Merge branch 'master' into master

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+    - name: osu!stable issues
+      url: https://github.com/ppy/osu-stable-issues
+      about: For issues regarding osu!stable (not osu!lazer), open them here.

.github/ISSUE_TEMPLATE/missing-for-live-issues.md

@@ -1,7 +0,0 @@
----
-name: Missing for Live
-about: Features which are available in osu!stable but not yet in osu!lazer.
----
-**Describe the missing feature:** 
-
-**Proposal designs of the feature:** 

osu.Android.props

@@ -62,6 +62,6 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="ppy.osu.Game.Resources" Version="2019.1010.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2019.1023.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2019.1029.0" />
   </ItemGroup>
 </Project>

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

@@ -38,7 +38,7 @@ namespace osu.Game.Rulesets.Catch.Tests
         private void load()
         {
             var controlPointInfo = new ControlPointInfo();
-            controlPointInfo.TimingPoints.Add(new TimingControlPoint());
+            controlPointInfo.Add(0, new TimingControlPoint());
 
             WorkingBeatmap beatmap = CreateWorkingBeatmap(new Beatmap
             {

osu.Game.Rulesets.Osu.Tests/TestSceneOsuDistanceSnapGrid.cs

@@ -64,9 +64,8 @@ namespace osu.Game.Rulesets.Osu.Tests
         public void Setup() => Schedule(() =>
         {
             editorBeatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier = 1;
-            editorBeatmap.ControlPointInfo.DifficultyPoints.Clear();
-            editorBeatmap.ControlPointInfo.TimingPoints.Clear();
-            editorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = beat_length });
+            editorBeatmap.ControlPointInfo.Clear();
+            editorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = beat_length });
         });
 
         [TestCase(1)]

osu.Game.Rulesets.Osu.Tests/TestSceneSlider.cs

@@ -308,7 +308,7 @@ namespace osu.Game.Rulesets.Osu.Tests
         private Drawable createDrawable(Slider slider, float circleSize, double speedMultiplier)
         {
             var cpi = new ControlPointInfo();
-            cpi.DifficultyPoints.Add(new DifficultyControlPoint { SpeedMultiplier = speedMultiplier });
+            cpi.Add(0, new DifficultyControlPoint { SpeedMultiplier = speedMultiplier });
 
             slider.ApplyDefaults(cpi, new BeatmapDifficulty { CircleSize = circleSize, SliderTickRate = 3 });
 

osu.Game.Rulesets.Osu.Tests/TestSceneSliderInput.cs

@@ -313,10 +313,6 @@ namespace osu.Game.Rulesets.Osu.Tests
                             }, 25),
                         }
                     },
-                    ControlPointInfo =
-                    {
-                        DifficultyPoints = { new DifficultyControlPoint { SpeedMultiplier = 0.1f } }
-                    },
                     BeatmapInfo =
                     {
                         BaseDifficulty = new BeatmapDifficulty { SliderTickRate = 3 },
@@ -324,6 +320,8 @@ namespace osu.Game.Rulesets.Osu.Tests
                     },
                 });
 
+                Beatmap.Value.Beatmap.ControlPointInfo.Add(0, new DifficultyControlPoint { SpeedMultiplier = 0.1f });
+
                 var p = new ScoreAccessibleReplayPlayer(new Score { Replay = new Replay { Frames = frames } });
 
                 p.OnLoadComplete += _ =>

osu.Game.Rulesets.Osu/Objects/Drawables/Pieces/NumberPiece.cs

@@ -7,7 +7,6 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Effects;
 using osu.Game.Graphics.Sprites;
 using osuTK.Graphics;
-using osu.Framework.Graphics.Shapes;
 using osu.Game.Graphics;
 using osu.Game.Skinning;
 
@@ -30,17 +29,15 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables.Pieces
 
             Children = new Drawable[]
             {
-                new CircularContainer
+                new Container
                 {
                     Masking = true,
-                    Origin = Anchor.Centre,
                     EdgeEffect = new EdgeEffectParameters
                     {
                         Type = EdgeEffectType.Glow,
                         Radius = 60,
                         Colour = Color4.White.Opacity(0.5f),
                     },
-                    Child = new Box()
                 },
                 number = new SkinnableSpriteText(new OsuSkinComponent(OsuSkinComponents.HitCircleText), _ => new OsuSpriteText
                 {

osu.Game.Rulesets.Taiko.Tests/TestSceneTaikoPlayfield.cs

@@ -66,7 +66,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
             AddStep("Reset height", () => changePlayfieldSize(6));
 
             var controlPointInfo = new ControlPointInfo();
-            controlPointInfo.TimingPoints.Add(new TimingControlPoint());
+            controlPointInfo.Add(0, new TimingControlPoint());
 
             WorkingBeatmap beatmap = CreateWorkingBeatmap(new Beatmap
             {
@@ -142,7 +142,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
             HitResult hitResult = RNG.Next(2) == 0 ? HitResult.Good : HitResult.Great;
 
             var cpi = new ControlPointInfo();
-            cpi.EffectPoints.Add(new EffectControlPoint { KiaiMode = kiai });
+            cpi.Add(0, new EffectControlPoint { KiaiMode = kiai });
 
             Hit hit = new Hit();
             hit.ApplyDefaults(cpi, new BeatmapDifficulty());
@@ -157,7 +157,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
             HitResult hitResult = RNG.Next(2) == 0 ? HitResult.Good : HitResult.Great;
 
             var cpi = new ControlPointInfo();
-            cpi.EffectPoints.Add(new EffectControlPoint { KiaiMode = kiai });
+            cpi.Add(0, new EffectControlPoint { KiaiMode = kiai });
 
             Hit hit = new Hit();
             hit.ApplyDefaults(cpi, new BeatmapDifficulty());

osu.Game.Rulesets.Taiko/Audio/DrumSampleMapping.cs

@@ -19,12 +19,7 @@ namespace osu.Game.Rulesets.Taiko.Audio
         {
             this.controlPoints = controlPoints;
 
-            IEnumerable<SampleControlPoint> samplePoints;
-            if (controlPoints.SamplePoints.Count == 0)
-                // Get the default sample point
-                samplePoints = new[] { controlPoints.SamplePointAt(double.MinValue) };
-            else
-                samplePoints = controlPoints.SamplePoints;
+            IEnumerable<SampleControlPoint> samplePoints = controlPoints.SamplePoints.Count == 0 ? new[] { controlPoints.SamplePointAt(double.MinValue) } : controlPoints.SamplePoints;
 
             foreach (var s in samplePoints)
             {

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

@@ -167,9 +167,9 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 var controlPoints = beatmap.ControlPointInfo;
 
                 Assert.AreEqual(4, controlPoints.TimingPoints.Count);
-                Assert.AreEqual(42, controlPoints.DifficultyPoints.Count);
-                Assert.AreEqual(42, controlPoints.SamplePoints.Count);
-                Assert.AreEqual(42, controlPoints.EffectPoints.Count);
+                Assert.AreEqual(5, controlPoints.DifficultyPoints.Count);
+                Assert.AreEqual(34, controlPoints.SamplePoints.Count);
+                Assert.AreEqual(8, controlPoints.EffectPoints.Count);
 
                 var timingPoint = controlPoints.TimingPointAt(0);
                 Assert.AreEqual(956, timingPoint.Time);
@@ -191,7 +191,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 Assert.AreEqual(1.0, difficultyPoint.SpeedMultiplier);
 
                 difficultyPoint = controlPoints.DifficultyPointAt(48428);
-                Assert.AreEqual(48428, difficultyPoint.Time);
+                Assert.AreEqual(0, difficultyPoint.Time);
                 Assert.AreEqual(1.0, difficultyPoint.SpeedMultiplier);
 
                 difficultyPoint = controlPoints.DifficultyPointAt(116999);
@@ -224,7 +224,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 Assert.IsFalse(effectPoint.OmitFirstBarLine);
 
                 effectPoint = controlPoints.EffectPointAt(119637);
-                Assert.AreEqual(119637, effectPoint.Time);
+                Assert.AreEqual(95901, effectPoint.Time);
                 Assert.IsFalse(effectPoint.KiaiMode);
                 Assert.IsFalse(effectPoint.OmitFirstBarLine);
             }
@@ -262,6 +262,21 @@ namespace osu.Game.Tests.Beatmaps.Formats
             }
         }
 
+        [Test]
+        public void TestTimingPointResetsSpeedMultiplier()
+        {
+            var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
+
+            using (var resStream = TestResources.OpenResource("timingpoint-speedmultiplier-reset.osu"))
+            using (var stream = new LineBufferedReader(resStream))
+            {
+                var controlPoints = decoder.Decode(stream).ControlPointInfo;
+
+                Assert.That(controlPoints.DifficultyPointAt(0).SpeedMultiplier, Is.EqualTo(0.5).Within(0.1));
+                Assert.That(controlPoints.DifficultyPointAt(2000).SpeedMultiplier, Is.EqualTo(1).Within(0.1));
+            }
+        }
+
         [Test]
         public void TestDecodeBeatmapColours()
         {
@@ -362,6 +377,23 @@ namespace osu.Game.Tests.Beatmaps.Formats
             }
         }
 
+        [Test]
+        public void TestDecodeControlPointDifficultyChange()
+        {
+            var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
+
+            using (var resStream = TestResources.OpenResource("controlpoint-difficulty-multiplier.osu"))
+            using (var stream = new LineBufferedReader(resStream))
+            {
+                var controlPointInfo = decoder.Decode(stream).ControlPointInfo;
+
+                Assert.That(controlPointInfo.DifficultyPointAt(5).SpeedMultiplier, Is.EqualTo(1));
+                Assert.That(controlPointInfo.DifficultyPointAt(1000).SpeedMultiplier, Is.EqualTo(10));
+                Assert.That(controlPointInfo.DifficultyPointAt(2000).SpeedMultiplier, Is.EqualTo(1.8518518518518519d));
+                Assert.That(controlPointInfo.DifficultyPointAt(3000).SpeedMultiplier, Is.EqualTo(0.5));
+            }
+        }
+
         [Test]
         public void TestDecodeControlPointCustomSampleBank()
         {

osu.Game.Tests/Editor/TestSceneHitObjectComposerDistanceSnapping.cs

@@ -25,11 +25,10 @@ namespace osu.Game.Tests.Editor
             BeatDivisor.Value = 1;
 
             composer.EditorBeatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier = 1;
-            composer.EditorBeatmap.ControlPointInfo.DifficultyPoints.Clear();
-            composer.EditorBeatmap.ControlPointInfo.TimingPoints.Clear();
+            composer.EditorBeatmap.ControlPointInfo.Clear();
 
-            composer.EditorBeatmap.ControlPointInfo.DifficultyPoints.Add(new DifficultyControlPoint { SpeedMultiplier = 1 });
-            composer.EditorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = 1000 });
+            composer.EditorBeatmap.ControlPointInfo.Add(0, new DifficultyControlPoint { SpeedMultiplier = 1 });
+            composer.EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 1000 });
         });
 
         [TestCase(1)]
@@ -47,8 +46,8 @@ namespace osu.Game.Tests.Editor
         {
             AddStep($"set multiplier = {multiplier}", () =>
             {
-                composer.EditorBeatmap.ControlPointInfo.DifficultyPoints.Clear();
-                composer.EditorBeatmap.ControlPointInfo.DifficultyPoints.Add(new DifficultyControlPoint { SpeedMultiplier = multiplier });
+                composer.EditorBeatmap.ControlPointInfo.Clear();
+                composer.EditorBeatmap.ControlPointInfo.Add(0, new DifficultyControlPoint { SpeedMultiplier = multiplier });
             });
 
             assertSnapDistance(100 * multiplier);
@@ -76,8 +75,8 @@ namespace osu.Game.Tests.Editor
 
             AddStep("set beat length = 500", () =>
             {
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Clear();
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = 500 });
+                composer.EditorBeatmap.ControlPointInfo.Clear();
+                composer.EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 500 });
             });
 
             assertDurationToDistance(500, 200);
@@ -97,8 +96,8 @@ namespace osu.Game.Tests.Editor
 
             AddStep("set beat length = 500", () =>
             {
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Clear();
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = 500 });
+                composer.EditorBeatmap.ControlPointInfo.Clear();
+                composer.EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 500 });
             });
 
             assertDistanceToDuration(200, 500);
@@ -124,8 +123,8 @@ namespace osu.Game.Tests.Editor
 
             AddStep("set beat length = 500", () =>
             {
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Clear();
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = 500 });
+                composer.EditorBeatmap.ControlPointInfo.Clear();
+                composer.EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 500 });
             });
 
             assertSnappedDuration(50, 0);
@@ -155,8 +154,8 @@ namespace osu.Game.Tests.Editor
 
