Merge branch 'master' into kps

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModConstantSpeed.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.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModHoldOff.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.Linq;
 using NUnit.Framework;
 using osu.Game.Beatmaps;

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModInvert.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 NUnit.Framework;
 using osu.Game.Rulesets.Mania.Mods;
 using osu.Game.Tests.Visual;

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModPerfect.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 NUnit.Framework;
 using osu.Game.Rulesets.Mania.Mods;
 using osu.Game.Rulesets.Mania.Objects;

osu.Game.Rulesets.Mania/Mods/IPlayfieldTypeMod.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaKeyMod.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.Linq;
 using osu.Game.Beatmaps;

osu.Game.Rulesets.Mania/Mods/ManiaModAutoplay.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.Collections.Generic;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Beatmaps;

osu.Game.Rulesets.Mania/Mods/ManiaModCinema.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.Collections.Generic;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Beatmaps;

osu.Game.Rulesets.Mania/Mods/ManiaModClassic.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModConstantSpeed.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 osu.Framework.Graphics.Sprites;
 using osu.Game.Configuration;
 using osu.Game.Rulesets.Mania.Objects;

osu.Game.Rulesets.Mania/Mods/ManiaModDaycore.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModDifficultyAdjust.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModDoubleTime.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModDualStages.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 osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mods;

osu.Game.Rulesets.Mania/Mods/ManiaModEasy.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModFadeIn.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.Linq;
 using osu.Game.Rulesets.Mania.UI;

osu.Game.Rulesets.Mania/Mods/ManiaModFlashlight.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 osu.Framework.Bindables;
 using osu.Framework.Graphics;

osu.Game.Rulesets.Mania/Mods/ManiaModHalfTime.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModHardRock.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModHidden.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.Linq;
 using osu.Game.Rulesets.Mania.UI;

osu.Game.Rulesets.Mania/Mods/ManiaModHoldOff.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.Linq;
 using osu.Game.Beatmaps;

osu.Game.Rulesets.Mania/Mods/ManiaModInvert.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 System.Linq;

osu.Game.Rulesets.Mania/Mods/ManiaModKey1.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey1 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey10.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey10 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey2.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey2 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey3.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey3 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey4.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey4 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey5.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey5 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey6.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey6 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey7.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey7 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey8.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey8 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModKey9.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
-
 namespace osu.Game.Rulesets.Mania.Mods
 {
     public class ManiaModKey9 : ManiaKeyMod

osu.Game.Rulesets.Mania/Mods/ManiaModMirror.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 osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mods;

osu.Game.Rulesets.Mania/Mods/ManiaModMuted.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 osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mods;
 

osu.Game.Rulesets.Mania/Mods/ManiaModNightcore.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 osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mods;
 

osu.Game.Rulesets.Mania/Mods/ManiaModNoFail.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModPerfect.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Mania/Mods/ManiaModPlayfieldCover.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.Linq;
 using osu.Framework.Graphics;

osu.Game.Rulesets.Mania/Mods/ManiaModRandom.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.Linq;
 using osu.Framework.Extensions.IEnumerableExtensions;

osu.Game.Rulesets.Mania/Mods/ManiaModSuddenDeath.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Mania.Mods

osu.Game.Rulesets.Taiko.Tests/Mods/TaikoModTestScene.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 osu.Game.Tests.Visual;
 
 namespace osu.Game.Rulesets.Taiko.Tests.Mods

osu.Game.Rulesets.Taiko.Tests/Mods/TestSceneTaikoModHidden.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.Linq;
 using NUnit.Framework;
 using osu.Game.Rulesets.Taiko.Mods;

osu.Game.Rulesets.Taiko.Tests/Mods/TestSceneTaikoModPerfect.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 NUnit.Framework;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.Taiko.Mods;

osu.Game.Rulesets.Taiko/Mods/TaikoModAutoplay.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.Collections.Generic;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;

osu.Game.Rulesets.Taiko/Mods/TaikoModCinema.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.Collections.Generic;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;

osu.Game.Rulesets.Taiko/Mods/TaikoModClassic.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.Diagnostics;
-
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Taiko.Objects;
 using osu.Game.Rulesets.Taiko.UI;
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Taiko.Mods
 {
     public class TaikoModClassic : ModClassic, IApplicableToDrawableRuleset<TaikoHitObject>, IUpdatableByPlayfield
     {
-        private DrawableTaikoRuleset drawableTaikoRuleset;
+        private DrawableTaikoRuleset? drawableTaikoRuleset;
 
         public void ApplyToDrawableRuleset(DrawableRuleset<TaikoHitObject> drawableRuleset)
         {
@@ -25,6 +24,8 @@ namespace osu.Game.Rulesets.Taiko.Mods
 
         public void Update(Playfield playfield)
         {
+            Debug.Assert(drawableTaikoRuleset != null);
+
             // Classic taiko scrolls at a constant 100px per 1000ms. More notes become visible as the playfield is lengthened.
             const float scroll_rate = 10;
 

osu.Game.Rulesets.Taiko/Mods/TaikoModDaycore.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModDifficultyAdjust.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.Linq;
 using osu.Game.Beatmaps;
 using osu.Game.Configuration;

osu.Game.Rulesets.Taiko/Mods/TaikoModDoubleTime.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModEasy.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 osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;
 

osu.Game.Rulesets.Taiko/Mods/TaikoModFlashlight.cs

@@ -1,9 +1,8 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Layout;
 using osu.Game.Configuration;
@@ -38,9 +37,9 @@ namespace osu.Game.Rulesets.Taiko.Mods
 
         public override float DefaultFlashlightSize => 250;
 
-        protected override Flashlight CreateFlashlight() => new TaikoFlashlight(this, playfield);
+        protected override Flashlight CreateFlashlight() => new TaikoFlashlight(this, playfield.AsNonNull());
 
-        private TaikoPlayfield playfield;
+        private TaikoPlayfield? playfield;
 
         public override void ApplyToDrawableRuleset(DrawableRuleset<TaikoHitObject> drawableRuleset)
         {

osu.Game.Rulesets.Taiko/Mods/TaikoModHalfTime.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModHardRock.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 osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;
 

osu.Game.Rulesets.Taiko/Mods/TaikoModHidden.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.Diagnostics;
-
 using osu.Framework.Graphics;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -32,7 +31,7 @@ namespace osu.Game.Rulesets.Taiko.Mods
         /// </summary>
         private const float fade_out_duration = 0.375f;
 
-        private DrawableTaikoRuleset drawableRuleset;
+        private DrawableTaikoRuleset? drawableRuleset;
 
         public void ApplyToDrawableRuleset(DrawableRuleset<TaikoHitObject> drawableRuleset)
         {
@@ -46,6 +45,8 @@ namespace osu.Game.Rulesets.Taiko.Mods
 
         protected override void ApplyNormalVisibilityState(DrawableHitObject hitObject, ArmedState state)
         {
+            Debug.Assert(drawableRuleset != null);
+
             switch (hitObject)
             {
                 case DrawableDrumRollTick:

osu.Game.Rulesets.Taiko/Mods/TaikoModMuted.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 osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Taiko.Objects;
 

osu.Game.Rulesets.Taiko/Mods/TaikoModNightcore.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 osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Taiko.Objects;
 

osu.Game.Rulesets.Taiko/Mods/TaikoModNoFail.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModPerfect.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModRandom.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.Linq;
 using osu.Framework.Utils;

osu.Game.Rulesets.Taiko/Mods/TaikoModRelax.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModSuddenDeath.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 osu.Game.Rulesets.Mods;
 
 namespace osu.Game.Rulesets.Taiko.Mods

osu.Game.Rulesets.Taiko/Mods/TaikoModSwap.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.Linq;
 using osu.Game.Beatmaps;

osu.Game.Tests/Beatmaps/WorkingBeatmapManagerTest.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Tests.Beatmaps
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio, RulesetStore rulesets)
         {
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
         }
 
