Merge branch 'master' into reversed-fruits

osu.Android.props

@@ -51,7 +51,7 @@
     <Reference Include="Java.Interop" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2021.412.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2021.422.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.416.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.422.1" />
   </ItemGroup>
 </Project>

osu.Game.Rulesets.Catch.Tests/TestSceneCatcher.cs

@@ -10,6 +10,7 @@ using osu.Game.Rulesets.Catch.UI;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
+using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Configuration;
@@ -20,6 +21,7 @@ using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Skinning;
 using osu.Game.Tests.Visual;
+using osuTK;
 
 namespace osu.Game.Rulesets.Catch.Tests
 {
@@ -170,16 +172,25 @@ namespace osu.Game.Rulesets.Catch.Tests
         }
 
         [Test]
-        public void TestCatcherStacking()
+        public void TestCatcherRandomStacking()
+        {
+            AddStep("catch more fruits", () => attemptCatch(() => new Fruit
+            {
+                X = (RNG.NextSingle() - 0.5f) * Catcher.CalculateCatchWidth(Vector2.One)
+            }, 50));
+        }
+
+        [Test]
+        public void TestCatcherStackingSameCaughtPosition()
         {
             AddStep("catch fruit", () => attemptCatch(new Fruit()));
             checkPlate(1);
-            AddStep("catch more fruits", () => attemptCatch(new Fruit(), 9));
+            AddStep("catch more fruits", () => attemptCatch(() => new Fruit(), 9));
             checkPlate(10);
             AddAssert("caught objects are stacked", () =>
-                catcher.CaughtObjects.All(obj => obj.Y <= 0) &&
+                catcher.CaughtObjects.All(obj => obj.Y <= Catcher.CAUGHT_FRUIT_VERTICAL_OFFSET) &&
-                catcher.CaughtObjects.Any(obj => obj.Y == 0) &&
+                catcher.CaughtObjects.Any(obj => obj.Y == Catcher.CAUGHT_FRUIT_VERTICAL_OFFSET) &&
-                catcher.CaughtObjects.Any(obj => obj.Y < -20));
+                catcher.CaughtObjects.Any(obj => obj.Y < -25));
         }
 
         [Test]
@@ -189,11 +200,11 @@ namespace osu.Game.Rulesets.Catch.Tests
             AddStep("catch tiny droplet", () => attemptCatch(new TinyDroplet()));
             AddAssert("tiny droplet is exploded", () => catcher.CaughtObjects.Count() == 1 && droppedObjectContainer.Count == 1);
             AddUntilStep("wait explosion", () => !droppedObjectContainer.Any());
-            AddStep("catch more fruits", () => attemptCatch(new Fruit(), 9));
+            AddStep("catch more fruits", () => attemptCatch(() => new Fruit(), 9));
             AddStep("explode", () => catcher.Explode());
             AddAssert("fruits are exploded", () => !catcher.CaughtObjects.Any() && droppedObjectContainer.Count == 10);
             AddUntilStep("wait explosion", () => !droppedObjectContainer.Any());
-            AddStep("catch fruits", () => attemptCatch(new Fruit(), 10));
+            AddStep("catch fruits", () => attemptCatch(() => new Fruit(), 10));
             AddStep("drop", () => catcher.Drop());
             AddAssert("fruits are dropped", () => !catcher.CaughtObjects.Any() && droppedObjectContainer.Count == 10);
         }
@@ -222,10 +233,15 @@ namespace osu.Game.Rulesets.Catch.Tests
 
         private void checkHyperDash(bool state) => AddAssert($"catcher is {(state ? "" : "not ")}hyper dashing", () => catcher.HyperDashing == state);
 
