Merge branch 'master' into editor-slider-control-point-quick-delete

.gitignore

@@ -334,3 +334,5 @@ inspectcode
 
 # BenchmarkDotNet
 /BenchmarkDotNet.Artifacts
+
+*.GeneratedMSBuildEditorConfig.editorconfig

CodeAnalysis/BannedSymbols.txt

@@ -4,5 +4,6 @@ M:System.ValueType.Equals(System.Object)~System.Boolean;Don't use object.Equals(
 M:System.Nullable`1.Equals(System.Object)~System.Boolean;Use == instead.
 T:System.IComparable;Don't use non-generic IComparable. Use generic version instead.
 M:osu.Framework.Graphics.Sprites.SpriteText.#ctor;Use OsuSpriteText.
+M:osu.Framework.Bindables.IBindableList`1.GetBoundCopy();Fails on iOS. Use manual ctor + BindTo instead. (see https://github.com/mono/mono/issues/19900)
 T:Microsoft.EntityFrameworkCore.Internal.EnumerableExtensions;Don't use internal extension methods.
 T:Microsoft.EntityFrameworkCore.Internal.TypeExtensions;Don't use internal extension methods.

osu.Game.Rulesets.Catch/Objects/Drawables/DrawableCatchHitObject.cs

@@ -62,6 +62,8 @@ namespace osu.Game.Rulesets.Catch.Objects.Drawables
 
     public abstract class DrawableCatchHitObject : DrawableHitObject<CatchHitObject>
     {
+        protected override double InitialLifetimeOffset => HitObject.TimePreempt;
+
         public virtual bool StaysOnPlate => HitObject.CanBePlated;
 
         public float DisplayRadius => DrawSize.X / 2 * Scale.X * HitObject.Scale;

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

@@ -52,7 +52,7 @@ namespace osu.Game.Rulesets.Catch.Replays
                 if (Position > lastCatchFrame.Position)
                     lastCatchFrame.Actions.Add(CatchAction.MoveRight);
                 else if (Position < lastCatchFrame.Position)
-                    Actions.Add(CatchAction.MoveLeft);
+                    lastCatchFrame.Actions.Add(CatchAction.MoveLeft);
             }
         }
 

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

@@ -22,7 +22,7 @@ namespace osu.Game.Rulesets.Taiko.Audio
         private readonly ControlPointInfo controlPoints;
         private readonly Dictionary<double, DrumSample> mappings = new Dictionary<double, DrumSample>();
 
-        private IBindableList<SampleControlPoint> samplePoints;
+        private readonly IBindableList<SampleControlPoint> samplePoints = new BindableList<SampleControlPoint>();
 
         public DrumSampleContainer(ControlPointInfo controlPoints)
         {
@@ -32,7 +32,7 @@ namespace osu.Game.Rulesets.Taiko.Audio
         [BackgroundDependencyLoader]
         private void load()
         {
-            samplePoints = controlPoints.SamplePoints.GetBoundCopy();
+            samplePoints.BindTo(controlPoints.SamplePoints);
             samplePoints.BindCollectionChanged((_, __) => recreateMappings(), true);
         }
 

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

@@ -41,7 +41,7 @@ namespace osu.Game.Tests.Visual.Editing
             AddToggleStep("toggle y", state => selectionBox.CanScaleY = state);
         }
 
-        private void handleScale(Vector2 amount, Anchor reference)
+        private bool handleScale(Vector2 amount, Anchor reference)
         {
             if ((reference & Anchor.y1) == 0)
             {
@@ -58,12 +58,15 @@ namespace osu.Game.Tests.Visual.Editing
                     selectionArea.X += amount.X;
                 selectionArea.Width += directionX * amount.X;
             }
+
+            return true;
         }
 
-        private void handleRotation(float angle)
+        private bool handleRotation(float angle)
         {
             // kinda silly and wrong, but just showing that the drag handles work.
             selectionArea.Rotation += angle;
+            return true;
         }
     }
 }

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

@@ -7,13 +7,14 @@ using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Primitives;
 using osu.Framework.Graphics.Shapes;
-using osu.Framework.Utils;
 using osu.Framework.Testing;
+using osu.Framework.Utils;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Cursor;
 using osu.Game.Screens.Edit.Compose.Components.Timeline;
 using osuTK;
 using osuTK.Graphics;
+using osuTK.Input;
 
 namespace osu.Game.Tests.Visual.Editing
 {
@@ -88,6 +89,7 @@ namespace osu.Game.Tests.Visual.Editing
 
             // Scroll in at 0.25
             AddStep("Move mouse to 0.25x", () => InputManager.MoveMouseTo(new Vector2(scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X, scrollQuad.Centre.Y)));
+            AddStep("Press alt down", () => InputManager.PressKey(Key.AltLeft));
             AddStep("Scroll by 3", () => InputManager.ScrollBy(new Vector2(0, 3)));
             AddAssert("Box not at 0", () => !Precision.AlmostEquals(boxQuad.TopLeft, scrollQuad.TopLeft));
             AddAssert("Box 1/4 at 1/4", () => Precision.AlmostEquals(boxQuad.TopLeft.X + 0.25f * boxQuad.Size.X, scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X));
@@ -96,6 +98,25 @@ namespace osu.Game.Tests.Visual.Editing
             AddStep("Scroll by -3", () => InputManager.ScrollBy(new Vector2(0, -3)));
             AddAssert("Box at 0", () => Precision.AlmostEquals(boxQuad.TopLeft, scrollQuad.TopLeft));
             AddAssert("Box 1/4 at 1/4", () => Precision.AlmostEquals(boxQuad.TopLeft.X + 0.25f * boxQuad.Size.X, scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X));
+            AddStep("Release alt", () => InputManager.ReleaseKey(Key.AltLeft));
+        }
+
+        [Test]
+        public void TestMouseZoomInThenScroll()
+        {
+            reset();
+
+            // Scroll in at 0.25
+            AddStep("Move mouse to 0.25x", () => InputManager.MoveMouseTo(new Vector2(scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X, scrollQuad.Centre.Y)));
+            AddStep("Press alt down", () => InputManager.PressKey(Key.AltLeft));
+            AddStep("Zoom by 3", () => InputManager.ScrollBy(new Vector2(0, 3)));
+            AddStep("Release alt", () => InputManager.ReleaseKey(Key.AltLeft));
+
+            AddStep("Scroll far left", () => InputManager.ScrollBy(new Vector2(0, 30)));
+            AddUntilStep("Scroll is at start", () => Precision.AlmostEquals(scrollQuad.TopLeft.X, boxQuad.TopLeft.X, 1));
+
+            AddStep("Scroll far right", () => InputManager.ScrollBy(new Vector2(0, -300)));
+            AddUntilStep("Scroll is at end", () => Precision.AlmostEquals(scrollQuad.TopRight.X, boxQuad.TopRight.X, 1));
         }
 