         [SetUpSteps]

osu.Game.Tests/Collections/IO/ImportCollectionsTest.cs

@@ -5,12 +5,15 @@
 
 using System;
 using System.IO;
+using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Extensions;
 using osu.Framework.Platform;
 using osu.Framework.Testing;
+using osu.Game.Collections;
+using osu.Game.Database;
 using osu.Game.Tests.Resources;
 
 namespace osu.Game.Tests.Collections.IO
@@ -29,7 +32,11 @@ namespace osu.Game.Tests.Collections.IO
 
                     await importCollectionsFromStream(osu, new MemoryStream());
 
-                    Assert.That(osu.CollectionManager.Collections.Count, Is.Zero);
+                    osu.Realm.Run(realm =>
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
+                        Assert.That(collections.Count, Is.Zero);
+                    });
                 }
                 finally
                 {
@@ -49,18 +56,22 @@ namespace osu.Game.Tests.Collections.IO
 
                     await importCollectionsFromStream(osu, TestResources.OpenResource("Collections/collections.db"));
 
-                    Assert.That(osu.CollectionManager.Collections.Count, Is.EqualTo(2));
+                    osu.Realm.Run(realm =>
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
+                        Assert.That(collections.Count, Is.EqualTo(2));
 
-                    // Even with no beatmaps imported, collections are tracking the hashes and will continue to.
+                        // Even with no beatmaps imported, collections are tracking the hashes and will continue to.
-                    // In the future this whole mechanism will be replaced with having the collections in realm,
+                        // In the future this whole mechanism will be replaced with having the collections in realm,
-                    // but until that happens it makes rough sense that we want to track not-yet-imported beatmaps
+                        // but until that happens it makes rough sense that we want to track not-yet-imported beatmaps
-                    // and have them associate with collections if/when they become available.
+                        // and have them associate with collections if/when they become available.
 
-                    Assert.That(osu.CollectionManager.Collections[0].Name.Value, Is.EqualTo("First"));
+                        Assert.That(collections[0].Name, Is.EqualTo("First"));
-                    Assert.That(osu.CollectionManager.Collections[0].BeatmapHashes.Count, Is.EqualTo(1));
+                        Assert.That(collections[0].BeatmapMD5Hashes.Count, Is.EqualTo(1));
 
-                    Assert.That(osu.CollectionManager.Collections[1].Name.Value, Is.EqualTo("Second"));
+                        Assert.That(collections[1].Name, Is.EqualTo("Second"));
-                    Assert.That(osu.CollectionManager.Collections[1].BeatmapHashes.Count, Is.EqualTo(12));
+                        Assert.That(collections[1].BeatmapMD5Hashes.Count, Is.EqualTo(12));
+                    });
                 }
                 finally
                 {
@@ -80,13 +91,18 @@ namespace osu.Game.Tests.Collections.IO
 
                     await importCollectionsFromStream(osu, TestResources.OpenResource("Collections/collections.db"));
 
-                    Assert.That(osu.CollectionManager.Collections.Count, Is.EqualTo(2));
+                    osu.Realm.Run(realm =>
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
 
-                    Assert.That(osu.CollectionManager.Collections[0].Name.Value, Is.EqualTo("First"));
+                        Assert.That(collections.Count, Is.EqualTo(2));
-                    Assert.That(osu.CollectionManager.Collections[0].BeatmapHashes.Count, Is.EqualTo(1));
 
-                    Assert.That(osu.CollectionManager.Collections[1].Name.Value, Is.EqualTo("Second"));
+                        Assert.That(collections[0].Name, Is.EqualTo("First"));
-                    Assert.That(osu.CollectionManager.Collections[1].BeatmapHashes.Count, Is.EqualTo(12));
+                        Assert.That(collections[0].BeatmapMD5Hashes.Count, Is.EqualTo(1));
+
+                        Assert.That(collections[1].Name, Is.EqualTo("Second"));
+                        Assert.That(collections[1].BeatmapMD5Hashes.Count, Is.EqualTo(12));
+                    });
                 }
                 finally
                 {
@@ -123,7 +139,11 @@ namespace osu.Game.Tests.Collections.IO
                     }
 
                     Assert.That(exceptionThrown, Is.False);
-                    Assert.That(osu.CollectionManager.Collections.Count, Is.EqualTo(0));
+                    osu.Realm.Run(realm =>
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
+                        Assert.That(collections.Count, Is.EqualTo(0));
+                    });
                 }
                 finally
                 {
@@ -148,12 +168,18 @@ namespace osu.Game.Tests.Collections.IO
 
                     await importCollectionsFromStream(osu, TestResources.OpenResource("Collections/collections.db"));
 
-                    // Move first beatmap from second collection into the first.
+                    // ReSharper disable once MethodHasAsyncOverload
-                    osu.CollectionManager.Collections[0].BeatmapHashes.Add(osu.CollectionManager.Collections[1].BeatmapHashes[0]);
+                    osu.Realm.Write(realm =>
-                    osu.CollectionManager.Collections[1].BeatmapHashes.RemoveAt(0);
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
 
-                    // Rename the second collecction.
+                        // Move first beatmap from second collection into the first.
-                    osu.CollectionManager.Collections[1].Name.Value = "Another";
+                        collections[0].BeatmapMD5Hashes.Add(collections[1].BeatmapMD5Hashes[0]);
+                        collections[1].BeatmapMD5Hashes.RemoveAt(0);
+
+                        // Rename the second collecction.
+                        collections[1].Name = "Another";
+                    });
                 }
                 finally
                 {
@@ -168,13 +194,17 @@ namespace osu.Game.Tests.Collections.IO
                 {
                     var osu = LoadOsuIntoHost(host, true);
 
-                    Assert.That(osu.CollectionManager.Collections.Count, Is.EqualTo(2));
+                    osu.Realm.Run(realm =>
+                    {
+                        var collections = realm.All<BeatmapCollection>().ToList();
+                        Assert.That(collections.Count, Is.EqualTo(2));
 
-                    Assert.That(osu.CollectionManager.Collections[0].Name.Value, Is.EqualTo("First"));
+                        Assert.That(collections[0].Name, Is.EqualTo("First"));
-                    Assert.That(osu.CollectionManager.Collections[0].BeatmapHashes.Count, Is.EqualTo(2));
+                        Assert.That(collections[0].BeatmapMD5Hashes.Count, Is.EqualTo(2));
 
-                    Assert.That(osu.CollectionManager.Collections[1].Name.Value, Is.EqualTo("Another"));
+                        Assert.That(collections[1].Name, Is.EqualTo("Another"));
-                    Assert.That(osu.CollectionManager.Collections[1].BeatmapHashes.Count, Is.EqualTo(11));
+                        Assert.That(collections[1].BeatmapMD5Hashes.Count, Is.EqualTo(11));
+                    });
                 }
                 finally
                 {
@@ -187,7 +217,7 @@ namespace osu.Game.Tests.Collections.IO
         {
             // intentionally spin this up on a separate task to avoid disposal deadlocks.
             // see https://github.com/EventStore/EventStore/issues/1179
-            await Task.Factory.StartNew(() => osu.CollectionManager.Import(stream).WaitSafely(), TaskCreationOptions.LongRunning);
+            await Task.Factory.StartNew(() => new LegacyCollectionImporter(osu.Realm).Import(stream).WaitSafely(), TaskCreationOptions.LongRunning);
         }
     }
 }

osu.Game.Tests/Database/BeatmapImporterUpdateTests.cs

@@ -9,6 +9,7 @@ using System.Linq.Expressions;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Game.Beatmaps;
+using osu.Game.Collections;
 using osu.Game.Database;
 using osu.Game.Models;
 using osu.Game.Overlays.Notifications;
@@ -51,6 +52,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importBeforeUpdate, Is.Not.Null);
                 Debug.Assert(importBeforeUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapSetInfo>(realm, 1, s => !s.DeletePending);
                 Assert.That(importBeforeUpdate.Value.Beatmaps, Has.Count.EqualTo(count_beatmaps - 1));
 
