfType<TransformSeek>().FirstOrDefault()?.EndValue ?? CurrentTime;
@@ -176,12 +181,29 @@ namespace osu.Game.Screens.Edit
 
         public bool Seek(double position)
         {
-            seekingOrStopped.Value = true;
+            seekingOrStopped.Value = IsSeeking = true;
 
             ClearTransforms();
             return underlyingClock.Seek(position);
         }
 
+        /// <summary>
+        /// Seek smoothly to the provided destination.
+        /// Use <see cref="Seek"/> to perform an immediate seek.
+        /// </summary>
+        /// <param name="seekDestination"></param>
+        public void SeekSmoothlyTo(double seekDestination)
+        {
+            seekingOrStopped.Value = true;
+
+            if (IsRunning)
+                Seek(seekDestination);
+            else
+            {
+                transformSeekTo(seekDestination, transform_time, Easing.OutQuint);
+            }
+        }
+
         public void ResetSpeedAdjustments() => underlyingClock.ResetSpeedAdjustments();
 
         double IAdjustableClock.Rate
@@ -229,6 +251,8 @@ namespace osu.Game.Screens.Edit
         {
             if (seekingOrStopped.Value)
             {
+                IsSeeking &= Transforms.Any();
+
                 if (track.Value?.IsRunning != true)
                 {
                     // seeking in the editor can happen while the track isn't running.
@@ -239,20 +263,10 @@ namespace osu.Game.Screens.Edit
                 // we are either running a seek tween or doing an immediate seek.
                 // in the case of an immediate seek the seeking bool will be set to false after one update.
                 // this allows for silencing hit sounds and the likes.
-                seekingOrStopped.Value = Transforms.Any();
+                seekingOrStopped.Value = IsSeeking;
             }
         }
 
-        public void SeekTo(double seekDestination)
-        {
-            seekingOrStopped.Value = true;
-
-            if (IsRunning)
-                Seek(seekDestination);
-            else
-                transformSeekTo(seekDestination, transform_time, Easing.OutQuint);
-        }
-
         private void transformSeekTo(double seek, double duration = 0, Easing easing = Easing.None)
             => this.TransformTo(this.PopulateTransform(new TransformSeek(), seek, duration, easing));
 

osu.Game/Screens/Edit/Timing/ControlPointTable.cs

@@ -206,7 +206,7 @@ namespace osu.Game.Screens.Edit.Timing
                 Action = () =>
                 {
                     selectedGroup.Value = controlGroup;
-                    clock.SeekTo(controlGroup.Time);
+                    clock.SeekSmoothlyTo(controlGroup.Time);
                 };
             }
 

osu.Game/Screens/OnlinePlay/Match/Components/MatchChatDisplay.cs

@@ -38,5 +38,11 @@ namespace osu.Game.Screens.OnlinePlay.Match.Components
 
             Channel.Value = channelManager?.JoinChannel(new Channel { Id = channelId.Value, Type = ChannelType.Multiplayer, Name = $"#lazermp_{roomId.Value}" });
         }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+            channelManager?.LeaveChannel(Channel.Value);
+        }
     }
 }

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

@@ -4,7 +4,6 @@
 using osu.Framework.Allocation;
 using osu.Framework.Logging;
 using osu.Framework.Screens;
-using osu.Game.Extensions;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.Multiplayer;
 using osu.Game.Online.Rooms;
@@ -23,7 +22,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
             base.OnResuming(last);
 
             if (client.Room != null)
-                client.ChangeState(MultiplayerUserState.Idle).CatchUnobservedExceptions(true);
+                client.ChangeState(MultiplayerUserState.Idle);
         }
 
         protected override void UpdatePollingRate(bool isIdle)

osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSongSelect.cs

@@ -13,6 +13,7 @@ using osu.Game.Beatmaps;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.Multiplayer;
 using osu.Game.Online.Rooms;
+using osu.Game.Overlays.Mods;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Screens.Select;
@@ -109,5 +110,9 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         }
 
         protected override BeatmapDetailArea CreateBeatmapDetailArea() => new PlayBeatmapDetailArea();
+
+        protected override ModSelectOverlay CreateModSelectOverlay() => new ModSelectOverlay(isValidMod);
+
+        private bool isValidMod(Mod mod) => !(mod is ModAutoplay) && (mod as MultiMod)?.Mods.Any(mm => mm is ModAutoplay) != true;
     }
 }

osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSubScreen.cs

@@ -11,7 +11,6 @@ using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Screens;
-using osu.Game.Extensions;
 using osu.Game.Online.Multiplayer;
 using osu.Game.Online.Rooms;
 using osu.Game.Screens.OnlinePlay.Components;
@@ -44,6 +43,8 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         [CanBeNull]
         private IDisposable readyClickOperation;
 
