Merge branch 'master' into exit-multiplayer-is-dangerous

osu.Game.Rulesets.Catch/Edit/CatchHitObjectComposer.cs

@@ -89,9 +89,9 @@ namespace osu.Game.Rulesets.Catch.Edit
             new TernaryButton(distanceSnapToggle, "Distance Snap", () => new SpriteIcon { Icon = FontAwesome.Solid.Ruler })
         });
 
-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
         {
-            var result = base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            var result = base.FindSnappedPositionAndTime(screenSpacePosition);
             result.ScreenSpacePosition.X = screenSpacePosition.X;
 
             if (distanceSnapGrid.IsPresent && distanceSnapGrid.GetSnappedPosition(result.ScreenSpacePosition) is SnapResult snapResult &&

osu.Game.Rulesets.Mania.Tests/Editor/TestSceneManiaBeatSnapGrid.cs

@@ -97,12 +97,12 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
             set => InternalChild = value;
         }
 
-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
         {
             throw new System.NotImplementedException();
         }
 
-        public override SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPosition(Vector2 screenSpacePosition)
         {
             throw new System.NotImplementedException();
         }

osu.Game.Rulesets.Mania/Edit/ManiaHitObjectComposer.cs

@@ -56,9 +56,9 @@ namespace osu.Game.Rulesets.Mania.Edit
         protected override Playfield PlayfieldAtScreenSpacePosition(Vector2 screenSpacePosition) =>
             Playfield.GetColumnByPosition(screenSpacePosition);
 
-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
         {
-            var result = base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            var result = base.FindSnappedPositionAndTime(screenSpacePosition);
 
             switch (ScrollingInfo.Direction.Value)
             {
@@ -112,7 +112,7 @@ namespace osu.Game.Rulesets.Mania.Edit
             }
             else
             {
-                var result = SnapScreenSpacePositionToValidTime(inputManager.CurrentState.Mouse.Position);
+                var result = FindSnappedPositionAndTime(inputManager.CurrentState.Mouse.Position);
                 if (result.Time is double time)
                     beatSnapGrid.SelectionTimeRange = (time, time);
                 else

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

@@ -182,10 +182,10 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
 
         private class SnapProvider : IDistanceSnapProvider
         {
-            public SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition) =>
+            public SnapResult FindSnappedPosition(Vector2 screenSpacePosition) =>
                 new SnapResult(screenSpacePosition, null);
 
-            public SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition) => new SnapResult(screenSpacePosition, 0);
+            public SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition) => new SnapResult(screenSpacePosition, 0);
 
             public IBindable<double> DistanceSpacingMultiplier { get; } = new BindableDouble(1);
 
@@ -195,9 +195,9 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
 
             public double DistanceToDuration(HitObject referenceObject, float distance) => distance;
 
-            public double GetSnappedDurationFromDistance(HitObject referenceObject, float distance) => 0;
+            public double FindSnappedDuration(HitObject referenceObject, float distance) => 0;
 
-            public float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance) => 0;
+            public float FindSnappedDistance(HitObject referenceObject, float distance) => 0;
         }
     }
 }

osu.Game.Rulesets.Osu/Difficulty/Skills/OsuStrainSkill.cs

@@ -38,7 +38,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
             double difficulty = 0;
             double weight = 1;
 
-            List<double> strains = GetCurrentStrainPeaks().OrderByDescending(d => d).ToList();
+            // Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
+            // These sections will not contribute to the difficulty.
+            var peaks = GetCurrentStrainPeaks().Where(p => p > 0);
+
+            List<double> strains = peaks.OrderByDescending(d => d).ToList();
 
             // We are reducing the highest strains first to account for extreme difficulty spikes
             for (int i = 0; i < Math.Min(strains.Count, ReducedSectionCount); i++)

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/Components/PathControlPointVisualiser.cs

@@ -255,7 +255,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
             {
                 // Special handling for selections containing head control point - the position of the slider changes which means the snapped position and time have to be taken into account
                 Vector2 newHeadPosition = Parent.ToScreenSpace(e.MousePosition + (dragStartPositions[0] - dragStartPositions[draggedControlPointIndex]));
-                var result = snapProvider?.SnapScreenSpacePositionToValidTime(newHeadPosition);
+                var result = snapProvider?.FindSnappedPositionAndTime(newHeadPosition);
 
                 Vector2 movementDelta = Parent.ToLocalSpace(result?.ScreenSpacePosition ?? newHeadPosition) - slider.Position;
 

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/SliderPlacementBlueprint.cs

@@ -220,7 +220,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
 
         private void updateSlider()
         {
-            HitObject.Path.ExpectedDistance.Value = snapProvider?.GetSnappedDistanceFromDistance(HitObject, (float)HitObject.Path.CalculatedDistance) ?? (float)HitObject.Path.CalculatedDistance;
+            HitObject.Path.ExpectedDistance.Value = snapProvider?.FindSnappedDistance(HitObject, (float)HitObject.Path.CalculatedDistance) ?? (float)HitObject.Path.CalculatedDistance;
 
             bodyPiece.UpdateFrom(HitObject);
             headCirclePiece.UpdateFrom(HitObject.HeadCircle);

osu.Game.Rulesets.Osu/Edit/OsuHitObjectComposer.cs

@@ -59,11 +59,6 @@ namespace osu.Game.Rulesets.Osu.Edit
         {
             LayerBelowRuleset.AddRange(new Drawable[]
             {
-                new PlayfieldBorder
-                {
-                    RelativeSizeAxes = Axes.Both,
-                    PlayfieldBorderStyle = { Value = PlayfieldBorderStyle.Corners }
-                },
                 distanceSnapGridContainer = new Container
                 {
                     RelativeSizeAxes = Axes.Both
@@ -128,7 +123,7 @@ namespace osu.Game.Rulesets.Osu.Edit
             }
         }
 
-        public override SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPosition(Vector2 screenSpacePosition)
         {
             if (snapToVisibleBlueprints(screenSpacePosition, out var snapResult))
                 return snapResult;
@@ -136,9 +131,9 @@ namespace osu.Game.Rulesets.Osu.Edit
             return new SnapResult(screenSpacePosition, null);
         }
 
-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
         {
-            var positionSnap = SnapScreenSpacePositionToValidPosition(screenSpacePosition);
+            var positionSnap = FindSnappedPosition(screenSpacePosition);
             if (positionSnap.ScreenSpacePosition != screenSpacePosition)
                 return positionSnap;
 
@@ -154,7 +149,7 @@ namespace osu.Game.Rulesets.Osu.Edit
                 return new SnapResult(rectangularPositionSnapGrid.ToScreenSpace(pos), null, PlayfieldAtScreenSpacePosition(screenSpacePosition));
             }
 
-            return base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            return base.FindSnappedPositionAndTime(screenSpacePosition);
         }
 
         private bool snapToVisibleBlueprints(Vector2 screenSpacePosition, out SnapResult snapResult)

osu.Game.Rulesets.Osu/Mods/OsuModAlternate.cs

@@ -25,7 +25,7 @@ namespace osu.Game.Rulesets.Osu.Mods
         public override string Acronym => @"AL";
         public override string Description => @"Don't use the same key twice in a row!";
         public override double ScoreMultiplier => 1.0;
-        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay) };
+        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay), typeof(ModRelax) };
         public override ModType Type => ModType.Conversion;
         public override IconUsage? Icon => FontAwesome.Solid.Keyboard;
 

osu.Game.Rulesets.Osu/Mods/OsuModAutoplay.cs

@@ -12,7 +12,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
     public class OsuModAutoplay : ModAutoplay
     {
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut), typeof(OsuModAlternate) }).ToArray();
 
         public override ModReplayData CreateReplayData(IBeatmap beatmap, IReadOnlyList<Mod> mods)
             => new ModReplayData(new OsuAutoGenerator(beatmap, mods).Generate(), new ModCreatedUser { Username = "Autoplay" });

osu.Game.Rulesets.Osu/Mods/OsuModCinema.cs

@@ -13,7 +13,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
     public class OsuModCinema : ModCinema<OsuHitObject>
     {
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut), typeof(OsuModAlternate) }).ToArray();
 
         public override ModReplayData CreateReplayData(IBeatmap beatmap, IReadOnlyList<Mod> mods)
             => new ModReplayData(new OsuAutoGenerator(beatmap, mods).Generate(), new ModCreatedUser { Username = "Autoplay" });

osu.Game.Rulesets.Osu/Mods/OsuModRelax.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Osu.Mods
     public class OsuModRelax : ModRelax, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>, IApplicableToPlayer
     {
         public override string Description => @"You don't need to click. Give your clicking/tapping fingers a break from the heat of things.";
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModAutopilot), typeof(OsuModMagnetised) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModAutopilot), typeof(OsuModMagnetised), typeof(OsuModAlternate) }).ToArray();
 
         /// <summary>
         /// How early before a hitobject's start time to trigger a hit.

osu.Game.Rulesets.Osu/Mods/OsuModStrictTracking.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Linq;
 using System.Threading;
-using osu.Framework.Graphics.Sprites;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mods;
@@ -23,9 +22,8 @@ namespace osu.Game.Rulesets.Osu.Mods
     {
         public override string Name => @"Strict Tracking";
         public override string Acronym => @"ST";
-        public override IconUsage? Icon => FontAwesome.Solid.PenFancy;
         public override ModType Type => ModType.DifficultyIncrease;
-        public override string Description => @"Follow circles just got serious...";
+        public override string Description => @"Once you start a slider, follow precisely or get a miss.";
         public override double ScoreMultiplier => 1.0;
         public override Type[] IncompatibleMods => new[] { typeof(ModClassic), typeof(OsuModTarget) };
 

osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyCalculator.cs

@@ -141,7 +141,13 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
                 double colourPeak = colourPeaks[i] * colour_skill_multiplier;
                 double rhythmPeak = rhythmPeaks[i] * rhythm_skill_multiplier;
                 double staminaPeak = (staminaRightPeaks[i] + staminaLeftPeaks[i]) * stamina_skill_multiplier * staminaPenalty;
-                peaks.Add(norm(2, colourPeak, rhythmPeak, staminaPeak));
+
+                double peak = norm(2, colourPeak, rhythmPeak, staminaPeak);
+
+                // Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
+                // These sections will not contribute to the difficulty.
+                if (peak > 0)
+                    peaks.Add(peak);
             }
 
             double difficulty = 0;

osu.Game.Tests/Editing/TestSceneHitObjectComposerDistanceSnapping.cs

@@ -213,10 +213,10 @@ namespace osu.Game.Tests.Editing
             => AddAssert($"distance = {distance} -> duration = {expectedDuration}", () => composer.DistanceToDuration(new HitObject(), distance) == expectedDuration);
 
         private void assertSnappedDuration(float distance, double expectedDuration)
-            => AddAssert($"distance = {distance} -> duration = {expectedDuration} (snapped)", () => composer.GetSnappedDurationFromDistance(new HitObject(), distance) == expectedDuration);
+            => AddAssert($"distance = {distance} -> duration = {expectedDuration} (snapped)", () => composer.FindSnappedDuration(new HitObject(), distance) == expectedDuration);
 
         private void assertSnappedDistance(float distance, float expectedDistance)
-            => AddAssert($"distance = {distance} -> distance = {expectedDistance} (snapped)", () => composer.GetSnappedDistanceFromDistance(new HitObject(), distance) == expectedDistance);
+            => AddAssert($"distance = {distance} -> distance = {expectedDistance} (snapped)", () => composer.FindSnappedDistance(new HitObject(), distance) == expectedDistance);
 
         private class TestHitObjectComposer : OsuHitObjectComposer
         {

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

@@ -162,10 +162,10 @@ namespace osu.Game.Tests.Visual.Editing
 
         private class SnapProvider : IDistanceSnapProvider
         {
-            public SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition) =>
+            public SnapResult FindSnappedPosition(Vector2 screenSpacePosition) =>
                 new SnapResult(screenSpacePosition, null);
 
-            public SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition) => new SnapResult(screenSpacePosition, 0);
+            public SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition) => new SnapResult(screenSpacePosition, 0);
 
             public IBindable<double> DistanceSpacingMultiplier { get; } = new BindableDouble(1);
 
@@ -175,9 +175,9 @@ namespace osu.Game.Tests.Visual.Editing
 
             public double DistanceToDuration(HitObject referenceObject, float distance) => distance;
 
-            public double GetSnappedDurationFromDistance(HitObject referenceObject, float distance) => 0;
+            public double FindSnappedDuration(HitObject referenceObject, float distance) => 0;
 
-            public float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance) => 0;
+            public float FindSnappedDistance(HitObject referenceObject, float distance) => 0;
         }
     }
 }

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

@@ -19,6 +19,7 @@ using osu.Game.Rulesets.Osu.Edit;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Screens.Edit;
 using osu.Game.Screens.Edit.Components.RadioButtons;
+using osu.Game.Screens.Edit.Components.TernaryButtons;
 using osu.Game.Screens.Edit.Compose.Components;
 using osuTK;
 using osuTK.Input;
@@ -70,6 +71,11 @@ namespace osu.Game.Tests.Visual.Editing
                 Child = editorBeatmapContainer = new EditorBeatmapContainer(Beatmap.Value)
                 {
                     Child = hitObjectComposer = new OsuHitObjectComposer(new OsuRuleset())
+                    {
+                        // force the composer to fully overlap the playfield area by setting a 4:3 aspect ratio.
+                        FillMode = FillMode.Fit,
+                        FillAspectRatio = 4 / 3f
+                    }
                 };
             });
         }
@@ -87,6 +93,65 @@ namespace osu.Game.Tests.Visual.Editing
             AddAssert("Tool changed", () => hitObjectComposer.ChildrenOfType<ComposeBlueprintContainer>().First().CurrentTool is HitCircleCompositionTool);
         }
 
+        [Test]
+        public void TestPlacementFailsWhenClickingButton()
+        {
+            AddStep("clear all control points and hitobjects", () =>
+            {
+                editorBeatmap.ControlPointInfo.Clear();
+                editorBeatmap.Clear();
+            });
+
+            AddStep("Add timing point", () => editorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint()));
+
+            AddStep("Change to hitcircle", () => hitObjectComposer.ChildrenOfType<EditorRadioButton>().First(d => d.Button.Label == "HitCircle").TriggerClick());
+
+            AddStep("move mouse to overlapping toggle button", () =>
+            {
+                var playfield = hitObjectComposer.Playfield.ScreenSpaceDrawQuad;
+                var button = hitObjectComposer
+                             .ChildrenOfType<ExpandingToolboxContainer>().First()
+                             .ChildrenOfType<DrawableTernaryButton>().First(b => playfield.Contains(b.ScreenSpaceDrawQuad.Centre));
+
+                InputManager.MoveMouseTo(button);
+            });
+
+            AddAssert("no circles placed", () => editorBeatmap.HitObjects.Count == 0);
+
+            AddStep("attempt place circle", () => InputManager.Click(MouseButton.Left));
+
+            AddAssert("no circles placed", () => editorBeatmap.HitObjects.Count == 0);
+        }
+
+        [Test]
+        public void TestPlacementWithinToolboxScrollArea()
+        {
+            AddStep("clear all control points and hitobjects", () =>
+            {
+                editorBeatmap.ControlPointInfo.Clear();
+                editorBeatmap.Clear();
+            });
+
+            AddStep("Add timing point", () => editorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint()));
+
+            AddStep("Change to hitcircle", () => hitObjectComposer.ChildrenOfType<EditorRadioButton>().First(d => d.Button.Label == "HitCircle").TriggerClick());
+
+            AddStep("move mouse to scroll area", () =>
+            {
+                // Specifically wanting to test the area of overlap between the left expanding toolbox container
+                // and the playfield/composer.
+                var scrollArea = hitObjectComposer.ChildrenOfType<ExpandingToolboxContainer>().First().ScreenSpaceDrawQuad;
+                var playfield = hitObjectComposer.Playfield.ScreenSpaceDrawQuad;
+                InputManager.MoveMouseTo(new Vector2(scrollArea.TopLeft.X + 1, playfield.Centre.Y));
+            });
+
+            AddAssert("no circles placed", () => editorBeatmap.HitObjects.Count == 0);
+
+            AddStep("place circle", () => InputManager.Click(MouseButton.Left));
+
+            AddAssert("circle placed", () => editorBeatmap.HitObjects.Count == 1);
+        }
+
         [Test]
         public void TestDistanceSpacingHotkeys()
         {

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

@@ -56,6 +56,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));
             AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
         }
 
         [Test]
@@ -73,6 +76,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));
             AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
         }
 
         [Test]
@@ -91,6 +97,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));
             AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("no item selected", () => playlist.SelectedItem.Value == null);
         }
 
         [Test]
@@ -147,6 +156,40 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("item 1 is selected", () => playlist.SelectedItem.Value == playlist.Items[1]);
         }
 
