Merge branch 'master' into hit-error-skinnable

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

@@ -39,7 +39,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
                 }
             };
 
-            AddBlueprint(new HoldNoteSelectionBlueprint(drawableObject));
+            AddBlueprint(new HoldNoteSelectionBlueprint(holdNote), drawableObject);
         }
 
         protected override void Update()

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

@@ -184,8 +184,8 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
             AddAssert("head note positioned correctly", () => Precision.AlmostEquals(holdNote.ScreenSpaceDrawQuad.BottomLeft, holdNote.Head.ScreenSpaceDrawQuad.BottomLeft));
             AddAssert("tail note positioned correctly", () => Precision.AlmostEquals(holdNote.ScreenSpaceDrawQuad.TopLeft, holdNote.Tail.ScreenSpaceDrawQuad.BottomLeft));
 
-            AddAssert("head blueprint positioned correctly", () => this.ChildrenOfType<HoldNoteNoteSelectionBlueprint>().ElementAt(0).DrawPosition == holdNote.Head.DrawPosition);
+            AddAssert("head blueprint positioned correctly", () => this.ChildrenOfType<HoldNoteNoteOverlay>().ElementAt(0).DrawPosition == holdNote.Head.DrawPosition);
-            AddAssert("tail blueprint positioned correctly", () => this.ChildrenOfType<HoldNoteNoteSelectionBlueprint>().ElementAt(1).DrawPosition == holdNote.Tail.DrawPosition);
+            AddAssert("tail blueprint positioned correctly", () => this.ChildrenOfType<HoldNoteNoteOverlay>().ElementAt(1).DrawPosition == holdNote.Tail.DrawPosition);
         }
 
         private void setScrollStep(ScrollingDirection direction)

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

@@ -15,7 +15,6 @@ using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
 using osu.Game.Tests.Visual;
-using osuTK;
 using osuTK.Input;
 
 namespace osu.Game.Rulesets.Mania.Tests.Editor
@@ -35,7 +34,11 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
         [Test]
         public void TestPlaceBeforeCurrentTimeDownwards()
         {
-            AddStep("move mouse before current time", () => InputManager.MoveMouseTo(this.ChildrenOfType<Column>().Single().ScreenSpaceDrawQuad.BottomLeft - new Vector2(0, 10)));
+            AddStep("move mouse before current time", () =>
+            {
+                var column = this.ChildrenOfType<Column>().Single();
+                InputManager.MoveMouseTo(column.ScreenSpacePositionAtTime(-100));
+            });
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));
 
@@ -45,7 +48,11 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
         [Test]
         public void TestPlaceAfterCurrentTimeDownwards()
         {
-            AddStep("move mouse after current time", () => InputManager.MoveMouseTo(this.ChildrenOfType<Column>().Single()));
+            AddStep("move mouse after current time", () =>
+            {
+                var column = this.ChildrenOfType<Column>().Single();
+                InputManager.MoveMouseTo(column.ScreenSpacePositionAtTime(100));
+            });
 
             AddStep("click", () => InputManager.Click(MouseButton.Left));
 

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

@@ -34,7 +34,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
                 Child = drawableObject = new DrawableNote(note)
             };
 
-            AddBlueprint(new NoteSelectionBlueprint(drawableObject));
+            AddBlueprint(new NoteSelectionBlueprint(note), drawableObject);
         }
     }
 }

osu.Game.Rulesets.Mania.Tests/Skinning/TestSceneColumnBackground.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Skinning
                     {
                         RelativeSizeAxes = Axes.Both,
                         Width = 0.5f,
-                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground, 0), _ => new DefaultColumnBackground())
+                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground), _ => new DefaultColumnBackground())
                         {
                             RelativeSizeAxes = Axes.Both
                         }
@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Skinning
                     {
                         RelativeSizeAxes = Axes.Both,
                         Width = 0.5f,
-                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground, 1), _ => new DefaultColumnBackground())
+                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground), _ => new DefaultColumnBackground())
                         {
                             RelativeSizeAxes = Axes.Both
                         }

osu.Game.Rulesets.Mania.Tests/Skinning/TestSceneKeyArea.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Skinning
                     {
                         RelativeSizeAxes = Axes.Both,
                         Width = 0.5f,
-                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea, 0), _ => new DefaultKeyArea())
+                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea), _ => new DefaultKeyArea())
                         {
                             RelativeSizeAxes = Axes.Both
                         },
@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Skinning
                     {
                         RelativeSizeAxes = Axes.Both,
                         Width = 0.5f,
-                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea, 1), _ => new DefaultKeyArea())
+                        Child = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea), _ => new DefaultKeyArea())
                         {
                             RelativeSizeAxes = Axes.Both
                         },

osu.Game.Rulesets.Mania.Tests/TestSceneDrawableManiaHitObject.cs

@@ -0,0 +1,67 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Timing;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Rulesets.Mania.Objects.Drawables;
+using osu.Game.Rulesets.Mania.UI;
+using osu.Game.Rulesets.UI.Scrolling;
+using osu.Game.Tests.Visual;
+using osuTK.Graphics;
+
+namespace osu.Game.Rulesets.Mania.Tests
+{
+    public class TestSceneDrawableManiaHitObject : OsuTestScene
+    {
+        private readonly ManualClock clock = new ManualClock();
+
+        private Column column;
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            Child = new ScrollingTestContainer(ScrollingDirection.Down)
+            {
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                AutoSizeAxes = Axes.X,
+                RelativeSizeAxes = Axes.Y,
+                TimeRange = 2000,
+                Clock = new FramedClock(clock),
+                Child = column = new Column(0)
+                {
+                    Action = { Value = ManiaAction.Key1 },
+                    Height = 0.85f,
+                    AccentColour = Color4.Gray
+                },
+            };
+        });
+
+        [Test]
+        public void TestHoldNoteHeadVisibility()
+        {
+            DrawableHoldNote note = null;
+            AddStep("Add hold note", () =>
+            {
+                var h = new HoldNote
+                {
+                    StartTime = 0,
+                    Duration = 1000
+                };
+                h.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+                column.Add(note = new DrawableHoldNote(h));
+            });
+            AddStep("Hold key", () =>
+            {
+                clock.CurrentTime = 0;
+                note.OnPressed(ManiaAction.Key1);
+            });
+            AddStep("progress time", () => clock.CurrentTime = 500);
+            AddAssert("head is visible", () => note.Head.Alpha == 1);
+        }
+    }
+}

osu.Game.Rulesets.Mania.Tests/TestSceneHoldNoteInput.cs

@@ -5,13 +5,11 @@ using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Screens;
-using osu.Framework.Testing;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Replays;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mania.Objects;
-using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.Mania.Replays;
 using osu.Game.Rulesets.Mania.Scoring;
 using osu.Game.Rulesets.Objects;
@@ -414,14 +412,7 @@ namespace osu.Game.Rulesets.Mania.Tests
             AddUntilStep("Beatmap at 0", () => Beatmap.Value.Track.CurrentTime == 0);
             AddUntilStep("Wait until player is loaded", () => currentPlayer.IsCurrentScreen());
 
-            AddUntilStep("wait for head", () => currentPlayer.GameplayClockContainer.GameplayClock.CurrentTime >= time_head);
+            AddUntilStep("Wait for completion", () => currentPlayer.ScoreProcessor?.HasCompleted.Value == true);
-            AddAssert("head is visible",
-                () => currentPlayer.ChildrenOfType<DrawableHoldNote>()
-                                   .Single(note => note.HitObject == beatmap.HitObjects[0])
-                                   .Head
-                                   .Alpha == 1);
-
-            AddUntilStep("Wait for completion", () => currentPlayer.ScoreProcessor.HasCompleted.Value);
         }
 
         private class ScoreAccessibleReplayPlayer : ReplayPlayer

osu.Game.Rulesets.Mania/Edit/Blueprints/HoldNoteNoteOverlay.cs

@@ -2,34 +2,35 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Game.Rulesets.Mania.Edit.Blueprints.Components;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Mania.Edit.Blueprints
 {
-    public class HoldNoteNoteSelectionBlueprint : ManiaSelectionBlueprint
+    public class HoldNoteNoteOverlay : CompositeDrawable
     {
-        protected new DrawableHoldNote DrawableObject => (DrawableHoldNote)base.DrawableObject;
+        private readonly HoldNoteSelectionBlueprint holdNoteBlueprint;
-
         private readonly HoldNotePosition position;
 
-        public HoldNoteNoteSelectionBlueprint(DrawableHoldNote holdNote, HoldNotePosition position)
+        public HoldNoteNoteOverlay(HoldNoteSelectionBlueprint holdNoteBlueprint, HoldNotePosition position)
-            : base(holdNote)
         {
+            this.holdNoteBlueprint = holdNoteBlueprint;
             this.position = position;
-            InternalChild = new EditNotePiece { RelativeSizeAxes = Axes.X };
 
-            Select();
+            InternalChild = new EditNotePiece { RelativeSizeAxes = Axes.X };
         }
 
         protected override void Update()
         {
             base.Update();
 
+            var drawableObject = holdNoteBlueprint.DrawableObject;
+
             // Todo: This shouldn't exist, mania should not reference the drawable hitobject directly.
-            if (DrawableObject.IsLoaded)
+            if (drawableObject.IsLoaded)
             {
-                DrawableNote note = position == HoldNotePosition.Start ? (DrawableNote)DrawableObject.Head : DrawableObject.Tail;
+                DrawableNote note = position == HoldNotePosition.Start ? (DrawableNote)drawableObject.Head : drawableObject.Tail;
 
                 Anchor = note.Anchor;
                 Origin = note.Origin;
@@ -38,8 +39,5 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
                 Position = note.DrawPosition;
             }
         }
-
-        // Todo: This is temporary, since the note masks don't do anything special yet. In the future they will handle input.
-        public override bool HandlePositionalInput => false;
     }
 }

osu.Game.Rulesets.Mania/Edit/Blueprints/HoldNoteSelectionBlueprint.cs

@@ -8,13 +8,14 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Primitives;
 using osu.Framework.Graphics.Shapes;
 using osu.Game.Graphics;
+using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.UI.Scrolling;
 using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Edit.Blueprints
 {
-    public class HoldNoteSelectionBlueprint : ManiaSelectionBlueprint
+    public class HoldNoteSelectionBlueprint : ManiaSelectionBlueprint<HoldNote>
     {
         public new DrawableHoldNote DrawableObject => (DrawableHoldNote)base.DrawableObject;
 
@@ -23,7 +24,7 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
         [Resolved]
         private OsuColour colours { get; set; }
 
-        public HoldNoteSelectionBlueprint(DrawableHoldNote hold)
+        public HoldNoteSelectionBlueprint(HoldNote hold)
             : base(hold)
         {
         }
@@ -32,16 +33,11 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
         private void load(IScrollingInfo scrollingInfo)
         {
             direction.BindTo(scrollingInfo.Direction);
-        }
-
-        protected override void LoadComplete()
-        {
-            base.LoadComplete();
 
             InternalChildren = new Drawable[]
             {
-                new HoldNoteNoteSelectionBlueprint(DrawableObject, HoldNotePosition.Start),
+                new HoldNoteNoteOverlay(this, HoldNotePosition.Start),
-                new HoldNoteNoteSelectionBlueprint(DrawableObject, HoldNotePosition.End),
+                new HoldNoteNoteOverlay(this, HoldNotePosition.End),
                 new Container
                 {
                     RelativeSizeAxes = Axes.Both,

osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaSelectionBlueprint.cs

@@ -4,22 +4,23 @@
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI.Scrolling;
 using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Edit.Blueprints
 {
-    public abstract class ManiaSelectionBlueprint : OverlaySelectionBlueprint
+    public abstract class ManiaSelectionBlueprint<T> : HitObjectSelectionBlueprint<T>
+        where T : ManiaHitObject
     {
         public new DrawableManiaHitObject DrawableObject => (DrawableManiaHitObject)base.DrawableObject;
 
         [Resolved]
         private IScrollingInfo scrollingInfo { get; set; }
 
-        protected ManiaSelectionBlueprint(DrawableHitObject drawableObject)
+        protected ManiaSelectionBlueprint(T hitObject)
-            : base(drawableObject)
+            : base(hitObject)
         {
             RelativeSizeAxes = Axes.None;
         }

osu.Game.Rulesets.Mania/Edit/Blueprints/NoteSelectionBlueprint.cs

@@ -3,13 +3,13 @@
 
 using osu.Framework.Graphics;
 using osu.Game.Rulesets.Mania.Edit.Blueprints.Components;
-using osu.Game.Rulesets.Mania.Objects.Drawables;
+using osu.Game.Rulesets.Mania.Objects;
 
 namespace osu.Game.Rulesets.Mania.Edit.Blueprints
 {
-    public class NoteSelectionBlueprint : ManiaSelectionBlueprint
+    public class NoteSelectionBlueprint : ManiaSelectionBlueprint<Note>
     {
-        public NoteSelectionBlueprint(DrawableNote note)
+        public NoteSelectionBlueprint(Note note)
             : base(note)
         {
             AddInternal(new EditNotePiece { RelativeSizeAxes = Axes.X });

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

@@ -101,7 +101,7 @@ namespace osu.Game.Rulesets.Mania.Edit
                 foreach (var line in grid.Objects.OfType<DrawableGridLine>())
                     availableLines.Push(line);
 
-                grid.Clear(false);
+                grid.Clear();
             }
 
             if (selectionTimeRange == null)

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

@@ -3,9 +3,8 @@
 
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Mania.Edit.Blueprints;
-using osu.Game.Rulesets.Mania.Objects.Drawables;
+using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Objects;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Screens.Edit.Compose.Components;
 
 namespace osu.Game.Rulesets.Mania.Edit
@@ -17,18 +16,18 @@ namespace osu.Game.Rulesets.Mania.Edit
         {
         }
 
-        public override OverlaySelectionBlueprint CreateBlueprintFor(DrawableHitObject hitObject)
+        public override HitObjectSelectionBlueprint CreateHitObjectBlueprintFor(HitObject hitObject)
         {
             switch (hitObject)
             {
-                case DrawableNote note:
+                case Note note:
                     return new NoteSelectionBlueprint(note);
 
-                case DrawableHoldNote holdNote:
+                case HoldNote holdNote:
                     return new HoldNoteSelectionBlueprint(holdNote);
             }
 
-            return base.CreateBlueprintFor(hitObject);
+            return base.CreateHitObjectBlueprintFor(hitObject);
         }
 
         protected override SelectionHandler<HitObject> CreateSelectionHandler() => new ManiaSelectionHandler();