             AddStep("set beat length = 500", () =>
             {
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Clear();
-                composer.EditorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = 500 });
+                composer.EditorBeatmap.ControlPointInfo.Clear();
+                composer.EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 500 });
             });
 
             assertSnappedDistance(50, 0);

osu.Game.Tests/NonVisual/ControlPointInfoTest.cs

@@ -0,0 +1,227 @@
+// 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.Game.Beatmaps.ControlPoints;
+
+namespace osu.Game.Tests.NonVisual
+{
+    [TestFixture]
+    public class ControlPointInfoTest
+    {
+        [Test]
+        public void TestAdd()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new TimingControlPoint());
+            cpi.Add(1000, new TimingControlPoint { BeatLength = 500 });
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(2));
+            Assert.That(cpi.TimingPoints.Count, Is.EqualTo(2));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(2));
+        }
+
+        [Test]
+        public void TestAddRedundantTiming()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new TimingControlPoint()); // is *not* redundant, special exception for first timing point.
+            cpi.Add(1000, new TimingControlPoint()); // is redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+            Assert.That(cpi.TimingPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestAddRedundantDifficulty()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new DifficultyControlPoint()); // is redundant
+            cpi.Add(1000, new DifficultyControlPoint()); // is redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(0));
+            Assert.That(cpi.TimingPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(0));
+
+            cpi.Add(1000, new DifficultyControlPoint { SpeedMultiplier = 2 }); // is not redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+            Assert.That(cpi.DifficultyPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestAddRedundantSample()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new SampleControlPoint()); // is redundant
+            cpi.Add(1000, new SampleControlPoint()); // is redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(0));
+            Assert.That(cpi.TimingPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(0));
+
+            cpi.Add(1000, new SampleControlPoint { SampleVolume = 50 }); // is not redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+            Assert.That(cpi.SamplePoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestAddRedundantEffect()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new EffectControlPoint()); // is redundant
+            cpi.Add(1000, new EffectControlPoint()); // is redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(0));
+            Assert.That(cpi.TimingPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(0));
+
+            cpi.Add(1000, new EffectControlPoint { KiaiMode = true }); // is not redundant
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+            Assert.That(cpi.EffectPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.AllControlPoints.Count(), Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestAddGroup()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(1000, true);
+            var group2 = cpi.GroupAt(1000, true);
+
+            Assert.That(group, Is.EqualTo(group2));
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestGroupAtLookupOnly()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(5000, true);
+            Assert.That(group, Is.Not.Null);
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+            Assert.That(cpi.GroupAt(1000), Is.Null);
+            Assert.That(cpi.GroupAt(5000), Is.Not.Null);
+        }
+
+        [Test]
+        public void TestAddRemoveGroup()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(1000, true);
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+
+            cpi.RemoveGroup(group);
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void TestAddControlPointToGroup()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(1000, true);
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+
+            // usually redundant, but adding to group forces it to be added
+            group.Add(new DifficultyControlPoint());
+
+            Assert.That(group.ControlPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.DifficultyPoints.Count, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestAddDuplicateControlPointToGroup()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(1000, true);
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+
+            group.Add(new DifficultyControlPoint());
+            group.Add(new DifficultyControlPoint { SpeedMultiplier = 2 });
+
+            Assert.That(group.ControlPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.DifficultyPoints.Count, Is.EqualTo(1));
+            Assert.That(cpi.DifficultyPoints.First().SpeedMultiplier, Is.EqualTo(2));
+        }
+
+        [Test]
+        public void TestRemoveControlPointFromGroup()
+        {
+            var cpi = new ControlPointInfo();
+
+            var group = cpi.GroupAt(1000, true);
+            Assert.That(cpi.Groups.Count, Is.EqualTo(1));
+
+            var difficultyPoint = new DifficultyControlPoint();
+
+            group.Add(difficultyPoint);
+            group.Remove(difficultyPoint);
+
+            Assert.That(group.ControlPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.DifficultyPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.AllControlPoints.Count, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void TestOrdering()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new TimingControlPoint());
+            cpi.Add(1000, new TimingControlPoint { BeatLength = 500 });
+            cpi.Add(10000, new TimingControlPoint { BeatLength = 200 });
+            cpi.Add(5000, new TimingControlPoint { BeatLength = 100 });
+            cpi.Add(3000, new DifficultyControlPoint { SpeedMultiplier = 2 });
+            cpi.GroupAt(7000, true).Add(new DifficultyControlPoint { SpeedMultiplier = 4 });
+            cpi.GroupAt(1000).Add(new SampleControlPoint { SampleVolume = 0 });
+            cpi.GroupAt(8000, true).Add(new EffectControlPoint { KiaiMode = true });
+
+            Assert.That(cpi.AllControlPoints.Count, Is.EqualTo(8));
+
+            Assert.That(cpi.Groups, Is.Ordered.Ascending.By(nameof(ControlPointGroup.Time)));
+
+            Assert.That(cpi.AllControlPoints, Is.Ordered.Ascending.By(nameof(ControlPoint.Time)));
+            Assert.That(cpi.TimingPoints, Is.Ordered.Ascending.By(nameof(ControlPoint.Time)));
+        }
+
+        [Test]
+        public void TestClear()
+        {
+            var cpi = new ControlPointInfo();
+
+            cpi.Add(0, new TimingControlPoint());
+            cpi.Add(1000, new TimingControlPoint { BeatLength = 500 });
+            cpi.Add(10000, new TimingControlPoint { BeatLength = 200 });
+            cpi.Add(5000, new TimingControlPoint { BeatLength = 100 });
+            cpi.Add(3000, new DifficultyControlPoint { SpeedMultiplier = 2 });
+            cpi.GroupAt(7000, true).Add(new DifficultyControlPoint { SpeedMultiplier = 4 });
+            cpi.GroupAt(1000).Add(new SampleControlPoint { SampleVolume = 0 });
+            cpi.GroupAt(8000, true).Add(new EffectControlPoint { KiaiMode = true });
+
+            cpi.Clear();
+
+            Assert.That(cpi.Groups.Count, Is.EqualTo(0));
+            Assert.That(cpi.DifficultyPoints.Count, Is.EqualTo(0));
+            Assert.That(cpi.AllControlPoints.Count, Is.EqualTo(0));
+        }
+    }
+}

osu.Game.Tests/Resources/controlpoint-difficulty-multiplier.osu

@@ -0,0 +1,8 @@
+osu file format v7
+
+[TimingPoints]
+0,100,4,2,0,100,1,0
+12,500,4,2,0,100,1,0
+1000,-10,4,2,0,100,0,0
+2000,-54,4,2,0,100,0,0
+3000,-200,4,2,0,100,0,0

osu.Game.Tests/Resources/timingpoint-speedmultiplier-reset.osu

@@ -0,0 +1,5 @@
+osu file format v14
+
+[TimingPoints]
+0,-200,4,1,0,100,0,0
+2000,100,1,1,0,100,1,0

osu.Game.Tests/Visual/Editor/TestSceneDistanceSnapGrid.cs

@@ -31,7 +31,7 @@ namespace osu.Game.Tests.Visual.Editor
         public TestSceneDistanceSnapGrid()
         {
             editorBeatmap = new EditorBeatmap<OsuHitObject>(new OsuBeatmap());
-            editorBeatmap.ControlPointInfo.TimingPoints.Add(new TimingControlPoint { BeatLength = beat_length });
+            editorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = beat_length });
 
             Children = new Drawable[]
             {

osu.Game.Tests/Visual/Editor/TestSceneEditorSeekSnapping.cs

@@ -28,18 +28,7 @@ namespace osu.Game.Tests.Visual.Editor
         {
             var testBeatmap = new Beatmap
             {
-                ControlPointInfo = new ControlPointInfo
-                {
-                    TimingPoints =
-                    {
-                        new TimingControlPoint { Time = 0, BeatLength = 200 },
-                        new TimingControlPoint { Time = 100, BeatLength = 400 },
-                        new TimingControlPoint { Time = 175, BeatLength = 800 },
-                        new TimingControlPoint { Time = 350, BeatLength = 200 },
-                        new TimingControlPoint { Time = 450, BeatLength = 100 },
-                        new TimingControlPoint { Time = 500, BeatLength = 307.69230769230802 }
-                    }
-                },
+                ControlPointInfo = new ControlPointInfo(),
                 HitObjects =
                 {
                     new HitCircle { StartTime = 0 },
@@ -47,6 +36,13 @@ namespace osu.Game.Tests.Visual.Editor
                 }
             };
 
+            testBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = 200 });
+            testBeatmap.ControlPointInfo.Add(100, new TimingControlPoint { BeatLength = 400 });
+            testBeatmap.ControlPointInfo.Add(175, new TimingControlPoint { BeatLength = 800 });
+            testBeatmap.ControlPointInfo.Add(350, new TimingControlPoint { BeatLength = 200 });
+            testBeatmap.ControlPointInfo.Add(450, new TimingControlPoint { BeatLength = 100 });
+            testBeatmap.ControlPointInfo.Add(500, new TimingControlPoint { BeatLength = 307.69230769230802 });
+
             Beatmap.Value = CreateWorkingBeatmap(testBeatmap);
 
             Child = new TimingPointVisualiser(testBeatmap, 5000) { Clock = Clock };

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

@@ -47,7 +47,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestRelativeBeatLengthScaleSingleTimingPoint()
         {
-            var beatmap = createBeatmap(new TimingControlPoint { BeatLength = time_range / 2 });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range / 2 });
 
             createTest(beatmap, d => d.RelativeScaleBeatLengthsOverride = true);
 
@@ -61,10 +62,10 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestRelativeBeatLengthScaleTimingPointBeyondEndDoesNotBecomeDominant()
         {
-            var beatmap = createBeatmap(
-                new TimingControlPoint { BeatLength = time_range / 2 },
-                new TimingControlPoint { Time = 12000, BeatLength = time_range },
-                new TimingControlPoint { Time = 100000, BeatLength = time_range });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range / 2 });
+            beatmap.ControlPointInfo.Add(12000, new TimingControlPoint { BeatLength = time_range });
+            beatmap.ControlPointInfo.Add(100000, new TimingControlPoint { BeatLength = time_range });
 
             createTest(beatmap, d => d.RelativeScaleBeatLengthsOverride = true);
 
@@ -75,9 +76,9 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestRelativeBeatLengthScaleFromSecondTimingPoint()
         {
-            var beatmap = createBeatmap(
-                new TimingControlPoint { BeatLength = time_range },
-                new TimingControlPoint { Time = 3 * time_range, BeatLength = time_range / 2 });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range });
+            beatmap.ControlPointInfo.Add(3 * time_range, new TimingControlPoint { BeatLength = time_range / 2 });
 
             createTest(beatmap, d => d.RelativeScaleBeatLengthsOverride = true);
 
@@ -97,9 +98,9 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestNonRelativeScale()
         {
-            var beatmap = createBeatmap(
-                new TimingControlPoint { BeatLength = time_range },
-                new TimingControlPoint { Time = 3 * time_range, BeatLength = time_range / 2 });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range });
+            beatmap.ControlPointInfo.Add(3 * time_range, new TimingControlPoint { BeatLength = time_range / 2 });
 
             createTest(beatmap);
 
@@ -119,7 +120,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestSliderMultiplierDoesNotAffectRelativeBeatLength()
         {
-            var beatmap = createBeatmap(new TimingControlPoint { BeatLength = time_range });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range });
             beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier = 2;
 
             createTest(beatmap, d => d.RelativeScaleBeatLengthsOverride = true);
@@ -132,7 +134,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestSliderMultiplierAffectsNonRelativeBeatLength()
         {
-            var beatmap = createBeatmap(new TimingControlPoint { BeatLength = time_range });
+            var beatmap = createBeatmap();
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = time_range });
             beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier = 2;
 
             createTest(beatmap);
@@ -154,14 +157,11 @@ namespace osu.Game.Tests.Visual.Gameplay
         /// Creates an <see cref="IBeatmap"/>, containing 10 hitobjects and user-provided timing points.
         /// The hitobjects are spaced <see cref="time_range"/> milliseconds apart.
         /// </summary>
-        /// <param name="timingControlPoints">The timing points to add to the beatmap.</param>
         /// <returns>The <see cref="IBeatmap"/>.</returns>
-        private IBeatmap createBeatmap(params TimingControlPoint[] timingControlPoints)
+        private IBeatmap createBeatmap()
         {
             var beatmap = new Beatmap<HitObject> { BeatmapInfo = { Ruleset = new OsuRuleset().RulesetInfo } };
 
-            beatmap.ControlPointInfo.TimingPoints.AddRange(timingControlPoints);
-
             for (int i = 0; i < 10; i++)
                 beatmap.HitObjects.Add(new HitObject { StartTime = i * time_range });
 

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

@@ -3,6 +3,7 @@
 
 using NUnit.Framework;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Screens.Play.HUD;
 using osu.Game.Screens.Play.PlayerSettings;
@@ -20,6 +21,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             {
                 Anchor = Anchor.TopRight,
                 Origin = Anchor.TopRight,
+                State = { Value = Visibility.Visible }
             });
 
             Add(container = new ExampleContainer());

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

@@ -33,23 +33,15 @@ namespace osu.Game.Tests.Visual.Menus
         [Test]
         public void TestInstantLoad()
         {
-            bool logoVisible = false;
+            // visual only, very impossible to test this using asserts.
 
