Merge pull request #18668 from smoogipoo/editor-controlpoint-undo-redo

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

@@ -374,7 +374,7 @@ namespace osu.Game.Rulesets.Osu.Mods
             int i = 0;
             double currentTime = timingPoint.Time;
 
-            while (!definitelyBigger(currentTime, mapEndTime) && controlPointInfo.TimingPointAt(currentTime) == timingPoint)
+            while (!definitelyBigger(currentTime, mapEndTime) && ReferenceEquals(controlPointInfo.TimingPointAt(currentTime), timingPoint))
             {
                 beats.Add(Math.Floor(currentTime));
                 i++;

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

@@ -117,8 +117,8 @@ namespace osu.Game.Tests.Visual.Editing
 
             // After placement these must be non-default as defaults are read-only.
             AddAssert("Placed object has non-default control points", () =>
-                EditorBeatmap.HitObjects[0].SampleControlPoint != SampleControlPoint.DEFAULT &&
+                !ReferenceEquals(EditorBeatmap.HitObjects[0].SampleControlPoint, SampleControlPoint.DEFAULT) &&
-                EditorBeatmap.HitObjects[0].DifficultyControlPoint != DifficultyControlPoint.DEFAULT);
+                !ReferenceEquals(EditorBeatmap.HitObjects[0].DifficultyControlPoint, DifficultyControlPoint.DEFAULT));
 
             ReloadEditorToSameBeatmap();
 
@@ -126,8 +126,8 @@ namespace osu.Game.Tests.Visual.Editing
 
             // After placement these must be non-default as defaults are read-only.
             AddAssert("Placed object still has non-default control points", () =>
-                EditorBeatmap.HitObjects[0].SampleControlPoint != SampleControlPoint.DEFAULT &&
+                !ReferenceEquals(EditorBeatmap.HitObjects[0].SampleControlPoint, SampleControlPoint.DEFAULT) &&
-                EditorBeatmap.HitObjects[0].DifficultyControlPoint != DifficultyControlPoint.DEFAULT);
+                !ReferenceEquals(EditorBeatmap.HitObjects[0].DifficultyControlPoint, DifficultyControlPoint.DEFAULT));
         }
 
         [Test]

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

@@ -269,7 +269,7 @@ namespace osu.Game.Tests.Visual.UserInterface
 
             private TimingControlPoint getNextTimingPoint(TimingControlPoint current)
             {
-                if (timingPoints[^1] == current)
+                if (ReferenceEquals(timingPoints[^1], current))
                     return current;
 
                 int index = timingPoints.IndexOf(current); // -1 means that this is a "default beat"
@@ -281,7 +281,7 @@ namespace osu.Game.Tests.Visual.UserInterface
             {
                 if (timingPoints.Count == 0) return 0;
 
-                if (timingPoints[^1] == current)
+                if (ReferenceEquals(timingPoints[^1], current))
                 {
                     Debug.Assert(BeatSyncSource.Clock != null);
 

osu.Game/Beatmaps/ControlPoints/ControlPoint.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using Newtonsoft.Json;
 using osu.Game.Graphics;
@@ -11,7 +9,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Beatmaps.ControlPoints
 {
-    public abstract class ControlPoint : IComparable<ControlPoint>, IDeepCloneable<ControlPoint>
+    public abstract class ControlPoint : IComparable<ControlPoint>, IDeepCloneable<ControlPoint>, IEquatable<ControlPoint>
     {
         /// <summary>
         /// The time at which the control point takes effect.
@@ -30,7 +28,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// </summary>
         /// <param name="existing">An existing control point to compare with.</param>
         /// <returns>Whether this <see cref="ControlPoint"/> is redundant when placed alongside <paramref name="existing"/>.</returns>
-        public abstract bool IsRedundant(ControlPoint existing);
+        public abstract bool IsRedundant(ControlPoint? existing);
 