@@ -60,6 +63,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
                 checkCount<BeatmapSetInfo>(realm, 1);
@@ -103,6 +108,8 @@ namespace osu.Game.Tests.Database
                         beatmap.ResetOnlineInfo();
                 });
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapSetInfo>(realm, 1, s => !s.DeletePending);
                 Assert.That(importBeforeUpdate.Value.Beatmaps, Has.Count.EqualTo(count_beatmaps - 1));
 
@@ -112,6 +119,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
                 checkCount<BeatmapSetInfo>(realm, 1);
@@ -148,6 +157,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importBeforeUpdate, Is.Not.Null);
                 Debug.Assert(importBeforeUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapSetInfo>(realm, 1, s => !s.DeletePending);
                 Assert.That(importBeforeUpdate.Value.Beatmaps, Has.Count.EqualTo(count_beatmaps));
 
@@ -161,6 +172,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importBeforeUpdate.Value.Beatmaps, Has.Count.EqualTo(1));
                 Assert.That(importAfterUpdate.Value.Beatmaps, Has.Count.EqualTo(count_beatmaps));
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps + 1);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps + 1);
 
@@ -198,6 +211,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
                 checkCount<BeatmapSetInfo>(realm, 2);
@@ -234,6 +249,8 @@ namespace osu.Game.Tests.Database
                 var importAfterUpdate = await importer.ImportAsUpdate(new ProgressNotification(), new ImportTask(pathEmpty), importBeforeUpdate.Value);
                 Assert.That(importAfterUpdate, Is.Null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapSetInfo>(realm, 1);
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
@@ -263,6 +280,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapSetInfo>(realm, 1);
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
@@ -307,6 +326,8 @@ namespace osu.Game.Tests.Database
                     s.Realm.Add(new ScoreInfo(beatmapInfo, s.Realm.All<RulesetInfo>().First(), new RealmUser()));
                 });
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<ScoreInfo>(realm, 1);
 
                 var importAfterUpdate = await importer.ImportAsUpdate(new ProgressNotification(), new ImportTask(pathMissingOneBeatmap), importBeforeUpdate.Value);
@@ -314,6 +335,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps);
                 checkCount<BeatmapSetInfo>(realm, 2);
@@ -348,6 +371,8 @@ namespace osu.Game.Tests.Database
                     s.Realm.Add(new ScoreInfo(beatmapInfo, s.Realm.All<RulesetInfo>().First(), new RealmUser()));
                 });
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<ScoreInfo>(realm, 1);
 
                 using var _ = getBeatmapArchiveWithModifications(out string pathModified, directory =>
@@ -365,6 +390,8 @@ namespace osu.Game.Tests.Database
                 Assert.That(importAfterUpdate, Is.Not.Null);
                 Debug.Assert(importAfterUpdate != null);
 
+                realm.Run(r => r.Refresh());
+
                 checkCount<BeatmapInfo>(realm, count_beatmaps + 1);
                 checkCount<BeatmapMetadata>(realm, count_beatmaps + 1);
                 checkCount<BeatmapSetInfo>(realm, 2);
@@ -406,6 +433,126 @@ namespace osu.Game.Tests.Database
             });
         }
 
+        /// <summary>
+        /// If all difficulties in the original beatmap set are in a collection, presume the user also wants new difficulties added.
+        /// </summary>
+        [TestCase(false)]
+        [TestCase(true)]
+        public void TestCollectionTransferNewBeatmap(bool allOriginalBeatmapsInCollection)
+        {
+            RunTestWithRealmAsync(async (realm, storage) =>
+            {
+                var importer = new BeatmapImporter(storage, realm);
+                using var rulesets = new RealmRulesetStore(realm, storage);
+
+                using var __ = getBeatmapArchive(out string pathOriginal);
+                using var _ = getBeatmapArchiveWithModifications(out string pathMissingOneBeatmap, directory =>
+                {
+                    // remove one difficulty before first import
+                    directory.GetFiles("*.osu").First().Delete();
+                });
+
+                var importBeforeUpdate = await importer.Import(new ImportTask(pathMissingOneBeatmap));
+
+                Assert.That(importBeforeUpdate, Is.Not.Null);
+                Debug.Assert(importBeforeUpdate != null);
+
+                int beatmapsToAddToCollection = 0;
+
+                importBeforeUpdate.PerformWrite(s =>
+                {
+                    var beatmapCollection = s.Realm.Add(new BeatmapCollection("test collection"));
+                    beatmapsToAddToCollection = s.Beatmaps.Count - (allOriginalBeatmapsInCollection ? 0 : 1);
+
+                    for (int i = 0; i < beatmapsToAddToCollection; i++)
+                        beatmapCollection.BeatmapMD5Hashes.Add(s.Beatmaps[i].MD5Hash);
+                });
+
+                // Second import matches first but contains one extra .osu file.
+                var importAfterUpdate = await importer.ImportAsUpdate(new ProgressNotification(), new ImportTask(pathOriginal), importBeforeUpdate.Value);
+
+                Assert.That(importAfterUpdate, Is.Not.Null);
+                Debug.Assert(importAfterUpdate != null);
+
+                importAfterUpdate.PerformRead(updated =>
+                {
+                    updated.Realm.Refresh();
+
+                    string[] hashes = updated.Realm.All<BeatmapCollection>().Single().BeatmapMD5Hashes.ToArray();
+
+                    if (allOriginalBeatmapsInCollection)
+                    {
+                        Assert.That(updated.Beatmaps.Count, Is.EqualTo(beatmapsToAddToCollection + 1));
+                        Assert.That(hashes, Has.Length.EqualTo(updated.Beatmaps.Count));
+                    }
+                    else
+                    {
+                        // Collection contains one less than the original beatmap, and two less after update (new difficulty included).
+                        Assert.That(updated.Beatmaps.Count, Is.EqualTo(beatmapsToAddToCollection + 2));
+                        Assert.That(hashes, Has.Length.EqualTo(beatmapsToAddToCollection));
+                    }
+                });
+            });
+        }
+
+        /// <summary>
+        /// If a difficulty in the original beatmap set is modified, the updated version should remain in any collections it was in.
+        /// </summary>
+        [Test]
+        public void TestCollectionTransferModifiedBeatmap()
+        {
+            RunTestWithRealmAsync(async (realm, storage) =>
+            {
+                var importer = new BeatmapImporter(storage, realm);
+                using var rulesets = new RealmRulesetStore(realm, storage);
+
+                using var __ = getBeatmapArchive(out string pathOriginal);
+                using var _ = getBeatmapArchiveWithModifications(out string pathModified, directory =>
+                {
+                    // Modify one .osu file with different content.
+                    var firstOsuFile = directory.GetFiles("*[Hard]*.osu").First();
+
+                    string existingContent = File.ReadAllText(firstOsuFile.FullName);
+
+                    File.WriteAllText(firstOsuFile.FullName, existingContent + "\n# I am new content");
+                });
+
+                var importBeforeUpdate = await importer.Import(new ImportTask(pathOriginal));
+
+                Assert.That(importBeforeUpdate, Is.Not.Null);
+                Debug.Assert(importBeforeUpdate != null);
+
+                string originalHash = string.Empty;
+
+                importBeforeUpdate.PerformWrite(s =>
+                {
+                    var beatmapCollection = s.Realm.Add(new BeatmapCollection("test collection"));
+                    originalHash = s.Beatmaps.Single(b => b.DifficultyName == "Hard").MD5Hash;
+
+                    beatmapCollection.BeatmapMD5Hashes.Add(originalHash);
+                });
+
+                // Second import matches first but contains a modified .osu file.
+                var importAfterUpdate = await importer.ImportAsUpdate(new ProgressNotification(), new ImportTask(pathModified), importBeforeUpdate.Value);
+
+                Assert.That(importAfterUpdate, Is.Not.Null);
+                Debug.Assert(importAfterUpdate != null);
+
+                importAfterUpdate.PerformRead(updated =>
+                {
+                    updated.Realm.Refresh();
+
+                    string[] hashes = updated.Realm.All<BeatmapCollection>().Single().BeatmapMD5Hashes.ToArray();
+                    string updatedHash = updated.Beatmaps.Single(b => b.DifficultyName == "Hard").MD5Hash;
+
+                    Assert.That(hashes, Has.Length.EqualTo(1));
+                    Assert.That(hashes.First(), Is.EqualTo(updatedHash));
+
+                    Assert.That(updatedHash, Is.Not.EqualTo(originalHash));
+                });
+            });
+        }
+
         private static void checkCount<T>(RealmAccess realm, int expected, Expression<Func<T, bool>>? condition = null) where T : RealmObject
         {
             var query = realm.Realm.All<T>();

osu.Game.Tests/Gameplay/TestSceneMasterGameplayClockContainer.cs

@@ -41,8 +41,6 @@ namespace osu.Game.Tests.Gameplay
             AddStep("create container", () =>
             {
                 var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
-                working.LoadTrack();
-
                 Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);
             });
 