+        private GridContainer mainContent;
+
         public MultiplayerMatchSubScreen(Room room)
         {
             Title = room.RoomID.Value == null ? "New room" : room.Name.Value;
@@ -55,7 +56,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         {
             InternalChildren = new Drawable[]
             {
-                new GridContainer
+                mainContent = new GridContainer
                 {
                     RelativeSizeAxes = Axes.Both,
                     Content = new[]
@@ -178,6 +179,19 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                     State = { Value = client.Room == null ? Visibility.Visible : Visibility.Hidden }
                 }
             };
+
+            if (client.Room == null)
+            {
+                // A new room is being created.
+                // The main content should be hidden until the settings overlay is hidden, signaling the room is ready to be displayed.
+                mainContent.Hide();
+
+                settingsOverlay.State.BindValueChanged(visibility =>
+                {
+                    if (visibility.NewValue == Visibility.Hidden)
+                        mainContent.Show();
+                }, true);
+            }
         }
 
         protected override void LoadComplete()
@@ -222,7 +236,6 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                           // accessing Exception here silences any potential errors from the antecedent task
                           if (t.Exception != null)
                           {
-                              t.CatchUnobservedExceptions(true); // will run immediately.
                               // gameplay was not started due to an exception; unblock button.
                               endOperation();
                           }
@@ -233,11 +246,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
             }
 
             client.ToggleReady()
-                  .ContinueWith(t =>
+                  .ContinueWith(t => endOperation());
-                  {
-                      t.CatchUnobservedExceptions(true); // will run immediately.
-                      endOperation();
-                  });
 
             void endOperation()
             {

osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomManager.cs

@@ -9,7 +9,6 @@ using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.ExceptionExtensions;
 using osu.Framework.Logging;
-using osu.Game.Extensions;
 using osu.Game.Online.Multiplayer;
 using osu.Game.Online.Rooms;
 using osu.Game.Online.Rooms.RoomStatuses;
@@ -69,7 +68,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
 
             base.PartRoom();
 
-            multiplayerClient.LeaveRoom().CatchUnobservedExceptions();
+            multiplayerClient.LeaveRoom();
 
             // Todo: This is not the way to do this. Basically when we're the only participant and the room closes, there's no way to know if this is actually the case.
             // This is delayed one frame because upon exiting the match subscreen, multiplayer updates the polling rate and messes with polling.

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

@@ -10,7 +10,6 @@ using osu.Framework.Graphics.Cursor;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.UserInterface;
-using osu.Game.Extensions;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
@@ -176,7 +175,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
                         if (Room.Host?.UserID != api.LocalUser.Value.Id)
                             return;
 
-                        Client.TransferHost(targetUser).CatchUnobservedExceptions(true);
+                        Client.TransferHost(targetUser);
                     })
                 };
             }

osu.Game/Screens/OnlinePlay/OngoingOperationTracker.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 
@@ -43,17 +42,46 @@ namespace osu.Game.Screens.OnlinePlay
             leasedInProgress = inProgress.BeginLease(true);
             leasedInProgress.Value = true;
 
-            // for extra safety, marshal the end of operation back to the update thread if necessary.
+            return new OngoingOperation(this, leasedInProgress);
-            return new InvokeOnDisposal(() => Scheduler.Add(endOperation, false));
         }
 
-        private void endOperation()
+        private void endOperationWithKnownLease(LeasedBindable<bool> lease)
         {
-            if (leasedInProgress == null)
+            if (lease != leasedInProgress)
-                throw new InvalidOperationException("Cannot end operation multiple times.");
+                return;
 
-            leasedInProgress.Return();
+            // for extra safety, marshal the end of operation back to the update thread if necessary.
+            Scheduler.Add(() =>
+            {
+                leasedInProgress?.Return();
+                leasedInProgress = null;
+            }, false);
+        }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+
+            // base call does an UnbindAllBindables().
+            // clean up the leased reference here so that it doesn't get returned twice.
             leasedInProgress = null;
         }
+
+        private class OngoingOperation : IDisposable
+        {
+            private readonly OngoingOperationTracker tracker;
+            private readonly LeasedBindable<bool> lease;
+
+            public OngoingOperation(OngoingOperationTracker tracker, LeasedBindable<bool> lease)
+            {
+                this.tracker = tracker;
+                this.lease = lease;
+            }
+
+            public void Dispose()
+            {
+                tracker.endOperationWithKnownLease(lease);
+            }
+        }
     }
 }

osu.Game/Screens/OnlinePlay/Playlists/PlaylistsRoomSubScreen.cs

@@ -33,6 +33,8 @@ namespace osu.Game.Screens.OnlinePlay.Playlists
 
         private OverlinedHeader participantsHeader;
 