         /// <summary>
         /// Create an unbound copy of this control point.
@@ -48,5 +46,20 @@ namespace osu.Game.Beatmaps.ControlPoints
         {
             Time = other.Time;
         }
+
+        public sealed override bool Equals(object? obj)
+            => obj is ControlPoint otherControlPoint
+               && Equals(otherControlPoint);
+
+        public virtual bool Equals(ControlPoint? other)
+        {
+            if (ReferenceEquals(other, null)) return false;
+            if (ReferenceEquals(other, this)) return true;
+
+            return Time == other.Time;
+        }
+
+        // ReSharper disable once NonReadonlyMemberInGetHashCode
+        public override int GetHashCode() => Time.GetHashCode();
     }
 }

osu.Game/Beatmaps/ControlPoints/ControlPointGroup.cs

@@ -1,18 +1,16 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using osu.Framework.Bindables;
 
 namespace osu.Game.Beatmaps.ControlPoints
 {
-    public class ControlPointGroup : IComparable<ControlPointGroup>
+    public class ControlPointGroup : IComparable<ControlPointGroup>, IEquatable<ControlPointGroup>
     {
-        public event Action<ControlPoint> ItemAdded;
+        public event Action<ControlPoint>? ItemAdded;
-        public event Action<ControlPoint> ItemRemoved;
+        public event Action<ControlPoint>? ItemRemoved;
 
         /// <summary>
         /// The time at which the control point takes effect.
@@ -48,5 +46,23 @@ namespace osu.Game.Beatmaps.ControlPoints
             controlPoints.Remove(point);
             ItemRemoved?.Invoke(point);
         }
+
+        public sealed override bool Equals(object? obj)
+            => obj is ControlPointGroup otherGroup
+               && Equals(otherGroup);
+
+        public virtual bool Equals(ControlPointGroup? other)
+            => other != null
+               && Time == other.Time
+               && ControlPoints.SequenceEqual(other.ControlPoints);
+
+        public override int GetHashCode()
+        {
+            HashCode hashCode = new HashCode();
+            hashCode.Add(Time);
+            foreach (var point in controlPoints)
+                hashCode.Add(point);
+            return hashCode.ToHashCode();
+        }
     }
 }

osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs

@@ -1,8 +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.
 
-#nullable disable
+using System;
-
 using osu.Framework.Bindables;
 using osu.Game.Graphics;
 using osuTK.Graphics;
@@ -12,7 +11,7 @@ namespace osu.Game.Beatmaps.ControlPoints
     /// <remarks>
     /// Note that going forward, this control point type should always be assigned directly to HitObjects.
     /// </remarks>
-    public class DifficultyControlPoint : ControlPoint
+    public class DifficultyControlPoint : ControlPoint, IEquatable<DifficultyControlPoint>
     {
         public static readonly DifficultyControlPoint DEFAULT = new DifficultyControlPoint
         {
@@ -41,7 +40,7 @@ namespace osu.Game.Beatmaps.ControlPoints
             set => SliderVelocityBindable.Value = value;
         }
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => existing is DifficultyControlPoint existingDifficulty
                && SliderVelocity == existingDifficulty.SliderVelocity;
 
@@ -51,5 +50,15 @@ namespace osu.Game.Beatmaps.ControlPoints
 
             base.CopyFrom(other);
         }
+
+        public override bool Equals(ControlPoint? other)
+            => other is DifficultyControlPoint otherDifficultyControlPoint
+               && Equals(otherDifficultyControlPoint);
+
+        public bool Equals(DifficultyControlPoint? other)
+            => base.Equals(other)
+               && SliderVelocity == other.SliderVelocity;
+
+        public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), SliderVelocity);
     }
 }

osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs

@@ -1,15 +1,14 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
+using System;
-
 using osu.Framework.Bindables;
 using osu.Game.Graphics;
 using osuTK.Graphics;
 