         [Test]
@@ -103,6 +124,8 @@ namespace osu.Game.Tests.Visual.Editing
         {
             reset();
 
+            AddStep("Press alt down", () => InputManager.PressKey(Key.AltLeft));
+
             // Scroll in at 0.25
             AddStep("Move mouse to 0.25x", () => InputManager.MoveMouseTo(new Vector2(scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X, scrollQuad.Centre.Y)));
             AddStep("Scroll by 1", () => InputManager.ScrollBy(new Vector2(0, 1)));
@@ -124,6 +147,8 @@ namespace osu.Game.Tests.Visual.Editing
             AddStep("Move mouse to 0.25x", () => InputManager.MoveMouseTo(new Vector2(scrollQuad.TopLeft.X + 0.25f * scrollQuad.Size.X, scrollQuad.Centre.Y)));
             AddStep("Scroll by -1", () => InputManager.ScrollBy(new Vector2(0, -1)));
             AddAssert("Box at 0", () => Precision.AlmostEquals(boxQuad.TopLeft, scrollQuad.TopLeft));
+
+            AddStep("Release alt", () => InputManager.ReleaseKey(Key.AltLeft));
         }
 
         private void reset()

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

@@ -3,8 +3,10 @@
 
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Screens;
 using osu.Framework.Testing;
@@ -227,12 +229,19 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddUntilStep("wait for screen load", () => spectatorScreen.LoadState == LoadState.Loaded);
         }
 
-        internal class TestSpectatorStreamingClient : SpectatorStreamingClient
+        public class TestSpectatorStreamingClient : SpectatorStreamingClient
         {
             public readonly User StreamingUser = new User { Id = 1234, Username = "Test user" };
 
+            public new BindableList<int> PlayingUsers => (BindableList<int>)base.PlayingUsers;
+
             private int beatmapId;
 
+            protected override Task Connect()
+            {
+                return Task.CompletedTask;
+            }
+
             public void StartPlay(int beatmapId)
             {
                 this.beatmapId = beatmapId;

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

@@ -43,7 +43,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
         private Replay replay;
 
-        private IBindableList<int> users;
+        private readonly IBindableList<int> users = new BindableList<int>();
 
         private TestReplayRecorder recorder;
 
@@ -67,7 +67,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         {
             replay = new Replay();
 
-            users = streamingClient.PlayingUsers.GetBoundCopy();
+            users.BindTo(streamingClient.PlayingUsers);
             users.BindCollectionChanged((obj, args) =>
             {
                 switch (args.Action)

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

@@ -0,0 +1,66 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Linq;
+using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Testing;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.Spectator;
+using osu.Game.Overlays.Dashboard;
+using osu.Game.Tests.Visual.Gameplay;
+using osu.Game.Users;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    public class TestSceneCurrentlyPlayingDisplay : OsuTestScene
+    {
+        [Cached(typeof(SpectatorStreamingClient))]
+        private TestSceneSpectator.TestSpectatorStreamingClient testSpectatorStreamingClient = new TestSceneSpectator.TestSpectatorStreamingClient();
+
+        private CurrentlyPlayingDisplay currentlyPlaying;
+
+        private DummyAPIAccess dummyAPI => (DummyAPIAccess)API;
+
+        [SetUpSteps]
+        public void SetUpSteps()
+        {
+            AddStep("register request handling", () => dummyAPI.HandleRequest = req =>
+            {
+                switch (req)
+                {
+                    case GetUserRequest cRequest:
+                        cRequest.TriggerSuccess(new User { Username = "peppy", Id = 2 });
+                        break;
+                }
+            });
+
+            AddStep("add streaming client", () =>
+            {
+                Remove(testSpectatorStreamingClient);
+
+                Children = new Drawable[]
+                {
+                    testSpectatorStreamingClient,
+                    currentlyPlaying = new CurrentlyPlayingDisplay
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                    }
+                };
+            });
+
+            AddStep("Reset players", () => testSpectatorStreamingClient.PlayingUsers.Clear());
+        }
+
+        [Test]
+        public void TestBasicDisplay()
+        {
+            AddStep("Add playing user", () => testSpectatorStreamingClient.PlayingUsers.Add(2));
+            AddUntilStep("Panel loaded", () => currentlyPlaying.ChildrenOfType<UserGridPanel>()?.FirstOrDefault()?.User.Id == 2);
+            AddStep("Remove playing user", () => testSpectatorStreamingClient.PlayingUsers.Remove(2));
+            AddUntilStep("Panel no longer present", () => !currentlyPlaying.ChildrenOfType<UserGridPanel>().Any());
+        }
+    }
+}

osu.Game/Configuration/OsuConfigManager.cs

@@ -42,6 +42,8 @@ namespace osu.Game.Configuration
             Set(OsuSetting.Username, string.Empty);
             Set(OsuSetting.Token, string.Empty);
 
+            Set(OsuSetting.AutomaticallyDownloadWhenSpectating, false);
+
             Set(OsuSetting.SavePassword, false).ValueChanged += enabled =>
             {
                 if (enabled.NewValue) Set(OsuSetting.SaveUsername, true);
@@ -132,6 +134,8 @@ namespace osu.Game.Configuration
 
             Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Skin);
             Set(OsuSetting.SeasonalBackgroundMode, SeasonalBackgroundMode.Sometimes);
+
+            Set(OsuSetting.EditorWaveformOpacity, 1f);
         }
 
         public OsuConfigManager(Storage storage)
@@ -241,6 +245,8 @@ namespace osu.Game.Configuration
         HitLighting,
         MenuBackgroundSource,
         GameplayDisableWinKey,
-        SeasonalBackgroundMode
+        SeasonalBackgroundMode,
+        EditorWaveformOpacity,
+        AutomaticallyDownloadWhenSpectating,
     }
 }

osu.Game/Online/Spectator/SpectatorStreamingClient.cs

@@ -93,14 +93,14 @@ namespace osu.Game.Online.Spectator
                     break;
 
                 case APIState.Online:
-                    Task.Run(connect);
+                    Task.Run(Connect);
                     break;
             }
         }
 
         private const string endpoint = "https://spectator.ppy.sh/spectator";
 