+        private GridContainer mainContent;
+
         public PlaylistsRoomSubScreen(Room room)
         {
             Title = room.RoomID.Value == null ? "New playlist" : room.Name.Value;
@@ -44,7 +46,7 @@ namespace osu.Game.Screens.OnlinePlay.Playlists
         {
             InternalChildren = new Drawable[]
             {
-                new GridContainer
+                mainContent = new GridContainer
                 {
                     RelativeSizeAxes = Axes.Both,
                     Content = new[]
@@ -190,6 +192,19 @@ namespace osu.Game.Screens.OnlinePlay.Playlists
                     State = { Value = roomId.Value == null ? Visibility.Visible : Visibility.Hidden }
                 }
             };
+
+            if (roomId.Value == null)
+            {
+                // A new room is being created.
+                // The main content should be hidden until the settings overlay is hidden, signaling the room is ready to be displayed.
+                mainContent.Hide();
+
+                settingsOverlay.State.BindValueChanged(visibility =>
+                {
+                    if (visibility.NewValue == Visibility.Hidden)
+                        mainContent.Show();
+                }, true);
+            }
         }
 
         [Resolved]

osu.Game/Screens/Play/GameplayBeatmap.cs

@@ -29,7 +29,11 @@ namespace osu.Game.Screens.Play
 
         public BeatmapMetadata Metadata => PlayableBeatmap.Metadata;
 
-        public ControlPointInfo ControlPointInfo => PlayableBeatmap.ControlPointInfo;
+        public ControlPointInfo ControlPointInfo
+        {
+            get => PlayableBeatmap.ControlPointInfo;
+            set => PlayableBeatmap.ControlPointInfo = value;
+        }
 
         public List<BreakPeriod> Breaks => PlayableBeatmap.Breaks;
 

osu.Game/Screens/Play/HUD/MultiplayerGameplayLeaderboard.cs

@@ -53,8 +53,6 @@ namespace osu.Game.Screens.Play.HUD
         [BackgroundDependencyLoader]
         private void load(OsuConfigManager config, IAPIProvider api)
         {
-            streamingClient.OnNewFrames += handleIncomingFrames;
-
             foreach (var userId in playingUsers)
             {
                 streamingClient.WatchUser(userId);
@@ -90,6 +88,9 @@ namespace osu.Game.Screens.Play.HUD
 
             playingUsers.BindTo(multiplayerClient.CurrentMatchPlayingUserIds);
             playingUsers.BindCollectionChanged(usersChanged);
+
+            // this leaderboard should be guaranteed to be completely loaded before the gameplay starts (is a prerequisite in MultiplayerPlayer).
+            streamingClient.OnNewFrames += handleIncomingFrames;
         }
 
         private void usersChanged(object sender, NotifyCollectionChangedEventArgs e)

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -918,15 +918,10 @@ namespace osu.Game.Screens.Select
             }
         }
 
-        protected class CarouselScrollContainer : OsuScrollContainer<DrawableCarouselItem>
+        protected class CarouselScrollContainer : UserTrackingScrollContainer<DrawableCarouselItem>
         {
             private bool rightMouseScrollBlocked;
 
-            /// <summary>
-            /// Whether the last scroll event was user triggered, directly on the scroll container.
-            /// </summary>
-            public bool UserScrolling { get; private set; }
-
             public CarouselScrollContainer()
             {
                 // size is determined by the carousel itself, due to not all content necessarily being loaded.
@@ -936,18 +931,6 @@ namespace osu.Game.Screens.Select
                 Masking = false;
             }
 
-            protected override void OnUserScroll(float value, bool animated = true, double? distanceDecay = default)
-            {
-                UserScrolling = true;
-                base.OnUserScroll(value, animated, distanceDecay);
-            }
-
-            public new void ScrollTo(float value, bool animated = true, double? distanceDecay = null)
-            {
-                UserScrolling = false;
-                base.ScrollTo(value, animated, distanceDecay);
-            }
-
             protected override bool OnMouseDown(MouseDownEvent e)
             {
                 if (e.Button == MouseButton.Right)

osu.Game/Screens/Select/MatchSongSelect.cs

@@ -10,6 +10,8 @@ using osu.Framework.Graphics;
 using osu.Framework.Screens;
 using osu.Game.Beatmaps;
 using osu.Game.Online.Rooms;
+using osu.Game.Overlays.Mods;
+using osu.Game.Rulesets.Mods;
 using osu.Game.Screens.OnlinePlay;
 using osu.Game.Screens.OnlinePlay.Components;
 