-            AddStep("begin loading", () =>
+            AddStep("load immediately", () =>
             {
                 loader = new TestLoader();
                 loader.AllowLoad.Set();
 
                 LoadScreen(loader);
             });
-
-            AddUntilStep("loaded", () =>
-            {
-                logoVisible = loader.Logo?.Alpha > 0;
-                return loader.Logo != null && loader.ScreenLoaded;
-            });
-
-            AddAssert("logo was not visible", () => !logoVisible);
         }
 
         [Test]
@@ -58,7 +50,7 @@ namespace osu.Game.Tests.Visual.Menus
             AddStep("begin loading", () => LoadScreen(loader = new TestLoader()));
             AddUntilStep("wait for logo visible", () => loader.Logo?.Alpha > 0);
             AddStep("finish loading", () => loader.AllowLoad.Set());
-            AddAssert("loaded", () => loader.Logo != null && loader.ScreenLoaded);
+            AddUntilStep("loaded", () => loader.Logo != null && loader.ScreenLoaded);
             AddUntilStep("logo gone", () => loader.Logo?.Alpha == 0);
         }
 

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

@@ -0,0 +1,102 @@
+// 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 NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Beatmaps;
+using osu.Game.Overlays.BeatmapSet;
+using osu.Game.Rulesets;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    public class TestSceneBeatmapRulesetSelector : OsuTestScene
+    {
+        public override IReadOnlyList<Type> RequiredTypes => new[]
+        {
+            typeof(BeatmapRulesetSelector),
+            typeof(BeatmapRulesetTabItem),
+        };
+
+        private readonly TestRulesetSelector selector;
+
+        public TestSceneBeatmapRulesetSelector()
+        {
+            Add(selector = new TestRulesetSelector());
+        }
+
+        [Resolved]
+        private RulesetStore rulesets { get; set; }
+
+        [Test]
+        public void TestMultipleRulesetsBeatmapSet()
+        {
+            var enabledRulesets = rulesets.AvailableRulesets.Skip(1).Take(2);
+
+            AddStep("load multiple rulesets beatmapset", () =>
+            {
+                selector.BeatmapSet = new BeatmapSetInfo
+                {
+                    Beatmaps = enabledRulesets.Select(r => new BeatmapInfo { Ruleset = r }).ToList()
+                };
+            });
+
+            var tabItems = selector.TabContainer.TabItems;
+            AddAssert("other rulesets disabled", () => tabItems.Except(tabItems.Where(t => enabledRulesets.Any(r => r.Equals(t.Value)))).All(t => !t.Enabled.Value));
+            AddAssert("left-most ruleset selected", () => tabItems.First(t => t.Enabled.Value).Active.Value);
+        }
+
+        [Test]
+        public void TestSingleRulesetBeatmapSet()
+        {
+            var enabledRuleset = rulesets.AvailableRulesets.Last();
+
+            AddStep("load single ruleset beatmapset", () =>
+            {
+                selector.BeatmapSet = new BeatmapSetInfo
+                {
+                    Beatmaps = new List<BeatmapInfo>
+                    {
+                        new BeatmapInfo
+                        {
+                            Ruleset = enabledRuleset
+                        }
+                    }
+                };
+            });
+
+            AddAssert("single ruleset selected", () => selector.SelectedTab.Value.Equals(enabledRuleset));
+        }
+
+        [Test]
+        public void TestEmptyBeatmapSet()
+        {
+            AddStep("load empty beatmapset", () => selector.BeatmapSet = new BeatmapSetInfo
+            {
+                Beatmaps = new List<BeatmapInfo>()
+            });
+
+            AddAssert("no ruleset selected", () => selector.SelectedTab == null);
+            AddAssert("all rulesets disabled", () => selector.TabContainer.TabItems.All(t => !t.Enabled.Value));
+        }
+
+        [Test]
+        public void TestNullBeatmapSet()
+        {
+            AddStep("load null beatmapset", () => selector.BeatmapSet = null);
+
+            AddAssert("no ruleset selected", () => selector.SelectedTab == null);
+            AddAssert("all rulesets disabled", () => selector.TabContainer.TabItems.All(t => !t.Enabled.Value));
+        }
+
+        private class TestRulesetSelector : BeatmapRulesetSelector
+        {
+            public new TabItem<RulesetInfo> SelectedTab => base.SelectedTab;
+
+            public new TabFillFlowContainer TabContainer => base.TabContainer;
+        }
+    }
+}

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

@@ -40,24 +40,19 @@ namespace osu.Game.Tests.Visual.Online
             typeof(PreviewButton),
             typeof(SuccessRate),
             typeof(BeatmapAvailability),
+            typeof(BeatmapRulesetSelector),
+            typeof(BeatmapRulesetTabItem),
         };
 
         protected override bool UseOnlineAPI => true;
 
-        private RulesetInfo taikoRuleset;
-        private RulesetInfo maniaRuleset;
-
         public TestSceneBeatmapSetOverlay()
         {
             Add(overlay = new TestBeatmapSetOverlay());
         }
 
-        [BackgroundDependencyLoader]
-        private void load(RulesetStore rulesets)
-        {
-            taikoRuleset = rulesets.GetRuleset(1);
-            maniaRuleset = rulesets.GetRuleset(3);
-        }
+        [Resolved]
+        private RulesetStore rulesets { get; set; }
 
         [Test]
         public void TestLoading()
@@ -111,7 +106,7 @@ namespace osu.Game.Tests.Visual.Online
                             StarDifficulty = 9.99,
                             Version = @"TEST",
                             Length = 456000,
-                            Ruleset = maniaRuleset,
+                            Ruleset = rulesets.GetRuleset(3),
                             BaseDifficulty = new BeatmapDifficulty
                             {
                                 CircleSize = 1,
@@ -189,7 +184,7 @@ namespace osu.Game.Tests.Visual.Online
                             StarDifficulty = 5.67,
                             Version = @"ANOTHER TEST",
                             Length = 123000,
-                            Ruleset = taikoRuleset,
+                            Ruleset = rulesets.GetRuleset(1),
                             BaseDifficulty = new BeatmapDifficulty
                             {
                                 CircleSize = 9,
@@ -217,6 +212,54 @@ namespace osu.Game.Tests.Visual.Online
             downloadAssert(false);
         }
 
+        [Test]
+        public void TestMultipleRulesets()
+        {
+            AddStep("show multiple rulesets beatmap", () =>
+            {
+                var beatmaps = new List<BeatmapInfo>();
+
+                foreach (var ruleset in rulesets.AvailableRulesets.Skip(1))
+                {
+                    beatmaps.Add(new BeatmapInfo
+                    {
+                        Version = ruleset.Name,
+                        Ruleset = ruleset,
+                        BaseDifficulty = new BeatmapDifficulty(),
+                        OnlineInfo = new BeatmapOnlineInfo(),
+                        Metrics = new BeatmapMetrics
+                        {
+                            Fails = Enumerable.Range(1, 100).Select(i => i % 12 - 6).ToArray(),
+                            Retries = Enumerable.Range(-2, 100).Select(i => i % 12 - 6).ToArray(),
+                        },
+                    });
+                }
+
+                overlay.ShowBeatmapSet(new BeatmapSetInfo
+                {
+                    Metadata = new BeatmapMetadata
+                    {
+                        Title = @"multiple rulesets beatmap",
+                        Artist = @"none",
+                        Author = new User
+                        {
+                            Username = "BanchoBot",
+                            Id = 3,
+                        }
+                    },
+                    OnlineInfo = new BeatmapSetOnlineInfo
+                    {
+                        Covers = new BeatmapSetOnlineCovers(),
+                    },
+                    Metrics = new BeatmapSetMetrics { Ratings = Enumerable.Range(0, 11).ToArray() },
+                    Beatmaps = beatmaps
+                });
+            });
+
+            AddAssert("shown beatmaps of current ruleset", () => overlay.Header.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);
+        }
+
         [Test]
         public void TestHide()
         {
@@ -281,12 +324,12 @@ namespace osu.Game.Tests.Visual.Online
 
         private void downloadAssert(bool shown)
         {
-            AddAssert($"is download button {(shown ? "shown" : "hidden")}", () => overlay.DownloadButtonsVisible == shown);
+            AddAssert($"is download button {(shown ? "shown" : "hidden")}", () => overlay.Header.DownloadButtonsVisible == shown);
         }
 
         private class TestBeatmapSetOverlay : BeatmapSetOverlay
         {
-            public bool DownloadButtonsVisible => Header.DownloadButtonsVisible;
+            public new Header Header => base.Header;
         }
     }
 }

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

@@ -7,6 +7,10 @@ using osu.Game.Online.Chat;
 using osu.Game.Users;
 using osuTK;
 using System;
+using System.Linq;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics.Containers;
+using osu.Game.Overlays.Chat;
 
 namespace osu.Game.Tests.Visual.Online
 {
@@ -42,14 +46,14 @@ namespace osu.Game.Tests.Visual.Online
         [Cached]
         private ChannelManager channelManager = new ChannelManager();
 
-        private readonly StandAloneChatDisplay chatDisplay;
-        private readonly StandAloneChatDisplay chatDisplay2;
+        private readonly TestStandAloneChatDisplay chatDisplay;
+        private readonly TestStandAloneChatDisplay chatDisplay2;
 
         public TestSceneStandAloneChatDisplay()
         {
             Add(channelManager);
 
-            Add(chatDisplay = new StandAloneChatDisplay
+            Add(chatDisplay = new TestStandAloneChatDisplay
             {
                 Anchor = Anchor.CentreLeft,
                 Origin = Anchor.CentreLeft,
@@ -57,7 +61,7 @@ namespace osu.Game.Tests.Visual.Online
                 Size = new Vector2(400, 80)
             });
 
-            Add(chatDisplay2 = new StandAloneChatDisplay(true)
+            Add(chatDisplay2 = new TestStandAloneChatDisplay(true)
             {
                 Anchor = Anchor.CentreRight,
                 Origin = Anchor.CentreRight,
@@ -119,6 +123,49 @@ namespace osu.Game.Tests.Visual.Online
                 Content = "Message from the future!",
                 Timestamp = DateTimeOffset.Now
             }));
+
+            AddUntilStep("ensure still scrolled to bottom", () => chatDisplay.ScrolledToBottom);
+
+            const int messages_per_call = 10;
+            AddRepeatStep("add many messages", () =>
+                {
+                    for (int i = 0; i < messages_per_call; i++)
+                        testChannel.AddNewMessages(new Message(sequence++)
+                        {
+                            Sender = longUsernameUser,
+                            Content = "Many messages! " + Guid.NewGuid(),
+                            Timestamp = DateTimeOffset.Now
+                        });
+                }, Channel.MAX_HISTORY / messages_per_call + 5);
+
+            AddAssert("Ensure no adjacent day separators", () =>
+            {
+                var indices = chatDisplay.FillFlow.OfType<DrawableChannel.DaySeparator>().Select(ds => chatDisplay.FillFlow.IndexOf(ds));
+
+                foreach (var i in indices)
+                    if (i < chatDisplay.FillFlow.Count && chatDisplay.FillFlow[i + 1] is DrawableChannel.DaySeparator)
+                        return false;
+
+                return true;
+            });
+
+            AddUntilStep("ensure still scrolled to bottom", () => chatDisplay.ScrolledToBottom);
+        }
+
+        private class TestStandAloneChatDisplay : StandAloneChatDisplay
+        {
+            public TestStandAloneChatDisplay(bool textbox = false)
+                : base(textbox)
+            {
+            }
+
+            protected DrawableChannel DrawableChannel => InternalChildren.OfType<DrawableChannel>().First();
+
+            protected OsuScrollContainer ScrollContainer => (OsuScrollContainer)((Container)DrawableChannel.Child).Child;
+
+            public FillFlowContainer FillFlow => (FillFlowContainer)ScrollContainer.Child;
+
+            public bool ScrolledToBottom => ScrollContainer.IsScrolledToEnd(1);
         }
     }
 }

osu.Game.Tests/Visual/SongSelect/TestSceneBeatmapCarousel.cs

@@ -245,6 +245,28 @@ namespace osu.Game.Tests.Visual.SongSelect
             AddAssert($"Check #{set_count} is at bottom", () => carousel.BeatmapSets.Last().Metadata.Title.EndsWith($"#{set_count}!"));
         }
 
+        [Test]
+        public void TestSortingStability()
+        {
+            var sets = new List<BeatmapSetInfo>();
+
+            for (int i = 0; i < 20; i++)
+            {
+                var set = createTestBeatmapSet(i);
+                set.Metadata.Artist = "same artist";
+                set.Metadata.Title = "same title";
+                sets.Add(set);
+            }
+
+            loadBeatmaps(sets);
+
+            AddStep("Sort by artist", () => carousel.Filter(new FilterCriteria { Sort = SortMode.Artist }, false));
+            AddAssert("Items remain in original order", () => carousel.BeatmapSets.Select((set, index) => set.ID == index).All(b => b));
+
+            AddStep("Sort by title", () => carousel.Filter(new FilterCriteria { Sort = SortMode.Title }, false));
+            AddAssert("Items remain in original order", () => carousel.BeatmapSets.Select((set, index) => set.ID == index).All(b => b));
+        }
+
         [Test]
         public void TestSortingWithFiltered()
         {

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

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio.Track;
@@ -10,7 +11,6 @@ using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
-using osu.Framework.Lists;
 using osu.Framework.Timing;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Graphics;
@@ -153,7 +153,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                 };
             }
 
-            private SortedList<TimingControlPoint> timingPoints => Beatmap.Value.Beatmap.ControlPointInfo.TimingPoints;
+            private List<TimingControlPoint> timingPoints => Beatmap.Value.Beatmap.ControlPointInfo.TimingPoints.ToList();
 
             private TimingControlPoint getNextTimingPoint(TimingControlPoint current)
             {

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

@@ -11,7 +11,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tests.Visual.UserInterface
 {
-    public class TestSceneLabelledComponent : OsuTestScene
+    public class TestSceneLabelledDrawable : OsuTestScene
     {
         [TestCase(false)]
         [TestCase(true)]
@@ -25,7 +25,7 @@ namespace osu.Game.Tests.Visual.UserInterface
         {
             AddStep("create component", () =>
             {
-                LabelledComponent<Drawable> component;
+                LabelledDrawable<Drawable> component;
 
                 Child = new Container
                 {
@@ -33,7 +33,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                     Origin = Anchor.Centre,
                     Width = 500,
                     AutoSizeAxes = Axes.Y,
-                    Child = component = padded ? (LabelledComponent<Drawable>)new PaddedLabelledComponent() : new NonPaddedLabelledComponent(),
+                    Child = component = padded ? (LabelledDrawable<Drawable>)new PaddedLabelledDrawable() : new NonPaddedLabelledDrawable(),
                 };
 
                 component.Label = "a sample component";
@@ -41,9 +41,9 @@ namespace osu.Game.Tests.Visual.UserInterface
             });
         }
 
-        private class PaddedLabelledComponent : LabelledComponent<Drawable>
+        private class PaddedLabelledDrawable : LabelledDrawable<Drawable>
         {
-            public PaddedLabelledComponent()
+            public PaddedLabelledDrawable()
                 : base(true)
             {
             }
@@ -57,9 +57,9 @@ namespace osu.Game.Tests.Visual.UserInterface
             };
         }
 