-        private void attemptCatch(CatchHitObject hitObject, int count = 1)
+        private void attemptCatch(CatchHitObject hitObject)
+        {
+            attemptCatch(() => hitObject, 1);
+        }
+
+        private void attemptCatch(Func<CatchHitObject> hitObject, int count)
         {
             for (var i = 0; i < count; i++)
-                attemptCatch(hitObject, out _, out _);
+                attemptCatch(hitObject(), out _, out _);
         }
 
         private void attemptCatch(CatchHitObject hitObject, out DrawableCatchHitObject drawableObject, out JudgementResult result)

osu.Game.Rulesets.Catch.Tests/TestSceneCatcherArea.cs

@@ -8,6 +8,8 @@ using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
+using osu.Framework.Threading;
+using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Configuration;
@@ -31,12 +33,32 @@ namespace osu.Game.Rulesets.Catch.Tests
 
         private float circleSize;
 
+        private ScheduledDelegate addManyFruit;
+
+        private BeatmapDifficulty beatmapDifficulty;
+
         public TestSceneCatcherArea()
         {
             AddSliderStep<float>("circle size", 0, 8, 5, createCatcher);
             AddToggleStep("hyper dash", t => this.ChildrenOfType<TestCatcherArea>().ForEach(area => area.ToggleHyperDash(t)));
 
-            AddStep("catch fruit", () => attemptCatch(new Fruit()));
+            AddStep("catch centered fruit", () => attemptCatch(new Fruit()));
+            AddStep("catch many random fruit", () =>
+            {
+                int count = 50;
+
+                addManyFruit?.Cancel();
+                addManyFruit = Scheduler.AddDelayed(() =>
+                {
+                    attemptCatch(new Fruit
+                    {
+                        X = (RNG.NextSingle() - 0.5f) * Catcher.CalculateCatchWidth(beatmapDifficulty) * 0.6f,
+                    });
+
+                    if (count-- == 0)
+                        addManyFruit?.Cancel();
+                }, 50, true);
+            });
             AddStep("catch fruit last in combo", () => attemptCatch(new Fruit { LastInCombo = true }));
             AddStep("catch kiai fruit", () => attemptCatch(new TestSceneCatcher.TestKiaiFruit()));
             AddStep("miss last in combo", () => attemptCatch(new Fruit { X = 100, LastInCombo = true }));
@@ -45,10 +67,7 @@ namespace osu.Game.Rulesets.Catch.Tests
         private void attemptCatch(Fruit fruit)
         {
             fruit.X = fruit.OriginalX + catcher.X;
-            fruit.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty
+            fruit.ApplyDefaults(new ControlPointInfo(), beatmapDifficulty);
-            {
-                CircleSize = circleSize
-            });
 
             foreach (var area in this.ChildrenOfType<CatcherArea>())
             {
@@ -71,6 +90,11 @@ namespace osu.Game.Rulesets.Catch.Tests
         {
             circleSize = size;
 
+            beatmapDifficulty = new BeatmapDifficulty
+            {
+                CircleSize = circleSize
+            };
+
             SetContents(() =>
             {
                 var droppedObjectContainer = new Container<CaughtObject>
@@ -84,7 +108,7 @@ namespace osu.Game.Rulesets.Catch.Tests
                     Children = new Drawable[]
                     {
                         droppedObjectContainer,
-                        new TestCatcherArea(droppedObjectContainer, new BeatmapDifficulty { CircleSize = size })
+                        new TestCatcherArea(droppedObjectContainer, beatmapDifficulty)
                         {
                             Anchor = Anchor.Centre,
                             Origin = Anchor.TopCentre,

osu.Game.Rulesets.Catch/CatchRuleset.cs

@@ -114,6 +114,7 @@ namespace osu.Game.Rulesets.Catch
                     return new Mod[]
                     {
                         new CatchModDifficultyAdjust(),
+                        new CatchModClassic(),
                     };
 
                 case ModType.Automation:

osu.Game.Rulesets.Catch/Mods/CatchModClassic.cs

@@ -0,0 +1,11 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Mods;
+
+namespace osu.Game.Rulesets.Catch.Mods
+{
+    public class CatchModClassic : ModClassic
+    {
+    }
+}

osu.Game.Rulesets.Catch/UI/Catcher.cs

@@ -53,6 +53,16 @@ namespace osu.Game.Rulesets.Catch.UI
         /// </summary>
         public const double BASE_SPEED = 1.0;
 