 namespace osu.Game.Beatmaps.ControlPoints
 {
-    public class EffectControlPoint : ControlPoint
+    public class EffectControlPoint : ControlPoint, IEquatable<EffectControlPoint>
     {
         public static readonly EffectControlPoint DEFAULT = new EffectControlPoint
         {
@@ -68,7 +67,7 @@ namespace osu.Game.Beatmaps.ControlPoints
             set => KiaiModeBindable.Value = value;
         }
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => !OmitFirstBarLine
                && existing is EffectControlPoint existingEffect
                && KiaiMode == existingEffect.KiaiMode
@@ -83,5 +82,17 @@ namespace osu.Game.Beatmaps.ControlPoints
 
             base.CopyFrom(other);
         }
+
+        public override bool Equals(ControlPoint? other)
+            => other is EffectControlPoint otherEffectControlPoint
+               && Equals(otherEffectControlPoint);
+
+        public bool Equals(EffectControlPoint? other)
+            => base.Equals(other)
+               && OmitFirstBarLine == other.OmitFirstBarLine
+               && ScrollSpeed == other.ScrollSpeed
+               && KiaiMode == other.KiaiMode;
+
+        public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), OmitFirstBarLine, ScrollSpeed, KiaiMode);
     }
 }

osu.Game/Beatmaps/ControlPoints/SampleControlPoint.cs

@@ -1,8 +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.
 
-#nullable disable
+using System;
-
 using osu.Framework.Bindables;
 using osu.Game.Audio;
 using osu.Game.Graphics;
@@ -13,7 +12,7 @@ namespace osu.Game.Beatmaps.ControlPoints
     /// <remarks>
     /// Note that going forward, this control point type should always be assigned directly to HitObjects.
     /// </remarks>
-    public class SampleControlPoint : ControlPoint
+    public class SampleControlPoint : ControlPoint, IEquatable<SampleControlPoint>
     {
         public const string DEFAULT_BANK = "normal";
 
@@ -73,7 +72,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         public virtual HitSampleInfo ApplyTo(HitSampleInfo hitSampleInfo)
             => hitSampleInfo.With(newBank: hitSampleInfo.Bank ?? SampleBank, newVolume: hitSampleInfo.Volume > 0 ? hitSampleInfo.Volume : SampleVolume);
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => existing is SampleControlPoint existingSample
                && SampleBank == existingSample.SampleBank
                && SampleVolume == existingSample.SampleVolume;
@@ -85,5 +84,16 @@ namespace osu.Game.Beatmaps.ControlPoints
 
             base.CopyFrom(other);
         }
+
+        public override bool Equals(ControlPoint? other)
+            => other is SampleControlPoint otherSampleControlPoint
+               && Equals(otherSampleControlPoint);
+
+        public bool Equals(SampleControlPoint? other)
+            => base.Equals(other)
+               && SampleBank == other.SampleBank
+               && SampleVolume == other.SampleVolume;
+
+        public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), SampleBank, SampleVolume);
     }
 }

osu.Game/Beatmaps/ControlPoints/TimingControlPoint.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using osu.Framework.Bindables;
 using osu.Game.Beatmaps.Timing;
 using osu.Game.Graphics;
@@ -8,7 +9,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Beatmaps.ControlPoints
 {
-    public class TimingControlPoint : ControlPoint
+    public class TimingControlPoint : ControlPoint, IEquatable<TimingControlPoint>
     {
         /// <summary>
         /// The time signature at this control point.
@@ -68,7 +69,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         public double BPM => 60000 / BeatLength;
 
         // Timing points are never redundant as they can change the time signature.
-        public override bool IsRedundant(ControlPoint existing) => false;
+        public override bool IsRedundant(ControlPoint? existing) => false;
 
         public override void CopyFrom(ControlPoint other)
         {
@@ -77,5 +78,16 @@ namespace osu.Game.Beatmaps.ControlPoints
 
             base.CopyFrom(other);
         }
+
+        public override bool Equals(ControlPoint? other)
+            => other is TimingControlPoint otherTimingControlPoint
+               && Equals(otherTimingControlPoint);
+
+        public bool Equals(TimingControlPoint? other)
+            => base.Equals(other)
+               && TimeSignature.Equals(other.TimeSignature)
+               && BeatLength.Equals(other.BeatLength);
+
+        public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), TimeSignature, BeatLength);
     }
 }

osu.Game/Beatmaps/Formats/LegacyDecoder.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using osu.Framework.Extensions;
@@ -145,7 +143,7 @@ namespace osu.Game.Beatmaps.Formats
 
         protected string CleanFilename(string path) => path.Trim('"').ToStandardisedPath();
 