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

@@ -5,7 +5,6 @@ using System;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Game.Rulesets.Edit;
-using osu.Game.Rulesets.Mania.Edit.Blueprints;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.UI.Scrolling;
@@ -23,8 +22,8 @@ namespace osu.Game.Rulesets.Mania.Edit
 
         public override bool HandleMovement(MoveSelectionEvent<HitObject> moveEvent)
         {
-            var maniaBlueprint = (ManiaSelectionBlueprint)moveEvent.Blueprint;
+            var hitObjectBlueprint = (HitObjectSelectionBlueprint)moveEvent.Blueprint;
-            int lastColumn = maniaBlueprint.DrawableObject.HitObject.Column;
+            int lastColumn = ((ManiaHitObject)hitObjectBlueprint.Item).Column;
 
             performColumnMovement(lastColumn, moveEvent);
 
@@ -59,8 +58,9 @@ namespace osu.Game.Rulesets.Mania.Edit
 
             EditorBeatmap.PerformOnSelection(h =>
             {
-                if (h is ManiaHitObject maniaObj)
+                maniaPlayfield.Remove(h);
-                    maniaObj.Column += columnDelta;
+                ((ManiaHitObject)h).Column += columnDelta;
+                maniaPlayfield.Add(h);
             });
         }
     }

osu.Game.Rulesets.Mania/ManiaSkinComponent.cs

@@ -9,12 +9,6 @@ namespace osu.Game.Rulesets.Mania
 {
     public class ManiaSkinComponent : GameplaySkinComponent<ManiaSkinComponents>
     {
-        /// <summary>
-        /// The intended <see cref="Column"/> index for this component.
-        /// May be null if the component does not exist in a <see cref="Column"/>.
-        /// </summary>
-        public readonly int? TargetColumn;
-
         /// <summary>
         /// The intended <see cref="StageDefinition"/> for this component.
         /// May be null if the component is not a direct member of a <see cref="Stage"/>.
@@ -25,12 +19,10 @@ namespace osu.Game.Rulesets.Mania
         /// Creates a new <see cref="ManiaSkinComponent"/>.
         /// </summary>
         /// <param name="component">The component.</param>
-        /// <param name="targetColumn">The intended <see cref="Column"/> index for this component. May be null if the component does not exist in a <see cref="Column"/>.</param>
         /// <param name="stageDefinition">The intended <see cref="StageDefinition"/> for this component. May be null if the component is not a direct member of a <see cref="Stage"/>.</param>
-        public ManiaSkinComponent(ManiaSkinComponents component, int? targetColumn = null, StageDefinition? stageDefinition = null)
+        public ManiaSkinComponent(ManiaSkinComponents component, StageDefinition? stageDefinition = null)
             : base(component)
         {
-            TargetColumn = targetColumn;
             StageDefinition = stageDefinition;
         }
 

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableHoldNote.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -12,6 +13,7 @@ using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI.Scrolling;
 using osu.Game.Skinning;
+using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Objects.Drawables
 {
@@ -29,21 +31,21 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
         public DrawableHoldNoteHead Head => headContainer.Child;
         public DrawableHoldNoteTail Tail => tailContainer.Child;
 
-        private readonly Container<DrawableHoldNoteHead> headContainer;
+        private Container<DrawableHoldNoteHead> headContainer;
-        private readonly Container<DrawableHoldNoteTail> tailContainer;
+        private Container<DrawableHoldNoteTail> tailContainer;
-        private readonly Container<DrawableHoldNoteTick> tickContainer;
+        private Container<DrawableHoldNoteTick> tickContainer;
 
         /// <summary>
         /// Contains the size of the hold note covering the whole head/tail bounds. The size of this container changes as the hold note is being pressed.
         /// </summary>
-        private readonly Container sizingContainer;
+        private Container sizingContainer;
 
         /// <summary>
         /// Contains the contents of the hold note that should be masked as the hold note is being pressed. Follows changes in the size of <see cref="sizingContainer"/>.
         /// </summary>
-        private readonly Container maskingContainer;
+        private Container maskingContainer;
 
-        private readonly SkinnableDrawable bodyPiece;
+        private SkinnableDrawable bodyPiece;
 
         /// <summary>
         /// Time at which the user started holding this hold note. Null if the user is not holding this hold note.
@@ -60,11 +62,19 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
         /// </summary>
         private double? releaseTime;
 
+        public DrawableHoldNote()
+            : this(null)
+        {
+        }
+
         public DrawableHoldNote(HoldNote hitObject)
             : base(hitObject)
         {
-            RelativeSizeAxes = Axes.X;
+        }
 
+        [BackgroundDependencyLoader]
+        private void load()
+        {
             Container maskedContents;
 
             AddRangeInternal(new Drawable[]
@@ -86,7 +96,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
                         headContainer = new Container<DrawableHoldNoteHead> { RelativeSizeAxes = Axes.Both }
                     }
                 },
-                bodyPiece = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HoldNoteBody, hitObject.Column), _ => new DefaultBodyPiece
+                bodyPiece = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HoldNoteBody), _ => new DefaultBodyPiece
                 {
                     RelativeSizeAxes = Axes.Both,
                 })
@@ -105,6 +115,16 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             });
         }
 
+        protected override void OnApply()
+        {
+            base.OnApply();
+
+            sizingContainer.Size = Vector2.One;
+            HoldStartTime = null;
+            HoldBrokenTime = null;
+            releaseTime = null;
+        }
+
         protected override void AddNestedHitObject(DrawableHitObject hitObject)
         {
             base.AddNestedHitObject(hitObject);
@@ -128,37 +148,23 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
         protected override void ClearNestedHitObjects()
         {
             base.ClearNestedHitObjects();
-            headContainer.Clear();
+            headContainer.Clear(false);
-            tailContainer.Clear();
+            tailContainer.Clear(false);
-            tickContainer.Clear();
+            tickContainer.Clear(false);
         }
 
         protected override DrawableHitObject CreateNestedHitObject(HitObject hitObject)
         {
             switch (hitObject)
             {
-                case TailNote _:
+                case TailNote tail:
-                    return new DrawableHoldNoteTail(this)
+                    return new DrawableHoldNoteTail(tail);
-                    {
-                        Anchor = Anchor.TopCentre,
-                        Origin = Anchor.TopCentre,
-                        AccentColour = { BindTarget = AccentColour }
-                    };
 
-                case Note _:
+                case HeadNote head:
-                    return new DrawableHoldNoteHead(this)
+                    return new DrawableHoldNoteHead(head);
-                    {
-                        Anchor = Anchor.TopCentre,
-                        Origin = Anchor.TopCentre,
-                        AccentColour = { BindTarget = AccentColour }
-                    };
 
                 case HoldNoteTick tick:
-                    return new DrawableHoldNoteTick(tick)
+                    return new DrawableHoldNoteTick(tick);
-                    {
-                        HoldStartTime = () => HoldStartTime,
-                        AccentColour = { BindTarget = AccentColour }
-                    };
             }
 
             return base.CreateNestedHitObject(hitObject);

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableHoldNoteHead.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Graphics;
 using osu.Game.Rulesets.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Mania.Objects.Drawables
@@ -12,11 +13,18 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
     {
         protected override ManiaSkinComponents Component => ManiaSkinComponents.HoldNoteHead;
 
-        public DrawableHoldNoteHead(DrawableHoldNote holdNote)
+        public DrawableHoldNoteHead()
-            : base(holdNote.HitObject.Head)
+            : this(null)
         {
         }
 
+        public DrawableHoldNoteHead(HeadNote headNote)
+            : base(headNote)
+        {
+            Anchor = Anchor.TopCentre;
+            Origin = Anchor.TopCentre;
+        }
+
         public void UpdateResult() => base.UpdateResult(true);
 
         protected override void UpdateInitialTransforms()

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableHoldNoteTail.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Diagnostics;
+using osu.Framework.Graphics;
 using osu.Game.Rulesets.Scoring;
 
 namespace osu.Game.Rulesets.Mania.Objects.Drawables
@@ -20,12 +21,18 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
 
         protected override ManiaSkinComponents Component => ManiaSkinComponents.HoldNoteTail;
 
-        private readonly DrawableHoldNote holdNote;
+        protected DrawableHoldNote HoldNote => (DrawableHoldNote)ParentHitObject;
 
-        public DrawableHoldNoteTail(DrawableHoldNote holdNote)
+        public DrawableHoldNoteTail()
-            : base(holdNote.HitObject.Tail)
+            : this(null)
         {
-            this.holdNote = holdNote;
+        }
+
+        public DrawableHoldNoteTail(TailNote tailNote)
+            : base(tailNote)
+        {
+            Anchor = Anchor.TopCentre;
+            Origin = Anchor.TopCentre;
         }
 
         public void UpdateResult() => base.UpdateResult(true);
@@ -54,7 +61,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             ApplyResult(r =>
             {
                 // If the head wasn't hit or the hold note was broken, cap the max score to Meh.
-                if (result > HitResult.Meh && (!holdNote.Head.IsHit || holdNote.HoldBrokenTime != null))
+                if (result > HitResult.Meh && (!HoldNote.Head.IsHit || HoldNote.HoldBrokenTime != null))
                     result = HitResult.Meh;
 
                 r.Type = result;

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableHoldNoteTick.cs

@@ -2,7 +2,8 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using osuTK;
+using System.Diagnostics;
+using osu.Framework.Allocation;
 using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -19,38 +20,48 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
         /// <summary>
         /// References the time at which the user started holding the hold note.
         /// </summary>
-        public Func<double?> HoldStartTime;
+        private Func<double?> holdStartTime;
+
+        private Container glowContainer;
+
+        public DrawableHoldNoteTick()
+            : this(null)
+        {
+        }
 
         public DrawableHoldNoteTick(HoldNoteTick hitObject)
             : base(hitObject)
         {
-            Container glowContainer;
-
             Anchor = Anchor.TopCentre;
             Origin = Anchor.TopCentre;
 
             RelativeSizeAxes = Axes.X;
-            Size = new Vector2(1);
+        }
 
-            AddRangeInternal(new[]
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            AddInternal(glowContainer = new CircularContainer
             {
-                glowContainer = new CircularContainer
+                Anchor = Anchor.TopCentre,
+                Origin = Anchor.TopCentre,
+                RelativeSizeAxes = Axes.Both,
+                Masking = true,
+                Children = new[]
                 {
-                    Anchor = Anchor.TopCentre,
+                    new Box
-                    Origin = Anchor.TopCentre,
-                    RelativeSizeAxes = Axes.Both,
-                    Masking = true,
-                    Children = new[]
                     {
-                        new Box
+                        RelativeSizeAxes = Axes.Both,
-                        {
+                        Alpha = 0,
-                            RelativeSizeAxes = Axes.Both,
+                        AlwaysPresent = true
-                            Alpha = 0,
-                            AlwaysPresent = true
-                        }
                     }
                 }
             });
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
 
             AccentColour.BindValueChanged(colour =>
             {
@@ -64,12 +75,29 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             }, true);
         }
 
+        protected override void OnApply()
+        {
+            base.OnApply();
+
+            Debug.Assert(ParentHitObject != null);
+
+            var holdNote = (DrawableHoldNote)ParentHitObject;
+            holdStartTime = () => holdNote.HoldStartTime;
+        }
+
+        protected override void OnFree()
+        {
+            base.OnFree();
+
+            holdStartTime = null;
+        }
+
         protected override void CheckForResult(bool userTriggered, double timeOffset)
         {
             if (Time.Current < HitObject.StartTime)
                 return;
 
-            var startTime = HoldStartTime?.Invoke();
+            var startTime = holdStartTime?.Invoke();
 
             if (startTime == null || startTime > HitObject.StartTime)
                 ApplyResult(r => r.Type = r.Judgement.MinResult);

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableManiaHitObject.cs

@@ -50,6 +50,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
         protected DrawableManiaHitObject(ManiaHitObject hitObject)
             : base(hitObject)
         {
+            RelativeSizeAxes = Axes.X;
         }
 
         [BackgroundDependencyLoader(true)]
@@ -59,9 +60,31 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
                 Action.BindTo(action);
 
             Direction.BindTo(scrollingInfo.Direction);
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
             Direction.BindValueChanged(OnDirectionChanged, true);
         }
 
+        protected override void OnApply()
+        {
+            base.OnApply();
+
+            if (ParentHitObject != null)
+                AccentColour.BindTo(ParentHitObject.AccentColour);
+        }
+
+        protected override void OnFree()
+        {
+            base.OnFree();
+
+            if (ParentHitObject != null)
+                AccentColour.UnbindFrom(ParentHitObject.AccentColour);
+        }
+
         private double computedLifetimeStart;
 
         public override double LifetimeStart
@@ -147,12 +170,11 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
     public abstract class DrawableManiaHitObject<TObject> : DrawableManiaHitObject
         where TObject : ManiaHitObject
     {
-        public new readonly TObject HitObject;
+        public new TObject HitObject => (TObject)base.HitObject;
 
         protected DrawableManiaHitObject(TObject hitObject)
             : base(hitObject)
         {
-            HitObject = hitObject;
         }
     }
 }

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableNote.cs

@@ -33,31 +33,37 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
 
         protected virtual ManiaSkinComponents Component => ManiaSkinComponents.Note;
 
-        private readonly Drawable headPiece;
+        private Drawable headPiece;
+
+        public DrawableNote()
+            : this(null)
+        {
+        }
 
         public DrawableNote(Note hitObject)
             : base(hitObject)
         {
-            RelativeSizeAxes = Axes.X;
             AutoSizeAxes = Axes.Y;
-
-            AddInternal(headPiece = new SkinnableDrawable(new ManiaSkinComponent(Component, hitObject.Column), _ => new DefaultNotePiece())
-            {
-                RelativeSizeAxes = Axes.X,
-                AutoSizeAxes = Axes.Y
-            });
         }
 