-        private class NonPaddedLabelledComponent : LabelledComponent<Drawable>
+        private class NonPaddedLabelledDrawable : LabelledDrawable<Drawable>
         {
-            public NonPaddedLabelledComponent()
+            public NonPaddedLabelledDrawable()
                 : base(false)
             {
             }

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

@@ -7,7 +7,6 @@ using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
-using osu.Game.Graphics.UserInterface;
 using osu.Game.Graphics.UserInterfaceV2;
 
 namespace osu.Game.Tests.Visual.UserInterface
@@ -28,7 +27,7 @@ namespace osu.Game.Tests.Visual.UserInterface
         {
             AddStep("create component", () =>
             {
-                LabelledComponent<OsuTextBox> component;
+                LabelledTextBox component;
 
                 Child = new Container
                 {

osu.Game.Tournament/Screens/SetupScreen.cs

@@ -89,7 +89,7 @@ namespace osu.Game.Tournament.Screens
             };
         }
 
-        private class ActionableInfo : LabelledComponent<Drawable>
+        private class ActionableInfo : LabelledDrawable<Drawable>
         {
             private OsuButton button;
 

osu.Game/Beatmaps/BeatmapManager.cs

@@ -392,8 +392,15 @@ namespace osu.Game.Beatmaps
 
                 req.Failure += e => { LogForModel(set, $"Online retrieval failed for {beatmap} ({e.Message})"); };
 
-                // intentionally blocking to limit web request concurrency
-                req.Perform(api);
+                try
+                {
+                    // intentionally blocking to limit web request concurrency
+                    req.Perform(api);
+                }
+                catch (Exception e)
+                {
+                    LogForModel(set, $"Online retrieval failed for {beatmap} ({e.Message})");
+                }
             }
         }
     }

osu.Game/Beatmaps/ControlPoints/ControlPoint.cs

@@ -1,4 +1,4 @@
-// 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 System;
@@ -10,12 +10,11 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// <summary>
         /// The time at which the control point takes effect.
         /// </summary>
-        public double Time;
+        public double Time => controlPointGroup?.Time ?? 0;
 
-        /// <summary>
-        /// Whether this timing point was generated internally, as opposed to parsed from the underlying beatmap.
-        /// </summary>
-        internal bool AutoGenerated;
+        private ControlPointGroup controlPointGroup;
+
+        public void AttachGroup(ControlPointGroup pointGroup) => this.controlPointGroup = pointGroup;
 
         public int CompareTo(ControlPoint other) => Time.CompareTo(other.Time);
 

osu.Game/Beatmaps/ControlPoints/ControlPointGroup.cs

@@ -0,0 +1,50 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.Linq;
+using osu.Framework.Bindables;
+
+namespace osu.Game.Beatmaps.ControlPoints
+{
+    public class ControlPointGroup : IComparable<ControlPointGroup>
+    {
+        public event Action<ControlPoint> ItemAdded;
+        public event Action<ControlPoint> ItemRemoved;
+
+        /// <summary>
+        /// The time at which the control point takes effect.
+        /// </summary>
+        public double Time { get; }
+
+        public IBindableList<ControlPoint> ControlPoints => controlPoints;
+
+        private readonly BindableList<ControlPoint> controlPoints = new BindableList<ControlPoint>();
+
+        public ControlPointGroup(double time)
+        {
+            Time = time;
+        }
+
+        public int CompareTo(ControlPointGroup other) => Time.CompareTo(other.Time);
+
+        public void Add(ControlPoint point)
+        {
+            var existing = controlPoints.FirstOrDefault(p => p.GetType() == point.GetType());
+
+            if (existing != null)
+                Remove(existing);
+
+            point.AttachGroup(this);
+
+            controlPoints.Add(point);
+            ItemAdded?.Invoke(point);
+        }
+
+        public void Remove(ControlPoint point)
+        {
+            controlPoints.Remove(point);
+            ItemRemoved?.Invoke(point);
+        }
+    }
+}

osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using Newtonsoft.Json;
+using osu.Framework.Bindables;
 using osu.Framework.Lists;
 
 namespace osu.Game.Beatmaps.ControlPoints
@@ -12,57 +13,78 @@ namespace osu.Game.Beatmaps.ControlPoints
     [Serializable]
     public class ControlPointInfo
     {
+        /// <summary>
+        /// All control points grouped by time.
+        /// </summary>
+        [JsonProperty]
+        public IBindableList<ControlPointGroup> Groups => groups;
+
+        private readonly BindableList<ControlPointGroup> groups = new BindableList<ControlPointGroup>();
+
         /// <summary>
         /// All timing points.
         /// </summary>
         [JsonProperty]
-        public SortedList<TimingControlPoint> TimingPoints { get; private set; } = new SortedList<TimingControlPoint>(Comparer<TimingControlPoint>.Default);
+        public IReadOnlyList<TimingControlPoint> TimingPoints => timingPoints;
+
+        private readonly SortedList<TimingControlPoint> timingPoints = new SortedList<TimingControlPoint>(Comparer<TimingControlPoint>.Default);
 
         /// <summary>
         /// All difficulty points.
         /// </summary>
         [JsonProperty]
-        public SortedList<DifficultyControlPoint> DifficultyPoints { get; private set; } = new SortedList<DifficultyControlPoint>(Comparer<DifficultyControlPoint>.Default);
+        public IReadOnlyList<DifficultyControlPoint> DifficultyPoints => difficultyPoints;
+
+        private readonly SortedList<DifficultyControlPoint> difficultyPoints = new SortedList<DifficultyControlPoint>(Comparer<DifficultyControlPoint>.Default);
 
         /// <summary>
         /// All sound points.
         /// </summary>
         [JsonProperty]
-        public SortedList<SampleControlPoint> SamplePoints { get; private set; } = new SortedList<SampleControlPoint>(Comparer<SampleControlPoint>.Default);
+        public IReadOnlyList<SampleControlPoint> SamplePoints => samplePoints;
+
+        private readonly SortedList<SampleControlPoint> samplePoints = new SortedList<SampleControlPoint>(Comparer<SampleControlPoint>.Default);
 
         /// <summary>
         /// All effect points.
         /// </summary>
         [JsonProperty]
-        public SortedList<EffectControlPoint> EffectPoints { get; private set; } = new SortedList<EffectControlPoint>(Comparer<EffectControlPoint>.Default);
+        public IReadOnlyList<EffectControlPoint> EffectPoints => effectPoints;
+
+        private readonly SortedList<EffectControlPoint> effectPoints = new SortedList<EffectControlPoint>(Comparer<EffectControlPoint>.Default);
+
+        /// <summary>
+        /// All control points, of all types.
+        /// </summary>
+        public IEnumerable<ControlPoint> AllControlPoints => Groups.SelectMany(g => g.ControlPoints).ToArray();
 
         /// <summary>
         /// Finds the difficulty control point that is active at <paramref name="time"/>.
         /// </summary>
         /// <param name="time">The time to find the difficulty control point at.</param>
         /// <returns>The difficulty control point.</returns>
-        public DifficultyControlPoint DifficultyPointAt(double time) => binarySearch(DifficultyPoints, time);
+        public DifficultyControlPoint DifficultyPointAt(double time) => binarySearchWithFallback(DifficultyPoints, time);
 
         /// <summary>
         /// Finds the effect control point that is active at <paramref name="time"/>.
         /// </summary>
         /// <param name="time">The time to find the effect control point at.</param>
         /// <returns>The effect control point.</returns>
-        public EffectControlPoint EffectPointAt(double time) => binarySearch(EffectPoints, time);
+        public EffectControlPoint EffectPointAt(double time) => binarySearchWithFallback(EffectPoints, time);
 
         /// <summary>
         /// Finds the sound control point that is active at <paramref name="time"/>.
         /// </summary>
         /// <param name="time">The time to find the sound control point at.</param>
         /// <returns>The sound control point.</returns>
-        public SampleControlPoint SamplePointAt(double time) => binarySearch(SamplePoints, time, SamplePoints.Count > 0 ? SamplePoints[0] : null);
+        public SampleControlPoint SamplePointAt(double time) => binarySearchWithFallback(SamplePoints, time, SamplePoints.Count > 0 ? SamplePoints[0] : null);
 
         /// <summary>
         /// Finds the timing control point that is active at <paramref name="time"/>.
         /// </summary>
         /// <param name="time">The time to find the timing control point at.</param>
         /// <returns>The timing control point.</returns>
-        public TimingControlPoint TimingPointAt(double time) => binarySearch(TimingPoints, time, TimingPoints.Count > 0 ? TimingPoints[0] : null);
+        public TimingControlPoint TimingPointAt(double time) => binarySearchWithFallback(TimingPoints, time, TimingPoints.Count > 0 ? TimingPoints[0] : null);
 
         /// <summary>
         /// Finds the maximum BPM represented by any timing control point.
@@ -85,24 +107,93 @@ namespace osu.Game.Beatmaps.ControlPoints
         public double BPMMode =>
             60000 / (TimingPoints.GroupBy(c => c.BeatLength).OrderByDescending(grp => grp.Count()).FirstOrDefault()?.FirstOrDefault() ?? new TimingControlPoint()).BeatLength;
 
+        /// <summary>
+        /// Remove all <see cref="ControlPointGroup"/>s and return to a pristine state.
+        /// </summary>
+        public void Clear()
+        {
+            groups.Clear();
+            timingPoints.Clear();
+            difficultyPoints.Clear();
+            samplePoints.Clear();
+            effectPoints.Clear();
+        }
+
+        /// <summary>
+        /// Add a new <see cref="ControlPoint"/>. Note that the provided control point may not be added if the correct state is already present at the provided time.
+        /// </summary>
+        /// <param name="time">The time at which the control point should be added.</param>
+        /// <param name="controlPoint">The control point to add.</param>
+        /// <returns>Whether the control point was added.</returns>
+        public bool Add(double time, ControlPoint controlPoint)
+        {
+            if (checkAlreadyExisting(time, controlPoint))
+                return false;
+
+            GroupAt(time, true).Add(controlPoint);
+            return true;
+        }
+
+        public ControlPointGroup GroupAt(double time, bool addIfNotExisting = false)
+        {
+            var newGroup = new ControlPointGroup(time);
+
+            int i = groups.BinarySearch(newGroup);
+
+            if (i >= 0)
+                return groups[i];
+
+            if (addIfNotExisting)
+            {
+                newGroup.ItemAdded += groupItemAdded;
+                newGroup.ItemRemoved += groupItemRemoved;
+
+                groups.Insert(~i, newGroup);
+                return newGroup;
+            }
+
+            return null;
+        }
+
+        public void RemoveGroup(ControlPointGroup group)
+        {
+            group.ItemAdded -= groupItemAdded;
+            group.ItemRemoved -= groupItemRemoved;
+
+            groups.Remove(group);
+        }
+
         /// <summary>
         /// Binary searches one of the control point lists to find the active control point at <paramref name="time"/>.
+        /// Includes logic for returning a specific point when no matching point is found.
         /// </summary>
         /// <param name="list">The list to search.</param>
         /// <param name="time">The time to find the control point at.</param>
         /// <param name="prePoint">The control point to use when <paramref name="time"/> is before any control points. If null, a new control point will be constructed.</param>
-        /// <returns>The active control point at <paramref name="time"/>.</returns>
-        private T binarySearch<T>(SortedList<T> list, double time, T prePoint = null)
+        /// <returns>The active control point at <paramref name="time"/>, or a fallback <see cref="ControlPoint"/> if none found.</returns>
+        private T binarySearchWithFallback<T>(IReadOnlyList<T> list, double time, T prePoint = null)
             where T : ControlPoint, new()
+        {
+            return binarySearch(list, time) ?? prePoint ?? new T();
+        }
+
+        /// <summary>
+        /// Binary searches one of the control point lists to find the active control point at <paramref name="time"/>.
+        /// </summary>
+        /// <param name="list">The list to search.</param>
+        /// <param name="time">The time to find the control point at.</param>
+        /// <returns>The active control point at <paramref name="time"/>.</returns>
+        private T binarySearch<T>(IReadOnlyList<T> list, double time)
+            where T : ControlPoint
         {
             if (list == null)
                 throw new ArgumentNullException(nameof(list));
 
             if (list.Count == 0)
-                return new T();
+                return null;
 
             if (time < list[0].Time)
-                return prePoint ?? new T();
+                return null;
 
             if (time >= list[list.Count - 1].Time)
                 return list[list.Count - 1];
@@ -125,5 +216,82 @@ namespace osu.Game.Beatmaps.ControlPoints
             // l will be the first control point with Time > time, but we want the one before it
             return list[l - 1];
         }
+
+        /// <summary>
+        /// Check whether <see cref="newPoint"/> should be added.
+        /// </summary>
+        /// <param name="time">The time to find the timing control point at.</param>
+        /// <param name="newPoint">A point to be added.</param>
+        /// <returns>Whether the new point should be added.</returns>
+        private bool checkAlreadyExisting(double time, ControlPoint newPoint)
+        {
+            ControlPoint existing = null;
+
+            switch (newPoint)
+            {
+                case TimingControlPoint _:
+                    // Timing points are a special case and need to be added regardless of fallback availability.
+                    existing = binarySearch(TimingPoints, time);
+                    break;
+
+                case EffectControlPoint _:
+                    existing = EffectPointAt(time);
+                    break;
+
+                case SampleControlPoint _:
+                    existing = SamplePointAt(time);
+                    break;
+
+                case DifficultyControlPoint _:
+                    existing = DifficultyPointAt(time);
+                    break;
+            }
+
+            return existing?.EquivalentTo(newPoint) == true;
+        }
+
+        private void groupItemAdded(ControlPoint controlPoint)
+        {
+            switch (controlPoint)
+            {
+                case TimingControlPoint typed:
+                    timingPoints.Add(typed);
+                    break;
+
+                case EffectControlPoint typed:
+                    effectPoints.Add(typed);
+                    break;
+
+                case SampleControlPoint typed:
+                    samplePoints.Add(typed);
+                    break;
+
+                case DifficultyControlPoint typed:
+                    difficultyPoints.Add(typed);
+                    break;
+            }
+        }
+
+        private void groupItemRemoved(ControlPoint controlPoint)
+        {
+            switch (controlPoint)
+            {
+                case TimingControlPoint typed:
+                    timingPoints.Remove(typed);
+                    break;
+
+                case EffectControlPoint typed:
+                    effectPoints.Remove(typed);
+                    break;
+
+                case SampleControlPoint typed:
+                    samplePoints.Remove(typed);
+                    break;
+
+                case DifficultyControlPoint typed:
+                    difficultyPoints.Remove(typed);
+                    break;
+            }
+        }
     }
 }

osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs

@@ -1,24 +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 osuTK;
+using osu.Framework.Bindables;
 
 namespace osu.Game.Beatmaps.ControlPoints
 {
     public class DifficultyControlPoint : ControlPoint
     {
+        /// <summary>
+        /// The speed multiplier at this control point.
+        /// </summary>
+        public readonly BindableDouble SpeedMultiplierBindable = new BindableDouble(1)
+        {
+            Precision = 0.1,
+            Default = 1,
+            MinValue = 0.1,
+            MaxValue = 10
+        };
+
         /// <summary>
         /// The speed multiplier at this control point.
         /// </summary>
         public double SpeedMultiplier
         {
-            get => speedMultiplier;
-            set => speedMultiplier = MathHelper.Clamp(value, 0.1, 10);
+            get => SpeedMultiplierBindable.Value;
+            set => SpeedMultiplierBindable.Value = value;
         }
 