-        protected enum Section
+        public enum Section
         {
             General,
             Editor,
@@ -162,7 +160,7 @@ namespace osu.Game.Beatmaps.Formats
         }
 
         [Obsolete("Do not use unless you're a legacy ruleset and 100% sure.")]
-        public class LegacyDifficultyControlPoint : DifficultyControlPoint
+        public class LegacyDifficultyControlPoint : DifficultyControlPoint, IEquatable<LegacyDifficultyControlPoint>
         {
             /// <summary>
             /// Legacy BPM multiplier that introduces floating-point errors for rulesets that depend on it.
@@ -188,9 +186,20 @@ namespace osu.Game.Beatmaps.Formats
 
                 BpmMultiplier = ((LegacyDifficultyControlPoint)other).BpmMultiplier;
             }
+
+            public override bool Equals(ControlPoint? other)
+                => other is LegacyDifficultyControlPoint otherLegacyDifficultyControlPoint
+                   && Equals(otherLegacyDifficultyControlPoint);
+
+            public bool Equals(LegacyDifficultyControlPoint? other)
+                => base.Equals(other)
+                   && BpmMultiplier == other.BpmMultiplier;
+
+            // ReSharper disable once NonReadonlyMemberInGetHashCode
+            public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), BpmMultiplier);
         }
 
-        internal class LegacySampleControlPoint : SampleControlPoint
+        internal class LegacySampleControlPoint : SampleControlPoint, IEquatable<LegacySampleControlPoint>
         {
             public int CustomSampleBank;
 
@@ -204,7 +213,7 @@ namespace osu.Game.Beatmaps.Formats
                 return baseInfo;
             }
 
-            public override bool IsRedundant(ControlPoint existing)
+            public override bool IsRedundant(ControlPoint? existing)
                 => base.IsRedundant(existing)
                    && existing is LegacySampleControlPoint existingSample
                    && CustomSampleBank == existingSample.CustomSampleBank;
@@ -215,6 +224,17 @@ namespace osu.Game.Beatmaps.Formats
 
                 CustomSampleBank = ((LegacySampleControlPoint)other).CustomSampleBank;
             }
+
+            public override bool Equals(ControlPoint? other)
+                => other is LegacySampleControlPoint otherLegacySampleControlPoint
+                   && Equals(otherLegacySampleControlPoint);
+
+            public bool Equals(LegacySampleControlPoint? other)
+                => base.Equals(other)
+                   && CustomSampleBank == other.CustomSampleBank;
+
+            // ReSharper disable once NonReadonlyMemberInGetHashCode
+            public override int GetHashCode() => HashCode.Combine(base.GetHashCode(), CustomSampleBank);
         }
     }
 }

osu.Game/Graphics/Containers/BeatSyncedContainer.cs

@@ -127,7 +127,7 @@ namespace osu.Game.Graphics.Containers
 
             TimeSinceLastBeat = beatLength - TimeUntilNextBeat;
 
-            if (timingPoint == lastTimingPoint && beatIndex == lastBeat)
+            if (ReferenceEquals(timingPoint, lastTimingPoint) && beatIndex == lastBeat)
                 return;
 
             // as this event is sometimes used for sound triggers where `BeginDelayedSequence` has no effect, avoid firing it if too far away from the beat.