         [BackgroundDependencyLoader(true)]
         private void load(ManiaRulesetConfigManager rulesetConfig)
         {
             rulesetConfig?.BindWith(ManiaRulesetSetting.TimingBasedNoteColouring, configTimingBasedNoteColouring);
+
+            AddInternal(headPiece = new SkinnableDrawable(new ManiaSkinComponent(Component), _ => new DefaultNotePiece())
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y
+            });
         }
 
         protected override void LoadComplete()
         {
-            HitObject.StartTimeBindable.BindValueChanged(_ => updateSnapColour());
+            base.LoadComplete();
-            configTimingBasedNoteColouring.BindValueChanged(_ => updateSnapColour(), true);
+
+            configTimingBasedNoteColouring.BindValueChanged(_ => updateSnapColour());
+            StartTimeBindable.BindValueChanged(_ => updateSnapColour(), true);
         }
 
         protected override void OnDirectionChanged(ValueChangedEvent<ScrollingDirection> e)
@@ -102,7 +108,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
 
         private void updateSnapColour()
         {
-            if (beatmap == null) return;
+            if (beatmap == null || HitObject == null) return;
 
             int snapDivisor = beatmap.ControlPointInfo.GetClosestBeatDivisor(HitObject.StartTime);
 

osu.Game.Rulesets.Mania/Objects/HeadNote.cs

@@ -0,0 +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.
+
+namespace osu.Game.Rulesets.Mania.Objects
+{
+    public class HeadNote : Note
+    {
+    }
+}

osu.Game.Rulesets.Mania/Objects/HoldNote.cs

@@ -72,7 +72,7 @@ namespace osu.Game.Rulesets.Mania.Objects
         /// <summary>
         /// The head note of the hold.
         /// </summary>
-        public Note Head { get; private set; }
+        public HeadNote Head { get; private set; }
 
         /// <summary>
         /// The tail note of the hold.
@@ -98,7 +98,7 @@ namespace osu.Game.Rulesets.Mania.Objects
 
             createTicks(cancellationToken);
 
-            AddNested(Head = new Note
+            AddNested(Head = new HeadNote
             {
                 StartTime = StartTime,
                 Column = Column,

osu.Game.Rulesets.Mania/UI/Column.cs

@@ -17,6 +17,7 @@ using osu.Game.Rulesets.UI.Scrolling;
 using osu.Game.Skinning;
 using osuTK;
 using osu.Game.Rulesets.Mania.Beatmaps;
+using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Mania.UI
@@ -55,7 +56,7 @@ namespace osu.Game.Rulesets.Mania.UI
             RelativeSizeAxes = Axes.Y;
             Width = COLUMN_WIDTH;
 
-            Drawable background = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground, Index), _ => new DefaultColumnBackground())
+            Drawable background = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.ColumnBackground), _ => new DefaultColumnBackground())
             {
                 RelativeSizeAxes = Axes.Both
             };
@@ -66,7 +67,7 @@ namespace osu.Game.Rulesets.Mania.UI
                 // For input purposes, the background is added at the highest depth, but is then proxied back below all other elements
                 background.CreateProxy(),
                 HitObjectArea = new ColumnHitObjectArea(Index, HitObjectContainer) { RelativeSizeAxes = Axes.Both },
-                new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea, Index), _ => new DefaultKeyArea())
+                new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.KeyArea), _ => new DefaultKeyArea())
                 {
                     RelativeSizeAxes = Axes.Both
                 },
@@ -83,6 +84,19 @@ namespace osu.Game.Rulesets.Mania.UI
             hitPolicy = new OrderedHitPolicy(HitObjectContainer);
 
             TopLevelContainer.Add(HitObjectArea.Explosions.CreateProxy());
+
+            RegisterPool<Note, DrawableNote>(10, 50);
+            RegisterPool<HoldNote, DrawableHoldNote>(10, 50);
+            RegisterPool<HeadNote, DrawableHoldNoteHead>(10, 50);
+            RegisterPool<TailNote, DrawableHoldNoteTail>(10, 50);
+            RegisterPool<HoldNoteTick, DrawableHoldNoteTick>(50, 250);
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            NewResult += OnNewResult;
         }
 
         public ColumnType ColumnType { get; set; }
@@ -98,28 +112,14 @@ namespace osu.Game.Rulesets.Mania.UI
             return dependencies;
         }
 
-        /// <summary>
+        protected override void OnNewDrawableHitObject(DrawableHitObject drawableHitObject)
-        /// Adds a DrawableHitObject to this Playfield.
-        /// </summary>
-        /// <param name="hitObject">The DrawableHitObject to add.</param>
-        public override void Add(DrawableHitObject hitObject)
         {
-            hitObject.AccentColour.Value = AccentColour;
+            base.OnNewDrawableHitObject(drawableHitObject);
-            hitObject.OnNewResult += OnNewResult;
 
-            DrawableManiaHitObject maniaObject = (DrawableManiaHitObject)hitObject;
+            DrawableManiaHitObject maniaObject = (DrawableManiaHitObject)drawableHitObject;
+
+            maniaObject.AccentColour.Value = AccentColour;
             maniaObject.CheckHittable = hitPolicy.IsHittable;
-
-            base.Add(hitObject);
-        }
-
-        public override bool Remove(DrawableHitObject h)
-        {
-            if (!base.Remove(h))
-                return false;
-
-            h.OnNewResult -= OnNewResult;
-            return true;
         }
 
         internal void OnNewResult(DrawableHitObject judgedObject, JudgementResult result)

osu.Game.Rulesets.Mania/UI/Components/ColumnHitObjectArea.cs

@@ -27,7 +27,7 @@ namespace osu.Game.Rulesets.Mania.UI.Components
                     RelativeSizeAxes = Axes.Both,
                     Depth = 2,
                 },
-                hitTarget = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HitTarget, columnIndex), _ => new DefaultHitTarget())
+                hitTarget = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HitTarget), _ => new DefaultHitTarget())
                 {
                     RelativeSizeAxes = Axes.X,
                     Depth = 1

osu.Game.Rulesets.Mania/UI/DrawableManiaRuleset.cs

@@ -18,7 +18,6 @@ using osu.Game.Replays;
 using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mania.Configuration;
 using osu.Game.Rulesets.Mania.Objects;
-using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.Mania.Replays;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -134,20 +133,7 @@ namespace osu.Game.Rulesets.Mania.UI
 
         protected override PassThroughInputManager CreateInputManager() => new ManiaInputManager(Ruleset.RulesetInfo, Variant);
 
-        public override DrawableHitObject<ManiaHitObject> CreateDrawableRepresentation(ManiaHitObject h)
+        public override DrawableHitObject<ManiaHitObject> CreateDrawableRepresentation(ManiaHitObject h) => null;
-        {
-            switch (h)
-            {
-                case HoldNote holdNote:
-                    return new DrawableHoldNote(holdNote);
-
-                case Note note:
-                    return new DrawableNote(note);
-
-                default:
-                    return null;
-            }
-        }
 
         protected override ReplayInputHandler CreateReplayInputHandler(Replay replay) => new ManiaFramedReplayInputHandler(replay);
 

osu.Game.Rulesets.Mania/UI/ManiaPlayfield.cs

@@ -9,6 +9,7 @@ using System.Linq;
 using osu.Framework.Allocation;
 using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI.Scrolling;
 using osuTK;
@@ -56,6 +57,10 @@ namespace osu.Game.Rulesets.Mania.UI
             }
         }
 
+        public override void Add(HitObject hitObject) => getStageByColumn(((ManiaHitObject)hitObject).Column).Add(hitObject);
+
+        public override bool Remove(HitObject hitObject) => getStageByColumn(((ManiaHitObject)hitObject).Column).Remove(hitObject);
+
         public override void Add(DrawableHitObject h) => getStageByColumn(((ManiaHitObject)h.HitObject).Column).Add(h);
 
         public override bool Remove(DrawableHitObject h) => getStageByColumn(((ManiaHitObject)h.HitObject).Column).Remove(h);

osu.Game.Rulesets.Mania/UI/PoolableHitExplosion.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Mania.UI
         [BackgroundDependencyLoader]
         private void load()
         {
-            InternalChild = skinnableExplosion = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HitExplosion, column.Index), _ => new DefaultHitExplosion())
+            InternalChild = skinnableExplosion = new SkinnableDrawable(new ManiaSkinComponent(ManiaSkinComponents.HitExplosion), _ => new DefaultHitExplosion())
             {
                 RelativeSizeAxes = Axes.Both
             };

osu.Game.Rulesets.Mania/UI/Stage.cs

@@ -11,6 +11,7 @@ using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.Mania.UI.Components;
+using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
@@ -132,33 +133,19 @@ namespace osu.Game.Rulesets.Mania.UI
             }
         }
 
-        public override void Add(DrawableHitObject h)
+        protected override void LoadComplete()
         {
-            var maniaObject = (ManiaHitObject)h.HitObject;
+            base.LoadComplete();
-
+            NewResult += OnNewResult;
-            int columnIndex = -1;
-
-            maniaObject.ColumnBindable.BindValueChanged(_ =>
-            {
-                if (columnIndex != -1)
-                    Columns.ElementAt(columnIndex).Remove(h);
-
-                columnIndex = maniaObject.Column - firstColumnIndex;
-                Columns.ElementAt(columnIndex).Add(h);
-            }, true);
-
-            h.OnNewResult += OnNewResult;
         }
 
-        public override bool Remove(DrawableHitObject h)
+        public override void Add(HitObject hitObject) => Columns.ElementAt(((ManiaHitObject)hitObject).Column - firstColumnIndex).Add(hitObject);
-        {
-            var maniaObject = (ManiaHitObject)h.HitObject;
-            int columnIndex = maniaObject.Column - firstColumnIndex;
-            Columns.ElementAt(columnIndex).Remove(h);
 
-            h.OnNewResult -= OnNewResult;
+        public override bool Remove(HitObject hitObject) => Columns.ElementAt(((ManiaHitObject)hitObject).Column - firstColumnIndex).Remove(hitObject);
-            return true;
+
-        }
+        public override void Add(DrawableHitObject h) => Columns.ElementAt(((ManiaHitObject)h.HitObject).Column - firstColumnIndex).Add(h);
+
+        public override bool Remove(DrawableHitObject h) => Columns.ElementAt(((ManiaHitObject)h.HitObject).Column - firstColumnIndex).Remove(h);
 
         public void Add(BarLine barline) => base.Add(new DrawableBarLine(barline));
 

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

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             hitCircle.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty { CircleSize = 2 });
 
             Add(drawableObject = new DrawableHitCircle(hitCircle));
-            AddBlueprint(blueprint = new TestBlueprint(drawableObject));
+            AddBlueprint(blueprint = new TestBlueprint(hitCircle), drawableObject);
         });
 
         [Test]
@@ -63,8 +63,8 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
         {
             public new HitCirclePiece CirclePiece => base.CirclePiece;
 
-            public TestBlueprint(DrawableHitCircle drawableCircle)
+            public TestBlueprint(HitCircle circle)
-                : base(drawableCircle)
+                : base(circle)
             {
             }
         }

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

@@ -44,7 +44,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty { CircleSize = 2 });
 
             Add(drawableObject = new DrawableSlider(slider));
-            AddBlueprint(new TestSliderBlueprint(drawableObject));
+            AddBlueprint(new TestSliderBlueprint(slider), drawableObject);
         });
 
         [Test]
@@ -150,23 +150,23 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
         private class TestSliderBlueprint : SliderSelectionBlueprint
         {
             public new SliderBodyPiece BodyPiece => base.BodyPiece;
-            public new TestSliderCircleBlueprint HeadBlueprint => (TestSliderCircleBlueprint)base.HeadBlueprint;
+            public new TestSliderCircleOverlay HeadOverlay => (TestSliderCircleOverlay)base.HeadOverlay;
-            public new TestSliderCircleBlueprint TailBlueprint => (TestSliderCircleBlueprint)base.TailBlueprint;
+            public new TestSliderCircleOverlay TailOverlay => (TestSliderCircleOverlay)base.TailOverlay;
             public new PathControlPointVisualiser ControlPointVisualiser => base.ControlPointVisualiser;
 
-            public TestSliderBlueprint(DrawableSlider slider)
+            public TestSliderBlueprint(Slider slider)
                 : base(slider)
             {
             }
 
-            protected override SliderCircleSelectionBlueprint CreateCircleSelectionBlueprint(DrawableSlider slider, SliderPosition position) => new TestSliderCircleBlueprint(slider, position);
+            protected override SliderCircleOverlay CreateCircleOverlay(Slider slider, SliderPosition position) => new TestSliderCircleOverlay(slider, position);
         }
 
-        private class TestSliderCircleBlueprint : SliderCircleSelectionBlueprint
+        private class TestSliderCircleOverlay : SliderCircleOverlay
         {
             public new HitCirclePiece CirclePiece => base.CirclePiece;
 
-            public TestSliderCircleBlueprint(DrawableSlider slider, SliderPosition position)
+            public TestSliderCircleOverlay(Slider slider, SliderPosition position)
                 : base(slider, position)
             {
             }

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

@@ -43,7 +43,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty { CircleSize = 2 });
 
             Add(drawableObject = new DrawableSlider(slider));
-            AddBlueprint(blueprint = new TestSliderBlueprint(drawableObject));
+            AddBlueprint(blueprint = new TestSliderBlueprint(slider), drawableObject);
         });
 
         [Test]
@@ -174,10 +174,10 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             AddAssert("body positioned correctly", () => blueprint.BodyPiece.Position == slider.StackedPosition);
 
             AddAssert("head positioned correctly",
-                () => Precision.AlmostEquals(blueprint.HeadBlueprint.CirclePiece.ScreenSpaceDrawQuad.Centre, drawableObject.HeadCircle.ScreenSpaceDrawQuad.Centre));
+                () => Precision.AlmostEquals(blueprint.HeadOverlay.CirclePiece.ScreenSpaceDrawQuad.Centre, drawableObject.HeadCircle.ScreenSpaceDrawQuad.Centre));
 
             AddAssert("tail positioned correctly",
-                () => Precision.AlmostEquals(blueprint.TailBlueprint.CirclePiece.ScreenSpaceDrawQuad.Centre, drawableObject.TailCircle.ScreenSpaceDrawQuad.Centre));
+                () => Precision.AlmostEquals(blueprint.TailOverlay.CirclePiece.ScreenSpaceDrawQuad.Centre, drawableObject.TailCircle.ScreenSpaceDrawQuad.Centre));
         }
 
         private void moveMouseToControlPoint(int index)
@@ -195,23 +195,23 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
         private class TestSliderBlueprint : SliderSelectionBlueprint
         {
             public new SliderBodyPiece BodyPiece => base.BodyPiece;
-            public new TestSliderCircleBlueprint HeadBlueprint => (TestSliderCircleBlueprint)base.HeadBlueprint;
+            public new TestSliderCircleOverlay HeadOverlay => (TestSliderCircleOverlay)base.HeadOverlay;
-            public new TestSliderCircleBlueprint TailBlueprint => (TestSliderCircleBlueprint)base.TailBlueprint;
+            public new TestSliderCircleOverlay TailOverlay => (TestSliderCircleOverlay)base.TailOverlay;
             public new PathControlPointVisualiser ControlPointVisualiser => base.ControlPointVisualiser;
 
-            public TestSliderBlueprint(DrawableSlider slider)
+            public TestSliderBlueprint(Slider slider)
                 : base(slider)
             {
             }
 