@@ -58,8 +56,6 @@ namespace osu.Game.Tests.Gameplay
             AddStep("create container", () =>
             {
                 var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
-                working.LoadTrack();
-
                 Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);
             });
 
@@ -102,8 +98,6 @@ namespace osu.Game.Tests.Gameplay
             AddStep("create container", () =>
             {
                 working = new ClockBackedTestWorkingBeatmap(new OsuRuleset().RulesetInfo, new FramedClock(new ManualClock()), Audio);
-                working.LoadTrack();
-
                 Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);
 
                 gameplayClockContainer.Reset(startClock: !whileStopped);

osu.Game.Tests/Gameplay/TestSceneStoryboardSamples.cs

@@ -69,7 +69,6 @@ namespace osu.Game.Tests.Gameplay
             AddStep("create container", () =>
             {
                 var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
-                working.LoadTrack();
 
                 Add(gameplayContainer = new MasterGameplayClockContainer(working, 0)
                 {
@@ -96,7 +95,6 @@ namespace osu.Game.Tests.Gameplay
             AddStep("create container", () =>
             {
                 var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
-                working.LoadTrack();
 
                 const double start_time = 1000;
 

osu.Game.Tests/ImportTest.cs

@@ -10,7 +10,7 @@ using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions;
 using osu.Framework.Platform;
-using osu.Game.Collections;
+using osu.Game.Database;
 using osu.Game.Tests.Resources;
 
 namespace osu.Game.Tests
@@ -47,7 +47,7 @@ namespace osu.Game.Tests
 
         public class TestOsuGameBase : OsuGameBase
         {
-            public CollectionManager CollectionManager { get; private set; }
+            public RealmAccess Realm => Dependencies.Get<RealmAccess>();
 
             private readonly bool withBeatmap;
 
@@ -62,8 +62,6 @@ namespace osu.Game.Tests
                 // Beatmap must be imported before the collection manager is loaded.
                 if (withBeatmap)
                     BeatmapManager.Import(TestResources.GetTestBeatmapForImport()).WaitSafely();
-
-                AddInternal(CollectionManager = new CollectionManager(Storage));
             }
         }
     }

osu.Game.Tests/Online/TestSceneOnlinePlayBeatmapAvailabilityTracker.cs

@@ -208,7 +208,7 @@ namespace osu.Game.Tests.Online
 
             public TestBeatmapManager(Storage storage, RealmAccess realm, RulesetStore rulesets, IAPIProvider api, [NotNull] AudioManager audioManager, IResourceStore<byte[]> resources,
                                       GameHost host = null, WorkingBeatmap defaultBeatmap = null)
-                : base(storage, realm, rulesets, api, audioManager, resources, host, defaultBeatmap)
+                : base(storage, realm, api, audioManager, resources, host, defaultBeatmap)
             {
             }
 

osu.Game.Tests/Skins/TestSceneBeatmapSkinResources.cs

@@ -32,7 +32,6 @@ namespace osu.Game.Tests.Skins
             imported?.PerformRead(s =>
             {
                 beatmap = beatmaps.GetWorkingBeatmap(s.Beatmaps[0]);
-                beatmap.LoadTrack();
             });
         }
 
@@ -40,6 +39,10 @@ namespace osu.Game.Tests.Skins
         public void TestRetrieveOggSample() => AddAssert("sample is non-null", () => beatmap.Skin.GetSample(new SampleInfo("sample")) != null);
 
         [Test]
-        public void TestRetrieveOggTrack() => AddAssert("track is non-null", () => !(beatmap.Track is TrackVirtual));
+        public void TestRetrieveOggTrack() => AddAssert("track is non-null", () =>
+        {
+            using (var track = beatmap.LoadTrack())
+                return track is not TrackVirtual;
+        });
     }
 }

osu.Game.Tests/Visual/Background/TestSceneUserDimBackgrounds.cs

@@ -49,7 +49,7 @@ namespace osu.Game.Tests.Visual.Background
         private void load(GameHost host, AudioManager audio)
         {
             Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(new OsuConfigManager(LocalStorage));
             Dependencies.Cache(Realm);
 

osu.Game.Tests/Visual/Collections/TestSceneManageCollectionsDialog.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.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
@@ -27,38 +25,32 @@ namespace osu.Game.Tests.Visual.Collections
     {
         protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };
 
-        private DialogOverlay dialogOverlay;
+        private DialogOverlay dialogOverlay = null!;
-        private CollectionManager manager;
+        private BeatmapManager beatmapManager = null!;
-
+        private ManageCollectionsDialog dialog = null!;
-        private RulesetStore rulesets;
-        private BeatmapManager beatmapManager;
-
-        private ManageCollectionsDialog dialog;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, rulesets, null, Audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, null, Audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             beatmapManager.Import(TestResources.GetQuickTestBeatmapForImport()).WaitSafely();
 
             base.Content.AddRange(new Drawable[]
             {
-                manager = new CollectionManager(LocalStorage),
                 Content,
                 dialogOverlay = new DialogOverlay(),
             });
 
-            Dependencies.Cache(manager);
             Dependencies.CacheAs<IDialogOverlay>(dialogOverlay);
         }
 
         [SetUp]
         public void SetUp() => Schedule(() =>
         {
-            manager.Collections.Clear();
+            Realm.Write(r => r.RemoveAll<BeatmapCollection>());
             Child = dialog = new ManageCollectionsDialog();
         });
 
@@ -78,17 +70,17 @@ namespace osu.Game.Tests.Visual.Collections
         [Test]
         public void TestLastItemIsPlaceholder()
         {
-            AddAssert("last item is placeholder", () => !manager.Collections.Contains(dialog.ChildrenOfType<DrawableCollectionListItem>().Last().Model));
+            AddAssert("last item is placeholder", () => !dialog.ChildrenOfType<DrawableCollectionListItem>().Last().Model.IsManaged);
         }
 
         [Test]
         public void TestAddCollectionExternal()
         {
-            AddStep("add collection", () => manager.Collections.Add(new BeatmapCollection { Name = { Value = "First collection" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "First collection"))));
             assertCollectionCount(1);
             assertCollectionName(0, "First collection");
 
-            AddStep("add another collection", () => manager.Collections.Add(new BeatmapCollection { Name = { Value = "Second collection" } }));
+            AddStep("add another collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "Second collection"))));
             assertCollectionCount(2);
             assertCollectionName(1, "Second collection");
         }
@@ -108,7 +100,7 @@ namespace osu.Game.Tests.Visual.Collections
         [Test]
         public void TestAddCollectionViaPlaceholder()
         {
-            DrawableCollectionListItem placeholderItem = null;
+            DrawableCollectionListItem placeholderItem = null!;
 
             AddStep("focus placeholder", () =>
             {
@@ -116,24 +108,37 @@ namespace osu.Game.Tests.Visual.Collections
                 InputManager.Click(MouseButton.Left);
             });
 