-        private double speedMultiplier = 1;
-
         public override bool EquivalentTo(ControlPoint other) =>
-            other is DifficultyControlPoint otherTyped && otherTyped.SpeedMultiplier.Equals(speedMultiplier);
+            other is DifficultyControlPoint otherTyped && otherTyped.SpeedMultiplier.Equals(SpeedMultiplier);
     }
 }

osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs

@@ -1,19 +1,39 @@
 // 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.Bindables;
+
 namespace osu.Game.Beatmaps.ControlPoints
 {
     public class EffectControlPoint : ControlPoint
     {
         /// <summary>
-        /// Whether this control point enables Kiai mode.
+        /// Whether the first bar line of this control point is ignored.
         /// </summary>
-        public bool KiaiMode;
+        public readonly BindableBool OmitFirstBarLineBindable = new BindableBool();
 
         /// <summary>
         /// Whether the first bar line of this control point is ignored.
         /// </summary>
-        public bool OmitFirstBarLine;
+        public bool OmitFirstBarLine
+        {
+            get => OmitFirstBarLineBindable.Value;
+            set => OmitFirstBarLineBindable.Value = value;
+        }
+
+        /// <summary>
+        /// Whether this control point enables Kiai mode.
+        /// </summary>
+        public readonly BindableBool KiaiModeBindable = new BindableBool();
+
+        /// <summary>
+        /// Whether this control point enables Kiai mode.
+        /// </summary>
+        public bool KiaiMode
+        {
+            get => KiaiModeBindable.Value;
+            set => KiaiModeBindable.Value = value;
+        }
 
         public override bool EquivalentTo(ControlPoint other) =>
             other is EffectControlPoint otherTyped &&

osu.Game/Beatmaps/ControlPoints/SampleControlPoint.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.Framework.Bindables;
 using osu.Game.Audio;
 
 namespace osu.Game.Beatmaps.ControlPoints
@@ -12,12 +13,35 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// <summary>
         /// The default sample bank at this control point.
         /// </summary>
-        public string SampleBank = DEFAULT_BANK;
+        public readonly Bindable<string> SampleBankBindable = new Bindable<string>(DEFAULT_BANK) { Default = DEFAULT_BANK };
+
+        /// <summary>
+        /// The speed multiplier at this control point.
+        /// </summary>
+        public string SampleBank
+        {
+            get => SampleBankBindable.Value;
+            set => SampleBankBindable.Value = value;
+        }
+
+        /// <summary>
+        /// The default sample bank at this control point.
+        /// </summary>
+        public readonly BindableInt SampleVolumeBindable = new BindableInt(100)
+        {
+            MinValue = 0,
+            MaxValue = 100,
+            Default = 100
+        };
 
         /// <summary>
         /// The default sample volume at this control point.
         /// </summary>
-        public int SampleVolume = 100;
+        public int SampleVolume
+        {
+            get => SampleVolumeBindable.Value;
+            set => SampleVolumeBindable.Value = value;
+        }
 
         /// <summary>
         /// Create a SampleInfo based on the sample settings in this control point.

osu.Game/Beatmaps/ControlPoints/TimingControlPoint.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 osuTK;
+using osu.Framework.Bindables;
 using osu.Game.Beatmaps.Timing;
 
 namespace osu.Game.Beatmaps.ControlPoints
@@ -11,23 +11,40 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// <summary>
         /// The time signature at this control point.
         /// </summary>
-        public TimeSignatures TimeSignature = TimeSignatures.SimpleQuadruple;
+        public readonly Bindable<TimeSignatures> TimeSignatureBindable = new Bindable<TimeSignatures>(TimeSignatures.SimpleQuadruple) { Default = TimeSignatures.SimpleQuadruple };
+
+        /// <summary>
+        /// The time signature at this control point.
+        /// </summary>
+        public TimeSignatures TimeSignature
+        {
+            get => TimeSignatureBindable.Value;
+            set => TimeSignatureBindable.Value = value;
+        }
 
         public const double DEFAULT_BEAT_LENGTH = 1000;
 
         /// <summary>
         /// The beat length at this control point.
         /// </summary>
-        public virtual double BeatLength
+        public readonly BindableDouble BeatLengthBindable = new BindableDouble(DEFAULT_BEAT_LENGTH)
         {
-            get => beatLength;
-            set => beatLength = MathHelper.Clamp(value, 6, 60000);
-        }
+            Default = DEFAULT_BEAT_LENGTH,
+            MinValue = 6,
+            MaxValue = 60000
+        };
 
-        private double beatLength = DEFAULT_BEAT_LENGTH;
+        /// <summary>
+        /// The beat length at this control point.
+        /// </summary>
+        public double BeatLength
+        {
+            get => BeatLengthBindable.Value;
+            set => BeatLengthBindable.Value = value;
+        }
 
         public override bool EquivalentTo(ControlPoint other) =>
             other is TimingControlPoint otherTyped
-            && TimeSignature == otherTyped.TimeSignature && beatLength.Equals(otherTyped.beatLength);
+            && TimeSignature == otherTyped.TimeSignature && BeatLength.Equals(otherTyped.BeatLength);
     }
 }

osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using osu.Framework.IO.File;
@@ -50,6 +51,8 @@ namespace osu.Game.Beatmaps.Formats
 
             base.ParseStreamInto(stream, beatmap);
 
+            flushPendingPoints();
+
             // Objects may be out of order *only* if a user has manually edited an .osu file.
             // Unfortunately there are ranked maps in this state (example: https://osu.ppy.sh/s/594828).
             // OrderBy is used to guarantee that the parsing order of hitobjects with equal start times is maintained (stably-sorted)
@@ -369,104 +372,64 @@ namespace osu.Game.Beatmaps.Formats
             if (timingChange)
             {
                 var controlPoint = CreateTimingControlPoint();
-                controlPoint.Time = time;
+
                 controlPoint.BeatLength = beatLength;
                 controlPoint.TimeSignature = timeSignature;
 
-                handleTimingControlPoint(controlPoint);
+                addControlPoint(time, controlPoint, true);
             }
 
-            handleDifficultyControlPoint(new DifficultyControlPoint
+            addControlPoint(time, new LegacyDifficultyControlPoint
             {
-                Time = time,
                 SpeedMultiplier = speedMultiplier,
-                AutoGenerated = timingChange
-            });
+            }, timingChange);
 
-            handleEffectControlPoint(new EffectControlPoint
+            addControlPoint(time, new EffectControlPoint
             {
-                Time = time,
                 KiaiMode = kiaiMode,
                 OmitFirstBarLine = omitFirstBarSignature,
-                AutoGenerated = timingChange
-            });
+            }, timingChange);
 
-            handleSampleControlPoint(new LegacySampleControlPoint
+            addControlPoint(time, new LegacySampleControlPoint
             {
-                Time = time,
                 SampleBank = stringSampleSet,
                 SampleVolume = sampleVolume,
                 CustomSampleBank = customSampleBank,
-                AutoGenerated = timingChange
-            });
+            }, timingChange);
+
+            // To handle the scenario where a non-timing line shares the same time value as a subsequent timing line but
+            // appears earlier in the file, we buffer non-timing control points and rewrite them *after* control points from the timing line
+            // with the same time value (allowing them to overwrite as necessary).
+            //
+            // The expected outcome is that we prefer the non-timing line's adjustments over the timing line's adjustments when time is equal.
+            if (timingChange)
+                flushPendingPoints();
         }
 
-        private void handleTimingControlPoint(TimingControlPoint newPoint)
+        private readonly List<ControlPoint> pendingControlPoints = new List<ControlPoint>();
+        private double pendingControlPointsTime;
+
+        private void addControlPoint(double time, ControlPoint point, bool timingChange)
         {
-            var existing = beatmap.ControlPointInfo.TimingPointAt(newPoint.Time);
+            if (time != pendingControlPointsTime)
+                flushPendingPoints();
 
-            if (existing.Time == newPoint.Time)
+            if (timingChange)
             {
-                // autogenerated points should not replace non-autogenerated.
-                // this allows for incorrectly ordered timing points to still be correctly handled.
-                if (newPoint.AutoGenerated && !existing.AutoGenerated)
-                    return;
-
-                beatmap.ControlPointInfo.TimingPoints.Remove(existing);
+                beatmap.ControlPointInfo.Add(time, point);
+                return;
             }
 
-            beatmap.ControlPointInfo.TimingPoints.Add(newPoint);
+            pendingControlPoints.Add(point);
+            pendingControlPointsTime = time;
         }
 
-        private void handleDifficultyControlPoint(DifficultyControlPoint newPoint)
+        private void flushPendingPoints()
         {
-            var existing = beatmap.ControlPointInfo.DifficultyPointAt(newPoint.Time);
+            foreach (var p in pendingControlPoints)
+                beatmap.ControlPointInfo.Add(pendingControlPointsTime, p);
 
-            if (existing.Time == newPoint.Time)
-            {
-                // autogenerated points should not replace non-autogenerated.
-                // this allows for incorrectly ordered timing points to still be correctly handled.
-                if (newPoint.AutoGenerated && !existing.AutoGenerated)
-                    return;
-
-                beatmap.ControlPointInfo.DifficultyPoints.Remove(existing);
-            }
-
-            beatmap.ControlPointInfo.DifficultyPoints.Add(newPoint);
-        }
-
-        private void handleEffectControlPoint(EffectControlPoint newPoint)
-        {
-            var existing = beatmap.ControlPointInfo.EffectPointAt(newPoint.Time);
-
-            if (existing.Time == newPoint.Time)
-            {
-                // autogenerated points should not replace non-autogenerated.
-                // this allows for incorrectly ordered timing points to still be correctly handled.
-                if (newPoint.AutoGenerated && !existing.AutoGenerated)
-                    return;
-
-                beatmap.ControlPointInfo.EffectPoints.Remove(existing);
-            }
-
-            beatmap.ControlPointInfo.EffectPoints.Add(newPoint);
-        }
-
-        private void handleSampleControlPoint(SampleControlPoint newPoint)
-        {
-            var existing = beatmap.ControlPointInfo.SamplePointAt(newPoint.Time);
-
-            if (existing.Time == newPoint.Time)
-            {
-                // autogenerated points should not replace non-autogenerated.
-                // this allows for incorrectly ordered timing points to still be correctly handled.
-                if (newPoint.AutoGenerated && !existing.AutoGenerated)
-                    return;
-
-                beatmap.ControlPointInfo.SamplePoints.Remove(existing);
-            }
-
-            beatmap.ControlPointInfo.SamplePoints.Add(newPoint);
+            pendingControlPoints.Clear();
         }
 
         private void handleHitObject(string line)

osu.Game/Beatmaps/Formats/LegacyDecoder.cs

@@ -189,6 +189,14 @@ namespace osu.Game.Beatmaps.Formats
             Foreground = 3
         }
 
+        internal class LegacyDifficultyControlPoint : DifficultyControlPoint
+        {
+            public LegacyDifficultyControlPoint()
+            {
+                SpeedMultiplierBindable.Precision = double.Epsilon;
+            }
+        }
+
         internal class LegacySampleControlPoint : SampleControlPoint
         {
             public int CustomSampleBank;

osu.Game/Beatmaps/Formats/LegacyDifficultyCalculatorBeatmapDecoder.cs

@@ -28,11 +28,15 @@ namespace osu.Game.Beatmaps.Formats
         }
 
         protected override TimingControlPoint CreateTimingControlPoint()
-            => new LegacyDifficultyCalculatorControlPoint();
+            => new LegacyDifficultyCalculatorTimingControlPoint();
 
-        private class LegacyDifficultyCalculatorControlPoint : TimingControlPoint
+        private class LegacyDifficultyCalculatorTimingControlPoint : TimingControlPoint
         {
-            public override double BeatLength { get; set; } = DEFAULT_BEAT_LENGTH;
+            public LegacyDifficultyCalculatorTimingControlPoint()
+            {
+                BeatLengthBindable.MinValue = double.MinValue;
+                BeatLengthBindable.MaxValue = double.MaxValue;
+            }
         }
     }
 }

osu.Game/Database/ArchiveModelManager.cs

@@ -108,7 +108,7 @@ namespace osu.Game.Database
             return Import(notification, paths);
         }
 