+        /// <summary>
+        /// The amount by which caught fruit should be offset from the plate surface to make them look visually "caught".
+        /// </summary>
+        public const float CAUGHT_FRUIT_VERTICAL_OFFSET = -5;
+
+        /// <summary>
+        /// The amount by which caught fruit should be scaled down to fit on the plate.
+        /// </summary>
+        private const float caught_fruit_scale_adjust = 0.5f;
+
         [NotNull]
         private readonly Container trailsTarget;
 
@@ -202,13 +212,13 @@ namespace osu.Game.Rulesets.Catch.UI
         /// Calculates the width of the area used for attempting catches in gameplay.
         /// </summary>
         /// <param name="scale">The scale of the catcher.</param>
-        internal static float CalculateCatchWidth(Vector2 scale) => CatcherArea.CATCHER_SIZE * Math.Abs(scale.X) * ALLOWED_CATCH_RANGE;
+        public static float CalculateCatchWidth(Vector2 scale) => CatcherArea.CATCHER_SIZE * Math.Abs(scale.X) * ALLOWED_CATCH_RANGE;
 
         /// <summary>
         /// Calculates the width of the area used for attempting catches in gameplay.
         /// </summary>
         /// <param name="difficulty">The beatmap difficulty.</param>
-        internal static float CalculateCatchWidth(BeatmapDifficulty difficulty) => CalculateCatchWidth(calculateScale(difficulty));
+        public static float CalculateCatchWidth(BeatmapDifficulty difficulty) => CalculateCatchWidth(calculateScale(difficulty));
 
         /// <summary>
         /// Determine if this catcher can catch a <see cref="CatchHitObject"/> in the current position.
@@ -240,7 +250,7 @@ namespace osu.Game.Rulesets.Catch.UI
 
             if (result.IsHit)
             {
-                var positionInStack = computePositionInStack(new Vector2(palpableObject.X - X, 0), palpableObject.DisplaySize.X / 2);
+                var positionInStack = computePositionInStack(new Vector2(palpableObject.X - X, 0), palpableObject.DisplaySize.X);
 
                 if (CatchFruitOnPlate)
                     placeCaughtObject(palpableObject, positionInStack);
@@ -384,16 +394,7 @@ namespace osu.Game.Rulesets.Catch.UI
         {
             updateTrailVisibility();
 
-            if (hyperDashing)
+            this.FadeColour(hyperDashing ? hyperDashColour : Color4.White, HYPER_DASH_TRANSITION_DURATION, Easing.OutQuint);
-            {
-                this.FadeColour(hyperDashColour, HYPER_DASH_TRANSITION_DURATION, Easing.OutQuint);
-                this.FadeTo(0.2f, HYPER_DASH_TRANSITION_DURATION, Easing.OutQuint);
-            }
-            else
-            {
-                this.FadeColour(Color4.White, HYPER_DASH_TRANSITION_DURATION, Easing.OutQuint);
-                this.FadeTo(1f, HYPER_DASH_TRANSITION_DURATION, Easing.OutQuint);
-            }
         }
 
         private void updateTrailVisibility() => trails.DisplayTrail = Dashing || HyperDashing;
@@ -479,7 +480,7 @@ namespace osu.Game.Rulesets.Catch.UI
             caughtObject.CopyStateFrom(drawableObject);
             caughtObject.Anchor = Anchor.TopCentre;
             caughtObject.Position = position;
-            caughtObject.Scale /= 2;
+            caughtObject.Scale *= caught_fruit_scale_adjust;
 
             caughtObjectContainer.Add(caughtObject);
 
@@ -489,19 +490,21 @@ namespace osu.Game.Rulesets.Catch.UI
 
         private Vector2 computePositionInStack(Vector2 position, float displayRadius)
         {
-            const float radius_div_2 = CatchHitObject.OBJECT_RADIUS / 2;
+            // this is taken from osu-stable (lenience should be 10 * 10 at standard scale).
-            const float allowance = 10;
+            const float lenience_adjust = 10 / CatchHitObject.OBJECT_RADIUS;
 