-        private async Task connect()
+        protected virtual async Task Connect()
         {
             if (connection != null)
                 return;

osu.Game/Overlays/Dashboard/CurrentlyPlayingDisplay.cs

@@ -0,0 +1,132 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Specialized;
+using System.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Screens;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.Spectator;
+using osu.Game.Screens.Multi.Match.Components;
+using osu.Game.Screens.Play;
+using osu.Game.Users;
+using osuTK;
+
+namespace osu.Game.Overlays.Dashboard
+{
+    internal class CurrentlyPlayingDisplay : CompositeDrawable
+    {
+        private readonly IBindableList<int> playingUsers = new BindableList<int>();
+
+        private FillFlowContainer<PlayingUserPanel> userFlow;
+
+        [Resolved]
+        private SpectatorStreamingClient spectatorStreaming { get; set; }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChild = userFlow = new FillFlowContainer<PlayingUserPanel>
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y,
+                Spacing = new Vector2(10),
+            };
+        }
+
+        [Resolved]
+        private IAPIProvider api { get; set; }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            playingUsers.BindTo(spectatorStreaming.PlayingUsers);
+            playingUsers.BindCollectionChanged((sender, e) => Schedule(() =>
+            {
+                switch (e.Action)
+                {
+                    case NotifyCollectionChangedAction.Add:
+                        foreach (var u in e.NewItems.OfType<int>())
+                        {
+                            var request = new GetUserRequest(u);
+                            request.Success += user => Schedule(() =>
+                            {
+                                if (playingUsers.Contains((int)user.Id))
+                                    userFlow.Add(createUserPanel(user));
+                            });
+                            api.Queue(request);
+                        }
+
+                        break;
+
+                    case NotifyCollectionChangedAction.Remove:
+                        foreach (var u in e.OldItems.OfType<int>())
+                            userFlow.FirstOrDefault(card => card.User.Id == u)?.Expire();
+                        break;
+
+                    case NotifyCollectionChangedAction.Reset:
+                        userFlow.Clear();
+                        break;
+                }
+            }), true);
+        }
+
+        private PlayingUserPanel createUserPanel(User user) =>
+            new PlayingUserPanel(user).With(panel =>
+            {
+                panel.Anchor = Anchor.TopCentre;
+                panel.Origin = Anchor.TopCentre;
+            });
+
+        private class PlayingUserPanel : CompositeDrawable
+        {
+            public readonly User User;
+
+            [Resolved(canBeNull: true)]
+            private OsuGame game { get; set; }
+
+            public PlayingUserPanel(User user)
+            {
+                User = user;
+
+                AutoSizeAxes = Axes.Both;
+
+                InternalChildren = new Drawable[]
+                {
+                    new FillFlowContainer
+                    {
+                        AutoSizeAxes = Axes.Y,
+                        Direction = FillDirection.Vertical,
+                        Spacing = new Vector2(2),
+                        Width = 290,
+                        Children = new Drawable[]
+                        {
+                            new UserGridPanel(user)
+                            {
+                                RelativeSizeAxes = Axes.X,
+                                Anchor = Anchor.TopCentre,
+                                Origin = Anchor.TopCentre,
+                            },
+                            new PurpleTriangleButton
+                            {
+                                RelativeSizeAxes = Axes.X,
+                                Text = "Watch",
+                                Anchor = Anchor.TopCentre,
+                                Origin = Anchor.TopCentre,
+                                Action = () => game?.PerformFromScreen(s => s.Push(new Spectator(user)))
+                            }
+                        }
+                    },
+                };
+            }
+        }
+    }
+}

osu.Game/Overlays/Dashboard/DashboardOverlayHeader.cs

@@ -1,6 +1,8 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.ComponentModel;
+
 namespace osu.Game.Overlays.Dashboard
 {
     public class DashboardOverlayHeader : TabControlOverlayHeader<DashboardOverlayTabs>
@@ -20,6 +22,9 @@ namespace osu.Game.Overlays.Dashboard
 
     public enum DashboardOverlayTabs
     {
-        Friends
+        Friends,
+
+        [Description("Currently Playing")]
+        CurrentlyPlaying
     }
 }

osu.Game/Overlays/DashboardOverlay.cs

@@ -130,6 +130,11 @@ namespace osu.Game.Overlays
                     loadDisplay(new FriendDisplay());
                     break;
 
+                case DashboardOverlayTabs.CurrentlyPlaying:
+                    //todo: enable once caching logic is better
+                    //loadDisplay(new CurrentlyPlayingDisplay());
+                    break;
+
                 default:
                     throw new NotImplementedException($"Display for {tab.NewValue} tab is not implemented");
             }

osu.Game/Overlays/Settings/Sections/Online/WebSettings.cs

@@ -27,6 +27,12 @@ namespace osu.Game.Overlays.Settings.Sections.Online
                     Keywords = new[] { "no-video" },
                     Current = config.GetBindable<bool>(OsuSetting.PreferNoVideo)
                 },
+                new SettingsCheckbox
+                {
+                    LabelText = "Automatically download beatmaps when spectating",
+                    Keywords = new[] { "spectator" },
+                    Current = config.GetBindable<bool>(OsuSetting.AutomaticallyDownloadWhenSpectating),
+                },
             };
         }
     }

osu.Game/Overlays/TabControlOverlayHeader.cs

@@ -1,9 +1,11 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
@@ -104,7 +106,7 @@ namespace osu.Game.Overlays
                 public OverlayHeaderTabItem(T value)
                     : base(value)
                 {
-                    Text.Text = value.ToString().ToLower();
+                    Text.Text = ((Value as Enum)?.GetDescription() ?? Value.ToString()).ToLower();
                     Text.Font = OsuFont.GetFont(size: 14);
                     Text.Margin = new MarginPadding { Vertical = 16.5f }; // 15px padding + 1.5px line-height difference compensation
                     Bar.Margin = new MarginPadding { Bottom = bar_height };

osu.Game/Screens/Edit/Components/Menus/EditorMenuBar.cs

@@ -163,30 +163,27 @@ namespace osu.Game.Screens.Edit.Components.Menus
 
             protected override Framework.Graphics.UserInterface.Menu CreateSubMenu() => new SubMenu();
 
-            protected override DrawableMenuItem CreateDrawableMenuItem(MenuItem item) => new DrawableSubMenuItem(item);
+            protected override DrawableMenuItem CreateDrawableMenuItem(MenuItem item)
-
-            private class DrawableSubMenuItem : DrawableOsuMenuItem
             {
-                public DrawableSubMenuItem(MenuItem item)
+                switch (item)
+                {
+                    case EditorMenuItemSpacer spacer:
+                        return new DrawableSpacer(spacer);
+                }
+
+                return base.CreateDrawableMenuItem(item);
+            }
+
+            private class DrawableSpacer : DrawableOsuMenuItem
+            {
+                public DrawableSpacer(MenuItem item)
                     : base(item)
                 {
                 }
 
-                protected override bool OnHover(HoverEvent e)
+                protected override bool OnHover(HoverEvent e) => true;
-                {
-                    if (Item is EditorMenuItemSpacer)
-                        return true;
 
-                    return base.OnHover(e);
+                protected override bool OnClick(ClickEvent e) => true;
-                }
-
-                protected override bool OnClick(ClickEvent e)
-                {
-                    if (Item is EditorMenuItemSpacer)
-                        return true;
-
-                    return base.OnClick(e);
-                }
             }
         }
     }