+        [Test]
+        public void TestKeyboardSelection()
+        {
+            createPlaylist(p => p.AllowSelection = true);
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("item 0 is selected", () => playlist.SelectedItem.Value == playlist.Items[0]);
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("item 1 is selected", () => playlist.SelectedItem.Value == playlist.Items[1]);
+
+            AddStep("press up", () => InputManager.Key(Key.Up));
+            AddAssert("item 0 is selected", () => playlist.SelectedItem.Value == playlist.Items[0]);
+
+            AddUntilStep("navigate to last item via keyboard", () =>
+            {
+                InputManager.Key(Key.Down);
+                return playlist.SelectedItem.Value == playlist.Items.Last();
+            });
+            AddAssert("last item is selected", () => playlist.SelectedItem.Value == playlist.Items.Last());
+            AddUntilStep("last item is scrolled into view", () =>
+            {
+                var drawableItem = playlist.ItemMap[playlist.Items.Last()];
+                return playlist.ScreenSpaceDrawQuad.Contains(drawableItem.ScreenSpaceDrawQuad.TopLeft)
+                       && playlist.ScreenSpaceDrawQuad.Contains(drawableItem.ScreenSpaceDrawQuad.BottomRight);
+            });
+
+            AddStep("press down", () => InputManager.Key(Key.Down));
+            AddAssert("last item is selected", () => playlist.SelectedItem.Value == playlist.Items.Last());
+
+            AddStep("press up", () => InputManager.Key(Key.Up));
+            AddAssert("second last item is selected", () => playlist.SelectedItem.Value == playlist.Items.Reverse().ElementAt(1));
+        }
+
         [Test]
         public void TestDownloadButtonHiddenWhenBeatmapExists()
         {

osu.Game.Tests/Visual/Online/TestSceneChatOverlayV2.cs

@@ -0,0 +1,422 @@
+// 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 System.Collections.Generic;
+using System.Net;
+using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Logging;
+using osu.Framework.Testing;
+using osu.Framework.Utils;
+using osu.Game.Configuration;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Chat;
+using osu.Game.Overlays;
+using osu.Game.Overlays.Chat;
+using osu.Game.Overlays.Chat.Listing;
+using osu.Game.Overlays.Chat.ChannelList;
+using osuTK;
+using osuTK.Input;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    [TestFixture]
+    public class TestSceneChatOverlayV2 : OsuManualInputManagerTestScene
+    {
+        private ChatOverlayV2 chatOverlay;
+        private ChannelManager channelManager;
+
+        private APIUser testUser;
+        private Channel testPMChannel;
+        private Channel[] testChannels;
+
+        private Channel testChannel1 => testChannels[0];
+        private Channel testChannel2 => testChannels[1];
+
+        [Resolved]
+        private OsuConfigManager config { get; set; } = null!;
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            testUser = new APIUser { Username = "test user", Id = 5071479 };
+            testPMChannel = new Channel(testUser);
+            testChannels = Enumerable.Range(1, 10).Select(createPublicChannel).ToArray();
+
+            Child = new DependencyProvidingContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                CachedDependencies = new (Type, object)[]
+                {
+                    (typeof(ChannelManager), channelManager = new ChannelManager()),
+                },
+                Children = new Drawable[]
+                {
+                    channelManager,
+                    chatOverlay = new ChatOverlayV2 { RelativeSizeAxes = Axes.Both },
+                },
+            };
+        });
+
+        [SetUpSteps]
+        public void SetUpSteps()
+        {
+            AddStep("Setup request handler", () =>
+            {
+                ((DummyAPIAccess)API).HandleRequest = req =>
+                {
+                    switch (req)
+                    {
+                        case GetUpdatesRequest getUpdates:
+                            getUpdates.TriggerFailure(new WebException());
+                            return true;
+
+                        case JoinChannelRequest joinChannel:
+                            joinChannel.TriggerSuccess();
+                            return true;
+
+                        case LeaveChannelRequest leaveChannel:
+                            leaveChannel.TriggerSuccess();
+                            return true;
+
+                        case GetMessagesRequest getMessages:
+                            getMessages.TriggerSuccess(createChannelMessages(getMessages.Channel));
+                            return true;
+
+                        case GetUserRequest getUser:
+                            if (getUser.Lookup == testUser.Username)
+                                getUser.TriggerSuccess(testUser);
+                            else
+                                getUser.TriggerFailure(new WebException());
+                            return true;
+
+                        case PostMessageRequest postMessage:
+                            postMessage.TriggerSuccess(new Message(RNG.Next(0, 10000000))
+                            {
+                                Content = postMessage.Message.Content,
+                                ChannelId = postMessage.Message.ChannelId,
+                                Sender = postMessage.Message.Sender,
+                                Timestamp = new DateTimeOffset(DateTime.Now),
+                            });
+                            return true;
+
+                        default:
+                            Logger.Log($"Unhandled Request Type: {req.GetType()}");
+                            return false;
+                    }
+                };
+            });
+
+            AddStep("Add test channels", () =>
+            {
+                (channelManager.AvailableChannels as BindableList<Channel>)?.AddRange(testChannels);
+            });
+        }
+
+        [Test]
+        public void TestShowHide()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("Overlay is visible", () => chatOverlay.State.Value == Visibility.Visible);
+            AddStep("Hide overlay", () => chatOverlay.Hide());
+            AddAssert("Overlay is hidden", () => chatOverlay.State.Value == Visibility.Hidden);
+        }
+
+        [Test]
+        public void TestChatHeight()
+        {
+            BindableFloat configChatHeight = new BindableFloat();
+            config.BindWith(OsuSetting.ChatDisplayHeight, configChatHeight);
+            float newHeight = 0;
+
+            AddStep("Reset config chat height", () => configChatHeight.SetDefault());
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("Overlay uses config height", () => chatOverlay.Height == configChatHeight.Default);
+            AddStep("Click top bar", () =>
+            {
+                InputManager.MoveMouseTo(chatOverlayTopBar);
+                InputManager.PressButton(MouseButton.Left);
+            });
+            AddStep("Drag overlay to new height", () => InputManager.MoveMouseTo(chatOverlayTopBar, new Vector2(0, -300)));
+            AddStep("Stop dragging", () => InputManager.ReleaseButton(MouseButton.Left));
+            AddStep("Store new height", () => newHeight = chatOverlay.Height);
+            AddAssert("Config height changed", () => !configChatHeight.IsDefault && configChatHeight.Value == newHeight);
+            AddStep("Hide overlay", () => chatOverlay.Hide());
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("Overlay uses new height", () => chatOverlay.Height == newHeight);
+        }
+
+        [Test]
+        public void TestChannelSelection()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("Listing is visible", () => listingVisibility == Visibility.Visible);
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddAssert("Listing is hidden", () => listingVisibility == Visibility.Hidden);
+            AddAssert("Loading is hidden", () => loadingVisibility == Visibility.Hidden);
+            AddAssert("Current channel is correct", () => channelManager.CurrentChannel.Value == testChannel1);
+            AddAssert("DrawableChannel is correct", () => currentDrawableChannel.Channel == testChannel1);
+        }
+
+        [Test]
+        public void TestSearchInListing()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("Listing is visible", () => listingVisibility == Visibility.Visible);
+            AddStep("Search for 'number 2'", () => chatOverlayTextBox.Text = "number 2");
+            AddUntilStep("Only channel 2 visibile", () =>
+            {
+                IEnumerable<ChannelListingItem> listingItems = chatOverlay.ChildrenOfType<ChannelListingItem>()
+                                                                          .Where(item => item.IsPresent);
+                return listingItems.Count() == 1 && listingItems.Single().Channel == testChannel2;
+            });
+        }
+
+        [Test]
+        public void TestChannelCloseButton()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join PM and public channels", () =>
+            {
+                channelManager.JoinChannel(testChannel1);
+                channelManager.JoinChannel(testPMChannel);
+            });
+            AddStep("Select PM channel", () => clickDrawable(getChannelListItem(testPMChannel)));
+            AddStep("Click close button", () =>
+            {
+                ChannelListItemCloseButton closeButton = getChannelListItem(testPMChannel).ChildrenOfType<ChannelListItemCloseButton>().Single();
+                clickDrawable(closeButton);
+            });
+            AddAssert("PM channel closed", () => !channelManager.JoinedChannels.Contains(testPMChannel));
+            AddStep("Select normal channel", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Click close button", () =>
+            {
+                ChannelListItemCloseButton closeButton = getChannelListItem(testChannel1).ChildrenOfType<ChannelListItemCloseButton>().Single();
+                clickDrawable(closeButton);
+            });
+            AddAssert("Normal channel closed", () => !channelManager.JoinedChannels.Contains(testChannel1));
+        }
+
+        [Test]
+        public void TestChatCommand()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Open chat with user", () => channelManager.PostCommand($"chat {testUser.Username}"));
+            AddAssert("PM channel is selected", () =>
+                channelManager.CurrentChannel.Value.Type == ChannelType.PM && channelManager.CurrentChannel.Value.Users.Single() == testUser);
+            AddStep("Open chat with non-existent user", () => channelManager.PostCommand("chat user_doesnt_exist"));
+            AddAssert("Last message is error", () => channelManager.CurrentChannel.Value.Messages.Last() is ErrorMessage);
+
+            // Make sure no unnecessary requests are made when the PM channel is already open.
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Unregister request handling", () => ((DummyAPIAccess)API).HandleRequest = null);
+            AddStep("Open chat with user", () => channelManager.PostCommand($"chat {testUser.Username}"));
+            AddAssert("PM channel is selected", () =>
+                channelManager.CurrentChannel.Value.Type == ChannelType.PM && channelManager.CurrentChannel.Value.Users.Single() == testUser);
+        }
+
+        [Test]
+        public void TestMultiplayerChannelIsNotShown()
+        {
+            Channel multiplayerChannel = null;
+
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join multiplayer channel", () => channelManager.JoinChannel(multiplayerChannel = new Channel(new APIUser())
+            {
+                Name = "#mp_1",
+                Type = ChannelType.Multiplayer,
+            }));
+            AddAssert("Channel is joined", () => channelManager.JoinedChannels.Contains(multiplayerChannel));
+            AddUntilStep("Channel not present in listing", () => !chatOverlay.ChildrenOfType<ChannelListingItem>()
+                                                                             .Where(item => item.IsPresent)
+                                                                             .Select(item => item.Channel)
+                                                                             .Contains(multiplayerChannel));
+        }
+
+        [Test]
+        public void TestHighlightOnCurrentChannel()
+        {
+            Message message = null;
+
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Send message in channel 1", () =>
+            {
+                testChannel1.AddNewMessages(message = new Message
+                {
+                    ChannelId = testChannel1.Id,
+                    Content = "Message to highlight!",
+                    Timestamp = DateTimeOffset.Now,
+                    Sender = testUser,
+                });
+            });
+            AddStep("Highlight message", () => chatOverlay.HighlightMessage(message, testChannel1));
+        }
+
+        [Test]
+        public void TestHighlightOnAnotherChannel()
+        {
+            Message message = null;
+
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Join channel 2", () => channelManager.JoinChannel(testChannel2));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Send message in channel 2", () =>
+            {
+                testChannel2.AddNewMessages(message = new Message
+                {
+                    ChannelId = testChannel2.Id,
+                    Content = "Message to highlight!",
+                    Timestamp = DateTimeOffset.Now,
+                    Sender = testUser,
+                });
+            });
+            AddStep("Highlight message", () => chatOverlay.HighlightMessage(message, testChannel2));
+            AddAssert("Channel 2 is selected", () => channelManager.CurrentChannel.Value == testChannel2);
+            AddAssert("Channel 2 is visible", () => currentDrawableChannel.Channel == testChannel2);
+        }
+
+        [Test]
+        public void TestHighlightOnLeftChannel()
+        {
+            Message message = null;
+
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Join channel 2", () => channelManager.JoinChannel(testChannel2));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddStep("Send message in channel 2", () =>
+            {
+                testChannel2.AddNewMessages(message = new Message
+                {
+                    ChannelId = testChannel2.Id,
+                    Content = "Message to highlight!",
+                    Timestamp = DateTimeOffset.Now,
+                    Sender = testUser,
+                });
+            });
+            AddStep("Leave channel 2", () => channelManager.LeaveChannel(testChannel2));
+            AddStep("Highlight message", () => chatOverlay.HighlightMessage(message, testChannel2));
+            AddAssert("Channel 2 is selected", () => channelManager.CurrentChannel.Value == testChannel2);
+            AddAssert("Channel 2 is visible", () => currentDrawableChannel.Channel == testChannel2);
+        }
+
+        [Test]
+        public void TestHighlightWhileChatNeverOpen()
+        {
+            Message message = null;
+
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Send message in channel 1", () =>
+            {
+                testChannel1.AddNewMessages(message = new Message
+                {
+                    ChannelId = testChannel1.Id,
+                    Content = "Message to highlight!",
+                    Timestamp = DateTimeOffset.Now,
+                    Sender = testUser,
+                });
+            });
+            AddStep("Highlight message", () => chatOverlay.HighlightMessage(message, testChannel1));
+        }
+
+        [Test]
+        public void TestHighlightWithNullChannel()
+        {
+            Message message = null;
+
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Send message in channel 1", () =>
+            {
+                testChannel1.AddNewMessages(message = new Message
+                {
+                    ChannelId = testChannel1.Id,
+                    Content = "Message to highlight!",
+                    Timestamp = DateTimeOffset.Now,
+                    Sender = testUser,
+                });
+            });
+            AddStep("Set null channel", () => channelManager.CurrentChannel.Value = null);
+            AddStep("Highlight message", () => chatOverlay.HighlightMessage(message, testChannel1));
+        }
+
+        [Test]
+        public void TextBoxRetainsFocus()
+        {
+            AddStep("Show overlay", () => chatOverlay.Show());
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Join channel 1", () => channelManager.JoinChannel(testChannel1));
+            AddStep("Select channel 1", () => clickDrawable(getChannelListItem(testChannel1)));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Click selector", () => clickDrawable(chatOverlay.ChildrenOfType<ChannelListSelector>().Single()));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Click listing", () => clickDrawable(chatOverlay.ChildrenOfType<ChannelListing>().Single()));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Click drawable channel", () => clickDrawable(chatOverlay.ChildrenOfType<DrawableChannel>().Single()));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Click channel list", () => clickDrawable(chatOverlay.ChildrenOfType<ChannelList>().Single()));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Click top bar", () => clickDrawable(chatOverlay.ChildrenOfType<ChatOverlayTopBar>().Single()));
+            AddAssert("TextBox is focused", () => InputManager.FocusedDrawable == chatOverlayTextBox);
+            AddStep("Hide overlay", () => chatOverlay.Hide());
+            AddAssert("TextBox is not focused", () => InputManager.FocusedDrawable == null);
+        }
+
+        private Visibility listingVisibility =>
+            chatOverlay.ChildrenOfType<ChannelListing>().Single().State.Value;
+
+        private Visibility loadingVisibility =>
+            chatOverlay.ChildrenOfType<LoadingLayer>().Single().State.Value;
+
+        private DrawableChannel currentDrawableChannel =>
+            chatOverlay.ChildrenOfType<Container<DrawableChannel>>().Single().Child;
+
+        private ChannelListItem getChannelListItem(Channel channel) =>
+            chatOverlay.ChildrenOfType<ChannelListItem>().Single(item => item.Channel == channel);
+
+        private ChatTextBox chatOverlayTextBox =>
+            chatOverlay.ChildrenOfType<ChatTextBox>().Single();
+
+        private ChatOverlayTopBar chatOverlayTopBar =>
+            chatOverlay.ChildrenOfType<ChatOverlayTopBar>().Single();
+
+        private void clickDrawable(Drawable d)
+        {
+            InputManager.MoveMouseTo(d);
+            InputManager.Click(MouseButton.Left);
+        }
+
+        private List<Message> createChannelMessages(Channel channel)
+        {
+            var message = new Message
+            {
+                ChannelId = channel.Id,
+                Content = $"Hello, this is a message in {channel.Name}",
+                Sender = testUser,
+                Timestamp = new DateTimeOffset(DateTime.Now),
+            };
+            return new List<Message> { message };
+        }
+
+        private Channel createPublicChannel(int id) => new Channel
+        {
+            Id = id,
+            Name = $"#channel-{id}",
+            Topic = $"We talk about the number {id} here",
+            Type = ChannelType.Public,
+        };
+    }
+}

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

@@ -1,10 +1,12 @@
 // 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.Threading;
 using NUnit.Framework;
+using osu.Framework.Allocation;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Sprites;
-using osu.Framework.Testing;
 using osu.Game.Overlays;
 using osu.Game.Overlays.Dialog;
 
@@ -15,15 +17,11 @@ namespace osu.Game.Tests.Visual.UserInterface
     {
         private DialogOverlay overlay;
 
-        [SetUpSteps]
-        public void SetUpSteps()
-        {
-            AddStep("create dialog overlay", () => Child = overlay = new DialogOverlay());
-        }
-
         [Test]
         public void TestBasic()
         {
+            AddStep("create dialog overlay", () => Child = overlay = new DialogOverlay());
+
             TestPopupDialog firstDialog = null;
             TestPopupDialog secondDialog = null;
 
@@ -37,12 +35,12 @@ namespace osu.Game.Tests.Visual.UserInterface
                     new PopupDialogOkButton
                     {
                         Text = @"I never want to see this again.",
-                        Action = () => System.Console.WriteLine(@"OK"),
+                        Action = () => Console.WriteLine(@"OK"),
                     },
                     new PopupDialogCancelButton
                     {
                         Text = @"Firetruck, I still want quick ranks!",
-                        Action = () => System.Console.WriteLine(@"Cancel"),
+                        Action = () => Console.WriteLine(@"Cancel"),
                     },
                 },
             }));
@@ -87,9 +85,49 @@ namespace osu.Game.Tests.Visual.UserInterface
             AddAssert("first dialog is not part of hierarchy", () => firstDialog.Parent == null);
         }
 