-        protected async Task Import(ProgressNotification notification, params string[] paths)
+        protected async Task<IEnumerable<TModel>> Import(ProgressNotification notification, params string[] paths)
         {
             notification.Progress = 0;
             notification.Text = $"{HumanisedModelName.Humanize(LetterCasing.Title)} import is initialising...";
@@ -168,6 +168,8 @@ namespace osu.Game.Database
 
                 notification.State = ProgressNotificationState.Completed;
             }
+
+            return imported;
         }
 
         /// <summary>

osu.Game/Database/DownloadableArchiveModelManager.cs

@@ -76,21 +76,17 @@ namespace osu.Game.Database
                 Task.Factory.StartNew(async () =>
                 {
                     // This gets scheduled back to the update thread, but we want the import to run in the background.
-                    await Import(notification, filename);
+                    var imported = await Import(notification, filename);
+
+                    // for now a failed import will be marked as a failed download for simplicity.
+                    if (!imported.Any())
+                        DownloadFailed?.Invoke(request);
+
                     currentDownloads.Remove(request);
                 }, TaskCreationOptions.LongRunning);
             };
 
-            request.Failure += error =>
-            {
-                DownloadFailed?.Invoke(request);
-
-                if (error is OperationCanceledException) return;
-
-                notification.State = ProgressNotificationState.Cancelled;
-                Logger.Error(error, $"{HumanisedModelName.Titleize()} download failed!");
-                currentDownloads.Remove(request);
-            };
+            request.Failure += triggerFailure;
 
             notification.CancelRequested += () =>
             {
@@ -103,11 +99,31 @@ namespace osu.Game.Database
             currentDownloads.Add(request);
             PostNotification?.Invoke(notification);
 
-            Task.Factory.StartNew(() => request.Perform(api), TaskCreationOptions.LongRunning);
+            Task.Factory.StartNew(() =>
+            {
+                try
+                {
+                    request.Perform(api);
+                }
+                catch (Exception error)
+                {
+                    triggerFailure(error);
+                }
+            }, TaskCreationOptions.LongRunning);
 
             DownloadBegan?.Invoke(request);
-
             return true;
+
+            void triggerFailure(Exception error)
+            {
+                DownloadFailed?.Invoke(request);
+
+                if (error is OperationCanceledException) return;
+
+                notification.State = ProgressNotificationState.Cancelled;
+                Logger.Error(error, $"{HumanisedModelName.Titleize()} download failed!");
+                currentDownloads.Remove(request);
+            }
         }
 
         public bool IsAvailableLocally(TModel model) => CheckLocalAvailability(model, modelStore.ConsumableItems.Where(m => !m.DeletePending));

osu.Game/Graphics/Containers/BeatSyncedContainer.cs

@@ -104,14 +104,10 @@ namespace osu.Game.Graphics.Containers
             defaultTiming = new TimingControlPoint
             {
                 BeatLength = default_beat_length,
-                AutoGenerated = true,
-                Time = 0
             };
 
             defaultEffect = new EffectControlPoint
             {
-                Time = 0,
-                AutoGenerated = true,
                 KiaiMode = false,
                 OmitFirstBarLine = false
             };

osu.Game/Graphics/UserInterface/OsuButton.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Graphics.UserInterface
         protected override bool OnHover(HoverEvent e)
         {
             hover.FadeIn(200);
-            return base.OnHover(e);
+            return true;
         }
 
         protected override void OnHoverLost(HoverLostEvent e)

osu.Game/Graphics/UserInterfaceV2/LabelledComponent.cs

@@ -1,132 +1,24 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Shapes;
-using osu.Game.Graphics.Containers;
-using osuTK;
+using osu.Framework.Graphics.UserInterface;
 
 namespace osu.Game.Graphics.UserInterfaceV2
 {
-    public abstract class LabelledComponent<T> : CompositeDrawable
-        where T : Drawable
+    public abstract class LabelledComponent<T, U> : LabelledDrawable<T>, IHasCurrentValue<U>
+        where T : Drawable, IHasCurrentValue<U>
     {
-        protected const float CONTENT_PADDING_VERTICAL = 10;
-        protected const float CONTENT_PADDING_HORIZONTAL = 15;
-        protected const float CORNER_RADIUS = 15;
-
-        /// <summary>
-        /// The component that is being displayed.
-        /// </summary>
-        protected readonly T Component;
-
-        private readonly OsuTextFlowContainer labelText;
-        private readonly OsuTextFlowContainer descriptionText;
-
-        /// <summary>
-        /// Creates a new <see cref="LabelledComponent{T}"/>.
-        /// </summary>
-        /// <param name="padded">Whether the component should be padded or should be expanded to the bounds of this <see cref="LabelledComponent{T}"/>.</param>
         protected LabelledComponent(bool padded)
+            : base(padded)
         {
-            RelativeSizeAxes = Axes.X;
-            AutoSizeAxes = Axes.Y;
-
-            CornerRadius = CORNER_RADIUS;
-            Masking = true;
-
-            InternalChildren = new Drawable[]
-            {
-                new Box
-                {
-                    RelativeSizeAxes = Axes.Both,
-                    Colour = OsuColour.FromHex("1c2125"),
-                },
-                new FillFlowContainer
-                {
-                    RelativeSizeAxes = Axes.X,
-                    AutoSizeAxes = Axes.Y,
-                    Direction = FillDirection.Vertical,
-                    Padding = padded
-                        ? new MarginPadding { Horizontal = CONTENT_PADDING_HORIZONTAL, Vertical = CONTENT_PADDING_VERTICAL }
-                        : new MarginPadding { Left = CONTENT_PADDING_HORIZONTAL },
-                    Spacing = new Vector2(0, 12),
-                    Children = new Drawable[]
-                    {
-                        new GridContainer
-                        {
-                            RelativeSizeAxes = Axes.X,
-                            AutoSizeAxes = Axes.Y,
-                            Content = new[]
-                            {
-                                new Drawable[]
-                                {
-                                    labelText = new OsuTextFlowContainer(s => s.Font = OsuFont.GetFont(weight: FontWeight.Bold))
-                                    {
-                                        Anchor = Anchor.CentreLeft,
-                                        Origin = Anchor.CentreLeft,
-                                        AutoSizeAxes = Axes.Both,
-                                        Padding = new MarginPadding { Right = 20 }
-                                    },
-                                    new Container
-                                    {
-                                        Anchor = Anchor.CentreRight,
-                                        Origin = Anchor.CentreRight,
-                                        RelativeSizeAxes = Axes.X,
-                                        AutoSizeAxes = Axes.Y,
-                                        Child = Component = CreateComponent().With(d =>
-                                        {
-                                            d.Anchor = Anchor.CentreRight;
-                                            d.Origin = Anchor.CentreRight;
-                                        })
-                                    }
-                                },
-                            },
-                            RowDimensions = new[] { new Dimension(GridSizeMode.AutoSize) },
-                            ColumnDimensions = new[] { new Dimension(GridSizeMode.AutoSize) }
-                        },
-                        descriptionText = new OsuTextFlowContainer(s => s.Font = OsuFont.GetFont(size: 12, weight: FontWeight.Bold, italics: true))
-                        {
-                            RelativeSizeAxes = Axes.X,
-                            AutoSizeAxes = Axes.Y,
-                            Padding = new MarginPadding { Bottom = padded ? 0 : CONTENT_PADDING_VERTICAL },
-                            Alpha = 0,
-                        }
-                    }
-                }
-            };
         }
 
-        [BackgroundDependencyLoader]
-        private void load(OsuColour osuColour)
+        public Bindable<U> Current
         {
-            descriptionText.Colour = osuColour.Yellow;
+            get => Component.Current;
+            set => Component.Current = value;
         }
-
-        public string Label
-        {
-            set => labelText.Text = value;
-        }
-
-        public string Description
-        {
-            set
-            {
-                descriptionText.Text = value;
-
-                if (!string.IsNullOrEmpty(value))
-                    descriptionText.Show();
-                else
-                    descriptionText.Hide();
-            }
-        }
-
-        /// <summary>
-        /// Creates the component that should be displayed.
-        /// </summary>
-        /// <returns>The component.</returns>
-        protected abstract T CreateComponent();
     }
 }

osu.Game/Graphics/UserInterfaceV2/LabelledDrawable.cs

@@ -0,0 +1,132 @@
+// 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.Framework.Graphics.Shapes;
+using osu.Game.Graphics.Containers;
+using osuTK;
+
+namespace osu.Game.Graphics.UserInterfaceV2
+{
+    public abstract class LabelledDrawable<T> : CompositeDrawable
+        where T : Drawable
+    {
+        protected const float CONTENT_PADDING_VERTICAL = 10;
+        protected const float CONTENT_PADDING_HORIZONTAL = 15;
+        protected const float CORNER_RADIUS = 15;
+
+        /// <summary>
+        /// The component that is being displayed.
+        /// </summary>
+        protected readonly T Component;
+
+        private readonly OsuTextFlowContainer labelText;
+        private readonly OsuTextFlowContainer descriptionText;
+
+        /// <summary>
+        /// Creates a new <see cref="LabelledComponent{T, U}"/>.
+        /// </summary>
+        /// <param name="padded">Whether the component should be padded or should be expanded to the bounds of this <see cref="LabelledComponent{T, U}"/>.</param>
+        protected LabelledDrawable(bool padded)
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            CornerRadius = CORNER_RADIUS;
+            Masking = true;
+
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Colour = OsuColour.FromHex("1c2125"),
+                },
+                new FillFlowContainer
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Direction = FillDirection.Vertical,
+                    Padding = padded
+                        ? new MarginPadding { Horizontal = CONTENT_PADDING_HORIZONTAL, Vertical = CONTENT_PADDING_VERTICAL }
+                        : new MarginPadding { Left = CONTENT_PADDING_HORIZONTAL },
+                    Spacing = new Vector2(0, 12),
+                    Children = new Drawable[]
+                    {
+                        new GridContainer
+                        {
+                            RelativeSizeAxes = Axes.X,
+                            AutoSizeAxes = Axes.Y,
+                            Content = new[]
+                            {
+                                new Drawable[]
+                                {
+                                    labelText = new OsuTextFlowContainer(s => s.Font = OsuFont.GetFont(weight: FontWeight.Bold))
+                                    {
+                                        Anchor = Anchor.CentreLeft,
+                                        Origin = Anchor.CentreLeft,
+                                        AutoSizeAxes = Axes.Both,
+                                        Padding = new MarginPadding { Right = 20 }
+                                    },
+                                    new Container
+                                    {
+                                        Anchor = Anchor.CentreRight,
+                                        Origin = Anchor.CentreRight,
+                                        RelativeSizeAxes = Axes.X,
+                                        AutoSizeAxes = Axes.Y,
+                                        Child = Component = CreateComponent().With(d =>
+                                        {
+                                            d.Anchor = Anchor.CentreRight;
+                                            d.Origin = Anchor.CentreRight;
+                                        })
+                                    }
+                                },
+                            },
+                            RowDimensions = new[] { new Dimension(GridSizeMode.AutoSize) },
+                            ColumnDimensions = new[] { new Dimension(GridSizeMode.AutoSize) }
+                        },
+                        descriptionText = new OsuTextFlowContainer(s => s.Font = OsuFont.GetFont(size: 12, weight: FontWeight.Bold, italics: true))
+                        {
+                            RelativeSizeAxes = Axes.X,
+                            AutoSizeAxes = Axes.Y,
+                            Padding = new MarginPadding { Bottom = padded ? 0 : CONTENT_PADDING_VERTICAL },
+                            Alpha = 0,
+                        }
+                    }
+                }
+            };
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour osuColour)
+        {
+            descriptionText.Colour = osuColour.Yellow;
+        }
+
+        public string Label
+        {
+            set => labelText.Text = value;
+        }
+
+        public string Description
+        {
+            set
+            {
+                descriptionText.Text = value;
+
+                if (!string.IsNullOrEmpty(value))
+                    descriptionText.Show();
+                else
+                    descriptionText.Hide();
+            }
+        }
+
+        /// <summary>
+        /// Creates the component that should be displayed.
+        /// </summary>
+        /// <returns>The component.</returns>
+        protected abstract T CreateComponent();
+    }
+}

osu.Game/Graphics/UserInterfaceV2/LabelledSwitchButton.cs

@@ -3,7 +3,7 @@
 
 namespace osu.Game.Graphics.UserInterfaceV2
 {
-    public class LabelledSwitchButton : LabelledComponent<SwitchButton>
+    public class LabelledSwitchButton : LabelledComponent<SwitchButton, bool>
     {
         public LabelledSwitchButton()
             : base(true)

osu.Game/Graphics/UserInterfaceV2/LabelledTextBox.cs

@@ -8,7 +8,7 @@ using osu.Game.Graphics.UserInterface;
 
 namespace osu.Game.Graphics.UserInterfaceV2
 {
-    public class LabelledTextBox : LabelledComponent<OsuTextBox>
+    public class LabelledTextBox : LabelledComponent<OsuTextBox, string>
     {
         public event TextBox.OnCommitHandler OnCommit;
 

osu.Game/Online/Chat/Channel.cs

@@ -14,7 +14,7 @@ namespace osu.Game.Online.Chat
 {
     public class Channel
     {
-        public readonly int MaxHistory = 300;
+        public const int MAX_HISTORY = 300;
 
         /// <summary>
         /// Contains every joined user except the current logged in user. Currently only returned for PM channels.
@@ -80,8 +80,6 @@ namespace osu.Game.Online.Chat
         /// </summary>
         public Bindable<bool> Joined = new Bindable<bool>();
 