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

@@ -14,13 +14,13 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     /// </summary>
     public class ControlPointPart : TimelinePart<GroupVisualisation>
     {
-        private IBindableList<ControlPointGroup> controlPointGroups;
+        private readonly IBindableList<ControlPointGroup> controlPointGroups = new BindableList<ControlPointGroup>();
 
         protected override void LoadBeatmap(WorkingBeatmap beatmap)
         {
             base.LoadBeatmap(beatmap);
 
-            controlPointGroups = beatmap.Beatmap.ControlPointInfo.Groups.GetBoundCopy();
+            controlPointGroups.BindTo(beatmap.Beatmap.ControlPointInfo.Groups);
             controlPointGroups.BindCollectionChanged((sender, args) =>
             {
                 switch (args.Action)

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

@@ -15,7 +15,7 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
     {
         public readonly ControlPointGroup Group;
 
-        private BindableList<ControlPoint> controlPoints;
+        private readonly IBindableList<ControlPoint> controlPoints = new BindableList<ControlPoint>();
 
         [Resolved]
         private OsuColour colours { get; set; }
@@ -30,7 +30,7 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
         {
             base.LoadComplete();
 
-            controlPoints = (BindableList<ControlPoint>)Group.ControlPoints.GetBoundCopy();
+            controlPoints.BindTo(Group.ControlPoints);
             controlPoints.BindCollectionChanged((_, __) =>
             {
                 if (controlPoints.Count == 0)

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

@@ -7,17 +7,19 @@ using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Sprites;
+using osu.Framework.Input.Events;
 using osu.Game.Graphics;
 using osuTK;
+using osuTK.Input;
 
 namespace osu.Game.Screens.Edit.Compose.Components
 {
     public class SelectionBox : CompositeDrawable
     {
-        public Action<float> OnRotation;
+        public Func<float, bool> OnRotation;
-        public Action<Vector2, Anchor> OnScale;
+        public Func<Vector2, Anchor, bool> OnScale;
-        public Action<Direction> OnFlip;
+        public Func<Direction, bool> OnFlip;
-        public Action OnReverse;
+        public Func<bool> OnReverse;
 
         public Action OperationStarted;
         public Action OperationEnded;
@@ -105,6 +107,26 @@ namespace osu.Game.Screens.Edit.Compose.Components
             recreate();
         }
 
+        protected override bool OnKeyDown(KeyDownEvent e)
+        {
+            if (e.Repeat || !e.ControlPressed)
+                return false;
+
+            switch (e.Key)
+            {
+                case Key.G:
+                    return CanReverse && OnReverse?.Invoke() == true;
+
+                case Key.H:
+                    return CanScaleX && OnFlip?.Invoke(Direction.Horizontal) == true;
+
+                case Key.J:
+                    return CanScaleY && OnFlip?.Invoke(Direction.Vertical) == true;
+            }
+
+            return base.OnKeyDown(e);
+        }
+
         private void recreate()
         {
             if (LoadState < LoadState.Loading)
@@ -143,7 +165,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             if (CanScaleX && CanScaleY) addFullScaleComponents();
             if (CanScaleY) addYScaleComponents();
             if (CanRotate) addRotationComponents();
-            if (CanReverse) addButton(FontAwesome.Solid.Backward, "Reverse pattern", () => OnReverse?.Invoke());
+            if (CanReverse) addButton(FontAwesome.Solid.Backward, "Reverse pattern (Ctrl-G)", () => OnReverse?.Invoke());
         }
 
         private void addRotationComponents()
@@ -178,7 +200,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         private void addYScaleComponents()
         {
-            addButton(FontAwesome.Solid.ArrowsAltV, "Flip vertically", () => OnFlip?.Invoke(Direction.Vertical));
+            addButton(FontAwesome.Solid.ArrowsAltV, "Flip vertically (Ctrl-J)", () => OnFlip?.Invoke(Direction.Vertical));
 
             addDragHandle(Anchor.TopCentre);
             addDragHandle(Anchor.BottomCentre);
@@ -194,7 +216,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         private void addXScaleComponents()
         {
-            addButton(FontAwesome.Solid.ArrowsAltH, "Flip horizontally", () => OnFlip?.Invoke(Direction.Horizontal));
+            addButton(FontAwesome.Solid.ArrowsAltH, "Flip horizontally (Ctrl-H)", () => OnFlip?.Invoke(Direction.Horizontal));
 
             addDragHandle(Anchor.CentreLeft);
             addDragHandle(Anchor.CentreRight);

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

@@ -99,10 +99,10 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 OperationStarted = OnOperationBegan,
                 OperationEnded = OnOperationEnded,
 
-                OnRotation = angle => HandleRotation(angle),
+                OnRotation = HandleRotation,
-                OnScale = (amount, anchor) => HandleScale(amount, anchor),
+                OnScale = HandleScale,
-                OnFlip = direction => HandleFlip(direction),
+                OnFlip = HandleFlip,
-                OnReverse = () => HandleReverse(),
+                OnReverse = HandleReverse,
             };
 
         /// <summary>

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

@@ -11,6 +11,7 @@ using osu.Framework.Graphics.Audio;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Input.Events;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Graphics;
 using osu.Game.Rulesets.Edit;
 using osuTK;
@@ -67,8 +68,10 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
         private TimelineControlPointDisplay controlPoints;
 
+        private Bindable<float> waveformOpacity;
+
         [BackgroundDependencyLoader]
-        private void load(IBindable<WorkingBeatmap> beatmap, OsuColour colours)
+        private void load(IBindable<WorkingBeatmap> beatmap, OsuColour colours, OsuConfigManager config)
         {
             AddRange(new Drawable[]
             {
@@ -95,7 +98,10 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             // We don't want the centre marker to scroll
             AddInternal(new CentreMarker { Depth = float.MaxValue });
 
-            WaveformVisible.ValueChanged += visible => waveform.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
+            waveformOpacity = config.GetBindable<float>(OsuSetting.EditorWaveformOpacity);
+            waveformOpacity.BindValueChanged(_ => updateWaveformOpacity(), true);
+
+            WaveformVisible.ValueChanged += _ => updateWaveformOpacity();
             ControlPointsVisible.ValueChanged += visible => controlPoints.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
             TicksVisible.ValueChanged += visible => ticks.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
 
@@ -115,6 +121,9 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             }, true);
         }
 
+        private void updateWaveformOpacity() =>
+            waveform.FadeTo(WaveformVisible.Value ? waveformOpacity.Value : 0, 200, Easing.OutQuint);
+
         private float getZoomLevelForVisibleMilliseconds(double milliseconds) => Math.Max(1, (float)(track.Length / milliseconds));
 
         protected override void Update()
@@ -165,6 +174,11 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             if (!track.IsLoaded || track.Length == 0)
                 return;
 