-            protected override SliderCircleSelectionBlueprint CreateCircleSelectionBlueprint(DrawableSlider slider, SliderPosition position) => new TestSliderCircleBlueprint(slider, position);
+            protected override SliderCircleOverlay CreateCircleOverlay(Slider slider, SliderPosition position) => new TestSliderCircleOverlay(slider, position);
         }
 
-        private class TestSliderCircleBlueprint : SliderCircleSelectionBlueprint
+        private class TestSliderCircleOverlay : SliderCircleOverlay
         {
             public new HitCirclePiece CirclePiece => base.CirclePiece;
 
-            public TestSliderCircleBlueprint(DrawableSlider slider, SliderPosition position)
+            public TestSliderCircleOverlay(Slider slider, SliderPosition position)
                 : base(slider, position)
             {
             }

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

@@ -35,7 +35,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
                 Child = drawableSpinner = new DrawableSpinner(spinner)
             });
 
-            AddBlueprint(new SpinnerSelectionBlueprint(drawableSpinner) { Size = new Vector2(0.5f) });
+            AddBlueprint(new SpinnerSelectionBlueprint(spinner) { Size = new Vector2(0.5f) }, drawableSpinner);
         }
     }
 }

osu.Game.Rulesets.Osu/Edit/Blueprints/HitCircles/HitCircleSelectionBlueprint.cs

@@ -15,8 +15,8 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles
 
         protected readonly HitCirclePiece CirclePiece;
 
-        public HitCircleSelectionBlueprint(DrawableHitCircle drawableCircle)
+        public HitCircleSelectionBlueprint(HitCircle circle)
-            : base(drawableCircle)
+            : base(circle)
         {
             InternalChild = CirclePiece = new HitCirclePiece();
         }

osu.Game.Rulesets.Osu/Edit/Blueprints/OsuSelectionBlueprint.cs

@@ -2,20 +2,20 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Game.Rulesets.Edit;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Osu.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Osu.Edit.Blueprints
 {
-    public abstract class OsuSelectionBlueprint<T> : OverlaySelectionBlueprint
+    public abstract class OsuSelectionBlueprint<T> : HitObjectSelectionBlueprint<T>
         where T : OsuHitObject
     {
-        protected T HitObject => (T)DrawableObject.HitObject;
+        protected new DrawableOsuHitObject DrawableObject => (DrawableOsuHitObject)base.DrawableObject;
 
         protected override bool AlwaysShowWhenSelected => true;
 
-        protected OsuSelectionBlueprint(DrawableHitObject drawableObject)
+        protected OsuSelectionBlueprint(T hitObject)
-            : base(drawableObject)
+            : base(hitObject)
         {
         }
     }

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

@@ -1,36 +1,32 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Graphics.Containers;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Objects;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
 {
-    public class SliderCircleSelectionBlueprint : OsuSelectionBlueprint<Slider>
+    public class SliderCircleOverlay : CompositeDrawable
     {
         protected readonly HitCirclePiece CirclePiece;
 
+        private readonly Slider slider;
         private readonly SliderPosition position;
 
-        public SliderCircleSelectionBlueprint(DrawableSlider slider, SliderPosition position)
+        public SliderCircleOverlay(Slider slider, SliderPosition position)
-            : base(slider)
         {
+            this.slider = slider;
             this.position = position;
 
             InternalChild = CirclePiece = new HitCirclePiece();
-
-            Select();
         }
 
         protected override void Update()
         {
             base.Update();
 
-            CirclePiece.UpdateFrom(position == SliderPosition.Start ? (HitCircle)HitObject.HeadCircle : HitObject.TailCircle);
+            CirclePiece.UpdateFrom(position == SliderPosition.Start ? (HitCircle)slider.HeadCircle : slider.TailCircle);
         }
-
-        // Todo: This is temporary, since the slider circle masks don't do anything special yet. In the future they will handle input.
-        public override bool HandlePositionalInput => false;
     }
 }

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

@@ -16,7 +16,6 @@ using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components;
 using osu.Game.Rulesets.Osu.Objects;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
 using osu.Game.Screens.Edit;
 using osu.Game.Screens.Edit.Compose;
 using osuTK;
@@ -27,14 +26,12 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
     public class SliderSelectionBlueprint : OsuSelectionBlueprint<Slider>
     {
         protected SliderBodyPiece BodyPiece { get; private set; }
-        protected SliderCircleSelectionBlueprint HeadBlueprint { get; private set; }
+        protected SliderCircleOverlay HeadOverlay { get; private set; }
-        protected SliderCircleSelectionBlueprint TailBlueprint { get; private set; }
+        protected SliderCircleOverlay TailOverlay { get; private set; }
 
         [CanBeNull]
         protected PathControlPointVisualiser ControlPointVisualiser { get; private set; }
 
-        private readonly DrawableSlider slider;
-
         [Resolved(CanBeNull = true)]
         private HitObjectComposer composer { get; set; }
 
@@ -52,10 +49,9 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
         private readonly BindableList<PathControlPoint> controlPoints = new BindableList<PathControlPoint>();
         private readonly IBindable<int> pathVersion = new Bindable<int>();
 
-        public SliderSelectionBlueprint(DrawableSlider slider)
+        public SliderSelectionBlueprint(Slider slider)
             : base(slider)
         {
-            this.slider = slider;
         }
 
         [BackgroundDependencyLoader]
@@ -64,8 +60,8 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
             InternalChildren = new Drawable[]
             {
                 BodyPiece = new SliderBodyPiece(),
-                HeadBlueprint = CreateCircleSelectionBlueprint(slider, SliderPosition.Start),
+                HeadOverlay = CreateCircleOverlay(HitObject, SliderPosition.Start),
-                TailBlueprint = CreateCircleSelectionBlueprint(slider, SliderPosition.End),
+                TailOverlay = CreateCircleOverlay(HitObject, SliderPosition.End),
             };
         }
 
@@ -103,7 +99,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
 
         protected override void OnSelected()
         {
-            AddInternal(ControlPointVisualiser = new PathControlPointVisualiser(slider.HitObject, true)
+            AddInternal(ControlPointVisualiser = new PathControlPointVisualiser(HitObject, true)
             {
                 RemoveControlPointsRequested = removeControlPoints
             });
@@ -215,7 +211,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
             }
 
             // If there are 0 or 1 remaining control points, the slider is in a degenerate (single point) form and should be deleted
-            if (controlPoints.Count <= 1 || !slider.HitObject.Path.HasValidLength)
+            if (controlPoints.Count <= 1 || !HitObject.Path.HasValidLength)
             {
                 placementHandler?.Delete(HitObject);
                 return;
@@ -245,6 +241,6 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) =>
             BodyPiece.ReceivePositionalInputAt(screenSpacePos) || ControlPointVisualiser?.Pieces.Any(p => p.ReceivePositionalInputAt(screenSpacePos)) == true;
 
-        protected virtual SliderCircleSelectionBlueprint CreateCircleSelectionBlueprint(DrawableSlider slider, SliderPosition position) => new SliderCircleSelectionBlueprint(slider, position);
+        protected virtual SliderCircleOverlay CreateCircleOverlay(Slider slider, SliderPosition position) => new SliderCircleOverlay(slider, position);
     }
 }

osu.Game.Rulesets.Osu/Edit/Blueprints/Spinners/SpinnerSelectionBlueprint.cs

@@ -3,7 +3,6 @@
 
 using osu.Game.Rulesets.Osu.Edit.Blueprints.Spinners.Components;
 using osu.Game.Rulesets.Osu.Objects;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
 using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Spinners
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Spinners
     {
         private readonly SpinnerPiece piece;
 
-        public SpinnerSelectionBlueprint(DrawableSpinner spinner)
+        public SpinnerSelectionBlueprint(Spinner spinner)
             : base(spinner)
         {
             InternalChild = piece = new SpinnerPiece();

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

@@ -3,11 +3,10 @@
 
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.Spinners;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
+using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Screens.Edit.Compose.Components;
 
 namespace osu.Game.Rulesets.Osu.Edit
@@ -21,21 +20,21 @@ namespace osu.Game.Rulesets.Osu.Edit
 
         protected override SelectionHandler<HitObject> CreateSelectionHandler() => new OsuSelectionHandler();
 
-        public override OverlaySelectionBlueprint CreateBlueprintFor(DrawableHitObject hitObject)
+        public override HitObjectSelectionBlueprint CreateHitObjectBlueprintFor(HitObject hitObject)
         {
             switch (hitObject)
             {
-                case DrawableHitCircle circle:
+                case HitCircle circle:
                     return new HitCircleSelectionBlueprint(circle);
 
-                case DrawableSlider slider:
+                case Slider slider:
                     return new SliderSelectionBlueprint(slider);
 
-                case DrawableSpinner spinner:
+                case Spinner spinner:
                     return new SpinnerSelectionBlueprint(spinner);
             }
 
-            return base.CreateBlueprintFor(hitObject);
+            return base.CreateHitObjectBlueprintFor(hitObject);
         }
     }
 }

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

@@ -12,12 +12,23 @@ using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Screens.Edit.Compose.Components;
-using osuTK;
+using Vector2 = osuTK.Vector2;
 
 namespace osu.Game.Rulesets.Osu.Edit
 {
     public class OsuSelectionHandler : EditorSelectionHandler
     {
+        /// <summary>
+        /// During a transform, the initial origin is stored so it can be used throughout the operation.
+        /// </summary>
+        private Vector2? referenceOrigin;
+
+        /// <summary>
+        /// During a transform, the initial path types of a single selected slider are stored so they
+        /// can be maintained throughout the operation.
+        /// </summary>
+        private List<PathType?> referencePathTypes;
+
         protected override void OnSelectionChanged()
         {
             base.OnSelectionChanged();
@@ -50,17 +61,6 @@ namespace osu.Game.Rulesets.Osu.Edit
             return true;
         }
 
-        /// <summary>
-        /// During a transform, the initial origin is stored so it can be used throughout the operation.
-        /// </summary>
-        private Vector2? referenceOrigin;
-
-        /// <summary>
-        /// During a transform, the initial path types of a single selected slider are stored so they
-        /// can be maintained throughout the operation.
-        /// </summary>
-        private List<PathType?> referencePathTypes;
-
         public override bool HandleReverse()
         {
             var hitObjects = EditorBeatmap.SelectedHitObjects;
@@ -114,24 +114,10 @@ namespace osu.Game.Rulesets.Osu.Edit
             var hitObjects = selectedMovableObjects;
 
             var selectedObjectsQuad = getSurroundingQuad(hitObjects);
-            var centre = selectedObjectsQuad.Centre;
 
             foreach (var h in hitObjects)
             {
-                var pos = h.Position;
+                h.Position = GetFlippedPosition(direction, selectedObjectsQuad, h.Position);
-
-                switch (direction)
-                {
-                    case Direction.Horizontal:
-                        pos.X = centre.X - (pos.X - centre.X);
-                        break;
-
-                    case Direction.Vertical:
-                        pos.Y = centre.Y - (pos.Y - centre.Y);
-                        break;
-                }
-
-                h.Position = pos;
 
                 if (h is Slider slider)
                 {
@@ -204,7 +190,7 @@ namespace osu.Game.Rulesets.Osu.Edit
         {
             referencePathTypes ??= slider.Path.ControlPoints.Select(p => p.Type.Value).ToList();
 
-            Quad sliderQuad = getSurroundingQuad(slider.Path.ControlPoints.Select(p => p.Position.Value));
+            Quad sliderQuad = GetSurroundingQuad(slider.Path.ControlPoints.Select(p => p.Position.Value));
 
             // Limit minimum distance between control points after scaling to almost 0. Less than 0 causes the slider to flip, exactly 0 causes a crash through division by 0.
             scale = Vector2.ComponentMax(new Vector2(Precision.FLOAT_EPSILON), sliderQuad.Size + scale) - sliderQuad.Size;
@@ -333,7 +319,7 @@ namespace osu.Game.Rulesets.Osu.Edit
         /// </summary>
         /// <param name="hitObjects">The hit objects to calculate a quad for.</param>
         private Quad getSurroundingQuad(OsuHitObject[] hitObjects) =>
-            getSurroundingQuad(hitObjects.SelectMany(h =>
+            GetSurroundingQuad(hitObjects.SelectMany(h =>
             {
                 if (h is IHasPath path)
                 {
@@ -348,30 +334,6 @@ namespace osu.Game.Rulesets.Osu.Edit
                 return new[] { h.Position };
             }));
 
-        /// <summary>
-        /// Returns a gamefield-space quad surrounding the provided points.
-        /// </summary>
-        /// <param name="points">The points to calculate a quad for.</param>
-        private Quad getSurroundingQuad(IEnumerable<Vector2> points)
-        {
-            if (!EditorBeatmap.SelectedHitObjects.Any())
-                return new Quad();
-
-            Vector2 minPosition = new Vector2(float.MaxValue, float.MaxValue);
-            Vector2 maxPosition = new Vector2(float.MinValue, float.MinValue);
-
-            // Go through all hitobjects to make sure they would remain in the bounds of the editor after movement, before any movement is attempted
-            foreach (var p in points)
-            {
-                minPosition = Vector2.ComponentMin(minPosition, p);
-                maxPosition = Vector2.ComponentMax(maxPosition, p);
-            }
-
-            Vector2 size = maxPosition - minPosition;
-
-            return new Quad(minPosition.X, minPosition.Y, size.X, size.Y);
-        }
-
         /// <summary>
         /// All osu! hitobjects which can be moved/rotated/scaled.
         /// </summary>

osu.Game.Rulesets.Osu/Statistics/AccuracyHeatmap.cs

@@ -166,7 +166,7 @@ namespace osu.Game.Rulesets.Osu.Statistics
 
                     var point = new HitPoint(pointType, this)
                     {
-                        Colour = pointType == HitPointType.Hit ? new Color4(102, 255, 204, 255) : new Color4(255, 102, 102, 255)
+                        BaseColour = pointType == HitPointType.Hit ? new Color4(102, 255, 204, 255) : new Color4(255, 102, 102, 255)
                     };
 
                     points[r][c] = point;
@@ -234,6 +234,11 @@ namespace osu.Game.Rulesets.Osu.Statistics
 
         private class HitPoint : Circle
         {
+            /// <summary>
+            /// The base colour which will be lightened/darkened depending on the value of this <see cref="HitPoint"/>.
+            /// </summary>
+            public Color4 BaseColour;
+
             private readonly HitPointType pointType;
             private readonly AccuracyHeatmap heatmap;
 
@@ -284,7 +289,7 @@ namespace osu.Game.Rulesets.Osu.Statistics
 
                 Alpha = Math.Min(amount / lighten_cutoff, 1);
                 if (pointType == HitPointType.Hit)
-                    Colour = ((Color4)Colour).Lighten(Math.Max(0, amount - lighten_cutoff));
+                    Colour = BaseColour.Lighten(Math.Max(0, amount - lighten_cutoff));
             }
         }
 