osu.Game/Rulesets/Objects/HitObject.cs

@@ -108,7 +108,7 @@ namespace osu.Game.Rulesets.Objects
 
             if (legacyInfo != null)
                 DifficultyControlPoint = (DifficultyControlPoint)legacyInfo.DifficultyPointAt(StartTime).DeepClone();
-            else if (DifficultyControlPoint == DifficultyControlPoint.DEFAULT)
+            else if (ReferenceEquals(DifficultyControlPoint, DifficultyControlPoint.DEFAULT))
                 DifficultyControlPoint = new DifficultyControlPoint();
 
             DifficultyControlPoint.Time = StartTime;
@@ -118,7 +118,7 @@ namespace osu.Game.Rulesets.Objects
             // This is done here after ApplyDefaultsToSelf as we may require custom defaults to be applied to have an accurate end time.
             if (legacyInfo != null)
                 SampleControlPoint = (SampleControlPoint)legacyInfo.SamplePointAt(this.GetEndTime() + control_point_leniency).DeepClone();
-            else if (SampleControlPoint == SampleControlPoint.DEFAULT)
+            else if (ReferenceEquals(SampleControlPoint, SampleControlPoint.DEFAULT))
                 SampleControlPoint = new SampleControlPoint();
 
             SampleControlPoint.Time = this.GetEndTime() + control_point_leniency;

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

@@ -49,7 +49,7 @@ namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
                     case NotifyCollectionChangedAction.Remove:
                         foreach (var group in args.OldItems.OfType<ControlPointGroup>())
                         {
-                            var matching = Children.SingleOrDefault(gv => gv.Group == group);
+                            var matching = Children.SingleOrDefault(gv => ReferenceEquals(gv.Group, group));
 
                             if (matching != null)
                                 matching.Expire();

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

@@ -40,7 +40,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                     case NotifyCollectionChangedAction.Remove:
                         foreach (var group in args.OldItems.OfType<ControlPointGroup>())
                         {
-                            var matching = Children.SingleOrDefault(gv => gv.Group == group);
+                            var matching = Children.SingleOrDefault(gv => ReferenceEquals(gv.Group, group));
 
                             matching?.Expire();
                         }

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

@@ -205,7 +205,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                     updateRepeats(repeats);
             }
 
-            if (difficultyControlPoint != Item.DifficultyControlPoint)
+            if (!ReferenceEquals(difficultyControlPoint, Item.DifficultyControlPoint))
             {
                 difficultyControlPoint = Item.DifficultyControlPoint;
                 difficultyOverrideDisplay?.Expire();
@@ -220,7 +220,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 }
             }
 
-            if (sampleControlPoint != Item.SampleControlPoint)
+            if (!ReferenceEquals(sampleControlPoint, Item.SampleControlPoint))
             {
                 sampleControlPoint = Item.SampleControlPoint;
                 sampleOverrideDisplay?.Expire();
@@ -393,7 +393,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
                                 if (e.CurrentState.Keyboard.ShiftPressed)
                                 {
-                                    if (hitObject.DifficultyControlPoint == DifficultyControlPoint.DEFAULT)
+                                    if (ReferenceEquals(hitObject.DifficultyControlPoint, DifficultyControlPoint.DEFAULT))
                                         hitObject.DifficultyControlPoint = new DifficultyControlPoint();
 
                                     double newVelocity = hitObject.DifficultyControlPoint.SliderVelocity * (repeatHitObject.Duration / proposedDuration);

osu.Game/Screens/Edit/EditorBeatmap.cs

@@ -73,31 +73,7 @@ namespace osu.Game.Screens.Edit
         public EditorBeatmap(IBeatmap playableBeatmap, ISkin beatmapSkin = null, BeatmapInfo beatmapInfo = null)
         {
             PlayableBeatmap = playableBeatmap;
-
+            PlayableBeatmap.ControlPointInfo = ConvertControlPoints(PlayableBeatmap.ControlPointInfo);
-            // ensure we are not working with legacy control points.
-            // if we leave the legacy points around they will be applied over any local changes on
-            // ApplyDefaults calls. this should eventually be removed once the default logic is moved to the decoder/converter.
-            if (PlayableBeatmap.ControlPointInfo is LegacyControlPointInfo)
-            {
-                var newControlPoints = new ControlPointInfo();
-
-                foreach (var controlPoint in PlayableBeatmap.ControlPointInfo.AllControlPoints)
-                {
-                    switch (controlPoint)
-                    {
-                        case DifficultyControlPoint _:
-                        case SampleControlPoint _:
-                            // skip legacy types.
-                            continue;
-
-                        default:
-                            newControlPoints.Add(controlPoint.Time, controlPoint);
-                            break;
-                    }
-                }
-
-                playableBeatmap.ControlPointInfo = newControlPoints;
-            }
 