+            // covers the case where the user starts playback after a drag is in progress.
+            // we want to ensure the clock is always stopped during drags to avoid weird audio playback.
+            if (handlingDragInput)
+                editorClock.Stop();
+
             ScrollTo((float)(editorClock.CurrentTime / track.Length) * Content.DrawWidth, false);
         }
 

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

@@ -16,7 +16,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
     /// </summary>
     public class TimelineControlPointDisplay : TimelinePart<TimelineControlPointGroup>
     {
-        private IBindableList<ControlPointGroup> controlPointGroups;
+        private readonly IBindableList<ControlPointGroup> controlPointGroups = new BindableList<ControlPointGroup>();
 
         public TimelineControlPointDisplay()
         {
@@ -27,7 +27,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
         {
             base.LoadBeatmap(beatmap);
 
-            controlPointGroups = beatmap.Beatmap.ControlPointInfo.Groups.GetBoundCopy();
+            controlPointGroups.BindTo(beatmap.Beatmap.ControlPointInfo.Groups);
             controlPointGroups.BindCollectionChanged((sender, args) =>
             {
                 switch (args.Action)

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

@@ -14,7 +14,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
     {
         public readonly ControlPointGroup Group;
 
-        private BindableList<ControlPoint> controlPoints;
+        private readonly IBindableList<ControlPoint> controlPoints = new BindableList<ControlPoint>();
 
         [Resolved]
         private OsuColour colours { get; set; }
@@ -34,7 +34,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
         {
             base.LoadComplete();
 
-            controlPoints = (BindableList<ControlPoint>)Group.ControlPoints.GetBoundCopy();
+            controlPoints.BindTo(Group.ControlPoints);
             controlPoints.BindCollectionChanged((_, __) =>
             {
                 ClearInternal();

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

@@ -113,19 +113,19 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
         protected override bool OnScroll(ScrollEvent e)
         {
-            if (e.IsPrecise)
+            if (e.AltPressed)
             {
-                // can't handle scroll correctly while playing.
+                // zoom when holding alt.
-                // the editor will handle this case for us.
+                setZoomTarget(zoomTarget + e.ScrollDelta.Y, zoomedContent.ToLocalSpace(e.ScreenSpaceMousePosition).X);
-                if (editorClock?.IsRunning == true)
+                return true;
-                    return false;
-
-                // for now, we don't support zoom when using a precision scroll device. this needs gesture support.
-                return base.OnScroll(e);
             }
 
-            setZoomTarget(zoomTarget + e.ScrollDelta.Y, zoomedContent.ToLocalSpace(e.ScreenSpaceMousePosition).X);
+            // can't handle scroll correctly while playing.
-            return true;
+            // the editor will handle this case for us.
+            if (editorClock?.IsRunning == true)
+                return false;
+
+            return base.OnScroll(e);
         }
 
         private void updateZoomedContentWidth() => zoomedContent.Width = DrawWidth * currentZoom;

osu.Game/Screens/Edit/Editor.cs

@@ -20,6 +20,7 @@ using osu.Framework.Platform;
 using osu.Framework.Screens;
 using osu.Framework.Timing;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Cursor;
 using osu.Game.Graphics.UserInterface;
@@ -103,7 +104,7 @@ namespace osu.Game.Screens.Edit
         private MusicController music { get; set; }
 
         [BackgroundDependencyLoader]
-        private void load(OsuColour colours, GameHost host)
+        private void load(OsuColour colours, GameHost host, OsuConfigManager config)
         {
             beatDivisor.Value = Beatmap.Value.BeatmapInfo.BeatDivisor;
             beatDivisor.BindValueChanged(divisor => Beatmap.Value.BeatmapInfo.BeatDivisor = divisor.NewValue);
@@ -208,6 +209,13 @@ namespace osu.Game.Screens.Edit
                                         copyMenuItem = new EditorMenuItem("Copy", MenuItemType.Standard, Copy),
                                         pasteMenuItem = new EditorMenuItem("Paste", MenuItemType.Standard, Paste),
                                     }
+                                },
+                                new MenuItem("View")
+                                {
+                                    Items = new[]
+                                    {
+                                        new WaveformOpacityMenu(config)
+                                    }
                                 }
                             }
                         }

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

@@ -98,7 +98,7 @@ namespace osu.Game.Screens.Edit.Timing
 
         private class ControlGroupAttributes : CompositeDrawable
         {
-            private readonly IBindableList<ControlPoint> controlPoints;
+            private readonly IBindableList<ControlPoint> controlPoints = new BindableList<ControlPoint>();
 
             private readonly FillFlowContainer fill;
 
@@ -112,7 +112,7 @@ namespace osu.Game.Screens.Edit.Timing
                     Spacing = new Vector2(2)
                 };
 
-                controlPoints = group.ControlPoints.GetBoundCopy();
+                controlPoints.BindTo(group.ControlPoints);
             }
 
             [Resolved]

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

@@ -56,7 +56,7 @@ namespace osu.Game.Screens.Edit.Timing
             private OsuButton deleteButton;
             private ControlPointTable table;
 
-            private IBindableList<ControlPointGroup> controlGroups;
+            private readonly IBindableList<ControlPointGroup> controlPointGroups = new BindableList<ControlPointGroup>();
 
             [Resolved]
             private EditorClock clock { get; set; }
@@ -124,11 +124,10 @@ namespace osu.Game.Screens.Edit.Timing
 
                 selectedGroup.BindValueChanged(selected => { deleteButton.Enabled.Value = selected.NewValue != null; }, true);
 
-                controlGroups = Beatmap.Value.Beatmap.ControlPointInfo.Groups.GetBoundCopy();
+                controlPointGroups.BindTo(Beatmap.Value.Beatmap.ControlPointInfo.Groups);
-
+                controlPointGroups.BindCollectionChanged((sender, args) =>
-                controlGroups.BindCollectionChanged((sender, args) =>
                 {
-                    table.ControlGroups = controlGroups;
+                    table.ControlGroups = controlPointGroups;
                     changeHandler.SaveState();
                 }, true);
             }