-            // Done directly via the collection since InputManager methods cannot add text to textbox...
+            assertCollectionCount(0);
-            AddStep("change collection name", () => placeholderItem.Model.Name.Value = "a");
-            assertCollectionCount(1);
-            AddAssert("collection now exists", () => manager.Collections.Contains(placeholderItem.Model));
 
-            AddAssert("last item is placeholder", () => !manager.Collections.Contains(dialog.ChildrenOfType<DrawableCollectionListItem>().Last().Model));
+            AddStep("change collection name", () =>
+            {
+                placeholderItem.ChildrenOfType<TextBox>().First().Text = "test text";
+                InputManager.Key(Key.Enter);
+            });
+
+            assertCollectionCount(1);
+
+            AddAssert("last item is placeholder", () => !dialog.ChildrenOfType<DrawableCollectionListItem>().Last().Model.IsManaged);
         }
 
         [Test]
         public void TestRemoveCollectionExternal()
         {
-            AddStep("add two collections", () => manager.Collections.AddRange(new[]
+            BeatmapCollection first = null!;
-            {
-                new BeatmapCollection { Name = { Value = "1" } },
-                new BeatmapCollection { Name = { Value = "2" } },
-            }));
 
-            AddStep("remove first collection", () => manager.Collections.RemoveAt(0));
+            AddStep("add two collections", () =>
+            {
+                Realm.Write(r =>
+                {
+                    r.Add(new[]
+                    {
+                        first = new BeatmapCollection(name: "1"),
+                        new BeatmapCollection(name: "2"),
+                    });
+                });
+            });
+
+            AddStep("remove first collection", () => Realm.Write(r => r.Remove(first)));
             assertCollectionCount(1);
             assertCollectionName(0, "2");
         }
@@ -143,7 +148,7 @@ namespace osu.Game.Tests.Visual.Collections
         {
             AddStep("add dropdown", () =>
             {
-                Add(new CollectionFilterDropdown
+                Add(new CollectionDropdown
                 {
                     Anchor = Anchor.TopRight,
                     Origin = Anchor.TopRight,
@@ -151,21 +156,27 @@ namespace osu.Game.Tests.Visual.Collections
                     Width = 0.4f,
                 });
             });
-            AddStep("add two collections with same name", () => manager.Collections.AddRange(new[]
+            AddStep("add two collections with same name", () => Realm.Write(r => r.Add(new[]
             {
-                new BeatmapCollection { Name = { Value = "1" } },
+                new BeatmapCollection(name: "1"),
-                new BeatmapCollection { Name = { Value = "1" }, BeatmapHashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash } },
+                new BeatmapCollection(name: "1")
-            }));
+                {
+                    BeatmapMD5Hashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash }
+                },
+            })));
         }
 
         [Test]
         public void TestRemoveCollectionViaButton()
         {
-            AddStep("add two collections", () => manager.Collections.AddRange(new[]
+            AddStep("add two collections", () => Realm.Write(r => r.Add(new[]
             {
-                new BeatmapCollection { Name = { Value = "1" } },
+                new BeatmapCollection(name: "1"),
-                new BeatmapCollection { Name = { Value = "2" }, BeatmapHashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash } },
+                new BeatmapCollection(name: "2")
-            }));
+                {
+                    BeatmapMD5Hashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash }
+                },
+            })));
 
             assertCollectionCount(2);
 
@@ -198,10 +209,13 @@ namespace osu.Game.Tests.Visual.Collections
         [Test]
         public void TestCollectionNotRemovedWhenDialogCancelled()
         {
-            AddStep("add two collections", () => manager.Collections.AddRange(new[]
+            AddStep("add collection", () => Realm.Write(r => r.Add(new[]
             {
-                new BeatmapCollection { Name = { Value = "1" }, BeatmapHashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash } },
+                new BeatmapCollection(name: "1")
-            }));
+                {
+                    BeatmapMD5Hashes = { beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0].MD5Hash }
+                },
+            })));
 
             assertCollectionCount(1);
 
@@ -224,34 +238,67 @@ namespace osu.Game.Tests.Visual.Collections
         [Test]
         public void TestCollectionRenamedExternal()
         {
-            AddStep("add two collections", () => manager.Collections.AddRange(new[]
+            BeatmapCollection first = null!;
+
+            AddStep("add two collections", () =>
             {
-                new BeatmapCollection { Name = { Value = "1" } },
+                Realm.Write(r =>
-                new BeatmapCollection { Name = { Value = "2" } },
+                {
-            }));
+                    r.Add(new[]
+                    {
+                        first = new BeatmapCollection(name: "1"),
+                        new BeatmapCollection(name: "2"),
+                    });
+                });
+            });
 
-            AddStep("change first collection name", () => manager.Collections[0].Name.Value = "First");
+            assertCollectionName(0, "1");
+            assertCollectionName(1, "2");
 
-            assertCollectionName(0, "First");
+            AddStep("change first collection name", () => Realm.Write(_ => first.Name = "First"));
+
+            // Item will have moved due to alphabetical sorting.
+            assertCollectionName(0, "2");
+            assertCollectionName(1, "First");
         }
 
         [Test]
         public void TestCollectionRenamedOnTextChange()
         {
-            AddStep("add two collections", () => manager.Collections.AddRange(new[]
+            BeatmapCollection first = null!;
+            DrawableCollectionListItem firstItem = null!;
+
+            AddStep("add two collections", () =>
             {
-                new BeatmapCollection { Name = { Value = "1" } },
+                Realm.Write(r =>
-                new BeatmapCollection { Name = { Value = "2" } },
+                {
-            }));
+                    r.Add(new[]
+                    {
+                        first = new BeatmapCollection(name: "1"),
+                        new BeatmapCollection(name: "2"),
+                    });
+                });
+            });
 
             assertCollectionCount(2);
 
-            AddStep("change first collection name", () => dialog.ChildrenOfType<TextBox>().First().Text = "First");
+            AddStep("focus first collection", () =>
-            AddAssert("collection has new name", () => manager.Collections[0].Name.Value == "First");
+            {
+                InputManager.MoveMouseTo(firstItem = dialog.ChildrenOfType<DrawableCollectionListItem>().First());
+                InputManager.Click(MouseButton.Left);
+            });
+
+            AddStep("change first collection name", () =>
+            {
+                firstItem.ChildrenOfType<TextBox>().First().Text = "First";
+                InputManager.Key(Key.Enter);
+            });
+
+            AddUntilStep("collection has new name", () => first.Name == "First");
         }
 
         private void assertCollectionCount(int count)
-            => AddUntilStep($"{count} collections shown", () => dialog.ChildrenOfType<DrawableCollectionListItem>().Count(i => i.IsCreated.Value) == count);
+            => AddUntilStep($"{count} collections shown", () => dialog.ChildrenOfType<DrawableCollectionListItem>().Count() == count + 1); // +1 for placeholder
 
         private void assertCollectionName(int index, string name)
             => AddUntilStep($"item {index + 1} has correct name", () => dialog.ChildrenOfType<DrawableCollectionListItem>().ElementAt(index).ChildrenOfType<TextBox>().First().Text == name);

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

@@ -159,6 +159,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             AddUntilStep("wait for hud load", () => hudOverlay.IsLoaded);
             AddUntilStep("wait for components to be hidden", () => hudOverlay.ChildrenOfType<SkinnableTargetContainer>().Single().Alpha == 0);
+            AddUntilStep("wait for hud load", () => hudOverlay.ChildrenOfType<SkinnableTargetContainer>().All(c => c.ComponentsLoaded));
 
             AddStep("bind on update", () =>
             {

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

@@ -36,7 +36,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         private void load(GameHost host, AudioManager audio)
         {
             Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(new ScoreManager(rulesets, () => beatmaps, LocalStorage, Realm, Scheduler, API));
             Dependencies.Cache(Realm);
         }

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

@@ -14,6 +14,7 @@ using osu.Game.Overlays.Settings;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Screens.Play.HUD.HitErrorMeters;
+using osu.Game.Skinning;
 using osu.Game.Skinning.Editor;
 using osuTK.Input;
 