@@ -78,5 +80,9 @@ namespace osu.Game.Screens.Select
             item.RequiredMods.Clear();
             item.RequiredMods.AddRange(Mods.Value.Select(m => m.CreateCopy()));
         }
+
+        protected override ModSelectOverlay CreateModSelectOverlay() => new ModSelectOverlay(isValidMod);
+
+        private bool isValidMod(Mod mod) => !(mod is ModAutoplay) && (mod as MultiMod)?.Mods.Any(mm => mm is ModAutoplay) != true;
     }
 }

osu.Game/Screens/Select/SongSelect.cs

@@ -251,11 +251,7 @@ namespace osu.Game.Screens.Select
                                     Children = new Drawable[]
                                     {
                                         BeatmapOptions = new BeatmapOptionsOverlay(),
-                                        ModSelect = new ModSelectOverlay
+                                        ModSelect = CreateModSelectOverlay()
-                                        {
-                                            Origin = Anchor.BottomCentre,
-                                            Anchor = Anchor.BottomCentre,
-                                        }
                                     }
                                 }
                             }
@@ -305,6 +301,8 @@ namespace osu.Game.Screens.Select
             }
         }
 
+        protected virtual ModSelectOverlay CreateModSelectOverlay() => new ModSelectOverlay();
+
         protected virtual void ApplyFilterToCarousel(FilterCriteria criteria)
         {
             // if not the current screen, we want to get carousel in a good presentation state before displaying (resume or enter).

osu.Game/Users/User.cs

@@ -126,6 +126,9 @@ namespace osu.Game.Users
         [JsonProperty(@"follower_count")]
         public int FollowerCount;
 
+        [JsonProperty(@"mapping_follower_count")]
+        public int MappingFollowerCount;
+
         [JsonProperty(@"favourite_beatmapset_count")]
         public int FavouriteBeatmapsetCount;
 

osu.Game/Utils/OrderAttribute.cs

@@ -1,52 +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;
-
-namespace osu.Game.Utils
-{
-    public static class OrderAttributeUtils
-    {
-        /// <summary>
-        /// Get values of an enum in order. Supports custom ordering via <see cref="OrderAttribute"/>.
-        /// </summary>
-        public static IEnumerable<T> GetValuesInOrder<T>()
-        {
-            var type = typeof(T);
-
-            if (!type.IsEnum)
-                throw new InvalidOperationException("T must be an enum");
-
-            IEnumerable<T> items = (T[])Enum.GetValues(type);
-
-            if (Attribute.GetCustomAttribute(type, typeof(HasOrderedElementsAttribute)) == null)
-                return items;
-
-            return items.OrderBy(i =>
-            {
-                if (type.GetField(i.ToString()).GetCustomAttributes(typeof(OrderAttribute), false).FirstOrDefault() is OrderAttribute attr)
-                    return attr.Order;
-
-                throw new ArgumentException($"Not all values of {nameof(T)} have {nameof(OrderAttribute)} specified.");
-            });
-        }
-    }
-
-    [AttributeUsage(AttributeTargets.Field)]
-    public class OrderAttribute : Attribute
-    {
-        public readonly int Order;
-
-        public OrderAttribute(int order)
-        {
-            Order = order;
-        }
-    }
-
-    [AttributeUsage(AttributeTargets.Enum)]
-    public class HasOrderedElementsAttribute : Attribute
-    {
-    }
-}

osu.Game/osu.Game.csproj

@@ -18,15 +18,16 @@
     </None>
   </ItemGroup>
   <ItemGroup Label="Package References">
-    <PackageReference Include="Dapper" Version="2.0.78" />
     <PackageReference Include="DiffPlex" Version="1.6.3" />
     <PackageReference Include="Humanizer" Version="2.8.26" />
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="3.1.10" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="3.1.11" />
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.NewtonsoftJson" Version="3.1.10" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.2.6" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.6" />
+    <PackageReference Include="Microsoft.NETCore.Targets" Version="3.1.0" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
-    <PackageReference Include="ppy.osu.Framework" Version="2021.118.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2021.128.0" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2020.1202.0" />
     <PackageReference Include="Sentry" Version="2.1.8" />
     <PackageReference Include="SharpCompress" Version="0.26.0" />

osu.iOS.props

@@ -70,7 +70,7 @@
     <Reference Include="System.Net.Http" />
   </ItemGroup>
   <ItemGroup Label="Package References">
-    <PackageReference Include="ppy.osu.Framework.iOS" Version="2021.118.0" />
+    <PackageReference Include="ppy.osu.Framework.iOS" Version="2021.128.0" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2020.1202.0" />
   </ItemGroup>
   <!-- See https://github.com/dotnet/runtime/issues/35988 (can be removed after Xamarin uses net5.0 / net6.0) -->
@@ -88,7 +88,7 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.2.6" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.6" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
-    <PackageReference Include="ppy.osu.Framework" Version="2021.118.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2021.128.0" />
     <PackageReference Include="SharpCompress" Version="0.26.0" />
     <PackageReference Include="NUnit" Version="3.12.0" />
     <PackageReference Include="SharpRaven" Version="2.4.0" />