osu.Game/Screens/Edit/WaveformOpacityMenu.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.Collections.Generic;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics.UserInterface;
+using osu.Game.Configuration;
+using osu.Game.Graphics.UserInterface;
+
+namespace osu.Game.Screens.Edit
+{
+    internal class WaveformOpacityMenu : MenuItem
+    {
+        private readonly Bindable<float> waveformOpacity;
+
+        private readonly Dictionary<float, ToggleMenuItem> menuItemLookup = new Dictionary<float, ToggleMenuItem>();
+
+        public WaveformOpacityMenu(OsuConfigManager config)
+            : base("Waveform opacity")
+        {
+            Items = new[]
+            {
+                createMenuItem(0.25f),
+                createMenuItem(0.5f),
+                createMenuItem(0.75f),
+                createMenuItem(1f),
+            };
+
+            waveformOpacity = config.GetBindable<float>(OsuSetting.EditorWaveformOpacity);
+            waveformOpacity.BindValueChanged(opacity =>
+            {
+                foreach (var kvp in menuItemLookup)
+                    kvp.Value.State.Value = kvp.Key == opacity.NewValue;
+            }, true);
+        }
+
+        private ToggleMenuItem createMenuItem(float opacity)
+        {
+            var item = new ToggleMenuItem($"{opacity * 100}%", MenuItemType.Standard, _ => updateOpacity(opacity));
+            menuItemLookup[opacity] = item;
+            return item;
+        }
+
+        private void updateOpacity(float opacity) => waveformOpacity.Value = opacity;
+    }
+}

osu.Game/Screens/Play/Spectator.cs

@@ -9,20 +9,26 @@ 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.Screens;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
 using osu.Game.Online.Spectator;
 using osu.Game.Overlays.BeatmapListing.Panels;
+using osu.Game.Overlays.Settings;
 using osu.Game.Replays;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Replays;
 using osu.Game.Rulesets.Replays.Types;
 using osu.Game.Scoring;
+using osu.Game.Screens.Multi.Match.Components;
 using osu.Game.Users;
 using osuTK;
 
@@ -63,6 +69,12 @@ namespace osu.Game.Screens.Play
 
         private IBindable<WeakReference<BeatmapSetInfo>> managerUpdated;
 
+        private TriangleButton watchButton;
+
+        private SettingsCheckbox automaticDownload;
+
+        private BeatmapSetInfo onlineBeatmap;
+
         /// <summary>
         /// Becomes true if a new state is waiting to be loaded (while this screen was not active).
         /// </summary>
@@ -74,47 +86,91 @@ namespace osu.Game.Screens.Play
         }
 
         [BackgroundDependencyLoader]
-        private void load()
+        private void load(OsuColour colours, OsuConfigManager config)
         {
-            InternalChildren = new Drawable[]
+            InternalChild = new Container
             {
-                new FillFlowContainer
+                Masking = true,
+                CornerRadius = 20,
+                AutoSizeAxes = Axes.Both,
+                AutoSizeDuration = 500,
+                AutoSizeEasing = Easing.OutQuint,
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Children = new Drawable[]
                 {
-                    AutoSizeAxes = Axes.Both,
+                    new Box
-                    Direction = FillDirection.Vertical,
-                    Anchor = Anchor.Centre,
-                    Origin = Anchor.Centre,
-                    Spacing = new Vector2(15),
-                    Children = new Drawable[]
                     {
-                        new OsuSpriteText
+                        Colour = colours.GreySeafoamDark,
+                        RelativeSizeAxes = Axes.Both,
+                    },
+                    new FillFlowContainer
+                    {
+                        Margin = new MarginPadding(20),
+                        AutoSizeAxes = Axes.Both,
+                        Direction = FillDirection.Vertical,
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        Spacing = new Vector2(15),
+                        Children = new Drawable[]
                         {
-                            Text = "Currently spectating",
+                            new OsuSpriteText
-                            Font = OsuFont.Default.With(size: 30),
+                            {
-                            Anchor = Anchor.Centre,
+                                Text = "Spectator Mode",
-                            Origin = Anchor.Centre,
+                                Font = OsuFont.Default.With(size: 30),
-                        },
+                                Anchor = Anchor.Centre,
-                        new UserGridPanel(targetUser)
+                                Origin = Anchor.Centre,
-                        {
+                            },
-                            Width = 290,
+                            new FillFlowContainer
-                            Anchor = Anchor.Centre,
+                            {
-                            Origin = Anchor.Centre,
+                                AutoSizeAxes = Axes.Both,
-                        },
+                                Direction = FillDirection.Horizontal,
-                        new OsuSpriteText
+                                Anchor = Anchor.Centre,
-                        {
+                                Origin = Anchor.Centre,
-                            Text = "playing",
+                                Spacing = new Vector2(15),
-                            Font = OsuFont.Default.With(size: 30),
+                                Children = new Drawable[]
-                            Anchor = Anchor.Centre,
+                                {
-                            Origin = Anchor.Centre,
+                                    new UserGridPanel(targetUser)
-                        },
+                                    {
-                        beatmapPanelContainer = new Container
+                                        Anchor = Anchor.CentreLeft,
-                        {
+                                        Origin = Anchor.CentreLeft,
-                            AutoSizeAxes = Axes.Both,
+                                        Height = 145,
-                            Anchor = Anchor.Centre,
+                                        Width = 290,
-                            Origin = Anchor.Centre,
+                                    },
-                        },
+                                    new SpriteIcon
+                                    {
+                                        Size = new Vector2(40),
+                                        Icon = FontAwesome.Solid.ArrowRight,
+                                        Anchor = Anchor.CentreLeft,
+                                        Origin = Anchor.CentreLeft,
+                                    },
+                                    beatmapPanelContainer = new Container
+                                    {
+                                        AutoSizeAxes = Axes.Both,
+                                        Anchor = Anchor.CentreLeft,
+                                        Origin = Anchor.CentreLeft,
+                                    },
+                                }
+                            },
+                            automaticDownload = new SettingsCheckbox
+                            {
+                                LabelText = "Automatically download beatmaps",
+                                Current = config.GetBindable<bool>(OsuSetting.AutomaticallyDownloadWhenSpectating),
+                                Anchor = Anchor.Centre,
+                                Origin = Anchor.Centre,
+                            },
+                            watchButton = new PurpleTriangleButton
+                            {
+                                Text = "Start Watching",
+                                Width = 250,
+                                Anchor = Anchor.Centre,
+                                Origin = Anchor.Centre,
+                                Action = attemptStart,
+                                Enabled = { Value = false }
+                            }
+                        }
                     }
-                },
+                }
             };
         }
 
@@ -130,12 +186,14 @@ namespace osu.Game.Screens.Play
 
             managerUpdated = beatmaps.ItemUpdated.GetBoundCopy();
             managerUpdated.BindValueChanged(beatmapUpdated);
+
+            automaticDownload.Current.BindValueChanged(_ => checkForAutomaticDownload());
         }
 
         private void beatmapUpdated(ValueChangedEvent<WeakReference<BeatmapSetInfo>> beatmap)
         {
             if (beatmap.NewValue.TryGetTarget(out var beatmapSet) && beatmapSet.Beatmaps.Any(b => b.OnlineBeatmapID == state.BeatmapID))
-                attemptStart();
+                Schedule(attemptStart);
         }
 
         private void userSentFrames(int userId, FrameDataBundle data)
@@ -189,14 +247,26 @@ namespace osu.Game.Screens.Play
             if (userId != targetUser.Id)
                 return;
 