+        [Test]
+        public void TestPushBeforeLoad()
+        {
+            PopupDialog dialog = null;
+
+            AddStep("create dialog overlay", () => overlay = new SlowLoadingDialogOverlay());
+
+            AddStep("start loading overlay", () => LoadComponentAsync(overlay, Add));
+
+            AddStep("push dialog before loaded", () =>
+            {
+                overlay.Push(dialog = new TestPopupDialog
+                {
+                    Buttons = new PopupDialogButton[]
+                    {
+                        new PopupDialogOkButton { Text = @"OK" },
+                    },
+                });
+            });
+
+            AddStep("complete load", () => ((SlowLoadingDialogOverlay)overlay).LoadEvent.Set());
+
+            AddUntilStep("wait for load", () => overlay.IsLoaded);
+
+            AddAssert("dialog displayed", () => overlay.CurrentDialog == dialog);
+        }
+
+        public class SlowLoadingDialogOverlay : DialogOverlay
+        {
+            public ManualResetEventSlim LoadEvent = new ManualResetEventSlim();
+
+            [BackgroundDependencyLoader]
+            private void load()
+            {
+                LoadEvent.Wait(10000);
+            }
+        }
+
         [Test]
         public void TestDismissBeforePush()
         {
+            AddStep("create dialog overlay", () => Child = overlay = new DialogOverlay());
+
             TestPopupDialog testDialog = null;
             AddStep("dismissed dialog push", () =>
             {
@@ -106,6 +144,8 @@ namespace osu.Game.Tests.Visual.UserInterface
         [Test]
         public void TestDismissBeforePushViaButtonPress()
         {
+            AddStep("create dialog overlay", () => Child = overlay = new DialogOverlay());
+
             TestPopupDialog testDialog = null;
             AddStep("dismissed dialog push", () =>
             {

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

@@ -2,17 +2,21 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
 using osu.Framework.Utils;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Overlays.Mods;
+using osu.Game.Overlays.Settings;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Mods;
 using osuTK.Input;
 
@@ -64,6 +68,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                 return Precision.AlmostEquals(multiplier, modSelectScreen.ChildrenOfType<DifficultyMultiplierDisplay>().Single().Current.Value);
             });
             assertCustomisationToggleState(disabled: false, active: false);
+            AddAssert("setting items created", () => modSelectScreen.ChildrenOfType<ISettingsItem>().Any());
         }
 
         [Test]
@@ -78,6 +83,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                 return Precision.AlmostEquals(multiplier, modSelectScreen.ChildrenOfType<DifficultyMultiplierDisplay>().Single().Current.Value);
             });
             assertCustomisationToggleState(disabled: false, active: false);
+            AddAssert("setting items created", () => modSelectScreen.ChildrenOfType<ISettingsItem>().Any());
         }
 
         [Test]
@@ -98,17 +104,25 @@ namespace osu.Game.Tests.Visual.UserInterface
 
             AddStep("activate DT", () => getPanelForMod(typeof(OsuModDoubleTime)).TriggerClick());
             AddAssert("DT active", () => SelectedMods.Value.Single().GetType() == typeof(OsuModDoubleTime));
+            AddAssert("DT panel active", () => getPanelForMod(typeof(OsuModDoubleTime)).Active.Value);
 
             AddStep("activate NC", () => getPanelForMod(typeof(OsuModNightcore)).TriggerClick());
             AddAssert("only NC active", () => SelectedMods.Value.Single().GetType() == typeof(OsuModNightcore));
+            AddAssert("DT panel not active", () => !getPanelForMod(typeof(OsuModDoubleTime)).Active.Value);
+            AddAssert("NC panel active", () => getPanelForMod(typeof(OsuModNightcore)).Active.Value);
 
             AddStep("activate HR", () => getPanelForMod(typeof(OsuModHardRock)).TriggerClick());
             AddAssert("NC+HR active", () => SelectedMods.Value.Any(mod => mod.GetType() == typeof(OsuModNightcore))
                                             && SelectedMods.Value.Any(mod => mod.GetType() == typeof(OsuModHardRock)));
+            AddAssert("NC panel active", () => getPanelForMod(typeof(OsuModNightcore)).Active.Value);
+            AddAssert("HR panel active", () => getPanelForMod(typeof(OsuModHardRock)).Active.Value);
 
             AddStep("activate MR", () => getPanelForMod(typeof(OsuModMirror)).TriggerClick());
             AddAssert("NC+MR active", () => SelectedMods.Value.Any(mod => mod.GetType() == typeof(OsuModNightcore))
                                             && SelectedMods.Value.Any(mod => mod.GetType() == typeof(OsuModMirror)));
+            AddAssert("NC panel active", () => getPanelForMod(typeof(OsuModNightcore)).Active.Value);
+            AddAssert("HR panel not active", () => !getPanelForMod(typeof(OsuModHardRock)).Active.Value);
+            AddAssert("MR panel active", () => getPanelForMod(typeof(OsuModMirror)).Active.Value);
         }
 
         [Test]
@@ -150,11 +164,19 @@ namespace osu.Game.Tests.Visual.UserInterface
             AddStep("select mod requiring configuration", () => SelectedMods.Value = new[] { new OsuModDifficultyAdjust() });
             assertCustomisationToggleState(disabled: false, active: true);
 
-            AddStep("dismiss mod customisation", () =>
+            AddStep("dismiss mod customisation via mouse", () =>
             {
                 InputManager.MoveMouseTo(modSelectScreen.ChildrenOfType<ShearedToggleButton>().Single());
                 InputManager.Click(MouseButton.Left);
             });
+            assertCustomisationToggleState(disabled: false, active: false);
+
+            AddStep("reset mods", () => SelectedMods.SetDefault());
+            AddStep("select mod requiring configuration", () => SelectedMods.Value = new[] { new OsuModDifficultyAdjust() });
+            assertCustomisationToggleState(disabled: false, active: true);
+
+            AddStep("dismiss mod customisation via keyboard", () => InputManager.Key(Key.Escape));
+            assertCustomisationToggleState(disabled: false, active: false);
 
             AddStep("append another mod not requiring config", () => SelectedMods.Value = SelectedMods.Value.Append(new OsuModFlashlight()).ToArray());
             assertCustomisationToggleState(disabled: false, active: false);
@@ -169,6 +191,206 @@ namespace osu.Game.Tests.Visual.UserInterface
             assertCustomisationToggleState(disabled: true, active: false); // config was dismissed without explicit user action.
         }
 
+        /// <summary>
+        /// Ensure that two mod overlays are not cross polluting via central settings instances.
+        /// </summary>
+        [Test]
+        public void TestSettingsNotCrossPolluting()
+        {
+            Bindable<IReadOnlyList<Mod>> selectedMods2 = null;
+            ModSelectScreen modSelectScreen2 = null;
+
+            createScreen();
+            AddStep("select diff adjust", () => SelectedMods.Value = new Mod[] { new OsuModDifficultyAdjust() });
+
+            AddStep("set setting", () => modSelectScreen.ChildrenOfType<SettingsSlider<float>>().First().Current.Value = 8);
+
+            AddAssert("ensure setting is propagated", () => SelectedMods.Value.OfType<OsuModDifficultyAdjust>().Single().CircleSize.Value == 8);
+
+            AddStep("create second bindable", () => selectedMods2 = new Bindable<IReadOnlyList<Mod>>(new Mod[] { new OsuModDifficultyAdjust() }));
+
+            AddStep("create second overlay", () =>
+            {
+                Add(modSelectScreen2 = new UserModSelectScreen().With(d =>
+                {
+                    d.Origin = Anchor.TopCentre;
+                    d.Anchor = Anchor.TopCentre;
+                    d.SelectedMods.BindTarget = selectedMods2;
+                }));
+            });
+
+            AddStep("show", () => modSelectScreen2.Show());
+
+            AddAssert("ensure first is unchanged", () => SelectedMods.Value.OfType<OsuModDifficultyAdjust>().Single().CircleSize.Value == 8);
+            AddAssert("ensure second is default", () => selectedMods2.Value.OfType<OsuModDifficultyAdjust>().Single().CircleSize.Value == null);
+        }
+
+        [Test]
+        public void TestSettingsResetOnDeselection()
+        {
+            var osuModDoubleTime = new OsuModDoubleTime { SpeedChange = { Value = 1.2 } };
+
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("set dt mod with custom rate", () => { SelectedMods.Value = new[] { osuModDoubleTime }; });
+
+            AddAssert("selected mod matches", () => (SelectedMods.Value.Single() as OsuModDoubleTime)?.SpeedChange.Value == 1.2);
+
+            AddStep("deselect", () => getPanelForMod(typeof(OsuModDoubleTime)).TriggerClick());
+            AddAssert("selected mods empty", () => SelectedMods.Value.Count == 0);
+
+            AddStep("reselect", () => getPanelForMod(typeof(OsuModDoubleTime)).TriggerClick());
+            AddAssert("selected mod has default value", () => (SelectedMods.Value.Single() as OsuModDoubleTime)?.SpeedChange.IsDefault == true);
+        }
+
+        [Test]
+        public void TestAnimationFlushOnClose()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("Select all fun mods", () =>
+            {
+                modSelectScreen.ChildrenOfType<ModColumn>()
+                               .Single(c => c.ModType == ModType.DifficultyIncrease)
+                               .SelectAll();
+            });
+
+            AddUntilStep("many mods selected", () => SelectedMods.Value.Count >= 5);
+
+            AddStep("trigger deselect and close overlay", () =>
+            {
+                modSelectScreen.ChildrenOfType<ModColumn>()
+                               .Single(c => c.ModType == ModType.DifficultyIncrease)
+                               .DeselectAll();
+
+                modSelectScreen.Hide();
+            });
+
+            AddAssert("all mods deselected", () => SelectedMods.Value.Count == 0);
+        }
+
+        [Test]
+        public void TestRulesetChanges()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            var noFailMod = new OsuRuleset().GetModsFor(ModType.DifficultyReduction).FirstOrDefault(m => m is OsuModNoFail);
+
+            AddStep("set mods externally", () => { SelectedMods.Value = new[] { noFailMod }; });
+
+            changeRuleset(0);
+
+            AddAssert("ensure mods still selected", () => SelectedMods.Value.SingleOrDefault(m => m is OsuModNoFail) != null);
+
+            changeRuleset(3);
+
+            AddAssert("ensure mods not selected", () => SelectedMods.Value.Count == 0);
+
+            changeRuleset(0);
+
+            AddAssert("ensure mods not selected", () => SelectedMods.Value.Count == 0);
+        }
+
+        [Test]
+        public void TestExternallySetCustomizedMod()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("set customized mod externally", () => SelectedMods.Value = new[] { new OsuModDoubleTime { SpeedChange = { Value = 1.01 } } });
+
+            AddAssert("ensure button is selected and customized accordingly", () =>
+            {
+                var button = getPanelForMod(SelectedMods.Value.Single().GetType());
+                return ((OsuModDoubleTime)button.Mod).SpeedChange.Value == 1.01;
+            });
+        }
+
+        [Test]
+        public void TestSettingsAreRetainedOnReload()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("set customized mod externally", () => SelectedMods.Value = new[] { new OsuModDoubleTime { SpeedChange = { Value = 1.01 } } });
+            AddAssert("setting remains", () => (SelectedMods.Value.SingleOrDefault() as OsuModDoubleTime)?.SpeedChange.Value == 1.01);
+
+            createScreen();
+            AddAssert("setting remains", () => (SelectedMods.Value.SingleOrDefault() as OsuModDoubleTime)?.SpeedChange.Value == 1.01);
+        }
+
+        [Test]
+        public void TestExternallySetModIsReplacedByOverlayInstance()
+        {
+            Mod external = new OsuModDoubleTime();
+            Mod overlayButtonMod = null;
+
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("set mod externally", () => { SelectedMods.Value = new[] { external }; });
+
+            AddAssert("ensure button is selected", () =>
+            {
+                var button = getPanelForMod(SelectedMods.Value.Single().GetType());
+                overlayButtonMod = button.Mod;
+                return button.Active.Value;
+            });
+
+            // Right now, when an external change occurs, the ModSelectOverlay will replace the global instance with its own
+            AddAssert("mod instance doesn't match", () => external != overlayButtonMod);
+
+            AddAssert("one mod present in global selected", () => SelectedMods.Value.Count == 1);
+            AddAssert("globally selected matches button's mod instance", () => SelectedMods.Value.Any(mod => ReferenceEquals(mod, overlayButtonMod)));
+            AddAssert("globally selected doesn't contain original external change", () => !SelectedMods.Value.Any(mod => ReferenceEquals(mod, external)));
+        }
+
+        [Test]
+        public void TestChangeIsValidChangesButtonVisibility()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddAssert("double time visible", () => modSelectScreen.ChildrenOfType<ModPanel>().Where(panel => panel.Mod is OsuModDoubleTime).Any(panel => !panel.Filtered.Value));
+
+            AddStep("make double time invalid", () => modSelectScreen.IsValidMod = m => !(m is OsuModDoubleTime));
+            AddUntilStep("double time not visible", () => modSelectScreen.ChildrenOfType<ModPanel>().Where(panel => panel.Mod is OsuModDoubleTime).All(panel => panel.Filtered.Value));
+            AddAssert("nightcore still visible", () => modSelectScreen.ChildrenOfType<ModPanel>().Where(panel => panel.Mod is OsuModNightcore).Any(panel => !panel.Filtered.Value));
+
+            AddStep("make double time valid again", () => modSelectScreen.IsValidMod = m => true);
+            AddUntilStep("double time visible", () => modSelectScreen.ChildrenOfType<ModPanel>().Where(panel => panel.Mod is OsuModDoubleTime).Any(panel => !panel.Filtered.Value));
+            AddAssert("nightcore still visible", () => modSelectScreen.ChildrenOfType<ModPanel>().Where(b => b.Mod is OsuModNightcore).Any(panel => !panel.Filtered.Value));
+        }
+
+        [Test]
+        public void TestChangeIsValidPreservesSelection()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("select DT + HD", () => SelectedMods.Value = new Mod[] { new OsuModDoubleTime(), new OsuModHidden() });
+            AddAssert("DT + HD selected", () => modSelectScreen.ChildrenOfType<ModPanel>().Count(panel => panel.Active.Value) == 2);
+
+            AddStep("make NF invalid", () => modSelectScreen.IsValidMod = m => !(m is ModNoFail));
+            AddAssert("DT + HD still selected", () => modSelectScreen.ChildrenOfType<ModPanel>().Count(panel => panel.Active.Value) == 2);
+        }
+
+        [Test]
+        public void TestUnimplementedModIsUnselectable()
+        {
+            var testRuleset = new TestUnimplementedModOsuRuleset();
+
+            createScreen();
+
+            AddStep("set ruleset", () => Ruleset.Value = testRuleset.RulesetInfo);
+            waitForColumnLoad();
+
+            AddAssert("unimplemented mod panel is filtered", () => getPanelForMod(typeof(TestUnimplementedMod)).Filtered.Value);
+        }
+
         private void waitForColumnLoad() => AddUntilStep("all column content loaded",
             () => modSelectScreen.ChildrenOfType<ModColumn>().Any() && modSelectScreen.ChildrenOfType<ModColumn>().All(column => column.IsLoaded && column.ItemsLoaded));
 
@@ -188,5 +410,26 @@ namespace osu.Game.Tests.Visual.UserInterface
 
         private ModPanel getPanelForMod(Type modType)
             => modSelectScreen.ChildrenOfType<ModPanel>().Single(panel => panel.Mod.GetType() == modType);
+
+        private class TestUnimplementedMod : Mod
+        {
+            public override string Name => "Unimplemented mod";
+            public override string Acronym => "UM";
+            public override string Description => "A mod that is not implemented.";
+            public override double ScoreMultiplier => 1;
+            public override ModType Type => ModType.Conversion;
+        }
+
+        private class TestUnimplementedModOsuRuleset : OsuRuleset
+        {
+            public override string ShortName => "unimplemented";
+
+            public override IEnumerable<Mod> GetModsFor(ModType type)
+            {
+                if (type == ModType.Conversion) return base.GetModsFor(type).Concat(new[] { new TestUnimplementedMod() });
+
+                return base.GetModsFor(type);
+            }
+        }
     }
 }

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

@@ -0,0 +1,46 @@
+// 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 NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Overlays;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    public class TestSceneShearedSearchTextBox : OsuTestScene
+    {
+        [Test]
+        public void TestAllColourSchemes()
+        {
+            foreach (var scheme in Enum.GetValues(typeof(OverlayColourScheme)).Cast<OverlayColourScheme>())
+                AddStep($"set {scheme} scheme", () => Child = createContent(scheme));
+        }
+
+        private Drawable createContent(OverlayColourScheme colourScheme)
+        {
+            var colourProvider = new OverlayColourProvider(colourScheme);
+
+            return new DependencyProvidingContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                CachedDependencies = new (Type, object)[]
+                {
+                    (typeof(OverlayColourProvider), colourProvider)
+                },
+                Children = new Drawable[]
+                {
+                    new ShearedSearchTextBox
+                    {
+                        Origin = Anchor.Centre,
+                        Anchor = Anchor.Centre,
+                        RelativeSizeAxes = Axes.X,
+                        Width = 0.5f
+                    }
+                }
+            };
+        }
+    }
+}

osu.Game/Beatmaps/BeatmapInfo.cs

@@ -1,21 +1,23 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+#nullable enable
+
 using System;
 using System.Linq;
 using JetBrains.Annotations;
 using Newtonsoft.Json;
 using osu.Framework.Testing;
+using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Database;
 using osu.Game.Models;
 using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Overlays.BeatmapSet.Scores;
 using osu.Game.Rulesets;
+using osu.Game.Rulesets.Edit;
 using osu.Game.Scoring;
 using Realms;
 