@@ -33,6 +34,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         {
             base.SetUpSteps();
 
+            AddUntilStep("wait for hud load", () => Player.ChildrenOfType<SkinnableTargetContainer>().All(c => c.ComponentsLoaded));
+
             AddStep("reload skin editor", () =>
             {
                 skinEditor?.Expire();

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

@@ -33,7 +33,6 @@ namespace osu.Game.Tests.Visual.Gameplay
             increment = skip_time;
 
             var working = CreateWorkingBeatmap(CreateBeatmap(new OsuRuleset().RulesetInfo));
-            working.LoadTrack();
 
             Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0)
             {

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

@@ -35,7 +35,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
         protected IScreen CurrentSubScreen => multiplayerComponents.MultiplayerScreen.CurrentSubScreen;
 
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
         private BeatmapSetInfo importedSet;
 
         private TestMultiplayerComponents multiplayerComponents;
@@ -45,8 +44,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -38,13 +38,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private TestPlaylist playlist;
 
         private BeatmapManager manager;
-        private RulesetStore rulesets;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -49,7 +49,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
     public class TestSceneMultiplayer : ScreenTestScene
     {
         private BeatmapManager beatmaps = null!;
-        private RulesetStore rulesets = null!;
         private BeatmapSetInfo importedSet = null!;
 
         private TestMultiplayerComponents multiplayerComponents = null!;
@@ -63,8 +62,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, API, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, API, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -47,7 +47,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private void load(GameHost host, AudioManager audio)
         {
             Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             importedBeatmapSet = manager.Import(TestResources.CreateTestBeatmapSetInfo(8, rulesets.AvailableRulesets.ToArray()));

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

@@ -40,7 +40,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private MultiplayerMatchSubScreen screen;
 
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
         private BeatmapSetInfo importedSet;
 
         public TestSceneMultiplayerMatchSubScreen()
@@ -51,8 +50,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             beatmaps.Import(TestResources.GetQuickTestBeatmapForImport()).WaitSafely();

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

@@ -31,15 +31,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         private MultiplayerPlaylist list;
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
         private BeatmapSetInfo importedSet;
         private BeatmapInfo importedBeatmap;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -29,15 +29,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         private MultiplayerQueueList playlist;
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
         private BeatmapSetInfo importedSet;
         private BeatmapInfo importedBeatmap;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, API, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, API, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -35,13 +35,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private BeatmapSetInfo importedSet;
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             beatmaps.Import(TestResources.GetQuickTestBeatmapForImport()).WaitSafely();

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

@@ -28,15 +28,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         private BeatmapManager manager;
 
-        private RulesetStore rulesets;
-
         private TestPlaylistsSongSelect songSelect;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             var beatmapSet = TestResources.CreateTestBeatmapSetInfo();

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

@@ -30,7 +30,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
     public class TestSceneTeamVersus : ScreenTestScene
     {
         private BeatmapManager beatmaps;
-        private RulesetStore rulesets;
         private BeatmapSetInfo importedSet;
 
         private TestMultiplayerComponents multiplayerComponents;
@@ -40,8 +39,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmaps = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

osu.Game.Tests/Visual/Navigation/TestSceneScreenNavigation.cs

@@ -74,14 +74,14 @@ namespace osu.Game.Tests.Visual.Navigation
             AddStep("set filter again", () => songSelect.ChildrenOfType<SearchTextBox>().Single().Current.Value = "test");
             AddStep("open collections dropdown", () =>
             {
-                InputManager.MoveMouseTo(songSelect.ChildrenOfType<CollectionFilterDropdown>().Single());
+                InputManager.MoveMouseTo(songSelect.ChildrenOfType<CollectionDropdown>().Single());
                 InputManager.Click(MouseButton.Left);
             });
 
             AddStep("press back once", () => InputManager.Click(MouseButton.Button1));
             AddAssert("still at song select", () => Game.ScreenStack.CurrentScreen == songSelect);
             AddAssert("collections dropdown closed", () => songSelect
-                                                           .ChildrenOfType<CollectionFilterDropdown>().Single()
+                                                           .ChildrenOfType<CollectionDropdown>().Single()
                                                            .ChildrenOfType<Dropdown<CollectionFilterMenuItem>.DropdownMenu>().Single().State == MenuState.Closed);
 
             AddStep("press back a second time", () => InputManager.Click(MouseButton.Button1));

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

@@ -3,6 +3,8 @@
 
 #nullable disable
 
+using osu.Framework.Graphics;
+using osu.Game.Graphics.Cursor;
 using osu.Game.Graphics.UserInterface;
 using osuTK;
 
@@ -12,9 +14,15 @@ namespace osu.Game.Tests.Visual.Online
     {
         public TestSceneExternalLinkButton()
         {
-            Child = new ExternalLinkButton("https://osu.ppy.sh/home")
+            Child = new OsuContextMenuContainer
             {
-                Size = new Vector2(50)
+                RelativeSizeAxes = Axes.Both,
+                Child = new ExternalLinkButton("https://osu.ppy.sh/home")
+                {
+                    Size = new Vector2(50),
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                }
             };
         }
     }

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsRoomCreation.cs

@@ -32,7 +32,6 @@ namespace osu.Game.Tests.Visual.Playlists
     public class TestScenePlaylistsRoomCreation : OnlinePlayTestScene
     {
         private BeatmapManager manager;
-        private RulesetStore rulesets;
 
         private TestPlaylistsRoomSubScreen match;
 
@@ -41,8 +40,8 @@ namespace osu.Game.Tests.Visual.Playlists
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, API, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, API, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
         }
 

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

@@ -46,7 +46,7 @@ namespace osu.Game.Tests.Visual.SongSelect
             var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
 
             dependencies.Cache(rulesetStore = new RealmRulesetStore(Realm));
-            dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, rulesetStore, null, dependencies.Get<AudioManager>(), Resources, dependencies.Get<GameHost>(), Beatmap.Default));
+            dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, null, dependencies.Get<AudioManager>(), Resources, dependencies.Get<GameHost>(), Beatmap.Default));
             dependencies.Cache(scoreManager = new ScoreManager(rulesetStore, () => beatmapManager, LocalStorage, Realm, Scheduler, API));
             Dependencies.Cache(Realm);
 

osu.Game.Tests/Visual/SongSelect/TestSceneFilterControl.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.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
@@ -28,35 +26,28 @@ namespace osu.Game.Tests.Visual.SongSelect
     {
         protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };
 
-        private CollectionManager collectionManager;
+        private BeatmapManager beatmapManager = null!;
-
+        private FilterControl control = null!;
-        private RulesetStore rulesets;
-        private BeatmapManager beatmapManager;
-
-        private FilterControl control;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host)
         {
-            Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
+            Dependencies.Cache(new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, rulesets, null, Audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, null, Audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(Realm);
 
             beatmapManager.Import(TestResources.GetQuickTestBeatmapForImport()).WaitSafely();
 
             base.Content.AddRange(new Drawable[]
             {
-                collectionManager = new CollectionManager(LocalStorage),
                 Content
             });
-
-            Dependencies.Cache(collectionManager);
         }
 
         [SetUp]
         public void SetUp() => Schedule(() =>
         {
-            collectionManager.Collections.Clear();
+            Realm.Write(r => r.RemoveAll<BeatmapCollection>());
 