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

@@ -40,7 +40,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
 
         [SetUpSteps]
         public void SetUp()
-            => AddStep("clear SHOC", () => hitObjectContainer.Clear(false));
+            => AddStep("clear SHOC", () => hitObjectContainer.Clear());
 
         protected void AddHitObject(DrawableHitObject hitObject)
             => AddStep("add to SHOC", () => hitObjectContainer.Add(hitObject));

osu.Game.Rulesets.Taiko/Edit/Blueprints/TaikoSelectionBlueprint.cs

@@ -3,14 +3,14 @@
 
 using osu.Framework.Graphics;
 using osu.Game.Rulesets.Edit;
-using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Objects;
 using osuTK;
 
 namespace osu.Game.Rulesets.Taiko.Edit.Blueprints
 {
-    public class TaikoSelectionBlueprint : OverlaySelectionBlueprint
+    public class TaikoSelectionBlueprint : HitObjectSelectionBlueprint
     {
-        public TaikoSelectionBlueprint(DrawableHitObject hitObject)
+        public TaikoSelectionBlueprint(HitObject hitObject)
             : base(hitObject)
         {
             RelativeSizeAxes = Axes.None;

osu.Game.Rulesets.Taiko/Edit/TaikoBlueprintContainer.cs

@@ -3,7 +3,6 @@
 
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Taiko.Edit.Blueprints;
 using osu.Game.Screens.Edit.Compose.Components;
 
@@ -18,7 +17,7 @@ namespace osu.Game.Rulesets.Taiko.Edit
 
         protected override SelectionHandler<HitObject> CreateSelectionHandler() => new TaikoSelectionHandler();
 
-        public override OverlaySelectionBlueprint CreateBlueprintFor(DrawableHitObject hitObject) =>
+        public override HitObjectSelectionBlueprint CreateHitObjectBlueprintFor(HitObject hitObject) =>
             new TaikoSelectionBlueprint(hitObject);
     }
 }

osu.Game.Tests/Editing/TestSceneHitObjectContainerEventBuffer.cs

@@ -0,0 +1,175 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Testing;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.UI;
+using osu.Game.Screens.Edit.Compose;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.Editing
+{
+    [HeadlessTest]
+    public class TestSceneHitObjectContainerEventBuffer : OsuTestScene
+    {
+        private readonly TestHitObject testObj = new TestHitObject();
+
+        private TestPlayfield playfield1;
+        private TestPlayfield playfield2;
+        private TestDrawable intermediateDrawable;
+        private HitObjectUsageEventBuffer eventBuffer;
+
+        private HitObject beganUsage;
+        private HitObject finishedUsage;
+        private HitObject transferredUsage;
+
+        [SetUp]
+        public void Setup() => Schedule(() =>
+        {
+            reset();
+
+            if (eventBuffer != null)
+            {
+                eventBuffer.HitObjectUsageBegan -= onHitObjectUsageBegan;
+                eventBuffer.HitObjectUsageFinished -= onHitObjectUsageFinished;
+                eventBuffer.HitObjectUsageTransferred -= onHitObjectUsageTransferred;
+            }
+
+            var topPlayfield = new TestPlayfield();
+            topPlayfield.AddNested(playfield1 = new TestPlayfield());
+            topPlayfield.AddNested(playfield2 = new TestPlayfield());
+
+            eventBuffer = new HitObjectUsageEventBuffer(topPlayfield);
+            eventBuffer.HitObjectUsageBegan += onHitObjectUsageBegan;
+            eventBuffer.HitObjectUsageFinished += onHitObjectUsageFinished;
+            eventBuffer.HitObjectUsageTransferred += onHitObjectUsageTransferred;
+
+            Children = new Drawable[]
+            {
+                topPlayfield,
+                intermediateDrawable = new TestDrawable(),
+            };
+        });
+
+        private void onHitObjectUsageBegan(HitObject obj) => beganUsage = obj;
+
+        private void onHitObjectUsageFinished(HitObject obj) => finishedUsage = obj;
+
+        private void onHitObjectUsageTransferred(HitObject obj, DrawableHitObject drawableObj) => transferredUsage = obj;
+
+        [Test]
+        public void TestUsageBeganAfterAdd()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addCheckStep(began: true);
+        }
+
+        [Test]
+        public void TestUsageFinishedAfterRemove()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("remove hitobject", () => playfield1.Remove(testObj));
+            addCheckStep(finished: true);
+        }
+
+        [Test]
+        public void TestUsageTransferredWhenMovedBetweenPlayfields()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("transfer hitobject to other playfield", () =>
+            {
+                playfield1.Remove(testObj);
+                playfield2.Add(testObj);
+            });
+
+            addCheckStep(transferred: true);
+        }
+
+        [Test]
+        public void TestRemoveImmediatelyAfterUsageBegan()
+        {
+            AddStep("add hitobject and schedule removal", () =>
+            {
+                playfield1.Add(testObj);
+                intermediateDrawable.Schedule(() => playfield1.Remove(testObj));
+            });
+
+            addCheckStep(began: true, finished: true);
+        }
+
+        [Test]
+        public void TestRemoveImmediatelyAfterTransferred()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("transfer hitobject to other playfield and schedule removal", () =>
+            {
+                playfield1.Remove(testObj);
+                playfield2.Add(testObj);
+                intermediateDrawable.Schedule(() => playfield2.Remove(testObj));
+            });
+
+            addCheckStep(transferred: true, finished: true);
+        }
+
+        protected override void UpdateAfterChildren()
+        {
+            base.UpdateAfterChildren();
+            eventBuffer.Update();
+        }
+
+        private void addResetStep() => AddStep("reset", reset);
+
+        private void reset()
+        {
+            beganUsage = null;
+            finishedUsage = null;
+            transferredUsage = null;
+        }
+
+        private void addCheckStep(bool began = false, bool finished = false, bool transferred = false)
+            => AddAssert($"began = {began}, finished = {finished}, transferred = {transferred}",
+                () => (beganUsage == testObj) == began && (finishedUsage == testObj) == finished && (transferredUsage == testObj) == transferred);
+
+        private class TestPlayfield : Playfield
+        {
+            public TestPlayfield()
+            {
+                RegisterPool<TestHitObject, TestDrawableHitObject>(1);
+            }
+
+            public new void AddNested(Playfield playfield)
+            {
+                AddInternal(playfield);
+                base.AddNested(playfield);
+            }
+
+            protected override HitObjectLifetimeEntry CreateLifetimeEntry(HitObject hitObject)
+            {
+                var entry = base.CreateLifetimeEntry(hitObject);
+                entry.KeepAlive = true;
+                return entry;
+            }
+        }
+
+        private class TestHitObject : HitObject
+        {
+            public override string ToString() => "TestHitObject";
+        }
+
+        private class TestDrawableHitObject : DrawableHitObject
+        {
+        }
+
+        private class TestDrawable : Drawable
+        {
+            public new void Schedule(Action action) => base.Schedule(action);
+        }
+    }
+}

osu.Game.Tests/Gameplay/TestSceneDrawableHitObject.cs

@@ -45,15 +45,16 @@ namespace osu.Game.Tests.Gameplay
             AddStep("Create DHO", () =>
             {
                 dho = new TestDrawableHitObject(null);
-                dho.Apply(entry = new TestLifetimeEntry(new HitObject())
+                dho.Apply(entry = new TestLifetimeEntry(new HitObject()));
-                {
-                    LifetimeStart = 0,
-                    LifetimeEnd = 1000,
-                });
                 Child = dho;
             });
 
-            AddStep("KeepAlive = true", () => entry.KeepAlive = true);
+            AddStep("KeepAlive = true", () =>
+            {
+                entry.LifetimeStart = 0;
+                entry.LifetimeEnd = 1000;
+                entry.KeepAlive = true;
+            });
             AddAssert("Lifetime is overriden", () => entry.LifetimeStart == double.MinValue && entry.LifetimeEnd == double.MaxValue);
 
             AddStep("Set LifetimeStart", () => dho.LifetimeStart = 500);

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

@@ -0,0 +1,152 @@
+// 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 NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Testing;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Overlays;
+using osu.Game.Overlays.News.Sidebar;
+using static osu.Game.Overlays.News.Sidebar.YearsPanel;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    public class TestSceneNewsSidebar : OsuTestScene
+    {
+        [Cached]
+        private readonly OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Purple);
+
+        private TestNewsSidebar sidebar;
+
+        [SetUp]
+        public void SetUp() => Schedule(() => Child = sidebar = new TestNewsSidebar { YearChanged = onYearChanged });
+
+        [Test]
+        public void TestBasic()
+        {
+            AddStep("Add metadata", () => sidebar.Metadata.Value = getMetadata(2021));
+            AddUntilStep("Month sections exist", () => sidebar.ChildrenOfType<MonthSection>().Any());
+        }
+
+        [Test]
+        public void TestMetadataWithNoPosts()
+        {
+            AddStep("Add data with no posts", () => sidebar.Metadata.Value = metadata_with_no_posts);
+            AddUntilStep("No month sections were created", () => !sidebar.ChildrenOfType<MonthSection>().Any());
+        }
+
+        [Test]
+        public void TestYearsPanelVisibility()
+        {
+            AddUntilStep("Years panel is hidden", () => yearsPanel?.Alpha == 0);
+            AddStep("Add data", () => sidebar.Metadata.Value = getMetadata(2021));
+            AddUntilStep("Years panel is visible", () => yearsPanel?.Alpha == 1);
+        }
+
+        private void onYearChanged(int year) => sidebar.Metadata.Value = getMetadata(year);
+
+        private YearsPanel yearsPanel => sidebar.ChildrenOfType<YearsPanel>().FirstOrDefault();
+
+        private APINewsSidebar getMetadata(int year) => new APINewsSidebar
+        {
+            CurrentYear = year,
+            Years = new[]
+            {
+                2021,
+                2020,
+                2019,
+                2018,
+                2017,
+                2016,
+                2015,
+                2014,
+                2013
+            },
+            NewsPosts = new List<APINewsPost>
+            {
+                new APINewsPost
+                {
+                    Title = "(Mar) Short title",
+                    PublishedAt = new DateTime(year, 3, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "(Mar) Oh boy that's a long post title I wonder if it will break anything",
+                    PublishedAt = new DateTime(year, 3, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "(Mar) Medium title, nothing to see here",
+                    PublishedAt = new DateTime(year, 3, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "(Feb) Short title",
+                    PublishedAt = new DateTime(year, 2, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "(Feb) Oh boy that's a long post title I wonder if it will break anything",
+                    PublishedAt = new DateTime(year, 2, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "(Feb) Medium title, nothing to see here",
+                    PublishedAt = new DateTime(year, 2, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "Short title",
+                    PublishedAt = new DateTime(year, 1, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "Oh boy that's a long post title I wonder if it will break anything",
+                    PublishedAt = new DateTime(year, 1, 1)
+                },
+                new APINewsPost
+                {
+                    Title = "Medium title, nothing to see here",
+                    PublishedAt = new DateTime(year, 1, 1)
+                }
+            }
+        };
+
+        private static readonly APINewsSidebar metadata_with_no_posts = new APINewsSidebar
+        {
+            CurrentYear = 2021,
+            Years = new[]
+            {
+                2021,
+                2020,
+                2019,
+                2018,
+                2017,
+                2016,
+                2015,
+                2014,
+                2013
+            },
+            NewsPosts = Array.Empty<APINewsPost>()
+        };
+
+        private class TestNewsSidebar : NewsSidebar
+        {
+            public Action<int> YearChanged;
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+
+                Metadata.BindValueChanged(metadata =>
+                {
+                    foreach (var b in this.ChildrenOfType<YearButton>())
+                        b.Action = () => YearChanged?.Invoke(b.Year);
+                }, true);
+            }
+        }
+    }
+}

osu.Game/Online/API/Requests/GetNewsResponse.cs

@@ -11,5 +11,8 @@ namespace osu.Game.Online.API.Requests
     {
         [JsonProperty("news_posts")]
         public IEnumerable<APINewsPost> NewsPosts;
+
+        [JsonProperty("news_sidebar")]
+        public APINewsSidebar SidebarMetadata;
     }
 }

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

@@ -0,0 +1,20 @@
+// 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 Newtonsoft.Json;
+using System.Collections.Generic;
+
+namespace osu.Game.Online.API.Requests.Responses
+{
+    public class APINewsSidebar
+    {
+        [JsonProperty("current_year")]
+        public int CurrentYear { get; set; }
+
+        [JsonProperty("news_posts")]
+        public IEnumerable<APINewsPost> NewsPosts { get; set; }
+
+        [JsonProperty("years")]
+        public int[] Years { get; set; }
+    }
+}

osu.Game/Online/Chat/DrawableLinkCompiler.cs

@@ -8,6 +8,7 @@ using osu.Framework.Graphics;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.UserInterface;
+using osu.Game.Overlays;
 using osuTK;
 
 namespace osu.Game.Online.Chat
@@ -20,7 +21,10 @@ namespace osu.Game.Online.Chat
         /// <summary>
         /// Each word part of a chat link (split for word-wrap support).
         /// </summary>
-        public List<Drawable> Parts;
+        public readonly List<Drawable> Parts;
+
+        [Resolved(CanBeNull = true)]
+        private OverlayColourProvider overlayColourProvider { get; set; }
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => Parts.Any(d => d.ReceivePositionalInputAt(screenSpacePos));
 
@@ -34,7 +38,7 @@ namespace osu.Game.Online.Chat
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
-            IdleColour = colours.Blue;
+            IdleColour = overlayColourProvider?.Light2 ?? colours.Blue;
         }
 
         protected override IEnumerable<Drawable> EffectTargets => Parts;

osu.Game/Online/Multiplayer/StatefulMultiplayerClient.cs

@@ -92,10 +92,6 @@ namespace osu.Game.Online.Multiplayer
         [Resolved]
         private UserLookupCache userLookupCache { get; set; } = null!;
 
-        // Only exists for compatibility with old osu-server-spectator build.
-        // Todo: Can be removed on 2021/02/26.
-        private long defaultPlaylistItemId;
-
         private Room? apiRoom;
 