-#nullable enable
-
 namespace osu.Game.Beatmaps
 {
     /// <summary>
@@ -109,6 +111,16 @@ namespace osu.Game.Beatmaps
 
         public bool SamplesMatchPlaybackRate { get; set; } = true;
 
+        /// <summary>
+        /// The ratio of distance travelled per time unit.
+        /// Generally used to decouple the spacing between hit objects from the enforced "velocity" of the beatmap (see <see cref="DifficultyControlPoint.SliderVelocity"/>).
+        /// </summary>
+        /// <remarks>
+        /// The most common method of understanding is that at a default value of 1.0, the time-to-distance ratio will match the slider velocity of the beatmap
+        /// at the current point in time. Increasing this value will make hit objects more spaced apart when compared to the cursor movement required to track a slider.
+        ///
+        /// This is only a hint property, used by the editor in <see cref="IDistanceSnapProvider"/> implementations. It does not directly affect the beatmap or gameplay.
+        /// </remarks>
         public double DistanceSpacing { get; set; } = 1.0;
 
         public int BeatDivisor { get; set; }

osu.Game/Beatmaps/BeatmapOnlineLookupQueue.cs

@@ -153,7 +153,7 @@ namespace osu.Game.Beatmaps
                 }
             };
 
-            cacheDownloadRequest.PerformAsync();
+            Task.Run(() => cacheDownloadRequest.PerformAsync());
         }
 
         private bool checkLocalCache(BeatmapSetInfo set, BeatmapInfo beatmapInfo)

osu.Game/Graphics/UserInterface/BasicSearchTextBox.cs

@@ -0,0 +1,26 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Sprites;
+using osuTK;
+
+namespace osu.Game.Graphics.UserInterface
+{
+    public class BasicSearchTextBox : SearchTextBox
+    {
+        public BasicSearchTextBox()
+        {
+            Add(new SpriteIcon
+            {
+                Icon = FontAwesome.Solid.Search,
+                Origin = Anchor.CentreRight,
+                Anchor = Anchor.CentreRight,
+                Margin = new MarginPadding { Right = 10 },
+                Size = new Vector2(20),
+            });
+
+            TextFlow.Padding = new MarginPadding { Right = 35 };
+        }
+    }
+}

osu.Game/Graphics/UserInterface/SearchTextBox.cs

@@ -1,12 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Sprites;
 using osu.Framework.Input;
 using osu.Framework.Input.Events;
 using osu.Game.Resources.Localisation.Web;
-using osuTK;
 using osuTK.Input;
 
 namespace osu.Game.Graphics.UserInterface
@@ -18,16 +15,6 @@ namespace osu.Game.Graphics.UserInterface
         public SearchTextBox()
         {
             Height = 35;
-            Add(new SpriteIcon
-            {
-                Icon = FontAwesome.Solid.Search,
-                Origin = Anchor.CentreRight,
-                Anchor = Anchor.CentreRight,
-                Margin = new MarginPadding { Right = 10 },
-                Size = new Vector2(20),
-            });
-
-            TextFlow.Padding = new MarginPadding { Right = 35 };
             PlaceholderText = HomeStrings.SearchPlaceholder;
         }
 

osu.Game/Graphics/UserInterface/SeekLimitedSearchTextBox.cs

@@ -6,7 +6,7 @@ namespace osu.Game.Graphics.UserInterface
     /// <summary>
     /// A <see cref="SearchTextBox"/> which does not handle left/right arrow keys for seeking.
     /// </summary>
-    public class SeekLimitedSearchTextBox : SearchTextBox
+    public class SeekLimitedSearchTextBox : BasicSearchTextBox
     {
         public override bool HandleLeftRightArrows => false;
     }

osu.Game/Graphics/UserInterface/ShearedSearchTextBox.cs

@@ -0,0 +1,137 @@
+// 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.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Overlays;
+using osu.Game.Overlays.Mods;
+using osu.Game.Resources.Localisation.Web;
+using osuTK;
+
+namespace osu.Game.Graphics.UserInterface
+{
+    public class ShearedSearchTextBox : CompositeDrawable, IHasCurrentValue<string>
+    {
+        private const float corner_radius = 7;
+
+        private readonly Box background;
+        private readonly SearchTextBox textBox;
+
+        public Bindable<string> Current
+        {
+            get => textBox.Current;
+            set => textBox.Current = value;
+        }
+
+        public bool HoldFocus
+        {
+            get => textBox.HoldFocus;
+            set => textBox.HoldFocus = value;
+        }
+
+        public void TakeFocus() => textBox.TakeFocus();
+
+        public void KillFocus() => textBox.KillFocus();
+
+        public ShearedSearchTextBox()
+        {
+            Height = 42;
+            Shear = new Vector2(ShearedOverlayContainer.SHEAR, 0);
+            Masking = true;
+            CornerRadius = corner_radius;
+
+            InternalChildren = new Drawable[]
+            {
+                background = new Box
+                {
+                    RelativeSizeAxes = Axes.Both
+                },
+                new GridContainer
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Content = new[]
+                    {
+                        new Drawable[]
+                        {
+                            textBox = new InnerSearchTextBox
+                            {
+                                Anchor = Anchor.CentreLeft,
+                                Origin = Anchor.CentreLeft,
+                                RelativeSizeAxes = Axes.Both,
+                                Size = Vector2.One
+                            },
+                            new SpriteIcon
+                            {
+                                Icon = FontAwesome.Solid.Search,
+                                Origin = Anchor.Centre,
+                                Anchor = Anchor.Centre,
+                                Size = new Vector2(16),
+                                Shear = -Shear
+                            }
+                        }
+                    },
+                    ColumnDimensions = new[]
+                    {
+                        new Dimension(),
+                        new Dimension(GridSizeMode.Absolute, 50),
+                    }
+                }
+            };
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OverlayColourProvider colourProvider)
+        {
+            background.Colour = colourProvider.Background3;
+        }
+
+        public override bool HandleNonPositionalInput => textBox.HandleNonPositionalInput;
+
+        private class InnerSearchTextBox : SearchTextBox
+        {
+            [BackgroundDependencyLoader]
+            private void load(OverlayColourProvider colourProvider)
+            {
+                BackgroundFocused = colourProvider.Background4;
+                BackgroundUnfocused = colourProvider.Background4;
+
+                Placeholder.Font = OsuFont.GetFont(size: CalculatedTextSize, weight: FontWeight.SemiBold);
+                PlaceholderText = CommonStrings.InputSearch;
+
+                CornerRadius = corner_radius;
+                TextContainer.Shear = new Vector2(-ShearedOverlayContainer.SHEAR, 0);
+            }
+
+            protected override SpriteText CreatePlaceholder() => new SearchPlaceholder();
+
+            internal class SearchPlaceholder : SpriteText
+            {
+                public override void Show()
+                {
+                    this
+                        .MoveToY(0, 250, Easing.OutQuint)
+                        .FadeIn(250, Easing.OutQuint);
+                }
+
+                public override void Hide()
+                {
+                    this
+                        .MoveToY(3, 250, Easing.OutQuint)
+                        .FadeOut(250, Easing.OutQuint);
+                }
+            }
+
+            protected override Drawable GetDrawableCharacter(char c) => new FallingDownContainer
+            {
+                AutoSizeAxes = Axes.Both,
+                Child = new OsuSpriteText { Text = c.ToString(), Font = OsuFont.GetFont(size: 20, weight: FontWeight.SemiBold) },
+            };
+        }
+    }
+}

osu.Game/Input/Bindings/GlobalActionContainer.cs

@@ -59,6 +59,9 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(InputKey.Up, GlobalAction.SelectPrevious),
             new KeyBinding(InputKey.Down, GlobalAction.SelectNext),
 
+            new KeyBinding(InputKey.Left, GlobalAction.SelectPreviousGroup),
+            new KeyBinding(InputKey.Right, GlobalAction.SelectNextGroup),
+
             new KeyBinding(InputKey.Space, GlobalAction.Select),
             new KeyBinding(InputKey.Enter, GlobalAction.Select),
             new KeyBinding(InputKey.KeypadEnter, GlobalAction.Select),
@@ -79,6 +82,8 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(new[] { InputKey.F5 }, GlobalAction.EditorTestGameplay),
             new KeyBinding(new[] { InputKey.Control, InputKey.H }, GlobalAction.EditorFlipHorizontally),
             new KeyBinding(new[] { InputKey.Control, InputKey.J }, GlobalAction.EditorFlipVertically),
+            new KeyBinding(new[] { InputKey.Control, InputKey.Alt, InputKey.MouseWheelDown }, GlobalAction.EditorDecreaseDistanceSpacing),
+            new KeyBinding(new[] { InputKey.Control, InputKey.Alt, InputKey.MouseWheelUp }, GlobalAction.EditorIncreaseDistanceSpacing),
         };
 
         public IEnumerable<KeyBinding> InGameKeyBindings => new[]
@@ -103,7 +108,7 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(InputKey.F1, GlobalAction.ToggleModSelection),
             new KeyBinding(InputKey.F2, GlobalAction.SelectNextRandom),
             new KeyBinding(new[] { InputKey.Shift, InputKey.F2 }, GlobalAction.SelectPreviousRandom),
-            new KeyBinding(InputKey.F3, GlobalAction.ToggleBeatmapOptions)
+            new KeyBinding(InputKey.F3, GlobalAction.ToggleBeatmapOptions),
         };
 
         public IEnumerable<KeyBinding> AudioControlKeyBindings => new[]
@@ -301,5 +306,17 @@ namespace osu.Game.Input.Bindings
 
         [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.EditorFlipVertically))]
         EditorFlipVertically,
+
+        [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.EditorIncreaseDistanceSpacing))]
+        EditorIncreaseDistanceSpacing,
+
+        [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.EditorDecreaseDistanceSpacing))]
+        EditorDecreaseDistanceSpacing,
+
+        [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.SelectPreviousGroup))]
+        SelectPreviousGroup,
+
+        [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.SelectNextGroup))]
+        SelectNextGroup,
     }
 }

osu.Game/Localisation/GlobalActionKeyBindingStrings.cs

@@ -129,6 +129,16 @@ namespace osu.Game.Localisation
         /// </summary>
         public static LocalisableString SelectNext => new TranslatableString(getKey(@"select_next"), @"Next selection");
 
+        /// <summary>
+        /// "Select previous group"
+        /// </summary>
+        public static LocalisableString SelectPreviousGroup => new TranslatableString(getKey(@"select_previous_group"), @"Select previous group");
+
+        /// <summary>
+        /// "Select next group"
+        /// </summary>
+        public static LocalisableString SelectNextGroup => new TranslatableString(getKey(@"select_next_group"), @"Select next group");
+
         /// <summary>
         /// "Home"
         /// </summary>
@@ -239,6 +249,16 @@ namespace osu.Game.Localisation
         /// </summary>
         public static LocalisableString EditorFlipVertically => new TranslatableString(getKey(@"editor_flip_vertically"), @"Flip selection vertically");
 
+        /// <summary>
+        /// "Increase distance spacing"
+        /// </summary>
+        public static LocalisableString EditorIncreaseDistanceSpacing => new TranslatableString(getKey(@"editor_increase_distance_spacing"), @"Increase distance spacing");
+
+        /// <summary>
+        /// "Decrease distance spacing"
+        /// </summary>
+        public static LocalisableString EditorDecreaseDistanceSpacing => new TranslatableString(getKey(@"editor_decrease_distance_spacing"), @"Decrease distance spacing");
+
         /// <summary>
         /// "Toggle skin editor"
         /// </summary>

osu.Game/Online/Chat/StandAloneChatDisplay.cs

@@ -14,6 +14,7 @@ using osu.Game.Graphics.UserInterface;
 using osu.Game.Overlays.Chat;
 using osu.Game.Resources.Localisation.Web;
 using osuTK.Graphics;
+using osuTK.Input;
 
 namespace osu.Game.Online.Chat
 {
@@ -119,6 +120,20 @@ namespace osu.Game.Online.Chat
 
         public class ChatTextBox : FocusedTextBox
         {
+            protected override bool OnKeyDown(KeyDownEvent e)
+            {
+                // Chat text boxes are generally used in places where they retain focus, but shouldn't block interaction with other
+                // elements on the same screen.
+                switch (e.Key)
+                {
+                    case Key.Up:
+                    case Key.Down:
+                        return false;
+                }
+
+                return base.OnKeyDown(e);
+            }
+
             protected override void LoadComplete()
             {
                 base.LoadComplete();

osu.Game/Overlays/BeatmapListing/BeatmapListingSearchControl.cs

@@ -163,7 +163,7 @@ namespace osu.Game.Overlays.BeatmapListing
 
         public void TakeFocus() => textBox.TakeFocus();
 
-        private class BeatmapSearchTextBox : SearchTextBox
+        private class BeatmapSearchTextBox : BasicSearchTextBox
         {
             /// <summary>
             /// Any time the text box receives key events (even while masked).

osu.Game/Overlays/Chat/ChannelList/ChannelListItem.cs

@@ -25,14 +25,14 @@ namespace osu.Game.Overlays.Chat.ChannelList
         public event Action<Channel>? OnRequestSelect;
         public event Action<Channel>? OnRequestLeave;
 
+        public readonly Channel Channel;
+
         public readonly BindableInt Mentions = new BindableInt();
 
         public readonly BindableBool Unread = new BindableBool();
 
         public readonly BindableBool SelectorActive = new BindableBool();
 
-        private readonly Channel channel;
-
         private Box hoverBox = null!;
         private Box selectBox = null!;
         private OsuSpriteText text = null!;
@@ -46,7 +46,7 @@ namespace osu.Game.Overlays.Chat.ChannelList
 
         public ChannelListItem(Channel channel)
         {
-            this.channel = channel;
+            Channel = channel;
         }
 
         [BackgroundDependencyLoader]
@@ -92,7 +92,7 @@ namespace osu.Game.Overlays.Chat.ChannelList
                                 {
                                     Anchor = Anchor.CentreLeft,
                                     Origin = Anchor.CentreLeft,
-                                    Text = channel.Name,
+                                    Text = Channel.Name,
                                     Font = OsuFont.Torus.With(size: 17, weight: FontWeight.SemiBold),
                                     Colour = colourProvider.Light3,
                                     Margin = new MarginPadding { Bottom = 2 },
@@ -111,7 +111,7 @@ namespace osu.Game.Overlays.Chat.ChannelList
                                     Anchor = Anchor.CentreLeft,
                                     Origin = Anchor.CentreLeft,
                                     Margin = new MarginPadding { Right = 3 },
-                                    Action = () => OnRequestLeave?.Invoke(channel),
+                                    Action = () => OnRequestLeave?.Invoke(Channel),
                                 }
                             }
                         },
@@ -119,20 +119,16 @@ namespace osu.Game.Overlays.Chat.ChannelList
                 },
             };
 
-            Action = () => OnRequestSelect?.Invoke(channel);
+            Action = () => OnRequestSelect?.Invoke(Channel);
         }
 
         protected override void LoadComplete()
         {
             base.LoadComplete();
 
-            selectedChannel.BindValueChanged(_ => updateSelectState(), true);
-            SelectorActive.BindValueChanged(_ => updateSelectState(), true);
-
-            Unread.BindValueChanged(change =>
-            {
-                text.FadeColour(change.NewValue ? colourProvider.Content1 : colourProvider.Light3, 300, Easing.OutQuint);
-            }, true);
+            selectedChannel.BindValueChanged(_ => updateState(), true);
+            SelectorActive.BindValueChanged(_ => updateState(), true);
+            Unread.BindValueChanged(_ => updateState(), true);
         }
 
         protected override bool OnHover(HoverEvent e)
@@ -151,10 +147,10 @@ namespace osu.Game.Overlays.Chat.ChannelList
 
         private Drawable createIcon()
         {
-            if (channel.Type != ChannelType.PM)
+            if (Channel.Type != ChannelType.PM)
                 return Drawable.Empty();
 
-            return new UpdateableAvatar(channel.Users.First(), isInteractive: false)
+            return new UpdateableAvatar(Channel.Users.First(), isInteractive: false)
             {
                 Size = new Vector2(20),
                 Margin = new MarginPadding { Right = 5 },
@@ -165,12 +161,19 @@ namespace osu.Game.Overlays.Chat.ChannelList
             };
         }
 
-        private void updateSelectState()
+        private void updateState()
         {
-            if (selectedChannel.Value == channel && !SelectorActive.Value)
+            bool selected = selectedChannel.Value == Channel && !SelectorActive.Value;
+
+            if (selected)
                 selectBox.FadeIn(300, Easing.OutQuint);
             else
                 selectBox.FadeOut(200, Easing.OutQuint);
+
+            if (Unread.Value || selected)
+                text.FadeColour(colourProvider.Content1, 300, Easing.OutQuint);
+            else
+                text.FadeColour(colourProvider.Light3, 200, Easing.OutQuint);
         }
     }
 }

osu.Game/Overlays/Chat/ChannelList/ChannelListSelector.cs

@@ -21,6 +21,10 @@ namespace osu.Game.Overlays.Chat.ChannelList
 
         private Box hoverBox = null!;
         private Box selectBox = null!;
+        private OsuSpriteText text = null!;
+
+        [Resolved]
+        private OverlayColourProvider colourProvider { get; set; } = null!;
 