             Child = control = new FilterControl
             {
@@ -77,8 +68,8 @@ namespace osu.Game.Tests.Visual.SongSelect
         [Test]
         public void TestCollectionAddedToDropdown()
         {
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "2" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "2"))));
             assertCollectionDropdownContains("1");
             assertCollectionDropdownContains("2");
         }
@@ -86,9 +77,11 @@ namespace osu.Game.Tests.Visual.SongSelect
         [Test]
         public void TestCollectionRemovedFromDropdown()
         {
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            BeatmapCollection first = null!;
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "2" } }));
+
-            AddStep("remove collection", () => collectionManager.Collections.RemoveAt(0));
+            AddStep("add collection", () => Realm.Write(r => r.Add(first = new BeatmapCollection(name: "1"))));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "2"))));
+            AddStep("remove collection", () => Realm.Write(r => r.Remove(first)));
 
             assertCollectionDropdownContains("1", false);
             assertCollectionDropdownContains("2");
@@ -97,16 +90,16 @@ namespace osu.Game.Tests.Visual.SongSelect
         [Test]
         public void TestCollectionRenamed()
         {
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
             AddStep("select collection", () =>
             {
-                var dropdown = control.ChildrenOfType<CollectionFilterDropdown>().Single();
+                var dropdown = control.ChildrenOfType<CollectionDropdown>().Single();
                 dropdown.Current.Value = dropdown.ItemSource.ElementAt(1);
             });
 
             addExpandHeaderStep();
 
-            AddStep("change name", () => collectionManager.Collections[0].Name.Value = "First");
+            AddStep("change name", () => Realm.Write(_ => getFirstCollection().Name = "First"));
 
             assertCollectionDropdownContains("First");
             assertCollectionHeaderDisplays("First");
@@ -124,7 +117,7 @@ namespace osu.Game.Tests.Visual.SongSelect
         public void TestCollectionFilterHasAddButton()
         {
             addExpandHeaderStep();
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
             AddStep("hover collection", () => InputManager.MoveMouseTo(getAddOrRemoveButton(1)));
             AddAssert("collection has add button", () => getAddOrRemoveButton(1).IsPresent);
         }
@@ -134,7 +127,7 @@ namespace osu.Game.Tests.Visual.SongSelect
         {
             addExpandHeaderStep();
 
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
 
             AddStep("select available beatmap", () => Beatmap.Value = beatmapManager.GetWorkingBeatmap(beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0]));
             AddAssert("button enabled", () => getAddOrRemoveButton(1).Enabled.Value);
@@ -150,13 +143,13 @@ namespace osu.Game.Tests.Visual.SongSelect
 
             AddStep("select available beatmap", () => Beatmap.Value = beatmapManager.GetWorkingBeatmap(beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0]));
 
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
             AddAssert("button is plus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.PlusSquare));
 
-            AddStep("add beatmap to collection", () => collectionManager.Collections[0].BeatmapHashes.Add(Beatmap.Value.BeatmapInfo.MD5Hash));
+            AddStep("add beatmap to collection", () => Realm.Write(r => getFirstCollection().BeatmapMD5Hashes.Add(Beatmap.Value.BeatmapInfo.MD5Hash)));
             AddAssert("button is minus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.MinusSquare));
 
-            AddStep("remove beatmap from collection", () => collectionManager.Collections[0].BeatmapHashes.Clear());
+            AddStep("remove beatmap from collection", () => Realm.Write(r => getFirstCollection().BeatmapMD5Hashes.Clear()));
             AddAssert("button is plus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.PlusSquare));
         }
 
@@ -167,24 +160,26 @@ namespace osu.Game.Tests.Visual.SongSelect
 
             AddStep("select available beatmap", () => Beatmap.Value = beatmapManager.GetWorkingBeatmap(beatmapManager.GetAllUsableBeatmapSets().First().Beatmaps[0]));
 
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1"))));
             AddAssert("button is plus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.PlusSquare));
 
             addClickAddOrRemoveButtonStep(1);
-            AddAssert("collection contains beatmap", () => collectionManager.Collections[0].BeatmapHashes.Contains(Beatmap.Value.BeatmapInfo.MD5Hash));
+            AddAssert("collection contains beatmap", () => getFirstCollection().BeatmapMD5Hashes.Contains(Beatmap.Value.BeatmapInfo.MD5Hash));
             AddAssert("button is minus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.MinusSquare));
 
             addClickAddOrRemoveButtonStep(1);
-            AddAssert("collection does not contain beatmap", () => !collectionManager.Collections[0].BeatmapHashes.Contains(Beatmap.Value.BeatmapInfo.MD5Hash));
+            AddAssert("collection does not contain beatmap", () => !getFirstCollection().BeatmapMD5Hashes.Contains(Beatmap.Value.BeatmapInfo.MD5Hash));
             AddAssert("button is plus", () => getAddOrRemoveButton(1).Icon.Equals(FontAwesome.Solid.PlusSquare));
         }
 
         [Test]
         public void TestManageCollectionsFilterIsNotSelected()
         {
+            bool received = false;
+
             addExpandHeaderStep();
 
-            AddStep("add collection", () => collectionManager.Collections.Add(new BeatmapCollection { Name = { Value = "1" } }));
+            AddStep("add collection", () => Realm.Write(r => r.Add(new BeatmapCollection(name: "1", new List<string> { "abc" }))));
             AddStep("select collection", () =>
             {
                 InputManager.MoveMouseTo(getCollectionDropdownItems().ElementAt(1));
@@ -193,18 +188,28 @@ namespace osu.Game.Tests.Visual.SongSelect
 
             addExpandHeaderStep();
 
+            AddStep("watch for filter requests", () =>
+            {
+                received = false;
+                control.ChildrenOfType<CollectionDropdown>().First().RequestFilter = () => received = true;
+            });
+
             AddStep("click manage collections filter", () =>
             {
                 InputManager.MoveMouseTo(getCollectionDropdownItems().Last());
                 InputManager.Click(MouseButton.Left);
             });
 
-            AddAssert("collection filter still selected", () => control.CreateCriteria().Collection?.Name.Value == "1");
+            AddAssert("collection filter still selected", () => control.CreateCriteria().CollectionBeatmapMD5Hashes.Any());
+
+            AddAssert("filter request not fired", () => !received);
         }
 
+        private BeatmapCollection getFirstCollection() => Realm.Run(r => r.All<BeatmapCollection>().First());
+
         private void assertCollectionHeaderDisplays(string collectionName, bool shouldDisplay = true)
             => AddAssert($"collection dropdown header displays '{collectionName}'",
-                () => shouldDisplay == (control.ChildrenOfType<CollectionFilterDropdown.CollectionDropdownHeader>().Single().ChildrenOfType<SpriteText>().First().Text == collectionName));
+                () => shouldDisplay == (control.ChildrenOfType<CollectionDropdown.CollectionDropdownHeader>().Single().ChildrenOfType<SpriteText>().First().Text == collectionName));
 
         private void assertCollectionDropdownContains(string collectionName, bool shouldContain = true) =>
             AddAssert($"collection dropdown {(shouldContain ? "contains" : "does not contain")} '{collectionName}'",
@@ -216,7 +221,7 @@ namespace osu.Game.Tests.Visual.SongSelect
 
         private void addExpandHeaderStep() => AddStep("expand header", () =>
         {
-            InputManager.MoveMouseTo(control.ChildrenOfType<CollectionFilterDropdown.CollectionDropdownHeader>().Single());
+            InputManager.MoveMouseTo(control.ChildrenOfType<CollectionDropdown.CollectionDropdownHeader>().Single());
             InputManager.Click(MouseButton.Left);
         });
 
@@ -227,6 +232,6 @@ namespace osu.Game.Tests.Visual.SongSelect
         });
 
         private IEnumerable<Dropdown<CollectionFilterMenuItem>.DropdownMenu.DrawableDropdownMenuItem> getCollectionDropdownItems()
-            => control.ChildrenOfType<CollectionFilterDropdown>().Single().ChildrenOfType<Dropdown<CollectionFilterMenuItem>.DropdownMenu.DrawableDropdownMenuItem>();
+            => control.ChildrenOfType<CollectionDropdown>().Single().ChildrenOfType<Dropdown<CollectionFilterMenuItem>.DropdownMenu.DrawableDropdownMenuItem>();
     }
 }

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

@@ -54,7 +54,7 @@ namespace osu.Game.Tests.Visual.SongSelect
             // At a point we have isolated interactive test runs enough, this can likely be removed.
             Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
             Dependencies.Cache(Realm);
-            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, defaultBeatmap = Beatmap.Default));
+            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, defaultBeatmap = Beatmap.Default));
 