             this.beatmapInfo = beatmapInfo ?? playableBeatmap.BeatmapInfo;
 
@@ -110,6 +86,39 @@ namespace osu.Game.Screens.Edit
                 trackStartTime(obj);
         }
 
+        /// <summary>
+        /// Converts a <see cref="ControlPointInfo"/> such that the resultant <see cref="ControlPointInfo"/> is non-legacy.
+        /// </summary>
+        /// <param name="incoming">The <see cref="ControlPointInfo"/> to convert.</param>
+        /// <returns>The non-legacy <see cref="ControlPointInfo"/>. <paramref name="incoming"/> is returned if already non-legacy.</returns>
+        public static ControlPointInfo ConvertControlPoints(ControlPointInfo incoming)
+        {
+            // ensure we are not working with legacy control points.
+            // if we leave the legacy points around they will be applied over any local changes on
+            // ApplyDefaults calls. this should eventually be removed once the default logic is moved to the decoder/converter.
+            if (!(incoming is LegacyControlPointInfo))
+                return incoming;
+
+            var newControlPoints = new ControlPointInfo();
+
+            foreach (var controlPoint in incoming.AllControlPoints)
+            {
+                switch (controlPoint)
+                {
+                    case DifficultyControlPoint _:
+                    case SampleControlPoint _:
+                        // skip legacy types.
+                        continue;
+
+                    default:
+                        newControlPoints.Add(controlPoint.Time, controlPoint);
+                        break;
+                }
+            }
+
+            return newControlPoints;
+        }
+
         public BeatmapInfo BeatmapInfo
         {
             get => beatmapInfo;

osu.Game/Screens/Edit/EditorClock.cs

@@ -141,7 +141,7 @@ namespace osu.Game.Screens.Edit
                 seekTime = timingPoint.Time + closestBeat * seekAmount;
             }
 
-            if (seekTime < timingPoint.Time && timingPoint != ControlPointInfo.TimingPoints.First())
+            if (seekTime < timingPoint.Time && !ReferenceEquals(timingPoint, ControlPointInfo.TimingPoints.First()))
                 seekTime = timingPoint.Time;
 
             SeekSmoothlyTo(seekTime);

osu.Game/Screens/Edit/EditorTable.cs

@@ -97,7 +97,7 @@ namespace osu.Game.Screens.Edit
             [BackgroundDependencyLoader]
             private void load(OverlayColourProvider colours)
             {
-                hoveredBackground.Colour = colourHover = colours.Background1;
+                colourHover = colours.Background1;
                 colourSelected = colours.Colour3;
             }
 
@@ -105,8 +105,7 @@ namespace osu.Game.Screens.Edit
             {
                 base.LoadComplete();
 
-                // Reduce flicker of rows when offset is being changed rapidly.
+                updateState();
-                // Probably need to reconsider this.
                 FinishTransforms(true);
             }
 

osu.Game/Screens/Edit/LegacyEditorBeatmapPatcher.cs

@@ -5,13 +5,16 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Text;
 using DiffPlex;
+using DiffPlex.Model;
 using osu.Framework.Audio.Track;
 using osu.Framework.Graphics.Textures;
 using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Beatmaps.Formats;
 using osu.Game.IO;
 using osu.Game.Skinning;
 using Decoder = osu.Game.Beatmaps.Formats.Decoder;
@@ -34,61 +37,107 @@ namespace osu.Game.Screens.Edit
         {
             // Diff the beatmaps
             var result = new Differ().CreateLineDiffs(readString(currentState), readString(newState), true, false);
+            IBeatmap newBeatmap = null;
 