         [BackgroundDependencyLoader]
         private void load(OverlayColourProvider colourProvider)
@@ -46,11 +50,11 @@ namespace osu.Game.Overlays.Chat.ChannelList
                 {
                     RelativeSizeAxes = Axes.Both,
                     Padding = new MarginPadding { Left = 18, Right = 10 },
-                    Child = new OsuSpriteText
+                    Child = text = new OsuSpriteText
                     {
                         Anchor = Anchor.CentreLeft,
                         Origin = Anchor.CentreLeft,
-                        Text = "Add More Channels",
+                        Text = "Add more channels",
                         Font = OsuFont.Torus.With(size: 17, weight: FontWeight.SemiBold),
                         Colour = colourProvider.Light3,
                         Margin = new MarginPadding { Bottom = 2 },
@@ -68,9 +72,15 @@ namespace osu.Game.Overlays.Chat.ChannelList
             SelectorActive.BindValueChanged(selector =>
             {
                 if (selector.NewValue)
+                {
+                    text.FadeColour(colourProvider.Content1, 300, Easing.OutQuint);
                     selectBox.FadeIn(300, Easing.OutQuint);
+                }
                 else
+                {
+                    text.FadeColour(colourProvider.Light3, 200, Easing.OutQuint);
                     selectBox.FadeOut(200, Easing.OutQuint);
+                }
             }, true);
 
             Action = () => SelectorActive.Value = true;

osu.Game/Overlays/Chat/ChatOverlayTopBar.cs

@@ -0,0 +1,83 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+#nullable enable
+
+using osu.Framework.Allocation;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Textures;
+using osu.Framework.Input.Events;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Overlays.Chat
+{
+    public class ChatOverlayTopBar : Container
+    {
+        private Box background = null!;
+
+        private Color4 backgroundColour;
+
+        [BackgroundDependencyLoader]
+        private void load(OverlayColourProvider colourProvider, TextureStore textures)
+        {
+            Children = new Drawable[]
+            {
+                background = new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Colour = backgroundColour = colourProvider.Background3,
+                },
+                new GridContainer
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    ColumnDimensions = new[]
+                    {
+                        new Dimension(GridSizeMode.Absolute, 50),
+                        new Dimension(),
+                    },
+                    Content = new[]
+                    {
+                        new Drawable[]
+                        {
+                            new Sprite
+                            {
+                                Anchor = Anchor.Centre,
+                                Origin = Anchor.Centre,
+                                Texture = textures.Get("Icons/Hexacons/messaging"),
+                                Size = new Vector2(18),
+                            },
+                            // Placeholder text
+                            new OsuSpriteText
+                            {
+                                Anchor = Anchor.CentreLeft,
+                                Origin = Anchor.CentreLeft,
+                                Text = "osu!chat",
+                                Font = OsuFont.Torus.With(size: 16, weight: FontWeight.SemiBold),
+                                Margin = new MarginPadding { Bottom = 2f },
+                            },
+                        },
+                    },
+                },
+            };
+        }
+
+        protected override bool OnHover(HoverEvent e)
+        {
+            background.FadeColour(backgroundColour.Lighten(0.1f), 300, Easing.OutQuint);
+            return base.OnHover(e);
+        }
+
+        protected override void OnHoverLost(HoverLostEvent e)
+        {
+            background.FadeColour(backgroundColour, 300, Easing.OutQuint);
+            base.OnHoverLost(e);
+        }
+    }
+}

osu.Game/Overlays/Chat/ChatTextBar.cs

@@ -11,7 +11,8 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.UserInterface;
-using osu.Game.Graphics.Containers;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
 using osu.Game.Online.Chat;
 using osuTK;
 
@@ -25,14 +26,19 @@ namespace osu.Game.Overlays.Chat
 
         public event Action<string>? OnSearchTermsChanged;
 
+        public void TextBoxTakeFocus() => chatTextBox.TakeFocus();
+
+        public void TextBoxKillFocus() => chatTextBox.KillFocus();
+
         [Resolved]
         private Bindable<Channel> currentChannel { get; set; } = null!;
 
-        private OsuTextFlowContainer chattingTextContainer = null!;
+        private Container chattingTextContainer = null!;
+        private OsuSpriteText chattingText = null!;
         private Container searchIconContainer = null!;
         private ChatTextBox chatTextBox = null!;
 
-        private const float chatting_text_width = 180;
+        private const float chatting_text_width = 240;
         private const float search_icon_width = 40;
 
         [BackgroundDependencyLoader]
@@ -61,16 +67,20 @@ namespace osu.Game.Overlays.Chat
                     {
                         new Drawable[]
                         {
-                            chattingTextContainer = new OsuTextFlowContainer(t => t.Font = t.Font.With(size: 20))
+                            chattingTextContainer = new Container
                             {
-                                Masking = true,
-                                Width = chatting_text_width,
-                                Padding = new MarginPadding { Left = 10 },
                                 RelativeSizeAxes = Axes.Y,
-                                TextAnchor = Anchor.CentreRight,
-                                Anchor = Anchor.CentreLeft,
-                                Origin = Anchor.CentreLeft,
-                                Colour = colourProvider.Background1,
+                                Width = chatting_text_width,
+                                Masking = true,
+                                Padding = new MarginPadding { Right = 5 },
+                                Child = chattingText = new OsuSpriteText
+                                {
+                                    Font = OsuFont.Torus.With(size: 20),
+                                    Colour = colourProvider.Background1,
+                                    Anchor = Anchor.CentreRight,
+                                    Origin = Anchor.CentreRight,
+                                    Truncate = true,
+                                },
                             },
                             searchIconContainer = new Container
                             {
@@ -131,15 +141,15 @@ namespace osu.Game.Overlays.Chat
                 switch (newChannel?.Type)
                 {
                     case ChannelType.Public:
-                        chattingTextContainer.Text = $"chatting in {newChannel.Name}";
+                        chattingText.Text = $"chatting in {newChannel.Name}";
                         break;
 
                     case ChannelType.PM:
-                        chattingTextContainer.Text = $"chatting with {newChannel.Name}";
+                        chattingText.Text = $"chatting with {newChannel.Name}";
                         break;
 
                     default:
-                        chattingTextContainer.Text = string.Empty;
+                        chattingText.Text = string.Empty;
                         break;
                 }
             }, true);

osu.Game/Overlays/Chat/Listing/ChannelListingItem.cs

@@ -25,11 +25,11 @@ namespace osu.Game.Overlays.Chat.Listing
         public event Action<Channel>? OnRequestJoin;
         public event Action<Channel>? OnRequestLeave;
 
-        public bool FilteringActive { get; set; }
-        public IEnumerable<string> FilterTerms => new[] { channel.Name, channel.Topic ?? string.Empty };
-        public bool MatchingFilter { set => this.FadeTo(value ? 1f : 0f, 100); }
+        public readonly Channel Channel;
 
-        private readonly Channel channel;
+        public bool FilteringActive { get; set; }
+        public IEnumerable<string> FilterTerms => new[] { Channel.Name, Channel.Topic ?? string.Empty };
+        public bool MatchingFilter { set => this.FadeTo(value ? 1f : 0f, 100); }
 
         private Box hoverBox = null!;
         private SpriteIcon checkbox = null!;
@@ -47,7 +47,7 @@ namespace osu.Game.Overlays.Chat.Listing
 
         public ChannelListingItem(Channel channel)
         {
-            this.channel = channel;
+            Channel = channel;
         }
 
         [BackgroundDependencyLoader]
@@ -94,7 +94,7 @@ namespace osu.Game.Overlays.Chat.Listing
                             {
                                 Anchor = Anchor.CentreLeft,
                                 Origin = Anchor.CentreLeft,
-                                Text = channel.Name,
+                                Text = Channel.Name,
                                 Font = OsuFont.Torus.With(size: text_size, weight: FontWeight.SemiBold),
                                 Margin = new MarginPadding { Bottom = 2 },
                             },
@@ -102,7 +102,7 @@ namespace osu.Game.Overlays.Chat.Listing
                             {
                                 Anchor = Anchor.CentreLeft,
                                 Origin = Anchor.CentreLeft,
-                                Text = channel.Topic,
+                                Text = Channel.Topic,
                                 Font = OsuFont.Torus.With(size: text_size),
                                 Margin = new MarginPadding { Bottom = 2 },
                             },
@@ -134,7 +134,7 @@ namespace osu.Game.Overlays.Chat.Listing
         {
             base.LoadComplete();
 
-            channelJoined = channel.Joined.GetBoundCopy();
+            channelJoined = Channel.Joined.GetBoundCopy();
             channelJoined.BindValueChanged(change =>
             {
                 const double duration = 500;
@@ -155,7 +155,7 @@ namespace osu.Game.Overlays.Chat.Listing
                 }
             }, true);
 
-            Action = () => (channelJoined.Value ? OnRequestLeave : OnRequestJoin)?.Invoke(channel);
+            Action = () => (channelJoined.Value ? OnRequestLeave : OnRequestJoin)?.Invoke(Channel);
         }
 
         protected override bool OnHover(HoverEvent e)

osu.Game/Overlays/Chat/Selection/ChannelSelectionOverlay.cs

@@ -181,7 +181,7 @@ namespace osu.Game.Overlays.Chat.Selection
             base.PopOut();
         }
 
-        private class HeaderSearchTextBox : SearchTextBox
+        private class HeaderSearchTextBox : BasicSearchTextBox
         {
             [BackgroundDependencyLoader]
             private void load()

osu.Game/Overlays/ChatOverlayV2.cs

@@ -0,0 +1,314 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+#nullable enable
+
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Diagnostics;
+using System.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Input.Events;
+using osu.Framework.Localisation;
+using osu.Game.Configuration;
+using osu.Game.Graphics.Containers;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Localisation;
+using osu.Game.Online.Chat;
+using osu.Game.Overlays.Chat;
+using osu.Game.Overlays.Chat.ChannelList;
+using osu.Game.Overlays.Chat.Listing;
+
+namespace osu.Game.Overlays
+{
+    public class ChatOverlayV2 : OsuFocusedOverlayContainer, INamedOverlayComponent
+    {
+        public string IconTexture => "Icons/Hexacons/messaging";
+        public LocalisableString Title => ChatStrings.HeaderTitle;
+        public LocalisableString Description => ChatStrings.HeaderDescription;
+
+        private ChatOverlayTopBar topBar = null!;
+        private ChannelList channelList = null!;
+        private LoadingLayer loading = null!;
+        private ChannelListing channelListing = null!;
+        private ChatTextBar textBar = null!;
+        private Container<DrawableChannel> currentChannelContainer = null!;
+
+        private readonly BindableFloat chatHeight = new BindableFloat();
+
+        private bool isDraggingTopBar;
+        private float dragStartChatHeight;
+
+        private const int transition_length = 500;
+        private const float default_chat_height = 0.4f;
+        private const float top_bar_height = 40;
+        private const float side_bar_width = 190;
+        private const float chat_bar_height = 60;
+
+        private readonly BindableBool selectorActive = new BindableBool();
+
+        [Resolved]
+        private OsuConfigManager config { get; set; } = null!;
+
+        [Resolved]
+        private ChannelManager channelManager { get; set; } = null!;
+
+        [Cached]
+        private readonly OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Pink);
+
+        [Cached]
+        private readonly Bindable<Channel> currentChannel = new Bindable<Channel>();
+
+        public ChatOverlayV2()
+        {
+            Height = default_chat_height;
+
+            Masking = true;
+
+            const float corner_radius = 7f;
+
+            CornerRadius = corner_radius;
+
+            // Hack to hide the bottom edge corner radius off-screen.
+            Margin = new MarginPadding { Bottom = -corner_radius };
+            Padding = new MarginPadding { Bottom = corner_radius };
+
+            Anchor = Anchor.BottomCentre;
+            Origin = Anchor.BottomCentre;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            // Required for the pop in/out animation
+            RelativePositionAxes = Axes.Both;
+
+            Children = new Drawable[]
+            {
+                topBar = new ChatOverlayTopBar
+                {
+                    RelativeSizeAxes = Axes.X,
+                    Height = top_bar_height,
+                },
+                channelList = new ChannelList
+                {
+                    RelativeSizeAxes = Axes.Y,
+                    Width = side_bar_width,
+                    Padding = new MarginPadding { Top = top_bar_height },
+                    SelectorActive = { BindTarget = selectorActive },
+                },
+                new Container
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Anchor = Anchor.TopRight,
+                    Origin = Anchor.TopRight,
+                    Padding = new MarginPadding
+                    {
+                        Top = top_bar_height,
+                        Left = side_bar_width,
+                        Bottom = chat_bar_height,
+                    },
+                    Children = new Drawable[]
+                    {
+                        new Box
+                        {
+                            RelativeSizeAxes = Axes.Both,
+                            Colour = colourProvider.Background4,
+                        },
+                        currentChannelContainer = new Container<DrawableChannel>
+                        {
+                            RelativeSizeAxes = Axes.Both,
+                        },
+                        loading = new LoadingLayer(true),
+                        channelListing = new ChannelListing
+                        {
+                            RelativeSizeAxes = Axes.Both,
+                        },
+                    },
+                },
+                textBar = new ChatTextBar
+                {
+                    RelativeSizeAxes = Axes.X,
+                    Anchor = Anchor.BottomRight,
+                    Origin = Anchor.BottomRight,
+                    Padding = new MarginPadding { Left = side_bar_width },
+                    ShowSearch = { BindTarget = selectorActive },
+                },
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            loading.Show();
+
+            config.BindWith(OsuSetting.ChatDisplayHeight, chatHeight);
+
+            chatHeight.BindValueChanged(height => { Height = height.NewValue; }, true);
+
+            currentChannel.BindTo(channelManager.CurrentChannel);
+            channelManager.CurrentChannel.BindValueChanged(currentChannelChanged, true);
+            channelManager.JoinedChannels.BindCollectionChanged(joinedChannelsChanged, true);
+            channelManager.AvailableChannels.BindCollectionChanged(availableChannelsChanged, true);
+
+            channelList.OnRequestSelect += channel =>
+            {
+                // Manually selecting a channel should dismiss the selector
+                selectorActive.Value = false;
+                channelManager.CurrentChannel.Value = channel;
+            };
+            channelList.OnRequestLeave += channel => channelManager.LeaveChannel(channel);
+
+            channelListing.OnRequestJoin += channel => channelManager.JoinChannel(channel);
+            channelListing.OnRequestLeave += channel => channelManager.LeaveChannel(channel);
+
+            textBar.OnSearchTermsChanged += searchTerms => channelListing.SearchTerm = searchTerms;
+            textBar.OnChatMessageCommitted += handleChatMessage;
+
+            selectorActive.BindValueChanged(v => channelListing.State.Value = v.NewValue ? Visibility.Visible : Visibility.Hidden, true);
+        }
+
+        /// <summary>
+        /// Highlights a certain message in the specified channel.
+        /// </summary>
+        /// <param name="message">The message to highlight.</param>
+        /// <param name="channel">The channel containing the message.</param>
+        public void HighlightMessage(Message message, Channel channel)
+        {
+            Debug.Assert(channel.Id == message.ChannelId);
+
+            if (currentChannel.Value?.Id != channel.Id)
+            {
+                if (!channel.Joined.Value)
+                    channel = channelManager.JoinChannel(channel);
+
+                channelManager.CurrentChannel.Value = channel;
+            }
+
+            selectorActive.Value = false;
+
+            channel.HighlightedMessage.Value = message;
+
+            Show();
+        }
+
+        protected override bool OnDragStart(DragStartEvent e)
+        {
+            isDraggingTopBar = topBar.IsHovered;
+
+            if (!isDraggingTopBar)
+                return base.OnDragStart(e);
+
+            dragStartChatHeight = chatHeight.Value;
+            return true;
+        }
+
+        protected override void OnDrag(DragEvent e)
+        {
+            if (!isDraggingTopBar)
+                return;
+
+            float targetChatHeight = dragStartChatHeight - (e.MousePosition.Y - e.MouseDownPosition.Y) / Parent.DrawSize.Y;
+            chatHeight.Value = targetChatHeight;
+        }
+
+        protected override void OnDragEnd(DragEndEvent e)
+        {
+            isDraggingTopBar = false;
+            base.OnDragEnd(e);
+        }
+
+        protected override void PopIn()
+        {
+            base.PopIn();
+
+            this.MoveToY(0, transition_length, Easing.OutQuint);
+            this.FadeIn(transition_length, Easing.OutQuint);
+        }
+
+        protected override void PopOut()
+        {
+            base.PopOut();
+
+            this.MoveToY(Height, transition_length, Easing.InSine);
+            this.FadeOut(transition_length, Easing.InSine);
+
+            textBar.TextBoxKillFocus();
+        }
+
+        protected override void OnFocus(FocusEvent e)
+        {
+            textBar.TextBoxTakeFocus();
+            base.OnFocus(e);
+        }
+
+        private void currentChannelChanged(ValueChangedEvent<Channel> channel)
+        {
+            Channel? newChannel = channel.NewValue;
+
+            loading.Show();
+
+            // Channel is null when leaving the currently selected channel
+            if (newChannel == null)
+            {
+                // Find another channel to switch to
+                newChannel = channelManager.JoinedChannels.FirstOrDefault(c => c != channel.OldValue);
+
+                if (newChannel == null)
+                    selectorActive.Value = true;
+                else
+                    currentChannel.Value = newChannel;
+
+                return;
+            }
+
+            LoadComponentAsync(new DrawableChannel(newChannel), loaded =>
+            {
+                currentChannelContainer.Clear();
+                currentChannelContainer.Add(loaded);
+                loading.Hide();
+            });
+        }
+
+        private void joinedChannelsChanged(object sender, NotifyCollectionChangedEventArgs args)
+        {
+            switch (args.Action)
+            {
+                case NotifyCollectionChangedAction.Add:
+                    IEnumerable<Channel> joinedChannels = filterChannels(args.NewItems);
+                    foreach (var channel in joinedChannels)
+                        channelList.AddChannel(channel);
+                    break;
+
+                case NotifyCollectionChangedAction.Remove:
+                    IEnumerable<Channel> leftChannels = filterChannels(args.OldItems);
+                    foreach (var channel in leftChannels)
+                        channelList.RemoveChannel(channel);
+                    break;
+            }
+        }
+
+        private void availableChannelsChanged(object sender, NotifyCollectionChangedEventArgs args)
+            => channelListing.UpdateAvailableChannels(channelManager.AvailableChannels);
+
+        private IEnumerable<Channel> filterChannels(IList channels)
+            => channels.Cast<Channel>().Where(c => c.Type == ChannelType.Public || c.Type == ChannelType.PM);
+
+        private void handleChatMessage(string message)
+        {
+            if (string.IsNullOrWhiteSpace(message))
+                return;
+
+            if (message[0] == '/')
+                channelManager.PostCommand(message.Substring(1));
+            else
+                channelManager.PostMessage(message);
+        }
+    }
+}

osu.Game/Overlays/DialogOverlay.cs

@@ -49,18 +49,24 @@ namespace osu.Game.Overlays
         {
             if (dialog == CurrentDialog || dialog.State.Value != Visibility.Visible) return;
 