             Dependencies.Cache(music = new MusicController());
 

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

@@ -31,7 +31,7 @@ namespace osu.Game.Tests.Visual.SongSelect
         private void load(GameHost host, AudioManager audio)
         {
             Dependencies.Cache(rulesets = new RealmRulesetStore(Realm));
-            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, rulesets, null, audio, Resources, host, Beatmap.Default));
+            Dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, null, audio, Resources, host, Beatmap.Default));
             Dependencies.Cache(scoreManager = new ScoreManager(rulesets, () => beatmapManager, LocalStorage, Realm, Scheduler, API));
             Dependencies.Cache(Realm);
 

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

@@ -37,7 +37,6 @@ namespace osu.Game.Tests.Visual.UserInterface
         private readonly ContextMenuContainer contextMenuContainer;
         private readonly BeatmapLeaderboard leaderboard;
 
-        private RulesetStore rulesetStore;
         private BeatmapManager beatmapManager;
         private ScoreManager scoreManager;
 
@@ -72,8 +71,8 @@ namespace osu.Game.Tests.Visual.UserInterface
         {
             var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
 
-            dependencies.Cache(rulesetStore = new RealmRulesetStore(Realm));
+            dependencies.Cache(new RealmRulesetStore(Realm));
-            dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, rulesetStore, null, dependencies.Get<AudioManager>(), Resources, dependencies.Get<GameHost>(), Beatmap.Default));
+            dependencies.Cache(beatmapManager = new BeatmapManager(LocalStorage, Realm, null, dependencies.Get<AudioManager>(), Resources, dependencies.Get<GameHost>(), Beatmap.Default));
             dependencies.Cache(scoreManager = new ScoreManager(dependencies.Get<RulesetStore>(), () => beatmapManager, LocalStorage, Realm, Scheduler, API));
             Dependencies.Cache(Realm);
 

osu.Game/Beatmaps/Beatmap.cs

@@ -14,9 +14,6 @@ using osu.Game.IO.Serialization.Converters;
 
 namespace osu.Game.Beatmaps
 {
-    /// <summary>
-    /// A Beatmap containing converted HitObjects.
-    /// </summary>
     public class Beatmap<T> : IBeatmap<T>
         where T : HitObject
     {

osu.Game/Beatmaps/BeatmapImporter.cs

@@ -14,6 +14,7 @@ using osu.Framework.Logging;
 using osu.Framework.Platform;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.Collections;
 using osu.Game.Database;
 using osu.Game.Extensions;
 using osu.Game.IO;
@@ -71,6 +72,8 @@ namespace osu.Game.Beatmaps
                 // Transfer local values which should be persisted across a beatmap update.
                 updated.DateAdded = original.DateAdded;
 
+                transferCollectionReferences(realm, original, updated);
+
                 foreach (var beatmap in original.Beatmaps.ToArray())
                 {
                     var updatedBeatmap = updated.Beatmaps.FirstOrDefault(b => b.Hash == beatmap.Hash);
@@ -112,6 +115,40 @@ namespace osu.Game.Beatmaps
             return first;
         }
 
+        private static void transferCollectionReferences(Realm realm, BeatmapSetInfo original, BeatmapSetInfo updated)
+        {
+            // First check if every beatmap in the original set is in any collections.
+            // In this case, we will assume they also want any newly added difficulties added to the collection.
+            foreach (var c in realm.All<BeatmapCollection>())
+            {
+                if (original.Beatmaps.Select(b => b.MD5Hash).All(c.BeatmapMD5Hashes.Contains))
+                {
+                    foreach (var b in original.Beatmaps)
+                        c.BeatmapMD5Hashes.Remove(b.MD5Hash);
+
+                    foreach (var b in updated.Beatmaps)
+                        c.BeatmapMD5Hashes.Add(b.MD5Hash);
+                }
+            }
+
+            // Handle collections using permissive difficulty name to track difficulties.
+            foreach (var originalBeatmap in original.Beatmaps)
+            {
+                var updatedBeatmap = updated.Beatmaps.FirstOrDefault(b => b.DifficultyName == originalBeatmap.DifficultyName);
+
+                if (updatedBeatmap == null)
+                    continue;
+
+                var collections = realm.All<BeatmapCollection>().AsEnumerable().Where(c => c.BeatmapMD5Hashes.Contains(originalBeatmap.MD5Hash));
+
+                foreach (var c in collections)
+                {
+                    c.BeatmapMD5Hashes.Remove(originalBeatmap.MD5Hash);
+                    c.BeatmapMD5Hashes.Add(updatedBeatmap.MD5Hash);
+                }
+            }
+        }
+
         protected override bool ShouldDeleteArchive(string path) => Path.GetExtension(path).ToLowerInvariant() == ".osz";
 
         protected override void Populate(BeatmapSetInfo beatmapSet, ArchiveReader? archive, Realm realm, CancellationToken cancellationToken = default)

osu.Game/Beatmaps/BeatmapInfo.cs

@@ -20,8 +20,12 @@ using Realms;
 namespace osu.Game.Beatmaps
 {
     /// <summary>
-    /// A single beatmap difficulty.
+    /// A realm model containing metadata for a single beatmap difficulty.
+    /// This should generally include anything which is required to be filtered on at song select, or anything pertaining to storage of beatmaps in the client.
     /// </summary>
+    /// <remarks>
+    /// There are some legacy fields in this model which are not persisted to realm. These are isolated in a code region within the class and should eventually be migrated to `Beatmap`.
+    /// </remarks>
     [ExcludeFromDynamicCompile]
     [Serializable]
     [MapTo("Beatmap")]

osu.Game/Beatmaps/BeatmapManager.cs

@@ -44,7 +44,7 @@ namespace osu.Game.Beatmaps
 
         public Action<BeatmapSetInfo>? ProcessBeatmap { private get; set; }
 
-        public BeatmapManager(Storage storage, RealmAccess realm, RulesetStore rulesets, IAPIProvider? api, AudioManager audioManager, IResourceStore<byte[]> gameResources, GameHost? host = null,
+        public BeatmapManager(Storage storage, RealmAccess realm, IAPIProvider? api, AudioManager audioManager, IResourceStore<byte[]> gameResources, GameHost? host = null,
                               WorkingBeatmap? defaultBeatmap = null, BeatmapDifficultyCache? difficultyCache = null, bool performOnlineLookups = false)
             : base(storage, realm)
         {

osu.Game/Beatmaps/BeatmapMetadata.cs

@@ -12,6 +12,17 @@ using Realms;
 
 namespace osu.Game.Beatmaps
 {
+    /// <summary>
+    /// A realm model containing metadata for a beatmap.
+    /// </summary>
+    /// <remarks>
+    /// This is currently stored against each beatmap difficulty, even when it is duplicated.
+    /// It is also provided via <see cref="BeatmapSetInfo"/> for convenience and historical purposes.
+    /// A future effort could see this converted to an <see cref="EmbeddedObject"/> or potentially de-duped
+    /// and shared across multiple difficulties in the same set, if required.
+    ///
+    /// Note that difficulty name is not stored in this metadata but in <see cref="BeatmapInfo"/>.
+    /// </remarks>
     [ExcludeFromDynamicCompile]
     [Serializable]
     [MapTo("BeatmapMetadata")]

osu.Game/Beatmaps/BeatmapSetInfo.cs

@@ -14,6 +14,9 @@ using Realms;
 
 namespace osu.Game.Beatmaps
 {
+    /// <summary>
+    /// A realm model containing metadata for a beatmap set (containing multiple <see cref="BeatmapInfo"/>s).
+    /// </summary>
     [ExcludeFromDynamicCompile]
     [MapTo("BeatmapSet")]
     public class BeatmapSetInfo : RealmObject, IHasGuidPrimaryKey, IHasRealmFiles, ISoftDelete, IEquatable<BeatmapSetInfo>, IBeatmapSetInfo