-            // Find the index of [HitObject] sections. Lines changed prior to this index are ignored.
+            editorBeatmap.BeginChange();
-            int oldHitObjectsIndex = Array.IndexOf(result.PiecesOld, "[HitObjects]");
+            processHitObjects(result, () => newBeatmap ??= readBeatmap(newState));
-            int newHitObjectsIndex = Array.IndexOf(result.PiecesNew, "[HitObjects]");
+            processTimingPoints(() => newBeatmap ??= readBeatmap(newState));
+            editorBeatmap.EndChange();
+        }
 
-            Debug.Assert(oldHitObjectsIndex >= 0);
+        private void processTimingPoints(Func<IBeatmap> getNewBeatmap)
-            Debug.Assert(newHitObjectsIndex >= 0);
+        {
+            ControlPointInfo newControlPoints = EditorBeatmap.ConvertControlPoints(getNewBeatmap().ControlPointInfo);
 
-            var toRemove = new List<int>();
+            // Remove all groups from the current beatmap which don't have a corresponding equal group in the new beatmap.
-            var toAdd = new List<int>();
+            foreach (var oldGroup in editorBeatmap.ControlPointInfo.Groups.ToArray())
+            {
+                var newGroup = newControlPoints.GroupAt(oldGroup.Time);
+
+                if (!oldGroup.Equals(newGroup))
+                    editorBeatmap.ControlPointInfo.RemoveGroup(oldGroup);
+            }
+
+            // Add all groups from the new beatmap which don't have a corresponding equal group in the old beatmap.
+            foreach (var newGroup in newControlPoints.Groups)
+            {
+                var oldGroup = editorBeatmap.ControlPointInfo.GroupAt(newGroup.Time);
+
+                if (!newGroup.Equals(oldGroup))
+                {
+                    foreach (var point in newGroup.ControlPoints)
+                        editorBeatmap.ControlPointInfo.Add(newGroup.Time, point);
+                }
+            }
+        }
+
+        private void processHitObjects(DiffResult result, Func<IBeatmap> getNewBeatmap)
+        {
+            findChangedIndices(result, LegacyDecoder<Beatmap>.Section.HitObjects, out var removedIndices, out var addedIndices);
+
+            for (int i = removedIndices.Count - 1; i >= 0; i--)
+                editorBeatmap.RemoveAt(removedIndices[i]);
+
+            if (addedIndices.Count > 0)
+            {
+                var newBeatmap = getNewBeatmap();
+
+                foreach (int i in addedIndices)
+                    editorBeatmap.Insert(i, newBeatmap.HitObjects[i]);
+            }
+        }
+
+        private void findChangedIndices(DiffResult result, LegacyDecoder<Beatmap>.Section section, out List<int> removedIndices, out List<int> addedIndices)
+        {
+            removedIndices = new List<int>();
+            addedIndices = new List<int>();
+
+            // Find the start and end indices of the relevant section headers in both the old and the new beatmap file. Lines changed outside of the modified ranges are ignored.
+            int oldSectionStartIndex = Array.IndexOf(result.PiecesOld, $"[{section}]");
+            if (oldSectionStartIndex == -1)
+                return;
+
+            int oldSectionEndIndex = Array.FindIndex(result.PiecesOld, oldSectionStartIndex + 1, s => s.StartsWith('['));
+            if (oldSectionEndIndex == -1)
+                oldSectionEndIndex = result.PiecesOld.Length;
+
+            int newSectionStartIndex = Array.IndexOf(result.PiecesNew, $"[{section}]");
+            if (newSectionStartIndex == -1)
+                return;
+
+            int newSectionEndIndex = Array.FindIndex(result.PiecesNew, newSectionStartIndex + 1, s => s.StartsWith('['));
+            if (newSectionEndIndex == -1)
+                newSectionEndIndex = result.PiecesNew.Length;
 
             foreach (var block in result.DiffBlocks)
             {
-                // Removed hitobjects
+                // Removed indices
                 for (int i = 0; i < block.DeleteCountA; i++)
                 {
-                    int hoIndex = block.DeleteStartA + i - oldHitObjectsIndex - 1;
+                    int objectIndex = block.DeleteStartA + i;
 