-            // if any existing dialog is being displayed, dismiss it before showing a new one.
-            CurrentDialog?.Hide();
+            var lastDialog = CurrentDialog;
 
+            // Immediately update the externally accessible property as this may be used for checks even before
+            // a DialogOverlay instance has finished loading.
             CurrentDialog = dialog;
-            CurrentDialog.State.ValueChanged += state => onDialogOnStateChanged(dialog, state.NewValue);
 
-            dialogContainer.Add(CurrentDialog);
+            Scheduler.Add(() =>
+            {
+                // if any existing dialog is being displayed, dismiss it before showing a new one.
+                lastDialog?.Hide();
+                dialog.State.ValueChanged += state => onDialogOnStateChanged(dialog, state.NewValue);
+                dialogContainer.Add(dialog);
 
-            Show();
+                Show();
+            }, false);
         }
 
-        public override bool IsPresent => dialogContainer.Children.Count > 0;
+        public override bool IsPresent => Scheduler.HasPendingTasks || dialogContainer.Children.Count > 0;
 
         protected override bool BlockNonPositionalInput => true;
 
@@ -81,23 +87,16 @@ namespace osu.Game.Overlays
         protected override void PopIn()
         {
             base.PopIn();
-            this.FadeIn(PopupDialog.ENTER_DURATION, Easing.OutQuint);
             lowPassFilter.CutoffTo(300, 100, Easing.OutCubic);
         }
 
         protected override void PopOut()
         {
             base.PopOut();
-
             lowPassFilter.CutoffTo(AudioFilter.MAX_LOWPASS_CUTOFF, 100, Easing.InCubic);
 
             if (CurrentDialog?.State.Value == Visibility.Visible)
-            {
                 CurrentDialog.Hide();
-                return;
-            }
-
-            this.FadeOut(PopupDialog.EXIT_DURATION, Easing.InSine);
         }
 
         public override bool OnPressed(KeyBindingPressEvent<GlobalAction> e)

osu.Game/Overlays/Mods/ModColumn.cs

@@ -1,6 +1,8 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -10,6 +12,7 @@ using Humanizer;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
@@ -25,8 +28,6 @@ using osuTK;
 using osuTK.Graphics;
 using osuTK.Input;
 
-#nullable enable
-
 namespace osu.Game.Overlays.Mods
 {
     public class ModColumn : CompositeDrawable
@@ -52,9 +53,22 @@ namespace osu.Game.Overlays.Mods
             }
         }
 
-        public Bindable<IReadOnlyList<Mod>> SelectedMods = new Bindable<IReadOnlyList<Mod>>(Array.Empty<Mod>());
         public Bindable<bool> Active = new BindableBool(true);
 
+        /// <summary>
+        /// List of mods marked as selected in this column.
+        /// </summary>
+        /// <remarks>
+        /// Note that the mod instances returned by this property are owned solely by this column
+        /// (as in, they are locally-managed clones, to ensure proper isolation from any other external instances).
+        /// </remarks>
+        public IReadOnlyList<Mod> SelectedMods { get; private set; } = Array.Empty<Mod>();
+
+        /// <summary>
+        /// Invoked when a mod panel has been selected interactively by the user.
+        /// </summary>
+        public event Action? SelectionChangedByUser;
+
         protected override bool ReceivePositionalInputAtSubTree(Vector2 screenSpacePos) => base.ReceivePositionalInputAtSubTree(screenSpacePos) && Active.Value;
 
         protected virtual ModPanel CreateModPanel(Mod mod) => new ModPanel(mod);
@@ -63,6 +77,15 @@ namespace osu.Game.Overlays.Mods
 
         private readonly Bindable<Dictionary<ModType, IReadOnlyList<Mod>>> availableMods = new Bindable<Dictionary<ModType, IReadOnlyList<Mod>>>();
 
+        /// <summary>
+        /// All mods that are available for the current ruleset in this particular column.
+        /// </summary>
+        /// <remarks>
+        /// Note that the mod instances in this list are owned solely by this column
+        /// (as in, they are locally-managed clones, to ensure proper isolation from any other external instances).
+        /// </remarks>
+        private IReadOnlyList<Mod> localAvailableMods = Array.Empty<Mod>();
+
         private readonly TextFlowContainer headerText;
         private readonly Box headerBackground;
         private readonly Container contentContainer;
@@ -226,6 +249,9 @@ namespace osu.Game.Overlays.Mods
         private void load(OsuGameBase game, OverlayColourProvider colourProvider, OsuColour colours)
         {
             availableMods.BindTo(game.AvailableMods);
+            // this `BindValueChanged` callback is intentionally here, to ensure that local available mods are constructed as early as possible.
+            // this is needed to make sure no external changes to mods are dropped while mod panels are asynchronously loading.
+            availableMods.BindValueChanged(_ => updateLocalAvailableMods(), true);
 
             headerBackground.Colour = accentColour = colours.ForModType(ModType);
 
@@ -239,31 +265,26 @@ namespace osu.Game.Overlays.Mods
             contentBackground.Colour = colourProvider.Background4;
         }
 
-        protected override void LoadComplete()
+        private void updateLocalAvailableMods()
         {
-            base.LoadComplete();
-            availableMods.BindValueChanged(_ => Scheduler.AddOnce(updateMods));
-            SelectedMods.BindValueChanged(_ =>
-            {
-                // if a load is in progress, don't try to update the selection - the load flow will do so.
-                if (latestLoadTask == null)
-                    updateActiveState();
-            });
-            updateMods();
+            var newMods = ModUtils.FlattenMods(availableMods.Value.GetValueOrDefault(ModType) ?? Array.Empty<Mod>())
+                                  .Select(m => m.DeepClone())
+                                  .ToList();
+
+            if (newMods.SequenceEqual(localAvailableMods))
+                return;
+
+            localAvailableMods = newMods;
+            Scheduler.AddOnce(loadPanels);
         }
 
         private CancellationTokenSource? cancellationTokenSource;
 
-        private void updateMods()
+        private void loadPanels()
         {
-            var newMods = ModUtils.FlattenMods(availableMods.Value.GetValueOrDefault(ModType) ?? Array.Empty<Mod>()).ToList();
-
-            if (newMods.SequenceEqual(panelFlow.Children.Select(p => p.Mod)))
-                return;
-
             cancellationTokenSource?.Cancel();
 
-            var panels = newMods.Select(mod => CreateModPanel(mod).With(panel => panel.Shear = new Vector2(-ShearedOverlayContainer.SHEAR, 0)));
+            var panels = localAvailableMods.Select(mod => CreateModPanel(mod).With(panel => panel.Shear = new Vector2(-ShearedOverlayContainer.SHEAR, 0)));
 
             Task? loadTask;
 
@@ -277,13 +298,7 @@ namespace osu.Game.Overlays.Mods
 
                 foreach (var panel in panelFlow)
                 {
-                    panel.Active.BindValueChanged(_ =>
-                    {
-                        updateToggleAllState();
-                        SelectedMods.Value = panel.Active.Value
-                            ? SelectedMods.Value.Append(panel.Mod).ToArray()
-                            : SelectedMods.Value.Except(new[] { panel.Mod }).ToArray();
-                    });
+                    panel.Active.BindValueChanged(_ => panelStateChanged(panel));
                 }
             }, (cancellationTokenSource = new CancellationTokenSource()).Token);
             loadTask.ContinueWith(_ =>
@@ -296,7 +311,62 @@ namespace osu.Game.Overlays.Mods
         private void updateActiveState()
         {
             foreach (var panel in panelFlow)
-                panel.Active.Value = SelectedMods.Value.Contains(panel.Mod, EqualityComparer<Mod>.Default);
+                panel.Active.Value = SelectedMods.Contains(panel.Mod);
+        }
+
+        /// <summary>
+        /// This flag helps to determine the source of changes to <see cref="SelectedMods"/>.
+        /// If the value is false, then <see cref="SelectedMods"/> are changing due to a user selection on the UI.
+        /// If the value is true, then <see cref="SelectedMods"/> are changing due to an external <see cref="SetSelection"/> call.
+        /// </summary>
+        private bool externalSelectionUpdateInProgress;
+
+        private void panelStateChanged(ModPanel panel)
+        {
+            updateToggleAllState();
+
+            var newSelectedMods = panel.Active.Value
+                ? SelectedMods.Append(panel.Mod)
+                : SelectedMods.Except(panel.Mod.Yield());
+
+            SelectedMods = newSelectedMods.ToArray();
+            if (!externalSelectionUpdateInProgress)
+                SelectionChangedByUser?.Invoke();
+        }
+
+        /// <summary>
+        /// Adjusts the set of selected mods in this column to match the passed in <paramref name="mods"/>.
+        /// </summary>
+        /// <remarks>
+        /// This method exists to be able to receive mod instances that come from potentially-external sources and to copy the changes across to this column's state.
+        /// <see cref="ModSelectScreen"/> uses this to substitute any external mod references in <see cref="ModSelectScreen.SelectedMods"/>
+        /// to references that are owned by this column.
+        /// </remarks>
+        internal void SetSelection(IReadOnlyList<Mod> mods)
+        {
+            externalSelectionUpdateInProgress = true;
+
+            var newSelection = new List<Mod>();
+
+            foreach (var mod in localAvailableMods)
+            {
+                var matchingSelectedMod = mods.SingleOrDefault(selected => selected.GetType() == mod.GetType());
+
+                if (matchingSelectedMod != null)
+                {
+                    mod.CopyFrom(matchingSelectedMod);
+                    newSelection.Add(mod);
+                }
+                else
+                {
+                    mod.ResetSettingsToDefaults();
+                }
+            }
+
+            SelectedMods = newSelection;
+            updateActiveState();
+
+            externalSelectionUpdateInProgress = false;
         }
 
         #region Bulk select / deselect
@@ -364,6 +434,15 @@ namespace osu.Game.Overlays.Mods
                 pendingSelectionOperations.Enqueue(() => button.Active.Value = false);
         }
 
+        /// <summary>
+        /// Run any delayed selections (due to animation) immediately to leave mods in a good (final) state.
+        /// </summary>
+        public void FlushPendingSelections()
+        {
+            while (pendingSelectionOperations.TryDequeue(out var dequeuedAction))
+                dequeuedAction();
+        }
+
         private class ToggleAllCheckbox : OsuCheckbox
         {
             private Color4 accentColour;

osu.Game/Overlays/Mods/ModSection.cs

@@ -250,9 +250,9 @@ namespace osu.Game.Overlays.Mods
         protected virtual ModButton CreateModButton(Mod mod) => new ModButton(mod);
 
         /// <summary>
-        /// Play out all remaining animations immediately to leave mods in a good (final) state.
+        /// Run any delayed selections (due to animation) immediately to leave mods in a good (final) state.
         /// </summary>
-        public void FlushAnimation()
+        public void FlushPendingSelections()
         {
             while (pendingSelectionOperations.TryDequeue(out var dequeuedAction))
                 dequeuedAction();

osu.Game/Overlays/Mods/ModSelectOverlay.cs

@@ -369,7 +369,7 @@ namespace osu.Game.Overlays.Mods
 
             foreach (var section in ModSectionsContainer)
             {
-                section.FlushAnimation();
+                section.FlushPendingSelections();
             }
 
             FooterContainer.MoveToX(content_width, WaveContainer.DISAPPEAR_DURATION, Easing.InSine);

osu.Game/Overlays/Mods/ModSelectScreen.cs

@@ -18,6 +18,7 @@ using osu.Game.Configuration;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.UserInterface;
+using osu.Game.Input.Bindings;
 using osu.Game.Rulesets.Mods;
 using osuTK;
 using osuTK.Input;
@@ -179,7 +180,7 @@ namespace osu.Game.Overlays.Mods
 
             foreach (var column in columnFlow.Columns)
             {
-                column.SelectedMods.BindValueChanged(updateBindableFromSelection);
+                column.SelectionChangedByUser += updateBindableFromSelection;
             }
 
             customisationVisible.BindValueChanged(_ => updateCustomisationVisualState(), true);
@@ -203,7 +204,7 @@ namespace osu.Game.Overlays.Mods
         private void updateAvailableMods()
         {
             foreach (var column in columnFlow.Columns)
-                column.Filter = isValidMod;
+                column.Filter = m => m.HasImplementation && isValidMod.Invoke(m);
         }
 
         private void updateCustomisation(ValueChangedEvent<IReadOnlyList<Mod>> valueChangedEvent)
@@ -217,7 +218,7 @@ namespace osu.Game.Overlays.Mods
             foreach (var mod in SelectedMods.Value)
             {
                 anyCustomisableMod |= mod.GetSettingsSourceProperties().Any();
-                anyModWithRequiredCustomisationAdded |= !valueChangedEvent.OldValue.Contains(mod) && mod.RequiresConfiguration;
+                anyModWithRequiredCustomisationAdded |= valueChangedEvent.OldValue.All(m => m.GetType() != mod.GetType()) && mod.RequiresConfiguration;
             }
 
             if (anyCustomisableMod)
@@ -250,33 +251,26 @@ namespace osu.Game.Overlays.Mods
 
         private void updateSelectionFromBindable()
         {
-            // note that selectionBindableSyncInProgress is purposefully not checked here.
-            // this is because in the case of mod selection in solo gameplay, a user selection of a mod can actually lead to deselection of other incompatible mods.
-            // to synchronise state correctly, updateBindableFromSelection() computes the final mods (including incompatibility rules) and updates SelectedMods,
-            // and this method then runs unconditionally again to make sure the new visual selection accurately reflects the final set of selected mods.
-            // selectionBindableSyncInProgress ensures that mutual infinite recursion does not happen after that unconditional call.
+            // `SelectedMods` may contain mod references that come from external sources.
+            // to ensure isolation, first pull in the potentially-external change into the mod columns...
             foreach (var column in columnFlow.Columns)
-                column.SelectedMods.Value = SelectedMods.Value.Where(mod => mod.Type == column.ModType).ToArray();
+                column.SetSelection(SelectedMods.Value);
+
+            // and then, when done, replace the potentially-external mod references in `SelectedMods` with ones we own.
+            updateBindableFromSelection();
         }
 
-        private bool selectionBindableSyncInProgress;
-
-        private void updateBindableFromSelection(ValueChangedEvent<IReadOnlyList<Mod>> modSelectionChange)
+        private void updateBindableFromSelection()
         {
-            if (selectionBindableSyncInProgress)
+            var candidateSelection = columnFlow.Columns.SelectMany(column => column.SelectedMods).ToArray();
+
+            if (candidateSelection.SequenceEqual(SelectedMods.Value))
                 return;
 
-            selectionBindableSyncInProgress = true;
-
-            SelectedMods.Value = ComputeNewModsFromSelection(
-                modSelectionChange.NewValue.Except(modSelectionChange.OldValue),
-                modSelectionChange.OldValue.Except(modSelectionChange.NewValue));
-
-            selectionBindableSyncInProgress = false;
+            SelectedMods.Value = ComputeNewModsFromSelection(SelectedMods.Value, candidateSelection);
         }
 
-        protected virtual IReadOnlyList<Mod> ComputeNewModsFromSelection(IEnumerable<Mod> addedMods, IEnumerable<Mod> removedMods)
-            => columnFlow.Columns.SelectMany(column => column.SelectedMods.Value).ToArray();
+        protected virtual IReadOnlyList<Mod> ComputeNewModsFromSelection(IReadOnlyList<Mod> oldSelection, IReadOnlyList<Mod> newSelection) => newSelection;
 
         protected override void PopIn()
         {
@@ -313,13 +307,26 @@ namespace osu.Game.Overlays.Mods
             {
                 const float distance = 700;
 