-            if (replay == null) return;
+            if (replay != null)
+            {
+                replay.HasReceivedAllFrames = true;
+                replay = null;
+            }
 
-            replay.HasReceivedAllFrames = true;
+            Schedule(clearDisplay);
-            replay = null;
+        }
+
+        private void clearDisplay()
+        {
+            watchButton.Enabled.Value = false;
+            beatmapPanelContainer.Clear();
         }
 
         private void attemptStart()
         {
+            clearDisplay();
+            showBeatmapPanel(state);
+
             var resolvedRuleset = rulesets.AvailableRulesets.FirstOrDefault(r => r.ID == state.RulesetID)?.CreateInstance();
 
             // ruleset not available
@@ -210,7 +280,6 @@ namespace osu.Game.Screens.Play
 
             if (resolvedBeatmap == null)
             {
-                showBeatmapPanel(state.BeatmapID.Value);
                 return;
             }
 
@@ -228,6 +297,7 @@ namespace osu.Game.Screens.Play
             rulesetInstance = resolvedRuleset;
 
             beatmap.Value = beatmaps.GetWorkingBeatmap(resolvedBeatmap);
+            watchButton.Enabled.Value = true;
 
             this.Push(new SpectatorPlayerLoader(new Score
             {
@@ -236,17 +306,43 @@ namespace osu.Game.Screens.Play
             }));
         }
 
-        private void showBeatmapPanel(int beatmapId)
+        private void showBeatmapPanel(SpectatorState state)
         {
-            var req = new GetBeatmapSetRequest(beatmapId, BeatmapSetLookupType.BeatmapId);
+            if (state?.BeatmapID == null)
+            {
+                beatmapPanelContainer.Clear();
+                onlineBeatmap = null;
+                return;
+            }
+
+            var req = new GetBeatmapSetRequest(state.BeatmapID.Value, BeatmapSetLookupType.BeatmapId);
             req.Success += res => Schedule(() =>
             {
-                beatmapPanelContainer.Child = new GridBeatmapPanel(res.ToBeatmapSet(rulesets));
+                if (state != this.state)
+                    return;
+
+                onlineBeatmap = res.ToBeatmapSet(rulesets);
+                beatmapPanelContainer.Child = new GridBeatmapPanel(onlineBeatmap);
+                checkForAutomaticDownload();
             });
 
             api.Queue(req);
         }
 
+        private void checkForAutomaticDownload()
+        {
+            if (onlineBeatmap == null)
+                return;
+
+            if (!automaticDownload.Current.Value)
+                return;
+
+            if (beatmaps.IsAvailableLocally(onlineBeatmap))
+                return;
+
+            beatmaps.Download(onlineBeatmap);
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);

osu.Game/Screens/Play/SpectatorPlayer.cs

@@ -3,33 +3,60 @@
 
 using System.Linq;
 using osu.Framework.Allocation;
+using osu.Framework.Graphics;
 using osu.Framework.Screens;
 using osu.Game.Beatmaps;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
 using osu.Game.Online.Spectator;
 using osu.Game.Scoring;
+using osu.Game.Screens.Ranking;
 
 namespace osu.Game.Screens.Play
 {
-    public class SpectatorPlayer : ReplayPlayer
+    public class SpectatorPlayer : Player
     {
-        [Resolved]
+        private readonly Score score;
-        private SpectatorStreamingClient spectatorStreaming { get; set; }
+
+        protected override bool CheckModsAllowFailure() => false; // todo: better support starting mid-way through beatmap
 
         public SpectatorPlayer(Score score)
-            : base(score)
         {
+            this.score = score;
         }
 
+        protected override ResultsScreen CreateResults(ScoreInfo score)
+        {
+            return new SpectatorResultsScreen(score);
+        }
+
+        [Resolved]
+        private SpectatorStreamingClient spectatorStreaming { get; set; }
+
         [BackgroundDependencyLoader]
         private void load()
         {
             spectatorStreaming.OnUserBeganPlaying += userBeganPlaying;
+
+            AddInternal(new OsuSpriteText
+            {
+                Text = $"Watching {score.ScoreInfo.User.Username} playing live!",
+                Font = OsuFont.Default.With(size: 30),
+                Y = 100,
+                Anchor = Anchor.TopCentre,
+                Origin = Anchor.TopCentre,
+            });
+        }
+
+        protected override void PrepareReplay()
+        {
+            DrawableRuleset?.SetReplayScore(score);
         }
 
         protected override GameplayClockContainer CreateGameplayClockContainer(WorkingBeatmap beatmap, double gameplayStart)
         {
             // if we already have frames, start gameplay at the point in time they exist, should they be too far into the beatmap.
-            double? firstFrameTime = Score.Replay.Frames.FirstOrDefault()?.Time;
+            double? firstFrameTime = score.Replay.Frames.FirstOrDefault()?.Time;
 
             if (firstFrameTime == null || firstFrameTime <= gameplayStart + 5000)
                 return base.CreateGameplayClockContainer(beatmap, gameplayStart);
@@ -43,6 +70,16 @@ namespace osu.Game.Screens.Play
             return base.OnExiting(next);
         }
 
+        private void userBeganPlaying(int userId, SpectatorState state)
+        {
+            if (userId != score.ScoreInfo.UserID) return;
+
+            Schedule(() =>
+            {
+                if (this.IsCurrentScreen()) this.Exit();
+            });
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);
@@ -50,11 +87,5 @@ namespace osu.Game.Screens.Play
             if (spectatorStreaming != null)
                 spectatorStreaming.OnUserBeganPlaying -= userBeganPlaying;
         }
-
-        private void userBeganPlaying(int userId, SpectatorState state)
-        {
-            if (userId == Score.ScoreInfo.UserID)
-                Schedule(this.Exit);
-        }
     }
 }

osu.Game/Screens/Play/SpectatorResultsScreen.cs

@@ -0,0 +1,47 @@
+// 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.Screens;
+using osu.Game.Online.Spectator;
+using osu.Game.Scoring;
+using osu.Game.Screens.Ranking;
+
+namespace osu.Game.Screens.Play
+{
+    public class SpectatorResultsScreen : SoloResultsScreen
+    {
+        public SpectatorResultsScreen(ScoreInfo score)
+            : base(score)
+        {
+        }
+
+        [Resolved]
+        private SpectatorStreamingClient spectatorStreaming { get; set; }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            spectatorStreaming.OnUserBeganPlaying += userBeganPlaying;
+        }
+
+        private void userBeganPlaying(int userId, SpectatorState state)
+        {
+            if (userId == Score.UserID)
+            {
+                Schedule(() =>
+                {
+                    if (this.IsCurrentScreen()) this.Exit();
+                });
+            }
+        }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+
+            if (spectatorStreaming != null)
+                spectatorStreaming.OnUserBeganPlaying -= userBeganPlaying;
+        }
+    }
+}

osu.Game/Screens/Select/BeatmapInfoWedge.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using JetBrains.Annotations;
 using osuTK;
 using osuTK.Graphics;
@@ -85,6 +86,8 @@ namespace osu.Game.Screens.Select
 
         private WorkingBeatmap beatmap;
 