-                    if (hoIndex < 0)
+                    if (objectIndex <= oldSectionStartIndex || objectIndex >= oldSectionEndIndex)
                         continue;
 
-                    toRemove.Add(hoIndex);
+                    removedIndices.Add(objectIndex - oldSectionStartIndex - 1);
                 }
 
-                // Added hitobjects
+                // Added indices
                 for (int i = 0; i < block.InsertCountB; i++)
                 {
-                    int hoIndex = block.InsertStartB + i - newHitObjectsIndex - 1;
+                    int objectIndex = block.InsertStartB + i;
 
-                    if (hoIndex < 0)
+                    if (objectIndex <= newSectionStartIndex || objectIndex >= newSectionEndIndex)
                         continue;
 
-                    toAdd.Add(hoIndex);
+                    addedIndices.Add(objectIndex - newSectionStartIndex - 1);
                 }
             }
 
             // Sort the indices to ensure that removal + insertion indices don't get jumbled up post-removal or post-insertion.
             // This isn't strictly required, but the differ makes no guarantees about order.
-            toRemove.Sort();
+            removedIndices.Sort();
-            toAdd.Sort();
+            addedIndices.Sort();
-
-            editorBeatmap.BeginChange();
-
-            // Apply the changes.
-            for (int i = toRemove.Count - 1; i >= 0; i--)
-                editorBeatmap.RemoveAt(toRemove[i]);
-
-            if (toAdd.Count > 0)
-            {
-                IBeatmap newBeatmap = readBeatmap(newState);
-                foreach (int i in toAdd)
-                    editorBeatmap.Insert(i, newBeatmap.HitObjects[i]);
-            }
-
-            editorBeatmap.EndChange();
         }
 
         private string readString(byte[] state) => Encoding.UTF8.GetString(state);

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

@@ -54,6 +54,8 @@ namespace osu.Game.Screens.Edit.Timing
 
                 Columns = createHeaders();
                 Content = value.Select(createContent).ToArray().ToRectangular();
+
+                updateSelectedGroup();
             }
         }
 
@@ -64,10 +66,17 @@ namespace osu.Game.Screens.Edit.Timing
             selectedGroup.BindValueChanged(group =>
             {
                 // TODO: This should scroll the selected row into view.
-                foreach (var b in BackgroundFlow) b.Selected = b.Item == group.NewValue;
+                updateSelectedGroup();
             }, true);
         }
 
+        private void updateSelectedGroup()
+        {
+            // TODO: This should scroll the selected row into view.
+            foreach (var b in BackgroundFlow)
+                b.Selected = ReferenceEquals(b.Item, selectedGroup?.Value);
+        }
+
         private TableColumn[] createHeaders()
         {
             var columns = new List<TableColumn>

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

@@ -222,7 +222,7 @@ namespace osu.Game.Screens.Edit.Timing
                     // Try and create matching types from the currently selected control point.
                     var selected = selectedGroup.Value;
 
-                    if (selected != null && selected != group)
+                    if (selected != null && !ReferenceEquals(selected, group))
                     {
                         foreach (var controlPoint in selected.ControlPoints)
                         {

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

@@ -128,7 +128,7 @@ namespace osu.Game.Screens.Edit.Timing
             double? offsetChange = newStartTime - selectedGroupStartTime;
 
             var nextGroup = editorBeatmap.ControlPointInfo.TimingPoints
-                                         .SkipWhile(g => g != tcp)
+                                         .SkipWhile(g => !ReferenceEquals(g, tcp))
                                          .Skip(1)
                                          .FirstOrDefault();