         [BackgroundDependencyLoader]
@@ -143,7 +139,6 @@ namespace osu.Game.Online.Multiplayer
                 {
                     Room = joinedRoom;
                     apiRoom = room;
-                    defaultPlaylistItemId = apiRoom.Playlist.FirstOrDefault()?.ID ?? 0;
                     foreach (var user in joinedRoom.Users)
                         updateUserPlayingState(user.UserID, user.State);
                 }, cancellationSource.Token).ConfigureAwait(false);
@@ -581,7 +576,7 @@ namespace osu.Game.Online.Multiplayer
 
             void updateItem(PlaylistItem item)
             {
-                item.ID = settings.PlaylistItemId == 0 ? defaultPlaylistItemId : settings.PlaylistItemId;
+                item.ID = settings.PlaylistItemId;
                 item.Beatmap.Value = beatmap;
                 item.Ruleset.Value = ruleset.RulesetInfo;
                 item.RequiredMods.Clear();

osu.Game/Overlays/News/Sidebar/MonthSection.cs

@@ -0,0 +1,179 @@
+// 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 osu.Framework.Bindables;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Graphics.Containers;
+using osuTK;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics;
+using System.Linq;
+using System.Collections.Generic;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics.Sprites;
+using System.Diagnostics;
+using osu.Framework.Platform;
+
+namespace osu.Game.Overlays.News.Sidebar
+{
+    public class MonthSection : CompositeDrawable
+    {
+        private const int animation_duration = 250;
+
+        public readonly BindableBool Expanded = new BindableBool();
+
+        public MonthSection(int month, int year, IEnumerable<APINewsPost> posts)
+        {
+            Debug.Assert(posts.All(p => p.PublishedAt.Month == month && p.PublishedAt.Year == year));
+
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+            Masking = true;
+
+            InternalChild = new FillFlowContainer
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y,
+                Direction = FillDirection.Vertical,
+                Children = new Drawable[]
+                {
+                    new DropdownHeader(month, year)
+                    {
+                        Expanded = { BindTarget = Expanded }
+                    },
+                    new PostsContainer
+                    {
+                        Expanded = { BindTarget = Expanded },
+                        Children = posts.Select(p => new PostButton(p)).ToArray()
+                    }
+                }
+            };
+        }
+
+        private class DropdownHeader : OsuClickableContainer
+        {
+            public readonly BindableBool Expanded = new BindableBool();
+
+            private readonly SpriteIcon icon;
+
+            public DropdownHeader(int month, int year)
+            {
+                var date = new DateTime(year, month, 1);
+
+                RelativeSizeAxes = Axes.X;
+                Height = 15;
+                Action = Expanded.Toggle;
+                Children = new Drawable[]
+                {
+                    new OsuSpriteText
+                    {
+                        Anchor = Anchor.CentreLeft,
+                        Origin = Anchor.CentreLeft,
+                        Font = OsuFont.GetFont(size: 12, weight: FontWeight.Bold),
+                        Text = date.ToString("MMM yyyy")
+                    },
+                    icon = new SpriteIcon
+                    {
+                        Anchor = Anchor.CentreRight,
+                        Origin = Anchor.CentreRight,
+                        Size = new Vector2(10),
+                        Icon = FontAwesome.Solid.ChevronDown
+                    }
+                };
+            }
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+
+                Expanded.BindValueChanged(open =>
+                {
+                    icon.Scale = new Vector2(1, open.NewValue ? -1 : 1);
+                }, true);
+            }
+        }
+
+        private class PostButton : OsuHoverContainer
+        {
+            protected override IEnumerable<Drawable> EffectTargets => new[] { text };
+
+            private readonly TextFlowContainer text;
+            private readonly APINewsPost post;
+
+            public PostButton(APINewsPost post)
+            {
+                this.post = post;
+
+                RelativeSizeAxes = Axes.X;
+                AutoSizeAxes = Axes.Y;
+                Child = text = new TextFlowContainer(t => t.Font = OsuFont.GetFont(size: 12))
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Text = post.Title
+                };
+            }
+
+            [BackgroundDependencyLoader]
+            private void load(OverlayColourProvider overlayColours, GameHost host)
+            {
+                IdleColour = overlayColours.Light2;
+                HoverColour = overlayColours.Light1;
+
+                TooltipText = "view in browser";
+                Action = () => host.OpenUrlExternally("https://osu.ppy.sh/home/news/" + post.Slug);
+            }
+        }
+
+        private class PostsContainer : Container
+        {
+            public readonly BindableBool Expanded = new BindableBool();
+
+            protected override Container<Drawable> Content { get; }
+
+            public PostsContainer()
+            {
+                RelativeSizeAxes = Axes.X;
+                AutoSizeAxes = Axes.Y;
+                AutoSizeDuration = animation_duration;
+                AutoSizeEasing = Easing.Out;
+                InternalChild = Content = new FillFlowContainer
+                {
+                    Margin = new MarginPadding { Top = 5 },
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Direction = FillDirection.Vertical,
+                    Spacing = new Vector2(0, 5),
+                    Alpha = 0
+                };
+            }
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+                Expanded.BindValueChanged(updateState, true);
+            }
+
+            private void updateState(ValueChangedEvent<bool> expanded)
+            {
+                ClearTransforms(true);
+
+                if (expanded.NewValue)
+                {
+                    AutoSizeAxes = Axes.Y;
+                    Content.FadeIn(animation_duration, Easing.OutQuint);
+                }
+                else
+                {
+                    AutoSizeAxes = Axes.None;
+                    this.ResizeHeightTo(0, animation_duration, Easing.OutQuint);
+
+                    Content.FadeOut(animation_duration, Easing.OutQuint);
+                }
+            }
+        }
+    }
+}

osu.Game/Overlays/News/Sidebar/NewsSidebar.cs

@@ -0,0 +1,103 @@
+// 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.Containers;
+using osu.Framework.Graphics;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Framework.Graphics.Shapes;
+using osuTK;
+using System.Linq;
+
+namespace osu.Game.Overlays.News.Sidebar
+{
+    public class NewsSidebar : CompositeDrawable
+    {
+        [Cached]
+        public readonly Bindable<APINewsSidebar> Metadata = new Bindable<APINewsSidebar>();
+
+        private FillFlowContainer<MonthSection> monthsFlow;
+
+        [BackgroundDependencyLoader]
+        private void load(OverlayColourProvider colourProvider)
+        {
+            RelativeSizeAxes = Axes.Y;
+            Width = 250;
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Colour = colourProvider.Background4
+                },
+                new Container
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Padding = new MarginPadding
+                    {
+                        Vertical = 20,
+                        Left = 50,
+                        Right = 30
+                    },
+                    Child = new FillFlowContainer
+                    {
+                        Direction = FillDirection.Vertical,
+                        RelativeSizeAxes = Axes.X,
+                        AutoSizeAxes = Axes.Y,
+                        Spacing = new Vector2(0, 20),
+                        Children = new Drawable[]
+                        {
+                            new YearsPanel(),
+                            monthsFlow = new FillFlowContainer<MonthSection>
+                            {
+                                AutoSizeAxes = Axes.Y,
+                                RelativeSizeAxes = Axes.X,
+                                Direction = FillDirection.Vertical,
+                                Spacing = new Vector2(0, 10)
+                            }
+                        }
+                    }
+                }
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Metadata.BindValueChanged(onMetadataChanged, true);
+        }
+
+        private void onMetadataChanged(ValueChangedEvent<APINewsSidebar> metadata)
+        {
+            monthsFlow.Clear();
+
+            if (metadata.NewValue == null)
+                return;
+
+            var allPosts = metadata.NewValue.NewsPosts;
+
+            if (allPosts?.Any() != true)
+                return;
+
+            var lookup = metadata.NewValue.NewsPosts.ToLookup(post => post.PublishedAt.Month);
+
+            var keys = lookup.Select(kvp => kvp.Key);
+            var sortedKeys = keys.OrderByDescending(k => k).ToList();
+
+            var year = metadata.NewValue.CurrentYear;
+
+            for (int i = 0; i < sortedKeys.Count; i++)
+            {
+                var month = sortedKeys[i];
+                var posts = lookup[month];
+
+                monthsFlow.Add(new MonthSection(month, year, posts)
+                {
+                    Expanded = { Value = i == 0 }
+                });
+            }
+        }
+    }
+}

osu.Game/Overlays/News/Sidebar/YearsPanel.cs

@@ -0,0 +1,113 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Containers;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Online.API.Requests.Responses;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Overlays.News.Sidebar
+{
+    public class YearsPanel : CompositeDrawable
+    {
+        private readonly Bindable<APINewsSidebar> metadata = new Bindable<APINewsSidebar>();
+
+        private FillFlowContainer yearsFlow;
+
+        [BackgroundDependencyLoader]
+        private void load(OverlayColourProvider overlayColours, Bindable<APINewsSidebar> metadata)
+        {
+            this.metadata.BindTo(metadata);
+
+            AutoSizeAxes = Axes.Y;
+            RelativeSizeAxes = Axes.X;
+            Masking = true;
+            CornerRadius = 6;
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Colour = overlayColours.Background3
+                },
+                new Container
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Padding = new MarginPadding(5),
+                    Child = yearsFlow = new FillFlowContainer
+                    {
+                        RelativeSizeAxes = Axes.X,
+                        AutoSizeAxes = Axes.Y,
+                        Spacing = new Vector2(0, 5)
+                    }
+                }
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            metadata.BindValueChanged(_ => recreateDrawables(), true);
+        }
+
+        private void recreateDrawables()
+        {
+            yearsFlow.Clear();
+
+            if (metadata.Value == null)
+            {
+                Hide();
+                return;
+            }
+
+            var currentYear = metadata.Value.CurrentYear;
+
+            foreach (var y in metadata.Value.Years)
+                yearsFlow.Add(new YearButton(y, y == currentYear));
+
+            Show();
+        }
+
+        public class YearButton : OsuHoverContainer
+        {
+            public int Year { get; }
+
+            private readonly bool isCurrent;
+
+            public YearButton(int year, bool isCurrent)
+            {
+                Year = year;
+                this.isCurrent = isCurrent;
+
+                RelativeSizeAxes = Axes.X;
+                Width = 0.25f;
+                Height = 15;
+
+                Child = new OsuSpriteText
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    Font = OsuFont.GetFont(size: 12, weight: isCurrent ? FontWeight.SemiBold : FontWeight.Medium),
+                    Text = year.ToString()
+                };
+            }
+
+            [BackgroundDependencyLoader]
+            private void load(OverlayColourProvider colourProvider)
+            {
+                IdleColour = isCurrent ? Color4.White : colourProvider.Light2;
+                HoverColour = isCurrent ? Color4.White : colourProvider.Light1;
+                Action = () => { }; // Avoid button being disabled since there's no proper action assigned.
+            }
+        }
+    }
+}

osu.Game/Rulesets/Edit/HitObjectSelectionBlueprint.cs

@@ -9,12 +9,12 @@ using osuTK;
 
 namespace osu.Game.Rulesets.Edit
 {
-    public abstract class OverlaySelectionBlueprint : SelectionBlueprint<HitObject>
+    public abstract class HitObjectSelectionBlueprint : SelectionBlueprint<HitObject>
     {
         /// <summary>
-        /// The <see cref="DrawableHitObject"/> which this <see cref="OverlaySelectionBlueprint"/> applies to.
+        /// The <see cref="DrawableHitObject"/> which this <see cref="HitObjectSelectionBlueprint"/> applies to.
         /// </summary>
-        public readonly DrawableHitObject DrawableObject;
+        public DrawableHitObject DrawableObject { get; internal set; }
 
         /// <summary>
         /// Whether the blueprint should be shown even when the <see cref="DrawableObject"/> is not alive.
@@ -23,10 +23,9 @@ namespace osu.Game.Rulesets.Edit
 
         protected override bool ShouldBeAlive => (DrawableObject.IsAlive && DrawableObject.IsPresent) || (AlwaysShowWhenSelected && State == SelectionState.Selected);
 
-        protected OverlaySelectionBlueprint(DrawableHitObject drawableObject)
+        protected HitObjectSelectionBlueprint(HitObject hitObject)
-            : base(drawableObject.HitObject)
+            : base(hitObject)
         {
-            DrawableObject = drawableObject;
         }
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => DrawableObject.ReceivePositionalInputAt(screenSpacePos);
@@ -35,4 +34,15 @@ namespace osu.Game.Rulesets.Edit
 
         public override Quad SelectionQuad => DrawableObject.ScreenSpaceDrawQuad;
     }
+
+    public abstract class HitObjectSelectionBlueprint<T> : HitObjectSelectionBlueprint
+        where T : HitObject
+    {
+        public T HitObject => (T)Item;
+
+        protected HitObjectSelectionBlueprint(T item)
+            : base(item)
+        {
+        }
+    }
 }

osu.Game/Rulesets/Edit/SelectionBlueprint.cs

@@ -105,34 +105,34 @@ namespace osu.Game.Rulesets.Edit
         protected override bool ShouldBeConsideredForInput(Drawable child) => State == SelectionState.Selected;
 
         /// <summary>
-        /// Selects this <see cref="OverlaySelectionBlueprint"/>, causing it to become visible.
+        /// Selects this <see cref="SelectionBlueprint{T}"/>, causing it to become visible.
         /// </summary>
         public void Select() => State = SelectionState.Selected;
 
         /// <summary>
-        /// Deselects this <see cref="OverlaySelectionBlueprint"/>, causing it to become invisible.
+        /// Deselects this <see cref="HitObjectSelectionBlueprint"/>, causing it to become invisible.
         /// </summary>
         public void Deselect() => State = SelectionState.NotSelected;
 
         /// <summary>
-        /// Toggles the selection state of this <see cref="OverlaySelectionBlueprint"/>.
+        /// Toggles the selection state of this <see cref="HitObjectSelectionBlueprint"/>.
         /// </summary>
         public void ToggleSelection() => State = IsSelected ? SelectionState.NotSelected : SelectionState.Selected;
 
         public bool IsSelected => State == SelectionState.Selected;
 
         /// <summary>
-        /// The <see cref="MenuItem"/>s to be displayed in the context menu for this <see cref="OverlaySelectionBlueprint"/>.
+        /// The <see cref="MenuItem"/>s to be displayed in the context menu for this <see cref="HitObjectSelectionBlueprint"/>.
         /// </summary>
         public virtual MenuItem[] ContextMenuItems => Array.Empty<MenuItem>();
 
         /// <summary>
-        /// The screen-space point that causes this <see cref="OverlaySelectionBlueprint"/> to be selected via a drag.
+        /// The screen-space point that causes this <see cref="HitObjectSelectionBlueprint"/> to be selected via a drag.
         /// </summary>
         public virtual Vector2 ScreenSpaceSelectionPoint => ScreenSpaceDrawQuad.Centre;
 