-        public const int MAX_HISTORY = 300;
-
         [JsonConstructor]
         public Channel()
         {
@@ -162,8 +160,8 @@ namespace osu.Game.Online.Chat
         {
             // never purge local echos
             int messageCount = Messages.Count - pendingMessages.Count;
-            if (messageCount > MaxHistory)
-                Messages.RemoveRange(0, messageCount - MaxHistory);
+            if (messageCount > MAX_HISTORY)
+                Messages.RemoveRange(0, messageCount - MAX_HISTORY);
         }
     }
 }

osu.Game/Overlays/BeatmapSet/BeatmapPicker.cs

@@ -17,6 +17,7 @@ using osu.Game.Beatmaps.Drawables;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.Sprites;
+using osu.Game.Rulesets;
 using osuTK;
 using osuTK.Graphics;
 
@@ -27,10 +28,11 @@ namespace osu.Game.Overlays.BeatmapSet
         private const float tile_icon_padding = 7;
         private const float tile_spacing = 2;
 
-        private readonly DifficultiesContainer difficulties;
         private readonly OsuSpriteText version, starRating;
         private readonly Statistic plays, favourites;
 
+        public readonly DifficultiesContainer Difficulties;
+
         public readonly Bindable<BeatmapInfo> Beatmap = new Bindable<BeatmapInfo>();
 
         private BeatmapSetInfo beatmapSet;
@@ -43,38 +45,10 @@ namespace osu.Game.Overlays.BeatmapSet
                 if (value == beatmapSet) return;
 
                 beatmapSet = value;
-
                 updateDisplay();
             }
         }
 
-        private void updateDisplay()
-        {
-            difficulties.Clear();
-
-            if (BeatmapSet != null)
-            {
-                difficulties.ChildrenEnumerable = BeatmapSet.Beatmaps.OrderBy(beatmap => beatmap.StarDifficulty).Select(b => new DifficultySelectorButton(b)
-                {
-                    State = DifficultySelectorState.NotSelected,
-                    OnHovered = beatmap =>
-                    {
-                        showBeatmap(beatmap);
-                        starRating.Text = beatmap.StarDifficulty.ToString("Star Difficulty 0.##");
-                        starRating.FadeIn(100);
-                    },
-                    OnClicked = beatmap => { Beatmap.Value = beatmap; },
-                });
-            }
-
-            starRating.FadeOut(100);
-            Beatmap.Value = BeatmapSet?.Beatmaps.FirstOrDefault();
-            plays.Value = BeatmapSet?.OnlineInfo.PlayCount ?? 0;
-            favourites.Value = BeatmapSet?.OnlineInfo.FavouriteCount ?? 0;
-
-            updateDifficultyButtons();
-        }
-
         public BeatmapPicker()
         {
             RelativeSizeAxes = Axes.X;
@@ -89,7 +63,7 @@ namespace osu.Game.Overlays.BeatmapSet
                     Direction = FillDirection.Vertical,
                     Children = new Drawable[]
                     {
-                        difficulties = new DifficultiesContainer
+                        Difficulties = new DifficultiesContainer
                         {
                             RelativeSizeAxes = Axes.X,
                             AutoSizeAxes = Axes.Y,
@@ -147,6 +121,9 @@ namespace osu.Game.Overlays.BeatmapSet
             };
         }
 
+        [Resolved]
+        private IBindable<RulesetInfo> ruleset { get; set; }
+
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
@@ -158,10 +135,39 @@ namespace osu.Game.Overlays.BeatmapSet
         {
             base.LoadComplete();
 
+            ruleset.ValueChanged += r => updateDisplay();
+
             // done here so everything can bind in intialization and get the first trigger
             Beatmap.TriggerChange();
         }
 
+        private void updateDisplay()
+        {
+            Difficulties.Clear();
+
+            if (BeatmapSet != null)
+            {
+                Difficulties.ChildrenEnumerable = BeatmapSet.Beatmaps.Where(b => b.Ruleset.Equals(ruleset.Value)).OrderBy(b => b.StarDifficulty).Select(b => new DifficultySelectorButton(b)
+                {
+                    State = DifficultySelectorState.NotSelected,
+                    OnHovered = beatmap =>
+                    {
+                        showBeatmap(beatmap);
+                        starRating.Text = beatmap.StarDifficulty.ToString("Star Difficulty 0.##");
+                        starRating.FadeIn(100);
+                    },
+                    OnClicked = beatmap => { Beatmap.Value = beatmap; },
+                });
+            }
+
+            starRating.FadeOut(100);
+            Beatmap.Value = Difficulties.FirstOrDefault()?.Beatmap;
+            plays.Value = BeatmapSet?.OnlineInfo.PlayCount ?? 0;
+            favourites.Value = BeatmapSet?.OnlineInfo.FavouriteCount ?? 0;
+
+            updateDifficultyButtons();
+        }
+
         private void showBeatmap(BeatmapInfo beatmap)
         {
             version.Text = beatmap?.Version;
@@ -169,10 +175,10 @@ namespace osu.Game.Overlays.BeatmapSet
 
         private void updateDifficultyButtons()
         {
-            difficulties.Children.ToList().ForEach(diff => diff.State = diff.Beatmap == Beatmap.Value ? DifficultySelectorState.Selected : DifficultySelectorState.NotSelected);
+            Difficulties.Children.ToList().ForEach(diff => diff.State = diff.Beatmap == Beatmap.Value ? DifficultySelectorState.Selected : DifficultySelectorState.NotSelected);
         }
 
-        private class DifficultiesContainer : FillFlowContainer<DifficultySelectorButton>
+        public class DifficultiesContainer : FillFlowContainer<DifficultySelectorButton>
         {
             public Action OnLostHover;
 
@@ -183,7 +189,7 @@ namespace osu.Game.Overlays.BeatmapSet
             }
         }
 
-        private class DifficultySelectorButton : OsuClickableContainer, IStateful<DifficultySelectorState>
+        public class DifficultySelectorButton : OsuClickableContainer, IStateful<DifficultySelectorState>
         {
             private const float transition_duration = 100;
             private const float size = 52;
@@ -320,7 +326,7 @@ namespace osu.Game.Overlays.BeatmapSet
             }
         }
 
-        private enum DifficultySelectorState
+        public enum DifficultySelectorState
         {
             Selected,
             NotSelected,

osu.Game/Overlays/BeatmapSet/BeatmapRulesetSelector.cs

@@ -0,0 +1,48 @@
+// 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.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
+using osuTK;
+using System.Linq;
+
+namespace osu.Game.Overlays.BeatmapSet
+{
+    public class BeatmapRulesetSelector : RulesetSelector
+    {
+        private readonly Bindable<BeatmapSetInfo> beatmapSet = new Bindable<BeatmapSetInfo>();
+
+        public BeatmapSetInfo BeatmapSet
+        {
+            get => beatmapSet.Value;
+            set
+            {
+                // propagate value to tab items first to enable only available rulesets.
+                beatmapSet.Value = value;
+
+                SelectTab(TabContainer.TabItems.FirstOrDefault(t => t.Enabled.Value));
+            }
+        }
+
+        public BeatmapRulesetSelector()
+        {
+            AutoSizeAxes = Axes.Both;
+        }
+
+        protected override TabItem<RulesetInfo> CreateTabItem(RulesetInfo value) => new BeatmapRulesetTabItem(value)
+        {
+            BeatmapSet = { BindTarget = beatmapSet }
+        };
+
+        protected override TabFillFlowContainer CreateTabFlow() => new TabFillFlowContainer
+        {
+            AutoSizeAxes = Axes.Both,
+            Direction = FillDirection.Horizontal,
+            Spacing = new Vector2(10, 0),
+        };
+    }
+}

osu.Game/Overlays/BeatmapSet/BeatmapRulesetTabItem.cs

@@ -0,0 +1,145 @@
+// 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.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.UserInterface;
+using osu.Framework.Input.Events;
+using osu.Game.Beatmaps;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Rulesets;
+using osuTK;
+using osuTK.Graphics;
+using System.Linq;
+
+namespace osu.Game.Overlays.BeatmapSet
+{
+    public class BeatmapRulesetTabItem : TabItem<RulesetInfo>
+    {
+        private readonly OsuSpriteText name, count;
+        private readonly Box bar;
+
+        public readonly Bindable<BeatmapSetInfo> BeatmapSet = new Bindable<BeatmapSetInfo>();
+
+        public override bool PropagatePositionalInputSubTree => Enabled.Value && !Active.Value && base.PropagatePositionalInputSubTree;
+
+        public BeatmapRulesetTabItem(RulesetInfo value)
+            : base(value)
+        {
+            AutoSizeAxes = Axes.Both;
+
+            FillFlowContainer nameContainer;
+
+            Children = new Drawable[]
+            {
+                nameContainer = new FillFlowContainer
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    AutoSizeAxes = Axes.Both,
+                    Direction = FillDirection.Horizontal,
+                    Margin = new MarginPadding { Bottom = 7.5f },
+                    Spacing = new Vector2(2.5f),
+                    Children = new Drawable[]
+                    {
+                        name = new OsuSpriteText
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Text = value.Name,
+                            Font = OsuFont.Default.With(size: 18),
+                        },
+                        new Container
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            AutoSizeAxes = Axes.Both,
+                            Masking = true,
+                            CornerRadius = 4f,
+                            Children = new Drawable[]
+                            {
+                                new Box
+                                {
+                                    RelativeSizeAxes = Axes.Both,
+                                    Colour = Color4.Black.Opacity(0.5f),
+                                },
+                                count = new OsuSpriteText
+                                {
+                                    Alpha = 0,
+                                    Anchor = Anchor.Centre,
+                                    Origin = Anchor.Centre,
+                                    Margin = new MarginPadding { Horizontal = 5f },
+                                    Font = OsuFont.Default.With(weight: FontWeight.SemiBold),
+                                }
+                            }
+                        }
+                    }
+                },
+                bar = new Box
+                {
+                    Anchor = Anchor.BottomCentre,
+                    Origin = Anchor.BottomCentre,
+                    RelativeSizeAxes = Axes.X,
+                },
+                new HoverClickSounds(),
+            };
+
+            BeatmapSet.BindValueChanged(setInfo =>
+            {
+                var beatmapsCount = setInfo.NewValue?.Beatmaps.Count(b => b.Ruleset.Equals(Value)) ?? 0;
+
+                count.Text = beatmapsCount.ToString();
+                count.Alpha = beatmapsCount > 0 ? 1f : 0f;
+
+                Enabled.Value = beatmapsCount > 0;
+            }, true);
+
+            Enabled.BindValueChanged(v => nameContainer.Alpha = v.NewValue ? 1f : 0.5f, true);
+        }
+
+        [Resolved]
+        private OsuColour colour { get; set; }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            count.Colour = colour.Gray9;
+            bar.Colour = colour.Blue;
+
+            updateState();
+        }
+
+        private void updateState()
+        {
+            var isHoveredOrActive = IsHovered || Active.Value;
+
+            bar.ResizeHeightTo(isHoveredOrActive ? 4 : 0, 200, Easing.OutQuint);
+
+            name.Colour = isHoveredOrActive ? colour.GrayE : colour.GrayC;
+            name.Font = name.Font.With(weight: Active.Value ? FontWeight.Bold : FontWeight.Regular);
+        }
+
+        #region Hovering and activation logic
+
+        protected override void OnActivated() => updateState();
+
+        protected override void OnDeactivated() => updateState();
+
+        protected override bool OnHover(HoverEvent e)
+        {
+            updateState();
+            return false;
+        }
+
+        protected override void OnHoverLost(HoverLostEvent e) => updateState();
+
+        #endregion
+    }
+}

osu.Game/Overlays/BeatmapSet/Header.cs

@@ -3,6 +3,7 @@
 
 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;
@@ -16,6 +17,7 @@ using osu.Game.Graphics.UserInterface;
 using osu.Game.Online;
 using osu.Game.Overlays.BeatmapSet.Buttons;
 using osu.Game.Overlays.Direct;
+using osu.Game.Rulesets;
 using osuTK;
 using osuTK.Graphics;
 
@@ -39,6 +41,7 @@ namespace osu.Game.Overlays.BeatmapSet
 
         public bool DownloadButtonsVisible => downloadButtonsContainer.Any();
 
+        public readonly BeatmapRulesetSelector RulesetSelector;
         public readonly BeatmapPicker Picker;
 
         private readonly FavouriteButton favouriteButton;
@@ -47,6 +50,9 @@ namespace osu.Game.Overlays.BeatmapSet
 
         private readonly LoadingAnimation loading;
 
+        [Cached(typeof(IBindable<RulesetInfo>))]
+        private readonly Bindable<RulesetInfo> ruleset = new Bindable<RulesetInfo>();
+
         public Header()
         {
             ExternalLinkButton externalLink;
@@ -69,12 +75,18 @@ namespace osu.Game.Overlays.BeatmapSet
                 {
                     RelativeSizeAxes = Axes.X,
                     Height = tabs_height,
-                    Children = new[]
+                    Children = new Drawable[]
                     {
                         tabsBg = new Box
                         {
                             RelativeSizeAxes = Axes.Both,
                         },
+                        RulesetSelector = new BeatmapRulesetSelector
+                        {
+                            Current = ruleset,
+                            Anchor = Anchor.BottomCentre,
+                            Origin = Anchor.BottomCentre,
+                        }
                     },
                 },
                 new Container
@@ -223,7 +235,7 @@ namespace osu.Game.Overlays.BeatmapSet
 
             BeatmapSet.BindValueChanged(setInfo =>
             {
-                Picker.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/Changelog/ChangelogSingleBuild.cs

@@ -44,7 +44,17 @@ namespace osu.Game.Overlays.Changelog
             req.Failure += _ => complete = true;
 