-                columnFlow[i].Column
-                             .TopLevelContent
-                             .MoveToY(i % 2 == 0 ? -distance : distance, fade_out_duration, Easing.OutQuint)
-                             .FadeOut(fade_out_duration, Easing.OutQuint);
+                var column = columnFlow[i].Column;
+
+                column.FlushPendingSelections();
+                column.TopLevelContent
+                      .MoveToY(i % 2 == 0 ? -distance : distance, fade_out_duration, Easing.OutQuint)
+                      .FadeOut(fade_out_duration, Easing.OutQuint);
             }
         }
 
+        public override bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
+        {
+            if (e.Action == GlobalAction.Back && customisationVisible.Value)
+            {
+                customisationVisible.Value = false;
+                return true;
+            }
+
+            return base.OnPressed(e);
+        }
+
         internal class ColumnScrollContainer : OsuScrollContainer<ColumnFlowContainer>
         {
             public ColumnScrollContainer()

osu.Game/Overlays/Mods/ModSettingsArea.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -21,7 +22,7 @@ namespace osu.Game.Overlays.Mods
 {
     public class ModSettingsArea : CompositeDrawable
     {
-        public Bindable<IReadOnlyList<Mod>> SelectedMods { get; } = new Bindable<IReadOnlyList<Mod>>();
+        public Bindable<IReadOnlyList<Mod>> SelectedMods { get; } = new Bindable<IReadOnlyList<Mod>>(Array.Empty<Mod>());
 
         public const float HEIGHT = 250;
 
@@ -77,7 +78,7 @@ namespace osu.Game.Overlays.Mods
         protected override void LoadComplete()
         {
             base.LoadComplete();
-            SelectedMods.BindValueChanged(_ => updateMods());
+            SelectedMods.BindValueChanged(_ => updateMods(), true);
         }
 
         private void updateMods()

osu.Game/Overlays/Mods/UserModSelectScreen.cs

@@ -14,9 +14,12 @@ namespace osu.Game.Overlays.Mods
     {
         protected override ModColumn CreateModColumn(ModType modType, Key[] toggleKeys = null) => new UserModColumn(modType, false, toggleKeys);
 
-        protected override IReadOnlyList<Mod> ComputeNewModsFromSelection(IEnumerable<Mod> addedMods, IEnumerable<Mod> removedMods)
+        protected override IReadOnlyList<Mod> ComputeNewModsFromSelection(IReadOnlyList<Mod> oldSelection, IReadOnlyList<Mod> newSelection)
         {
-            IEnumerable<Mod> modsAfterRemoval = SelectedMods.Value.Except(removedMods).ToList();
+            var addedMods = newSelection.Except(oldSelection);
+            var removedMods = oldSelection.Except(newSelection);
+
+            IEnumerable<Mod> modsAfterRemoval = newSelection.Except(removedMods).ToList();
 
             // the preference is that all new mods should override potential incompatible old mods.
             // in general that's a bit difficult to compute if more than one mod is added at a time,

osu.Game/Overlays/Music/FilterControl.cs

@@ -56,7 +56,7 @@ namespace osu.Game.Overlays.Music
             Collection = collectionDropdown.Current.Value?.Collection
         };
 
-        public class FilterTextBox : SearchTextBox
+        public class FilterTextBox : BasicSearchTextBox
         {
             protected override bool AllowCommit => true;
 

osu.Game/Overlays/Volume/VolumeMeter.cs

@@ -372,12 +372,12 @@ namespace osu.Game.Overlays.Volume
 
             switch (e.Action)
             {
-                case GlobalAction.SelectPrevious:
+                case GlobalAction.SelectPreviousGroup:
                     State = SelectionState.Selected;
                     adjust(1, false);
                     return true;
 
-                case GlobalAction.SelectNext:
+                case GlobalAction.SelectNextGroup:
                     State = SelectionState.Selected;
                     adjust(-1, false);
                     return true;

osu.Game/Rulesets/Difficulty/Skills/StrainSkill.cs

@@ -100,9 +100,13 @@ namespace osu.Game.Rulesets.Difficulty.Skills
             double difficulty = 0;
             double weight = 1;
 
+            // Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
+            // These sections will not contribute to the difficulty.
+            var peaks = GetCurrentStrainPeaks().Where(p => p > 0);
+
             // Difficulty is the weighted sum of the highest strains from every section.
             // We're sorting from highest to lowest strain.
-            foreach (double strain in GetCurrentStrainPeaks().OrderByDescending(d => d))
+            foreach (double strain in peaks.OrderByDescending(d => d))
             {
                 difficulty += strain * weight;
                 weight *= DecayWeight;

osu.Game/Rulesets/Edit/DistancedHitObjectComposer.cs

@@ -3,13 +3,19 @@
 
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions;
+using osu.Framework.Extensions.LocalisationExtensions;
 using osu.Framework.Graphics;
+using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
-using osu.Game.Graphics.Containers;
+using osu.Framework.Localisation;
+using osu.Game.Configuration;
 using osu.Game.Graphics.UserInterface;
+using osu.Game.Input.Bindings;
+using osu.Game.Overlays;
+using osu.Game.Overlays.OSD;
 using osu.Game.Overlays.Settings.Sections;
 using osu.Game.Rulesets.Objects;
-using osuTK;
 
 namespace osu.Game.Rulesets.Edit
 {
@@ -17,8 +23,7 @@ namespace osu.Game.Rulesets.Edit
     /// Represents a <see cref="HitObjectComposer{TObject}"/> for rulesets with the concept of distances between objects.
     /// </summary>
     /// <typeparam name="TObject">The base type of supported objects.</typeparam>
-    [Cached(typeof(IDistanceSnapProvider))]
-    public abstract class DistancedHitObjectComposer<TObject> : HitObjectComposer<TObject>, IDistanceSnapProvider
+    public abstract class DistancedHitObjectComposer<TObject> : HitObjectComposer<TObject>, IDistanceSnapProvider, IScrollBindingHandler<GlobalAction>
         where TObject : HitObject
     {
         protected Bindable<double> DistanceSpacingMultiplier { get; } = new BindableDouble(1.0)
@@ -33,7 +38,9 @@ namespace osu.Game.Rulesets.Edit
         protected ExpandingToolboxContainer RightSideToolboxContainer { get; private set; }
 
         private ExpandableSlider<double, SizeSlider<double>> distanceSpacingSlider;
-        private bool distanceSpacingScrollActive;
+
+        [Resolved(canBeNull: true)]
+        private OnScreenDisplay onScreenDisplay { get; set; }
 
         protected DistancedHitObjectComposer(Ruleset ruleset)
             : base(ruleset)
@@ -43,8 +50,9 @@ namespace osu.Game.Rulesets.Edit
         [BackgroundDependencyLoader]
         private void load()
         {
-            AddInternal(RightSideToolboxContainer = new ExpandingToolboxContainer
+            AddInternal(RightSideToolboxContainer = new ExpandingToolboxContainer(130, 250)
             {
+                Padding = new MarginPadding { Right = 10 },
                 Alpha = DistanceSpacingMultiplier.Disabled ? 0 : 1,
                 Anchor = Anchor.TopRight,
                 Origin = Anchor.TopRight,
@@ -66,45 +74,58 @@ namespace osu.Game.Rulesets.Edit
             if (!DistanceSpacingMultiplier.Disabled)
             {
                 DistanceSpacingMultiplier.Value = EditorBeatmap.BeatmapInfo.DistanceSpacing;
-                DistanceSpacingMultiplier.BindValueChanged(v =>
+                DistanceSpacingMultiplier.BindValueChanged(multiplier =>
                 {
-                    distanceSpacingSlider.ContractedLabelText = $"D. S. ({v.NewValue:0.##x})";
-                    distanceSpacingSlider.ExpandedLabelText = $"Distance Spacing ({v.NewValue:0.##x})";
-                    EditorBeatmap.BeatmapInfo.DistanceSpacing = v.NewValue;
+                    distanceSpacingSlider.ContractedLabelText = $"D. S. ({multiplier.NewValue:0.##x})";
+                    distanceSpacingSlider.ExpandedLabelText = $"Distance Spacing ({multiplier.NewValue:0.##x})";
+
+                    if (multiplier.NewValue != multiplier.OldValue)
+                        onScreenDisplay?.Display(new DistanceSpacingToast(multiplier.NewValue.ToLocalisableString(@"0.##x"), multiplier));
+
+                    EditorBeatmap.BeatmapInfo.DistanceSpacing = multiplier.NewValue;
                 }, true);
             }
         }
 
-        protected override bool OnKeyDown(KeyDownEvent e)
+        public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
         {
-            if (!DistanceSpacingMultiplier.Disabled && e.ControlPressed && e.AltPressed && !e.Repeat)
+            switch (e.Action)
             {
-                RightSideToolboxContainer.Expanded.Value = true;
-                distanceSpacingScrollActive = true;
-                return true;
+                case GlobalAction.EditorIncreaseDistanceSpacing:
+                case GlobalAction.EditorDecreaseDistanceSpacing:
+                    return adjustDistanceSpacing(e.Action, 0.1f);
             }
 
-            return base.OnKeyDown(e);
+            return false;
         }
 
-        protected override void OnKeyUp(KeyUpEvent e)
+        public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
         {
-            if (!DistanceSpacingMultiplier.Disabled && distanceSpacingScrollActive && (!e.AltPressed || !e.ControlPressed))
-            {
-                RightSideToolboxContainer.Expanded.Value = false;
-                distanceSpacingScrollActive = false;
-            }
         }
 
-        protected override bool OnScroll(ScrollEvent e)
+        public bool OnScroll(KeyBindingScrollEvent<GlobalAction> e)
         {
-            if (distanceSpacingScrollActive)
+            switch (e.Action)
             {
-                DistanceSpacingMultiplier.Value += e.ScrollDelta.Y * (e.IsPrecise ? 0.01f : 0.1f);
-                return true;
+                case GlobalAction.EditorIncreaseDistanceSpacing:
+                case GlobalAction.EditorDecreaseDistanceSpacing:
+                    return adjustDistanceSpacing(e.Action, e.ScrollAmount * (e.IsPrecise ? 0.01f : 0.1f));
             }
 
-            return base.OnScroll(e);
+            return false;
+        }
+
+        private bool adjustDistanceSpacing(GlobalAction action, float amount)
+        {
+            if (DistanceSpacingMultiplier.Disabled)
+                return false;
+
+            if (action == GlobalAction.EditorIncreaseDistanceSpacing)
+                DistanceSpacingMultiplier.Value += amount;
+            else if (action == GlobalAction.EditorDecreaseDistanceSpacing)
+                DistanceSpacingMultiplier.Value -= amount;
+
+            return true;
         }
 
         public virtual float GetBeatSnapDistanceAt(HitObject referenceObject)
@@ -124,10 +145,10 @@ namespace osu.Game.Rulesets.Edit
             return distance / GetBeatSnapDistanceAt(referenceObject) * beatLength;
         }
 
-        public virtual double GetSnappedDurationFromDistance(HitObject referenceObject, float distance)
+        public virtual double FindSnappedDuration(HitObject referenceObject, float distance)
             => BeatSnapProvider.SnapTime(referenceObject.StartTime + DistanceToDuration(referenceObject, distance), referenceObject.StartTime) - referenceObject.StartTime;
 
-        public virtual float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance)
+        public virtual float FindSnappedDistance(HitObject referenceObject, float distance)
         {
             double startTime = referenceObject.StartTime;
 
@@ -145,18 +166,25 @@ namespace osu.Game.Rulesets.Edit
             return DurationToDistance(referenceObject, snappedEndTime - startTime);
         }
 
-        protected class ExpandingToolboxContainer : ExpandingContainer
+        private class DistanceSpacingToast : Toast
         {
-            protected override double HoverExpansionDelay => 250;
+            private readonly ValueChangedEvent<double> change;
 
-            public ExpandingToolboxContainer()
-                : base(130, 250)
+            public DistanceSpacingToast(LocalisableString value, ValueChangedEvent<double> change)
+                : base(getAction(change).GetLocalisableDescription(), value, string.Empty)
             {
-                RelativeSizeAxes = Axes.Y;
-                Padding = new MarginPadding { Left = 10 };
-
-                FillFlow.Spacing = new Vector2(10);
+                this.change = change;
             }
+
+            [BackgroundDependencyLoader]
+            private void load(OsuConfigManager config)
+            {
+                ShortcutText.Text = config.LookupKeyBindings(getAction(change)).ToUpper();
+            }
+
+            private static GlobalAction getAction(ValueChangedEvent<double> change) => change.NewValue - change.OldValue > 0
+                ? GlobalAction.EditorIncreaseDistanceSpacing
+                : GlobalAction.EditorDecreaseDistanceSpacing;
         }
     }
 }

osu.Game/Rulesets/Edit/ExpandingToolboxContainer.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Linq;
+using osu.Framework.Graphics;
+using osu.Framework.Input.Events;
+using osu.Game.Graphics.Containers;
+using osuTK;
+
+namespace osu.Game.Rulesets.Edit
+{
+    public class ExpandingToolboxContainer : ExpandingContainer
+    {
+        protected override double HoverExpansionDelay => 250;
+
+        public ExpandingToolboxContainer(float contractedWidth, float expandedWidth)
+            : base(contractedWidth, expandedWidth)
+        {
+            RelativeSizeAxes = Axes.Y;
+
+            FillFlow.Spacing = new Vector2(10);
+        }
+
+        protected override bool ReceivePositionalInputAtSubTree(Vector2 screenSpacePos) => base.ReceivePositionalInputAtSubTree(screenSpacePos) && anyToolboxHovered(screenSpacePos);
+
+        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => base.ReceivePositionalInputAt(screenSpacePos) && anyToolboxHovered(screenSpacePos);
+
+        private bool anyToolboxHovered(Vector2 screenSpacePos) => FillFlow.Children.Any(d => d.ScreenSpaceDrawQuad.Contains(screenSpacePos));
+
+        protected override bool OnMouseDown(MouseDownEvent e) => true;
+
+        protected override bool OnClick(ClickEvent e) => true;
+    }
+}

osu.Game/Rulesets/Edit/HitObjectComposer.cs

@@ -13,7 +13,6 @@ using osu.Framework.Input;
 using osu.Framework.Input.Events;
 using osu.Framework.Logging;
 using osu.Game.Beatmaps;
-using osu.Game.Graphics.Containers;
 using osu.Game.Rulesets.Configuration;
 using osu.Game.Rulesets.Edit.Tools;
 using osu.Game.Rulesets.Mods;
@@ -36,7 +35,6 @@ namespace osu.Game.Rulesets.Edit
     /// Responsible for providing snapping and generally gluing components together.
     /// </summary>
     /// <typeparam name="TObject">The base type of supported objects.</typeparam>
-    [Cached(Type = typeof(IPlacementHandler))]
     public abstract class HitObjectComposer<TObject> : HitObjectComposer, IPlacementHandler
         where TObject : HitObject
     {
@@ -115,8 +113,9 @@ namespace osu.Game.Rulesets.Edit
                                               .WithChild(BlueprintContainer = CreateBlueprintContainer())
                     }
                 },
-                new LeftToolboxFlow
+                new ExpandingToolboxContainer(80, 200)
                 {
+                    Padding = new MarginPadding { Left = 10 },
                     Children = new Drawable[]
                     {
                         new EditorToolboxGroup("toolbox (1-9)")
@@ -362,7 +361,7 @@ namespace osu.Game.Rulesets.Edit
         /// <returns>The most relevant <see cref="Playfield"/>.</returns>
         protected virtual Playfield PlayfieldAtScreenSpacePosition(Vector2 screenSpacePosition) => drawableRulesetWrapper.Playfield;
 
-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
         {
             var playfield = PlayfieldAtScreenSpacePosition(screenSpacePosition);
             double? targetTime = null;
@@ -382,26 +381,13 @@ namespace osu.Game.Rulesets.Edit
         }
 
         #endregion
-
-        private class LeftToolboxFlow : ExpandingButtonContainer
-        {
-            public LeftToolboxFlow()
-                : base(80, 200)
-            {
-                RelativeSizeAxes = Axes.Y;
-                Padding = new MarginPadding { Right = 10 };
-
-                FillFlow.Spacing = new Vector2(10);
-            }
-        }
     }
 
     /// <summary>
     /// A non-generic definition of a HitObject composer class.
     /// Generally used to access certain methods without requiring a generic type for <see cref="HitObjectComposer{T}" />.
     /// </summary>
-    [Cached(typeof(HitObjectComposer))]
-    [Cached(typeof(IPositionSnapProvider))]
+    [Cached]
     public abstract class HitObjectComposer : CompositeDrawable, IPositionSnapProvider
     {
         protected HitObjectComposer()
@@ -428,9 +414,9 @@ namespace osu.Game.Rulesets.Edit
 
         #region IPositionSnapProvider
 
-        public abstract SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition);
+        public abstract SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition);
 
-        public virtual SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition) =>
+        public virtual SnapResult FindSnappedPosition(Vector2 screenSpacePosition) =>
             new SnapResult(screenSpacePosition, null);
 
         #endregion

osu.Game/Rulesets/Edit/IDistanceSnapProvider.cs

@@ -1,16 +1,21 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects;
 
 namespace osu.Game.Rulesets.Edit
 {
+    /// <summary>
+    /// A snap provider which given a reference hit object and proposed distance from it, offers a more correct duration or distance value.
+    /// </summary>
+    [Cached]
     public interface IDistanceSnapProvider : IPositionSnapProvider
     {
         /// <summary>
-        /// The spacing multiplier applied to beat snap distances.
+        /// A multiplier which changes the ratio of distance travelled per time unit.
         /// </summary>
         /// <seealso cref="BeatmapInfo.DistanceSpacing"/>
         IBindable<double> DistanceSpacingMultiplier { get; }
@@ -23,7 +28,7 @@ namespace osu.Game.Rulesets.Edit
         float GetBeatSnapDistanceAt(HitObject referenceObject);
 