-            while (caughtObjectContainer.Any(f => Vector2Extensions.Distance(f.Position, position) < (displayRadius + radius_div_2) / (allowance / 2)))
+            float adjustedRadius = displayRadius * lenience_adjust;
+            float checkDistance = MathF.Pow(adjustedRadius, 2);
+
+            // offset fruit vertically to better place "above" the plate.
+            position.Y += CAUGHT_FRUIT_VERTICAL_OFFSET;
+
+            while (caughtObjectContainer.Any(f => Vector2Extensions.DistanceSquared(f.Position, position) < checkDistance))
             {
-                float diff = (displayRadius + radius_div_2) / allowance;
+                position.X += RNG.NextSingle(-adjustedRadius, adjustedRadius);
-
+                position.Y -= RNG.NextSingle(0, 5);
-                position.X += (RNG.NextSingle() - 0.5f) * diff * 2;
-                position.Y -= RNG.NextSingle() * diff;
             }
 
-            position.X = Math.Clamp(position.X, -CatcherArea.CATCHER_SIZE / 2, CatcherArea.CATCHER_SIZE / 2);
-
             return position;
         }
 

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

@@ -324,6 +324,33 @@ namespace osu.Game.Rulesets.Mania.Tests
             assertTailJudgement(HitResult.Ok);
         }
 
+        [Test]
+        public void TestZeroLength()
+        {
+            var beatmap = new Beatmap<ManiaHitObject>
+            {
+                HitObjects =
+                {
+                    new HoldNote
+                    {
+                        StartTime = 1000,
+                        Duration = 0,
+                        Column = 0,
+                    },
+                },
+                BeatmapInfo = { Ruleset = new ManiaRuleset().RulesetInfo },
+            };
+
+            performTest(new List<ReplayFrame>
+            {
+                new ManiaReplayFrame(beatmap.HitObjects[0].StartTime, ManiaAction.Key1),
+                new ManiaReplayFrame(beatmap.HitObjects[0].GetEndTime() + 1),
+            }, beatmap);
+
+            AddAssert("hold note hit", () => judgementResults.Where(j => beatmap.HitObjects[0].NestedHitObjects.Contains(j.HitObject))
+                                                             .All(j => j.Type.IsHit()));
+        }
+
         private void assertHeadJudgement(HitResult result)
             => AddAssert($"head judged as {result}", () => judgementResults.First(j => j.HitObject is Note).Type == result);
 

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

@@ -73,7 +73,7 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
                 return;
 
             base.OnMouseUp(e);
-            EndPlacement(true);
+            EndPlacement(HitObject.Duration > 0);
         }
 
         private double originalStartTime;

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -239,6 +239,7 @@ namespace osu.Game.Rulesets.Mania
                         new ManiaModDualStages(),
                         new ManiaModMirror(),
                         new ManiaModDifficultyAdjust(),
+                        new ManiaModClassic(),
                         new ManiaModInvert(),
                         new ManiaModConstantSpeed()
                     };

osu.Game.Rulesets.Mania/Mods/ManiaModClassic.cs

@@ -0,0 +1,11 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Mods;
+
+namespace osu.Game.Rulesets.Mania.Mods
+{
+    public class ManiaModClassic : ModClassic
+    {
+    }
+}

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

@@ -221,7 +221,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             // As the note is being held, adjust the size of the sizing container. This has two effects:
             // 1. The contained masking container will mask the body and ticks.
             // 2. The head note will move along with the new "head position" in the container.
-            if (Head.IsHit && releaseTime == null)
+            if (Head.IsHit && releaseTime == null && DrawHeight > 0)
             {
                 // How far past the hit target this hold note is. Always a positive value.
                 float yOffset = Math.Max(0, Direction.Value == ScrollingDirection.Up ? -Y : Y);

osu.Game.Rulesets.Osu.Tests/Editor/Checks/CheckOffscreenObjectsTest.cs

@@ -10,6 +10,7 @@ using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu.Edit.Checks;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.UI;
+using osu.Game.Tests.Beatmaps;
 using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
@@ -30,25 +31,23 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
         [Test]
         public void TestCircleInCenter()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOk(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
                     new HitCircle
                     {
                         StartTime = 3000,
-                        Position = playfield_centre // Playfield is 640 x 480.
+                        Position = playfield_centre
                     }
                 }
-            };
+            });
-
-            Assert.That(check.Run(beatmap), Is.Empty);
         }
 