             // This is done on a separate thread to support cancellation below
-            Task.Run(() => req.Perform(api));
+            Task.Run(() =>
+            {
+                try
+                {
+                    req.Perform(api);
+                }
+                catch
+                {
+                    complete = true;
+                }
+            });
 
             while (!complete)
             {

osu.Game/Overlays/ChangelogOverlay.cs

@@ -170,6 +170,7 @@ namespace osu.Game.Overlays
                 var tcs = new TaskCompletionSource<bool>();
 
                 var req = new GetChangelogRequest();
+
                 req.Success += res => Schedule(() =>
                 {
                     // remap streams to builds to ensure model equality
@@ -183,8 +184,22 @@ namespace osu.Game.Overlays
 
                     tcs.SetResult(true);
                 });
-                req.Failure += _ => initialFetchTask = null;
-                req.Perform(API);
+
+                req.Failure += _ =>
+                {
+                    initialFetchTask = null;
+                    tcs.SetResult(false);
+                };
+
+                try
+                {
+                    req.Perform(API);
+                }
+                catch
+                {
+                    initialFetchTask = null;
+                    tcs.SetResult(false);
+                }
 
                 await tcs.Task;
             });

osu.Game/Overlays/Chat/DrawableChannel.cs

@@ -1,4 +1,4 @@
-// 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 System;
@@ -89,8 +89,10 @@ namespace osu.Game.Overlays.Chat
 
         private void newMessagesArrived(IEnumerable<Message> newMessages)
         {
+            bool shouldScrollToEnd = scroll.IsScrolledToEnd(10) || !chatLines.Any() || newMessages.Any(m => m is LocalMessage);
+
             // Add up to last Channel.MAX_HISTORY messages
-            var displayMessages = newMessages.Skip(Math.Max(0, newMessages.Count() - Channel.MaxHistory));
+            var displayMessages = newMessages.Skip(Math.Max(0, newMessages.Count() - Channel.MAX_HISTORY));
 
             Message lastMessage = chatLines.LastOrDefault()?.Message;
 
@@ -103,19 +105,32 @@ namespace osu.Game.Overlays.Chat
                 lastMessage = message;
             }
 
-            if (scroll.IsScrolledToEnd(10) || !chatLines.Any() || newMessages.Any(m => m is LocalMessage))
-                scrollToEnd();
-
             var staleMessages = chatLines.Where(c => c.LifetimeEnd == double.MaxValue).ToArray();
-            int count = staleMessages.Length - Channel.MaxHistory;
+            int count = staleMessages.Length - Channel.MAX_HISTORY;
 
-            for (int i = 0; i < count; i++)
+            if (count > 0)
             {
-                var d = staleMessages[i];
-                if (!scroll.IsScrolledToEnd(10))
+                void expireAndAdjustScroll(Drawable d)
+                {
                     scroll.OffsetScrollPosition(-d.DrawHeight);
-                d.Expire();
+                    d.Expire();
+                }
+
+                for (int i = 0; i < count; i++)
+                    expireAndAdjustScroll(staleMessages[i]);
+
+                // remove all adjacent day separators after stale message removal
+                for (int i = 0; i < ChatLineFlow.Count - 1; i++)
+                {
+                    if (!(ChatLineFlow[i] is DaySeparator)) break;
+                    if (!(ChatLineFlow[i + 1] is DaySeparator)) break;
+
+                    expireAndAdjustScroll(ChatLineFlow[i]);
+                }
             }
+
+            if (shouldScrollToEnd)
+                scrollToEnd();
         }
 
         private void pendingMessageResolved(Message existing, Message updated)
@@ -141,7 +156,7 @@ namespace osu.Game.Overlays.Chat
 
         private void scrollToEnd() => ScheduleAfterChildren(() => scroll.ScrollToEnd());
 
-        protected class DaySeparator : Container
+        public class DaySeparator : Container
         {
             public float TextSize
             {

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

@@ -200,6 +200,7 @@ namespace osu.Game.Overlays.Settings.Sections.General
         {
             private TextBox username;
             private TextBox password;
+            private ShakeContainer shakeSignIn;
             private IAPIProvider api;
 
             public Action RequestHide;
@@ -208,6 +209,8 @@ namespace osu.Game.Overlays.Settings.Sections.General
             {
                 if (!string.IsNullOrEmpty(username.Text) && !string.IsNullOrEmpty(password.Text))
                     api.Login(username.Text, password.Text);
+                else
+                    shakeSignIn.Shake();
             }
 
             [BackgroundDependencyLoader(permitNulls: true)]
@@ -244,10 +247,23 @@ namespace osu.Game.Overlays.Settings.Sections.General
                         LabelText = "Stay signed in",
                         Bindable = config.GetBindable<bool>(OsuSetting.SavePassword),
                     },
-                    new SettingsButton
+                    new Container
                     {
-                        Text = "Sign in",
-                        Action = performLogin
+                        RelativeSizeAxes = Axes.X,
+                        AutoSizeAxes = Axes.Y,
+                        Children = new Drawable[]
+                        {
+                            shakeSignIn = new ShakeContainer
+                            {
+                                RelativeSizeAxes = Axes.X,
+                                AutoSizeAxes = Axes.Y,
+                                Child = new SettingsButton
+                                {
+                                    Text = "Sign in",
+                                    Action = performLogin
+                                },
+                            }
+                        }
                     },
                     new SettingsButton
                     {

osu.Game/Rulesets/UI/Scrolling/ScrollingHitObjectContainer.cs

@@ -13,12 +13,6 @@ namespace osu.Game.Rulesets.UI.Scrolling
 {
     public class ScrollingHitObjectContainer : HitObjectContainer
     {
-        /// <summary>
-        /// A multiplier applied to the length of the scrolling area to determine a safe default lifetime end for hitobjects.
-        /// This is only used to limit the lifetime end within reason, as proper lifetime management should be implemented on hitobjects themselves.
-        /// </summary>
-        private const float safe_lifetime_end_multiplier = 2;
-
         private readonly IBindable<double> timeRange = new BindableDouble();
         private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();
 
@@ -123,28 +117,22 @@ namespace osu.Game.Rulesets.UI.Scrolling
             if (cached.IsValid)
                 return;
 
-            double endTime = hitObject.HitObject.StartTime;
-
             if (hitObject.HitObject is IHasEndTime e)
             {
-                endTime = e.EndTime;
-
                 switch (direction.Value)
                 {
                     case ScrollingDirection.Up:
                     case ScrollingDirection.Down:
-                        hitObject.Height = scrollingInfo.Algorithm.GetLength(hitObject.HitObject.StartTime, endTime, timeRange.Value, scrollLength);
+                        hitObject.Height = scrollingInfo.Algorithm.GetLength(hitObject.HitObject.StartTime, e.EndTime, timeRange.Value, scrollLength);
                         break;
 
                     case ScrollingDirection.Left:
                     case ScrollingDirection.Right:
-                        hitObject.Width = scrollingInfo.Algorithm.GetLength(hitObject.HitObject.StartTime, endTime, timeRange.Value, scrollLength);
+                        hitObject.Width = scrollingInfo.Algorithm.GetLength(hitObject.HitObject.StartTime, e.EndTime, timeRange.Value, scrollLength);
                         break;
                 }
             }
 
-            hitObject.LifetimeEnd = scrollingInfo.Algorithm.TimeAt(scrollLength * safe_lifetime_end_multiplier, endTime, timeRange.Value, scrollLength);
-
             foreach (var obj in hitObject.NestedHitObjects)
             {
                 computeInitialStateRecursive(obj);

osu.Game/Screens/Edit/EditorClock.cs

@@ -57,7 +57,7 @@ namespace osu.Game.Screens.Edit
 
             // Depending on beatSnapLength, we may snap to a beat that is beyond timingPoint's end time, but we want to instead snap to
             // the next timing point's start time
-            var nextTimingPoint = ControlPointInfo.TimingPoints.Find(t => t.Time > timingPoint.Time);
+            var nextTimingPoint = ControlPointInfo.TimingPoints.FirstOrDefault(t => t.Time > timingPoint.Time);
             if (position > nextTimingPoint?.Time)
                 position = nextTimingPoint.Time;
 
@@ -85,12 +85,8 @@ namespace osu.Game.Screens.Edit
             var timingPoint = ControlPointInfo.TimingPointAt(CurrentTime);
 
             if (direction < 0 && timingPoint.Time == CurrentTime)
-            {
                 // When going backwards and we're at the boundary of two timing points, we compute the seek distance with the timing point which we are seeking into
-                int activeIndex = ControlPointInfo.TimingPoints.IndexOf(timingPoint);
-                while (activeIndex > 0 && CurrentTime == timingPoint.Time)
-                    timingPoint = ControlPointInfo.TimingPoints[--activeIndex];
-            }
+                timingPoint = ControlPointInfo.TimingPointAt(CurrentTime - 1);
 
             double seekAmount = timingPoint.BeatLength / beatDivisor.Value * amount;
             double seekTime = CurrentTime + seekAmount * direction;
@@ -124,7 +120,7 @@ namespace osu.Game.Screens.Edit
             if (seekTime < timingPoint.Time && timingPoint != ControlPointInfo.TimingPoints.First())
                 seekTime = timingPoint.Time;
 
-            var nextTimingPoint = ControlPointInfo.TimingPoints.Find(t => t.Time > timingPoint.Time);
+            var nextTimingPoint = ControlPointInfo.TimingPoints.FirstOrDefault(t => t.Time > timingPoint.Time);
             if (seekTime > nextTimingPoint?.Time)
                 seekTime = nextTimingPoint.Time;
 

osu.Game/Screens/Menu/IntroSequence.cs

@@ -42,6 +42,7 @@ namespace osu.Game.Screens.Menu
         public IntroSequence()
         {
             RelativeSizeAxes = Axes.Both;
+            Alpha = 0;
         }
 
         [BackgroundDependencyLoader]

osu.Game/Screens/Multi/Multiplayer.cs

@@ -212,6 +212,8 @@ namespace osu.Game.Screens.Multi
 
         public override bool OnExiting(IScreen next)
         {
+            roomManager.PartRoom();
+
             if (screenStack.CurrentScreen != null && !(screenStack.CurrentScreen is LoungeSubScreen))
             {
                 screenStack.Exit();

osu.Game/Screens/Multi/RoomManager.cs

@@ -87,9 +87,8 @@ namespace osu.Game.Screens.Multi
         public void JoinRoom(Room room, Action<Room> onSuccess = null, Action<string> onError = null)
         {
             currentJoinRoomRequest?.Cancel();
-            currentJoinRoomRequest = null;
-
             currentJoinRoomRequest = new JoinRoomRequest(room, api.LocalUser.Value);
+
             currentJoinRoomRequest.Success += () =>
             {
                 joinedRoom = room;
@@ -98,7 +97,8 @@ namespace osu.Game.Screens.Multi
 
             currentJoinRoomRequest.Failure += exception =>
             {
-                Logger.Log($"Failed to join room: {exception}", level: LogLevel.Important);
+                if (!(exception is OperationCanceledException))
+                    Logger.Log($"Failed to join room: {exception}", level: LogLevel.Important);
                 onError?.Invoke(exception.ToString());
             };
 
@@ -107,6 +107,8 @@ namespace osu.Game.Screens.Multi
 
         public void PartRoom()
         {
+            currentJoinRoomRequest?.Cancel();
+
             if (joinedRoom == null)
                 return;
 

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

@@ -45,8 +45,6 @@ namespace osu.Game.Screens.Play.HUD
                     VisualSettings = new VisualSettings { Expanded = false }
                 }
             };
-
-            Show();
         }
 
         protected override void PopIn() => this.FadeIn(fade_duration);

osu.Game/Screens/Play/SongProgress.cs

@@ -106,6 +106,8 @@ namespace osu.Game.Screens.Play
 
         protected override void LoadComplete()
         {
+            base.LoadComplete();
+
             Show();
 
             replayLoaded.ValueChanged += loaded => AllowSeeking = loaded.NewValue;

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

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using System.Linq;
 
 namespace osu.Game.Screens.Select.Carousel
 {
@@ -81,12 +82,10 @@ namespace osu.Game.Screens.Select.Carousel
         {
             base.Filter(criteria);
 
-            var children = new List<CarouselItem>(InternalChildren);
-
-            children.ForEach(c => c.Filter(criteria));
-            children.Sort((x, y) => x.CompareTo(criteria, y));
-
-            InternalChildren = children;
+            InternalChildren.ForEach(c => c.Filter(criteria));
+            // IEnumerable<T>.OrderBy() is used instead of List<T>.Sort() to ensure sorting stability
+            var criteriaComparer = Comparer<CarouselItem>.Create((x, y) => x.CompareTo(criteria, y));
+            InternalChildren = InternalChildren.OrderBy(c => c, criteriaComparer).ToList();
         }
 
         protected virtual void ChildItemStateChanged(CarouselItem item, CarouselItemState value)

osu.Game/osu.Game.csproj

@@ -26,7 +26,7 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.6" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2019.1010.0" />
-    <PackageReference Include="ppy.osu.Framework" Version="2019.1023.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2019.1029.0" />
     <PackageReference Include="SharpCompress" Version="0.24.0" />
     <PackageReference Include="NUnit" Version="3.12.0" />
     <PackageReference Include="SharpRaven" Version="2.4.0" />

osu.iOS.props

@@ -118,8 +118,8 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.1" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2019.1010.0" />
-    <PackageReference Include="ppy.osu.Framework" Version="2019.1023.0" />
-    <PackageReference Include="ppy.osu.Framework.iOS" Version="2019.1023.0" />
+    <PackageReference Include="ppy.osu.Framework" Version="2019.1029.0" />
+    <PackageReference Include="ppy.osu.Framework.iOS" Version="2019.1029.0" />
     <PackageReference Include="SharpCompress" Version="0.24.0" />
     <PackageReference Include="NUnit" Version="3.11.0" />
     <PackageReference Include="SharpRaven" Version="2.4.0" />