         /// <summary>
-        /// The screen-space quad that outlines this <see cref="OverlaySelectionBlueprint"/> for selections.
+        /// The screen-space quad that outlines this <see cref="HitObjectSelectionBlueprint"/> for selections.
         /// </summary>
         public virtual Quad SelectionQuad => ScreenSpaceDrawQuad;
 

osu.Game/Rulesets/Objects/Pooling/PoolableDrawableWithLifetime.cs

@@ -3,6 +3,7 @@
 
 #nullable enable
 
+using System;
 using System.Diagnostics;
 using osu.Framework.Graphics.Performance;
 using osu.Framework.Graphics.Pooling;
@@ -18,7 +19,7 @@ namespace osu.Game.Rulesets.Objects.Pooling
         /// <summary>
         /// The entry holding essential state of this <see cref="PoolableDrawableWithLifetime{TEntry}"/>.
         /// </summary>
-        protected TEntry? Entry { get; private set; }
+        public TEntry? Entry { get; private set; }
 
         /// <summary>
         /// Whether <see cref="Entry"/> is applied to this <see cref="PoolableDrawableWithLifetime{TEntry}"/>.
@@ -28,14 +29,28 @@ namespace osu.Game.Rulesets.Objects.Pooling
 
         public override double LifetimeStart
         {
-            get => base.LifetimeStart;
+            get => Entry?.LifetimeStart ?? double.MinValue;
-            set => setLifetime(value, LifetimeEnd);
+            set
+            {
+                if (Entry == null && LifetimeStart != value)
+                    throw new InvalidOperationException($"Cannot modify lifetime of {nameof(PoolableDrawableWithLifetime<TEntry>)} when entry is not set");
+
+                if (Entry != null)
+                    Entry.LifetimeStart = value;
+            }
         }
 
         public override double LifetimeEnd
         {
-            get => base.LifetimeEnd;
+            get => Entry?.LifetimeEnd ?? double.MaxValue;
-            set => setLifetime(LifetimeStart, value);
+            set
+            {
+                if (Entry == null && LifetimeEnd != value)
+                    throw new InvalidOperationException($"Cannot modify lifetime of {nameof(PoolableDrawableWithLifetime<TEntry>)} when entry is not set");
+
+                if (Entry != null)
+                    Entry.LifetimeEnd = value;
+            }
         }
 
         public override bool RemoveWhenNotAlive => false;
@@ -64,11 +79,8 @@ namespace osu.Game.Rulesets.Objects.Pooling
             if (HasEntryApplied)
                 free();
 
-            setLifetime(entry.LifetimeStart, entry.LifetimeEnd);
             Entry = entry;
-
             OnApply(entry);
-
             HasEntryApplied = true;
         }
 
@@ -95,27 +107,12 @@ namespace osu.Game.Rulesets.Objects.Pooling
         {
         }
 
-        private void setLifetime(double start, double end)
-        {
-            base.LifetimeStart = start;
-            base.LifetimeEnd = end;
-
-            if (Entry != null)
-            {
-                Entry.LifetimeStart = start;
-                Entry.LifetimeEnd = end;
-            }
-        }
-
         private void free()
         {
             Debug.Assert(Entry != null && HasEntryApplied);
 
             OnFree(Entry);
-
             Entry = null;
-            setLifetime(double.MaxValue, double.MaxValue);
-
             HasEntryApplied = false;
         }
     }

osu.Game/Rulesets/UI/HitObjectContainer.cs

@@ -17,8 +17,18 @@ using osu.Game.Rulesets.Objects.Drawables;
 
 namespace osu.Game.Rulesets.UI
 {
-    public class HitObjectContainer : LifetimeManagementContainer, IHitObjectContainer
+    public class HitObjectContainer : CompositeDrawable, IHitObjectContainer
     {
+        /// <summary>
+        /// All entries in this <see cref="HitObjectContainer"/> including dead entries.
+        /// </summary>
+        public IEnumerable<HitObjectLifetimeEntry> Entries => allEntries;
+
+        /// <summary>
+        /// All alive entries and <see cref="DrawableHitObject"/>s used by the entries.
+        /// </summary>
+        public IEnumerable<(HitObjectLifetimeEntry Entry, DrawableHitObject Drawable)> AliveEntries => aliveDrawableMap.Select(x => (x.Key, x.Value));
+
         public IEnumerable<DrawableHitObject> Objects => InternalChildren.Cast<DrawableHitObject>().OrderBy(h => h.HitObject.StartTime);
 
         public IEnumerable<DrawableHitObject> AliveObjects => AliveInternalChildren.Cast<DrawableHitObject>().OrderBy(h => h.HitObject.StartTime);
@@ -60,8 +70,12 @@ namespace osu.Game.Rulesets.UI
         internal double FutureLifetimeExtension { get; set; }
 
         private readonly Dictionary<DrawableHitObject, IBindable> startTimeMap = new Dictionary<DrawableHitObject, IBindable>();
-        private readonly Dictionary<HitObjectLifetimeEntry, DrawableHitObject> drawableMap = new Dictionary<HitObjectLifetimeEntry, DrawableHitObject>();
+
+        private readonly Dictionary<HitObjectLifetimeEntry, DrawableHitObject> aliveDrawableMap = new Dictionary<HitObjectLifetimeEntry, DrawableHitObject>();
+        private readonly Dictionary<HitObjectLifetimeEntry, DrawableHitObject> nonPooledDrawableMap = new Dictionary<HitObjectLifetimeEntry, DrawableHitObject>();
+
         private readonly LifetimeEntryManager lifetimeManager = new LifetimeEntryManager();
+        private readonly HashSet<HitObjectLifetimeEntry> allEntries = new HashSet<HitObjectLifetimeEntry>();
 
         [Resolved(CanBeNull = true)]
         private IPooledHitObjectProvider pooledObjectProvider { get; set; }
@@ -72,6 +86,7 @@ namespace osu.Game.Rulesets.UI
 
             lifetimeManager.EntryBecameAlive += entryBecameAlive;
             lifetimeManager.EntryBecameDead += entryBecameDead;
+            lifetimeManager.EntryCrossedBoundary += entryCrossedBoundary;
         }
 
         protected override void LoadAsyncComplete()
@@ -84,93 +99,113 @@ namespace osu.Game.Rulesets.UI
 
         #region Pooling support
 
-        public void Add(HitObjectLifetimeEntry entry) => lifetimeManager.AddEntry(entry);
+        public void Add(HitObjectLifetimeEntry entry)
-
-        public bool Remove(HitObjectLifetimeEntry entry) => lifetimeManager.RemoveEntry(entry);
-
-        private void entryBecameAlive(LifetimeEntry entry) => addDrawable((HitObjectLifetimeEntry)entry);
-
-        private void entryBecameDead(LifetimeEntry entry) => removeDrawable((HitObjectLifetimeEntry)entry);
-
-        private void addDrawable(HitObjectLifetimeEntry entry)
         {
-            Debug.Assert(!drawableMap.ContainsKey(entry));
+            allEntries.Add(entry);
+            lifetimeManager.AddEntry(entry);
+        }
 
-            var drawable = pooledObjectProvider?.GetPooledDrawableRepresentation(entry.HitObject, null);
+        public bool Remove(HitObjectLifetimeEntry entry)
+        {
+            if (!lifetimeManager.RemoveEntry(entry)) return false;
+
+            // This logic is not in `Remove(DrawableHitObject)` because a non-pooled drawable may be removed by specifying its entry.
+            if (nonPooledDrawableMap.Remove(entry, out var drawable))
+                removeDrawable(drawable);
+
+            allEntries.Remove(entry);
+            return true;
+        }
+
+        private void entryBecameAlive(LifetimeEntry lifetimeEntry)
+        {
+            var entry = (HitObjectLifetimeEntry)lifetimeEntry;
+            Debug.Assert(!aliveDrawableMap.ContainsKey(entry));
+
+            bool isNonPooled = nonPooledDrawableMap.TryGetValue(entry, out var drawable);
+            drawable ??= pooledObjectProvider?.GetPooledDrawableRepresentation(entry.HitObject, null);
             if (drawable == null)
                 throw new InvalidOperationException($"A drawable representation could not be retrieved for hitobject type: {entry.HitObject.GetType().ReadableName()}.");
 
+            aliveDrawableMap[entry] = drawable;
+            OnAdd(drawable);
+
+            if (isNonPooled) return;
+
+            addDrawable(drawable);
+            HitObjectUsageBegan?.Invoke(entry.HitObject);
+        }
+
+        private void entryBecameDead(LifetimeEntry lifetimeEntry)
+        {
+            var entry = (HitObjectLifetimeEntry)lifetimeEntry;
+            Debug.Assert(aliveDrawableMap.ContainsKey(entry));
+
+            var drawable = aliveDrawableMap[entry];
+            bool isNonPooled = nonPooledDrawableMap.ContainsKey(entry);
+
+            drawable.OnKilled();
+            aliveDrawableMap.Remove(entry);
+            OnRemove(drawable);
+
+            if (isNonPooled) return;
+
+            removeDrawable(drawable);
+            // The hit object is not freed when the DHO was not pooled.
+            HitObjectUsageFinished?.Invoke(entry.HitObject);
+        }
+
+        private void addDrawable(DrawableHitObject drawable)
+        {
             drawable.OnNewResult += onNewResult;
             drawable.OnRevertResult += onRevertResult;
 
             bindStartTime(drawable);
-            AddInternal(drawableMap[entry] = drawable, false);
+            AddInternal(drawable);
-            OnAdd(drawable);
-
-            HitObjectUsageBegan?.Invoke(entry.HitObject);
         }
 
-        private void removeDrawable(HitObjectLifetimeEntry entry)
+        private void removeDrawable(DrawableHitObject drawable)
         {
-            Debug.Assert(drawableMap.ContainsKey(entry));
-
-            var drawable = drawableMap[entry];
-
-            // OnKilled can potentially change the hitobject's result, so it needs to run first before unbinding.
-            drawable.OnKilled();
             drawable.OnNewResult -= onNewResult;
             drawable.OnRevertResult -= onRevertResult;
 
-            drawableMap.Remove(entry);
-
-            OnRemove(drawable);
             unbindStartTime(drawable);
-            RemoveInternal(drawable);
 
-            HitObjectUsageFinished?.Invoke(entry.HitObject);
+            RemoveInternal(drawable);
         }
 
         #endregion
 
         #region Non-pooling support
 
-        public virtual void Add(DrawableHitObject hitObject)
+        public virtual void Add(DrawableHitObject drawable)
         {
-            bindStartTime(hitObject);
+            if (drawable.Entry == null)
+                throw new InvalidOperationException($"May not add a {nameof(DrawableHitObject)} without {nameof(HitObject)} associated");
 
-            hitObject.OnNewResult += onNewResult;
+            nonPooledDrawableMap.Add(drawable.Entry, drawable);
-            hitObject.OnRevertResult += onRevertResult;
+            addDrawable(drawable);
-
+            Add(drawable.Entry);
-            AddInternal(hitObject);
-            OnAdd(hitObject);
         }
 
-        public virtual bool Remove(DrawableHitObject hitObject)
+        public virtual bool Remove(DrawableHitObject drawable)
         {
-            OnRemove(hitObject);
+            if (drawable.Entry == null)
-            if (!RemoveInternal(hitObject))
                 return false;
 
-            hitObject.OnNewResult -= onNewResult;
+            return Remove(drawable.Entry);
-            hitObject.OnRevertResult -= onRevertResult;
-
-            unbindStartTime(hitObject);
-
-            return true;
         }
 
         public int IndexOf(DrawableHitObject hitObject) => IndexOfInternal(hitObject);
 
-        protected override void OnChildLifetimeBoundaryCrossed(LifetimeBoundaryCrossedEvent e)
+        private void entryCrossedBoundary(LifetimeEntry entry, LifetimeBoundaryKind kind, LifetimeBoundaryCrossingDirection direction)
         {
-            if (!(e.Child is DrawableHitObject hitObject))
+            if (nonPooledDrawableMap.TryGetValue((HitObjectLifetimeEntry)entry, out var drawable))
-                return;
+                OnChildLifetimeBoundaryCrossed(new LifetimeBoundaryCrossedEvent(drawable, kind, direction));
+        }
 
-            if ((e.Kind == LifetimeBoundaryKind.End && e.Direction == LifetimeBoundaryCrossingDirection.Forward)
+        protected virtual void OnChildLifetimeBoundaryCrossed(LifetimeBoundaryCrossedEvent e)
-                || (e.Kind == LifetimeBoundaryKind.Start && e.Direction == LifetimeBoundaryCrossingDirection.Backward))
+        {
-            {
-                hitObject.OnKilled();
-            }
         }
 
         #endregion
@@ -195,12 +230,13 @@ namespace osu.Game.Rulesets.UI
         {
         }
 
-        public virtual void Clear(bool disposeChildren = true)
+        public virtual void Clear()
         {
             lifetimeManager.ClearEntries();
-
+            foreach (var drawable in nonPooledDrawableMap.Values)
-            ClearInternal(disposeChildren);
+                removeDrawable(drawable);
-            unbindAllStartTimes();
+            nonPooledDrawableMap.Clear();
+            Debug.Assert(InternalChildren.Count == 0 && startTimeMap.Count == 0 && aliveDrawableMap.Count == 0, "All hit objects should have been removed");
         }
 
         protected override bool CheckChildrenLife()

osu.Game/Rulesets/UI/Playfield.cs

@@ -354,8 +354,11 @@ namespace osu.Game.Rulesets.UI
 
                     // If this is the first time this DHO is being used, then apply the DHO mods.
                     // This is done before Apply() so that the state is updated once when the hitobject is applied.
-                    foreach (var m in mods.OfType<IApplicableToDrawableHitObjects>())
+                    if (mods != null)
-                        m.ApplyToDrawableHitObjects(dho.Yield());
+                    {
+                        foreach (var m in mods.OfType<IApplicableToDrawableHitObjects>())
+                            m.ApplyToDrawableHitObjects(dho.Yield());
+                    }
                 }
 
                 if (!lifetimeEntryMap.TryGetValue(hitObject, out var entry))

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

@@ -50,9 +50,9 @@ namespace osu.Game.Rulesets.UI.Scrolling
             timeRange.ValueChanged += _ => layoutCache.Invalidate();
         }
 
-        public override void Clear(bool disposeChildren = true)
+        public override void Clear()
         {
-            base.Clear(disposeChildren);
+            base.Clear();
 
             toComputeLifetime.Clear();
             layoutComputed.Clear();

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

@@ -299,6 +299,13 @@ namespace osu.Game.Screens.Edit.Compose.Components
         {
         }
 
+        /// <summary>
+        /// Retrieves an item's blueprint.
+        /// </summary>
+        /// <param name="item">The item to retrieve the blueprint of.</param>
+        /// <returns>The blueprint.</returns>
+        protected SelectionBlueprint<T> GetBlueprintFor(T item) => blueprintMap[item];
+
         #endregion
 