+        private CancellationTokenSource cancellationSource;
+
         public WorkingBeatmap Beatmap
         {
             get => beatmap;
@@ -93,9 +96,11 @@ namespace osu.Game.Screens.Select
                 if (beatmap == value) return;
 
                 beatmap = value;
+                cancellationSource?.Cancel();
+                cancellationSource = new CancellationTokenSource();
 
                 beatmapDifficulty?.UnbindAll();
-                beatmapDifficulty = difficultyManager.GetBindableDifficulty(beatmap.BeatmapInfo);
+                beatmapDifficulty = difficultyManager.GetBindableDifficulty(beatmap.BeatmapInfo, cancellationSource.Token);
                 beatmapDifficulty.BindValueChanged(_ => updateDisplay());
 
                 updateDisplay();
@@ -108,33 +113,44 @@ namespace osu.Game.Screens.Select
 
         private void updateDisplay()
         {
-            void removeOldInfo()
+            Scheduler.AddOnce(perform);
-            {
-                State.Value = beatmap == null ? Visibility.Hidden : Visibility.Visible;
 
-                Info?.FadeOut(250);
+            void perform()
-                Info?.Expire();
+            {
-                Info = null;
+                void removeOldInfo()
+                {
+                    State.Value = beatmap == null ? Visibility.Hidden : Visibility.Visible;
+
+                    Info?.FadeOut(250);
+                    Info?.Expire();
+                    Info = null;
+                }
+
+                if (beatmap == null)
+                {
+                    removeOldInfo();
+                    return;
+                }
+
+                LoadComponentAsync(loadingInfo = new BufferedWedgeInfo(beatmap, ruleset.Value, beatmapDifficulty.Value)
+                {
+                    Shear = -Shear,
+                    Depth = Info?.Depth + 1 ?? 0
+                }, loaded =>
+                {
+                    // ensure we are the most recent loaded wedge.
+                    if (loaded != loadingInfo) return;
+
+                    removeOldInfo();
+                    Add(Info = loaded);
+                });
             }
+        }
 
-            if (beatmap == null)
+        protected override void Dispose(bool isDisposing)
-            {
+        {
-                removeOldInfo();
+            base.Dispose(isDisposing);
-                return;
+            cancellationSource?.Cancel();
-            }
-
-            LoadComponentAsync(loadingInfo = new BufferedWedgeInfo(beatmap, ruleset.Value, beatmapDifficulty.Value)
-            {
-                Shear = -Shear,
-                Depth = Info?.Depth + 1 ?? 0
-            }, loaded =>
-            {
-                // ensure we are the most recent loaded wedge.
-                if (loaded != loadingInfo) return;
-
-                removeOldInfo();
-                Add(Info = loaded);
-            });
         }
 
         public class BufferedWedgeInfo : BufferedContainer

osu.Game/Screens/Select/SongSelect.cs

@@ -37,6 +37,7 @@ using osu.Framework.Input.Bindings;
 using osu.Game.Collections;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Scoring;
+using System.Diagnostics;
 
 namespace osu.Game.Screens.Select
 {
@@ -519,7 +520,7 @@ namespace osu.Game.Screens.Select
 
             ModSelect.SelectedMods.BindTo(selectedMods);
 
-            music.TrackChanged += ensureTrackLooping;
+            beginLooping();
         }
 
         private const double logo_transition = 250;
@@ -570,8 +571,7 @@ namespace osu.Game.Screens.Select
 
             BeatmapDetails.Refresh();
 
-            music.CurrentTrack.Looping = true;
+            beginLooping();
-            music.TrackChanged += ensureTrackLooping;
             music.ResetTrackAdjustments();
 
             if (Beatmap != null && !Beatmap.Value.BeatmapSetInfo.DeletePending)
@@ -597,8 +597,7 @@ namespace osu.Game.Screens.Select
 
             BeatmapOptions.Hide();
 
-            music.CurrentTrack.Looping = false;
+            endLooping();
-            music.TrackChanged -= ensureTrackLooping;
 
             this.ScaleTo(1.1f, 250, Easing.InSine);
 
@@ -619,12 +618,33 @@ namespace osu.Game.Screens.Select
 
             FilterControl.Deactivate();
 
-            music.CurrentTrack.Looping = false;
+            endLooping();
-            music.TrackChanged -= ensureTrackLooping;
 
             return false;
         }
 
+        private bool isHandlingLooping;
+
+        private void beginLooping()
+        {
+            Debug.Assert(!isHandlingLooping);
+
+            music.CurrentTrack.Looping = isHandlingLooping = true;
+
+            music.TrackChanged += ensureTrackLooping;
+        }
+
+        private void endLooping()
+        {
+            // may be called multiple times during screen exit process.
+            if (!isHandlingLooping)
+                return;
+
+            music.CurrentTrack.Looping = isHandlingLooping = false;
+
+            music.TrackChanged -= ensureTrackLooping;
+        }
+
         private void ensureTrackLooping(WorkingBeatmap beatmap, TrackChangeDirection changeDirection)
             => music.CurrentTrack.Looping = true;
 

osu.Game/Users/UserPanel.cs

@@ -20,6 +20,10 @@ namespace osu.Game.Users
     {
         public readonly User User;
 
+        /// <summary>
+        /// Perform an action in addition to showing the user's profile.
+        /// This should be used to perform auxiliary tasks and not as a primary action for clicking a user panel (to maintain a consistent UX).
+        /// </summary>
         public new Action Action;
 
         protected Action ViewProfile { get; private set; }

osu.iOS.props

@@ -73,6 +73,14 @@
     <PackageReference Include="ppy.osu.Framework.iOS" Version="2020.1029.1" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2020.1030.0" />
   </ItemGroup>
+  <!-- See https://github.com/dotnet/runtime/issues/35988 (can be removed after Xamarin uses net5.0 / net6.0) -->
+  <PropertyGroup>
+    <NoWarn>$(NoWarn);NU1605</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="3.0.3" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="3.0.3" />
+  </ItemGroup>
   <!-- Xamarin.iOS does not automatically handle transitive dependencies from NuGet packages. -->
   <ItemGroup Label="Transitive Dependencies">
     <PackageReference Include="DiffPlex" Version="1.6.3" />