         /// <summary>
-        /// Converts a duration to a distance.
+        /// Converts a duration to a distance without applying any snapping.
         /// </summary>
         /// <param name="referenceObject">An object to be used as a reference point for this operation.</param>
         /// <param name="duration">The duration to convert.</param>
@@ -31,7 +36,7 @@ namespace osu.Game.Rulesets.Edit
         float DurationToDistance(HitObject referenceObject, double duration);
 
         /// <summary>
-        /// Converts a distance to a duration.
+        /// Converts a distance to a duration without applying any snapping.
         /// </summary>
         /// <param name="referenceObject">An object to be used as a reference point for this operation.</param>
         /// <param name="distance">The distance to convert.</param>
@@ -39,20 +44,22 @@ namespace osu.Game.Rulesets.Edit
         double DistanceToDuration(HitObject referenceObject, float distance);
 
         /// <summary>
-        /// Converts a distance to a snapped duration.
+        /// Given a distance from the provided hit object, find the valid snapped duration.
         /// </summary>
         /// <param name="referenceObject">An object to be used as a reference point for this operation.</param>
         /// <param name="distance">The distance to convert.</param>
         /// <returns>A value that represents <paramref name="distance"/> as a duration snapped to the closest beat of the timing point.</returns>
-        double GetSnappedDurationFromDistance(HitObject referenceObject, float distance);
+        double FindSnappedDuration(HitObject referenceObject, float distance);
 
         /// <summary>
-        /// Converts an unsnapped distance to a snapped distance.
-        /// The returned distance will always be floored (as to never exceed the provided <paramref name="distance"/>.
+        /// Given a distance from the provided hit object, find the valid snapped distance.
         /// </summary>
         /// <param name="referenceObject">An object to be used as a reference point for this operation.</param>
         /// <param name="distance">The distance to convert.</param>
-        /// <returns>A value that represents <paramref name="distance"/> snapped to the closest beat of the timing point.</returns>
-        float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance);
+        /// <returns>
+        /// A value that represents <paramref name="distance"/> snapped to the closest beat of the timing point.
+        /// The distance will always be less than or equal to the provided <paramref name="distance"/>.
+        /// </returns>
+        float FindSnappedDistance(HitObject referenceObject, float distance);
     }
 }

osu.Game/Rulesets/Edit/IPositionSnapProvider.cs

@@ -1,27 +1,33 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Allocation;
 using osuTK;
 
 namespace osu.Game.Rulesets.Edit
 {
+    /// <summary>
+    /// A snap provider which given a proposed position for a hit object, potentially offers a more correct position and time value inferred from the context of the beatmap.
+    /// Provided values are inferred in an isolated context, without consideration of other nearby hit objects.
+    /// </summary>
+    [Cached]
     public interface IPositionSnapProvider
     {
         /// <summary>
         /// Given a position, find a valid time and position snap.
         /// </summary>
         /// <remarks>
-        /// This call should be equivalent to running <see cref="SnapScreenSpacePositionToValidPosition"/> with any additional logic that can be performed without the time immutability restriction.
+        /// This call should be equivalent to running <see cref="FindSnappedPosition"/> with any additional logic that can be performed without the time immutability restriction.
         /// </remarks>
         /// <param name="screenSpacePosition">The screen-space position to be snapped.</param>
         /// <returns>The time and position post-snapping.</returns>
-        SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition);
+        SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition);
 
         /// <summary>
-        /// Given a position, find a value position snap, restricting time to its input value.
+        /// Given a position, find a valid position snap, without changing the time value.
         /// </summary>
         /// <param name="screenSpacePosition">The screen-space position to be snapped.</param>
         /// <returns>The position post-snapping. Time will always be null.</returns>
-        SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition);
+        SnapResult FindSnappedPosition(Vector2 screenSpacePosition);
     }
 }

osu.Game/Rulesets/Edit/ScrollingToolboxGroup.cs

@@ -1,34 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
-using osu.Game.Graphics.Containers;
-
-namespace osu.Game.Rulesets.Edit
-{
-    public class ScrollingToolboxGroup : EditorToolboxGroup
-    {
-        protected readonly OsuScrollContainer Scroll;
-
-        protected readonly FillFlowContainer FillFlow;
-
-        protected override Container<Drawable> Content { get; }
-
-        public ScrollingToolboxGroup(string title, float scrollAreaHeight)
-            : base(title)
-        {
-            base.Content.Add(Scroll = new OsuScrollContainer
-            {
-                RelativeSizeAxes = Axes.X,
-                Height = scrollAreaHeight,
-                Child = Content = FillFlow = new FillFlowContainer
-                {
-                    RelativeSizeAxes = Axes.X,
-                    AutoSizeAxes = Axes.Y,
-                    Direction = FillDirection.Vertical,
-                },
-            });
-        }
-    }
-}

osu.Game/Rulesets/Objects/SliderPathExtensions.cs

@@ -18,7 +18,7 @@ namespace osu.Game.Rulesets.Objects
         public static void SnapTo<THitObject>(this THitObject hitObject, IDistanceSnapProvider? snapProvider)
             where THitObject : HitObject, IHasPath
         {
-            hitObject.Path.ExpectedDistance.Value = snapProvider?.GetSnappedDistanceFromDistance(hitObject, (float)hitObject.Path.CalculatedDistance) ?? hitObject.Path.CalculatedDistance;
+            hitObject.Path.ExpectedDistance.Value = snapProvider?.FindSnappedDistance(hitObject, (float)hitObject.Path.CalculatedDistance) ?? hitObject.Path.CalculatedDistance;
         }
 
         /// <summary>

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

@@ -486,7 +486,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
                     Vector2 originalPosition = movementBlueprintOriginalPositions[i];
                     var testPosition = originalPosition + distanceTravelled;
 
-                    var positionalResult = snapProvider.SnapScreenSpacePositionToValidPosition(testPosition);
+                    var positionalResult = snapProvider.FindSnappedPosition(testPosition);
 
                     if (positionalResult.ScreenSpacePosition == testPosition) continue;
 
@@ -505,7 +505,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             Vector2 movePosition = movementBlueprintOriginalPositions.First() + distanceTravelled;
 
             // Retrieve a snapped position.
-            var result = snapProvider?.SnapScreenSpacePositionToValidTime(movePosition);
+            var result = snapProvider?.FindSnappedPositionAndTime(movePosition);
 
             if (result == null)
             {

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

@@ -80,7 +80,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             Vector2 normalisedDirection = direction * new Vector2(1f / distance);
             Vector2 snappedPosition = StartPosition + normalisedDirection * radialCount * radius;
 
-            return (snappedPosition, StartTime + SnapProvider.GetSnappedDurationFromDistance(ReferenceObject, (snappedPosition - StartPosition).Length));
+            return (snappedPosition, StartTime + SnapProvider.FindSnappedDuration(ReferenceObject, (snappedPosition - StartPosition).Length));
         }
     }
 }

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

@@ -214,7 +214,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         private void updatePlacementPosition()
         {
-            var snapResult = Composer.SnapScreenSpacePositionToValidTime(inputManager.CurrentState.Mouse.Position);
+            var snapResult = Composer.FindSnappedPositionAndTime(inputManager.CurrentState.Mouse.Position);
 
             // if no time was found from positional snapping, we should still quantize to the beat.
             snapResult.Time ??= Beatmap.SnapTime(EditorClock.CurrentTime, null);

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

@@ -2,10 +2,13 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Layout;
+using osu.Framework.Utils;
 using osuTK;
 
 namespace osu.Game.Screens.Edit.Compose.Components
@@ -72,33 +75,47 @@ namespace osu.Game.Screens.Edit.Compose.Components
             int index = 0;
             float currentPosition = startPosition;
 
-            while ((endPosition - currentPosition) * Math.Sign(step) > 0)
+            // Make lines the same width independent of display resolution.
+            float lineWidth = DrawWidth / ScreenSpaceDrawQuad.Width;
+
+            List<Box> generatedLines = new List<Box>();
+
+            while (Precision.AlmostBigger((endPosition - currentPosition) * Math.Sign(step), 0))
             {
                 var gridLine = new Box
                 {
                     Colour = Colour4.White,
-                    Alpha = index == 0 ? 0.3f : 0.1f,
-                    EdgeSmoothness = new Vector2(0.2f)
+                    Alpha = 0.1f,
                 };
 
                 if (direction == Direction.Horizontal)
                 {
+                    gridLine.Origin = Anchor.CentreLeft;
                     gridLine.RelativeSizeAxes = Axes.X;
-                    gridLine.Height = 1;
+                    gridLine.Height = lineWidth;
                     gridLine.Y = currentPosition;
                 }
                 else
                 {
+                    gridLine.Origin = Anchor.TopCentre;
                     gridLine.RelativeSizeAxes = Axes.Y;
-                    gridLine.Width = 1;
+                    gridLine.Width = lineWidth;
                     gridLine.X = currentPosition;
                 }
 
-                AddInternal(gridLine);
+                generatedLines.Add(gridLine);
 
                 index += 1;
                 currentPosition = startPosition + index * step;
             }
+
+            if (generatedLines.Count == 0)
+                return;
+
+            generatedLines.First().Alpha = 0.3f;
+            generatedLines.Last().Alpha = 0.3f;
+
+            AddRangeInternal(generatedLines);
         }
 
         public Vector2 GetSnappedPosition(Vector2 original)

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

@@ -19,7 +19,6 @@ using osuTK;
 
 namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 {
-    [Cached(typeof(IPositionSnapProvider))]
     [Cached]
     public class Timeline : ZoomableScrollContainer, IPositionSnapProvider
     {
@@ -307,10 +306,10 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
         /// </summary>
         public double VisibleRange => track.Length / Zoom;
 
-        public SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition) =>
+        public SnapResult FindSnappedPosition(Vector2 screenSpacePosition) =>
             new SnapResult(screenSpacePosition, null);
 
-        public SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition) =>
+        public SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition) =>
             new SnapResult(screenSpacePosition, beatSnapProvider.SnapTime(getTimeFromPosition(Content.ToLocalSpace(screenSpacePosition))));
 
         private double getTimeFromPosition(Vector2 localPosition) =>

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

@@ -382,7 +382,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 {
                     OnDragHandled?.Invoke(e);
 
-                    if (timeline.SnapScreenSpacePositionToValidTime(e.ScreenSpaceMousePosition).Time is double time)
+                    if (timeline.FindSnappedPositionAndTime(e.ScreenSpaceMousePosition).Time is double time)
                     {
                         switch (hitObject)
                         {

osu.Game/Screens/Edit/Compose/IPlacementHandler.cs

@@ -1,10 +1,12 @@
 // 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.Game.Rulesets.Objects;
 
 namespace osu.Game.Screens.Edit.Compose
 {
+    [Cached]
     public interface IPlacementHandler
     {
         /// <summary>

osu.Game/Screens/OnlinePlay/DrawableRoomPlaylist.cs

@@ -6,7 +6,10 @@ using System.Linq;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Input.Bindings;
+using osu.Framework.Input.Events;
 using osu.Game.Graphics.Containers;
+using osu.Game.Input.Bindings;
 using osu.Game.Online.Rooms;
 using osuTK;
 
@@ -15,7 +18,7 @@ namespace osu.Game.Screens.OnlinePlay
     /// <summary>
     /// A scrollable list which displays the <see cref="PlaylistItem"/>s in a <see cref="Room"/>.
     /// </summary>
-    public class DrawableRoomPlaylist : OsuRearrangeableListContainer<PlaylistItem>
+    public class DrawableRoomPlaylist : OsuRearrangeableListContainer<PlaylistItem>, IKeyBindingHandler<GlobalAction>
     {
         /// <summary>
         /// The currently-selected item. Selection is visually represented with a border.
@@ -169,5 +172,78 @@ namespace osu.Game.Screens.OnlinePlay
         });
 
         protected virtual DrawableRoomPlaylistItem CreateDrawablePlaylistItem(PlaylistItem item) => new DrawableRoomPlaylistItem(item);
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            // schedules added as the properties may change value while the drawable items haven't been created yet.
+            SelectedItem.BindValueChanged(_ => Scheduler.AddOnce(scrollToSelection));
+            Items.BindCollectionChanged((_, __) => Scheduler.AddOnce(scrollToSelection), true);
+        }
+
+        private void scrollToSelection()
+        {
+            // SelectedItem and ItemMap/drawable items are managed separately,
+            // so if the item can't be unmapped to a drawable, don't try to scroll to it.
+            // best effort is made to not drop any updates, by subscribing to both sources.
+            if (SelectedItem.Value == null || !ItemMap.TryGetValue(SelectedItem.Value, out var drawableItem))
+                return;
+
+            // ScrollIntoView does not handle non-loaded items appropriately, delay scroll until the item finishes loading.
+            // see: https://github.com/ppy/osu-framework/issues/5158
+            if (!drawableItem.IsLoaded)
+                drawableItem.OnLoadComplete += _ => ScrollContainer.ScrollIntoView(drawableItem);
+            else
+                ScrollContainer.ScrollIntoView(drawableItem);
+        }
+
+        #region Key selection logic (shared with BeatmapCarousel and RoomsContainer)
+
+        public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
+        {
+            switch (e.Action)
+            {
+                case GlobalAction.SelectNext:
+                    selectNext(1);
+                    return true;
+
+                case GlobalAction.SelectPrevious:
+                    selectNext(-1);
+                    return true;
+            }
+
+            return false;
+        }
+
+        public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
+        {
+        }
+
+        private void selectNext(int direction)
+        {
+            if (!AllowSelection)
+                return;
+
+            var visibleItems = ListContainer.AsEnumerable().Where(r => r.IsPresent);
+
+            PlaylistItem item;
+
+            if (SelectedItem.Value == null)
+                item = visibleItems.FirstOrDefault()?.Model;
+            else
+            {
+                if (direction < 0)
+                    visibleItems = visibleItems.Reverse();
+
+                item = visibleItems.SkipWhile(r => r.Model != SelectedItem.Value).Skip(1).FirstOrDefault()?.Model;
+            }
+
+            // we already have a valid selection only change selection if we still have a room to switch to.
+            if (item != null)
+                SelectedItem.Value = item;
+        }
+
+        #endregion
     }
 }

osu.Game/Screens/OnlinePlay/FreeModSelectScreen.cs

@@ -16,7 +16,7 @@ namespace osu.Game.Screens.OnlinePlay
         public new Func<Mod, bool> IsValidMod
         {
             get => base.IsValidMod;
-            set => base.IsValidMod = m => m.HasImplementation && m.UserPlayable && value.Invoke(m);
+            set => base.IsValidMod = m => m.UserPlayable && value.Invoke(m);
         }
 
         public FreeModSelectScreen()

osu.Game/Screens/OnlinePlay/Lounge/Components/RoomsContainer.cs

@@ -139,7 +139,7 @@ namespace osu.Game.Screens.OnlinePlay.Lounge.Components
             return base.OnClick(e);
         }
 
-        #region Key selection logic (shared with BeatmapCarousel)
+        #region Key selection logic (shared with BeatmapCarousel and DrawableRoomPlaylist)
 
         public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
         {

osu.Game/Screens/OnlinePlay/Lounge/LoungeSubScreen.cs

@@ -129,7 +129,7 @@ namespace osu.Game.Screens.OnlinePlay.Lounge
                         {
                             RelativeSizeAxes = Axes.X,
                             Height = Header.HEIGHT,
-                            Child = searchTextBox = new SearchTextBox
+                            Child = searchTextBox = new BasicSearchTextBox
                             {
                                 Anchor = Anchor.CentreRight,
                                 Origin = Anchor.CentreRight,

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -604,34 +604,20 @@ namespace osu.Game.Screens.Select
         public void ScrollToSelected(bool immediate = false) =>
             pendingScrollOperation = immediate ? PendingScrollOperation.Immediate : PendingScrollOperation.Standard;
 
-        #region Key / button selection logic
-
-        protected override bool OnKeyDown(KeyDownEvent e)
-        {
-            switch (e.Key)
-            {
-                case Key.Left:
-                    SelectNext(-1);
-                    return true;
-
-                case Key.Right:
-                    SelectNext();
-                    return true;
-            }
-
-            return false;
-        }
+        #region Button selection logic
 
         public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
         {
             switch (e.Action)
             {
                 case GlobalAction.SelectNext:
-                    SelectNext(1, false);
+                case GlobalAction.SelectNextGroup:
+                    SelectNext(1, e.Action == GlobalAction.SelectNextGroup);
                     return true;
 
                 case GlobalAction.SelectPrevious:
-                    SelectNext(-1, false);
+                case GlobalAction.SelectPreviousGroup:
+                    SelectNext(-1, e.Action == GlobalAction.SelectPreviousGroup);
                     return true;
             }
 

osu.Game/Tests/Visual/PlacementBlueprintTestScene.cs

@@ -14,7 +14,6 @@ using osu.Game.Screens.Edit.Compose;
 
 namespace osu.Game.Tests.Visual
 {
-    [Cached(Type = typeof(IPlacementHandler))]
     public abstract class PlacementBlueprintTestScene : OsuManualInputManagerTestScene, IPlacementHandler
     {
         protected readonly Container HitObjectContainer;