         #region Selection

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

@@ -74,6 +74,14 @@ namespace osu.Game.Screens.Edit.Compose.Components
             }
         }
 
+        protected override void TransferBlueprintFor(HitObject hitObject, DrawableHitObject drawableObject)
+        {
+            base.TransferBlueprintFor(hitObject, drawableObject);
+
+            var blueprint = (HitObjectSelectionBlueprint)GetBlueprintFor(hitObject);
+            blueprint.DrawableObject = drawableObject;
+        }
+
         protected override bool OnKeyDown(KeyDownEvent e)
         {
             if (e.ControlPressed)
@@ -246,10 +254,10 @@ namespace osu.Game.Screens.Edit.Compose.Components
             if (drawable == null)
                 return null;
 
-            return CreateBlueprintFor(drawable);
+            return CreateHitObjectBlueprintFor(item).With(b => b.DrawableObject = drawable);
         }
 
-        public virtual OverlaySelectionBlueprint CreateBlueprintFor(DrawableHitObject hitObject) => null;
+        public virtual HitObjectSelectionBlueprint CreateHitObjectBlueprintFor(HitObject hitObject) => null;
 
         protected override void OnBlueprintAdded(HitObject item)
         {

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

@@ -9,6 +9,7 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Input.Events;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
 
 namespace osu.Game.Screens.Edit.Compose.Components
 {
@@ -22,6 +23,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         protected readonly HitObjectComposer Composer;
 
+        private HitObjectUsageEventBuffer usageEventBuffer;
+
         protected EditorBlueprintContainer(HitObjectComposer composer)
         {
             Composer = composer;
@@ -45,11 +48,19 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 foreach (var obj in Composer.HitObjects)
                     AddBlueprintFor(obj.HitObject);
 
-                Composer.Playfield.HitObjectUsageBegan += AddBlueprintFor;
+                usageEventBuffer = new HitObjectUsageEventBuffer(Composer.Playfield);
-                Composer.Playfield.HitObjectUsageFinished += RemoveBlueprintFor;
+                usageEventBuffer.HitObjectUsageBegan += AddBlueprintFor;
+                usageEventBuffer.HitObjectUsageFinished += RemoveBlueprintFor;
+                usageEventBuffer.HitObjectUsageTransferred += TransferBlueprintFor;
             }
         }
 
+        protected override void Update()
+        {
+            base.Update();
+            usageEventBuffer?.Update();
+        }
+
         protected override IEnumerable<SelectionBlueprint<HitObject>> SortForMovement(IReadOnlyList<SelectionBlueprint<HitObject>> blueprints)
             => blueprints.OrderBy(b => b.Item.StartTime);
 
@@ -80,6 +91,15 @@ namespace osu.Game.Screens.Edit.Compose.Components
             base.AddBlueprintFor(item);
         }
 
+        /// <summary>
+        /// Invoked when a <see cref="HitObject"/> has been transferred to another <see cref="DrawableHitObject"/>.
+        /// </summary>
+        /// <param name="hitObject">The hit object which has been assigned to a new drawable.</param>
+        /// <param name="drawableObject">The new drawable that is representing the hit object.</param>
+        protected virtual void TransferBlueprintFor(HitObject hitObject, DrawableHitObject drawableObject)
+        {
+        }
+
         protected override void DragOperationCompleted()
         {
             base.DragOperationCompleted();
@@ -133,11 +153,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 Beatmap.HitObjectRemoved -= RemoveBlueprintFor;
             }
 
-            if (Composer != null)
+            usageEventBuffer?.Dispose();
-            {
-                Composer.Playfield.HitObjectUsageBegan -= AddBlueprintFor;
-                Composer.Playfield.HitObjectUsageFinished -= RemoveBlueprintFor;
-            }
         }
     }
 }

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

@@ -7,7 +7,7 @@ using osuTK;
 namespace osu.Game.Screens.Edit.Compose.Components
 {
     /// <summary>
-    /// An event which occurs when a <see cref="OverlaySelectionBlueprint"/> is moved.
+    /// An event which occurs when a <see cref="SelectionBlueprint{T}"/> is moved.
     /// </summary>
     public class MoveSelectionEvent<T>
     {

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

@@ -350,5 +350,55 @@ namespace osu.Game.Screens.Edit.Compose.Components
             => Enumerable.Empty<MenuItem>();
 
         #endregion
+
+        #region Helper Methods
+
+        /// <summary>
+        /// Given a flip direction, a surrounding quad for all selected objects, and a position,
+        /// will return the flipped position in screen space coordinates.
+        /// </summary>
+        protected static Vector2 GetFlippedPosition(Direction direction, Quad quad, Vector2 position)
+        {
+            var centre = quad.Centre;
+
+            switch (direction)
+            {
+                case Direction.Horizontal:
+                    position.X = centre.X - (position.X - centre.X);
+                    break;
+
+                case Direction.Vertical:
+                    position.Y = centre.Y - (position.Y - centre.Y);
+                    break;
+            }
+
+            return position;
+        }
+
+        /// <summary>
+        /// Returns a quad surrounding the provided points.
+        /// </summary>
+        /// <param name="points">The points to calculate a quad for.</param>
+        protected static Quad GetSurroundingQuad(IEnumerable<Vector2> points)
+        {
+            if (!points.Any())
+                return new Quad();
+
+            Vector2 minPosition = new Vector2(float.MaxValue, float.MaxValue);
+            Vector2 maxPosition = new Vector2(float.MinValue, float.MinValue);
+
+            // Go through all hitobjects to make sure they would remain in the bounds of the editor after movement, before any movement is attempted
+            foreach (var p in points)
+            {
+                minPosition = Vector2.ComponentMin(minPosition, p);
+                maxPosition = Vector2.ComponentMax(maxPosition, p);
+            }
+
+            Vector2 size = maxPosition - minPosition;
+
+            return new Quad(minPosition.X, minPosition.Y, size.X, size.Y);
+        }
+
+        #endregion
     }
 }

osu.Game/Screens/Edit/Compose/HitObjectUsageEventBuffer.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.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using JetBrains.Annotations;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.UI;
+
+namespace osu.Game.Screens.Edit.Compose
+{
+    /// <summary>
+    /// Buffers events from the many <see cref="HitObjectContainer"/>s in a nested <see cref="Playfield"/> hierarchy
+    /// to ensure correct ordering of events.
+    /// </summary>
+    internal class HitObjectUsageEventBuffer : IDisposable
+    {
+        /// <summary>
+        /// Invoked when a <see cref="HitObject"/> becomes used by a <see cref="DrawableHitObject"/>.
+        /// </summary>
+        /// <remarks>
+        /// If the ruleset uses pooled objects, this represents the time when the <see cref="HitObject"/>s become alive.
+        /// </remarks>
+        public event Action<HitObject> HitObjectUsageBegan;
+
+        /// <summary>
+        /// Invoked when a <see cref="HitObject"/> becomes unused by a <see cref="DrawableHitObject"/>.
+        /// </summary>
+        /// <remarks>
+        /// If the ruleset uses pooled objects, this represents the time when the <see cref="HitObject"/>s become dead.
+        /// </remarks>
+        public event Action<HitObject> HitObjectUsageFinished;
+
+        /// <summary>
+        /// Invoked when a <see cref="HitObject"/> has been transferred to another <see cref="DrawableHitObject"/>.
+        /// </summary>
+        public event Action<HitObject, DrawableHitObject> HitObjectUsageTransferred;
+
+        private readonly Playfield playfield;
+
+        /// <summary>
+        /// Creates a new <see cref="HitObjectUsageEventBuffer"/>.
+        /// </summary>
+        /// <param name="playfield">The most top-level <see cref="Playfield"/>.</param>
+        public HitObjectUsageEventBuffer([NotNull] Playfield playfield)
+        {
+            this.playfield = playfield;
+
+            playfield.HitObjectUsageBegan += onHitObjectUsageBegan;
+            playfield.HitObjectUsageFinished += onHitObjectUsageFinished;
+        }
+
+        private readonly List<HitObject> usageFinishedHitObjects = new List<HitObject>();
+
+        private void onHitObjectUsageBegan(HitObject hitObject)
+        {
+            if (usageFinishedHitObjects.Remove(hitObject))
+                HitObjectUsageTransferred?.Invoke(hitObject, playfield.AllHitObjects.Single(d => d.HitObject == hitObject));
+            else
+                HitObjectUsageBegan?.Invoke(hitObject);
+        }
+
+        private void onHitObjectUsageFinished(HitObject hitObject) => usageFinishedHitObjects.Add(hitObject);
+
+        public void Update()
+        {
+            foreach (var hitObject in usageFinishedHitObjects)
+                HitObjectUsageFinished?.Invoke(hitObject);
+            usageFinishedHitObjects.Clear();
+        }
+
+        public void Dispose()
+        {
+            if (playfield != null)
+            {
+                playfield.HitObjectUsageBegan -= onHitObjectUsageBegan;
+                playfield.HitObjectUsageFinished -= onHitObjectUsageFinished;
+            }
+        }
+    }
+}

osu.Game/Screens/Play/Player.cs

@@ -154,6 +154,9 @@ namespace osu.Game.Screens.Play
         {
             base.LoadComplete();
 
+            if (!LoadedBeatmapSuccessfully)
+                return;
+
             // replays should never be recorded or played back when autoplay is enabled
             if (!Mods.Value.Any(m => m is ModAutoplay))
                 PrepareReplay();
@@ -926,11 +929,11 @@ namespace osu.Game.Screens.Play
         /// </summary>
         /// <param name="score">The <see cref="Score"/> to import.</param>
         /// <returns>The imported score.</returns>
-        protected virtual Task ImportScore(Score score)
+        protected virtual async Task ImportScore(Score score)
         {
             // Replays are already populated and present in the game's database, so should not be re-imported.
             if (DrawableRuleset.ReplayScore != null)
-                return Task.CompletedTask;
+                return;
 
             LegacyByteArrayReader replayReader;
 
@@ -940,7 +943,18 @@ namespace osu.Game.Screens.Play
                 replayReader = new LegacyByteArrayReader(stream.ToArray(), "replay.osr");
             }
 
-            return scoreManager.Import(score.ScoreInfo, replayReader);
+            // For the time being, online ID responses are not really useful for anything.
+            // In addition, the IDs provided via new (lazer) endpoints are based on a different autoincrement from legacy (stable) scores.
+            //
+            // Until we better define the server-side logic behind this, let's not store the online ID to avoid potential unique constraint
+            // conflicts across various systems (ie. solo and multiplayer).
+            long? onlineScoreId = score.ScoreInfo.OnlineScoreID;
+            score.ScoreInfo.OnlineScoreID = null;
+
+            await scoreManager.Import(score.ScoreInfo, replayReader).ConfigureAwait(false);
+
+            // ... And restore the online ID for other processes to handle correctly (e.g. de-duplication for the results screen).
+            score.ScoreInfo.OnlineScoreID = onlineScoreId;
         }
 
         /// <summary>

osu.Game/Screens/Play/SubmittingPlayer.cs

@@ -116,12 +116,7 @@ namespace osu.Game.Screens.Play
 
             request.Success += s =>
             {
-                // For the time being, online ID responses are not really useful for anything.
+                score.ScoreInfo.OnlineScoreID = s.ID;
-                // In addition, the IDs provided via new (lazer) endpoints are based on a different autoincrement from legacy (stable) scores.
-                //
-                // Until we better define the server-side logic behind this, let's not store the online ID to avoid potential unique constraint
-                // conflicts across various systems (ie. solo and multiplayer).
-                // score.ScoreInfo.OnlineScoreID = s.ID;
                 tcs.SetResult(true);
             };
 

osu.Game/Skinning/Editor/SkinBlueprint.cs

@@ -124,7 +124,7 @@ namespace osu.Game.Skinning.Editor
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => drawable.ReceivePositionalInputAt(screenSpacePos);
 
-        public override Vector2 ScreenSpaceSelectionPoint => drawable.ScreenSpaceDrawQuad.Centre;
+        public override Vector2 ScreenSpaceSelectionPoint => drawable.ToScreenSpace(drawable.OriginPosition);
 
         public override Quad SelectionQuad => drawable.ScreenSpaceDrawQuad;
     }

osu.Game/Skinning/Editor/SkinComponentToolbox.cs

@@ -57,7 +57,10 @@ namespace osu.Game.Skinning.Editor
                 Spacing = new Vector2(20)
             };
 
-            var skinnableTypes = typeof(OsuGame).Assembly.GetTypes().Where(t => typeof(ISkinnableDrawable).IsAssignableFrom(t)).ToArray();
+            var skinnableTypes = typeof(OsuGame).Assembly.GetTypes()
+                                                .Where(t => !t.IsInterface)
+                                                .Where(t => typeof(ISkinnableDrawable).IsAssignableFrom(t))
+                                                .ToArray();
 
             foreach (var type in skinnableTypes)
             {

osu.Game/Skinning/Editor/SkinSelectionHandler.cs

@@ -43,10 +43,16 @@ namespace osu.Game.Skinning.Editor
 
         public override bool HandleFlip(Direction direction)
         {
-            // TODO: this is temporary as well.
+            var selectionQuad = GetSurroundingQuad(SelectedBlueprints.Select(b => b.ScreenSpaceSelectionPoint));
-            foreach (var c in SelectedBlueprints)
+
+            foreach (var b in SelectedBlueprints)
             {
-                ((Drawable)c.Item).Scale *= new Vector2(
+                var drawableItem = (Drawable)b.Item;
+
+                drawableItem.Position =
+                    drawableItem.Parent.ToLocalSpace(GetFlippedPosition(direction, selectionQuad, b.ScreenSpaceSelectionPoint)) - drawableItem.AnchorPosition;
+
+                drawableItem.Scale *= new Vector2(
                     direction == Direction.Horizontal ? -1 : 1,
                     direction == Direction.Vertical ? -1 : 1
                 );

osu.Game/Tests/Visual/SelectionBlueprintTestScene.cs

@@ -5,6 +5,7 @@ using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Timing;
 using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects.Drawables;
 
 namespace osu.Game.Tests.Visual
 {
@@ -22,10 +23,11 @@ namespace osu.Game.Tests.Visual
             });
         }
 
-        protected void AddBlueprint(OverlaySelectionBlueprint blueprint)
+        protected void AddBlueprint(HitObjectSelectionBlueprint blueprint, DrawableHitObject drawableObject)
         {
             Add(blueprint.With(d =>
             {
+                d.DrawableObject = drawableObject;
                 d.Depth = float.MinValue;
                 d.Select();
             }));