         [Test]
         public void TestCircleNearEdge()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOk(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -58,15 +57,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         Position = new Vector2(5, 5)
                     }
                 }
-            };
+            });
-
-            Assert.That(check.Run(beatmap), Is.Empty);
         }
 
         [Test]
         public void TestCircleNearEdgeStackedOffscreen()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenCircle(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -77,15 +74,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         StackHeight = 5
                     }
                 }
-            };
+            });
-
-            assertOffscreenCircle(beatmap);
         }
 
         [Test]
         public void TestCircleOffscreen()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenCircle(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -95,15 +90,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         Position = new Vector2(0, 0)
                     }
                 }
-            };
+            });
-
-            assertOffscreenCircle(beatmap);
         }
 
         [Test]
         public void TestSliderInCenter()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOk(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -118,15 +111,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         }),
                     }
                 }
-            };
+            });
-
-            Assert.That(check.Run(beatmap), Is.Empty);
         }
 
         [Test]
         public void TestSliderNearEdge()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOk(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -141,15 +132,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         }),
                     }
                 }
-            };
+            });
-
-            Assert.That(check.Run(beatmap), Is.Empty);
         }
 
         [Test]
         public void TestSliderNearEdgeStackedOffscreen()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenSlider(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -165,15 +154,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         StackHeight = 5
                     }
                 }
-            };
+            });
-
-            assertOffscreenSlider(beatmap);
         }
 
         [Test]
         public void TestSliderOffscreenStart()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenSlider(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -188,15 +175,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         }),
                     }
                 }
-            };
+            });
-
-            assertOffscreenSlider(beatmap);
         }
 
         [Test]
         public void TestSliderOffscreenEnd()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenSlider(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -211,15 +196,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         }),
                     }
                 }
-            };
+            });
-
-            assertOffscreenSlider(beatmap);
         }
 
         [Test]
         public void TestSliderOffscreenPath()
         {
-            var beatmap = new Beatmap<HitObject>
+            assertOffscreenSlider(new Beatmap<HitObject>
             {
                 HitObjects = new List<HitObject>
                 {
@@ -236,14 +219,17 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
                         }),
                     }
                 }
-            };
+            });
+        }
 
-            assertOffscreenSlider(beatmap);
+        private void assertOk(IBeatmap beatmap)
+        {
+            Assert.That(check.Run(beatmap, new TestWorkingBeatmap(beatmap)), Is.Empty);
         }
 
         private void assertOffscreenCircle(IBeatmap beatmap)
         {
-            var issues = check.Run(beatmap).ToList();
+            var issues = check.Run(beatmap, new TestWorkingBeatmap(beatmap)).ToList();
 
             Assert.That(issues, Has.Count.EqualTo(1));
             Assert.That(issues.Single().Template is CheckOffscreenObjects.IssueTemplateOffscreenCircle);
@@ -251,7 +237,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
 
         private void assertOffscreenSlider(IBeatmap beatmap)
         {
-            var issues = check.Run(beatmap).ToList();
+            var issues = check.Run(beatmap, new TestWorkingBeatmap(beatmap)).ToList();
 
             Assert.That(issues, Has.Count.EqualTo(1));
             Assert.That(issues.Single().Template is CheckOffscreenObjects.IssueTemplateOffscreenSlider);

osu.Game.Rulesets.Osu.Tests/TestSceneHitCircleApplication.cs

@@ -32,7 +32,7 @@ namespace osu.Game.Rulesets.Osu.Tests
             {
                 Position = new Vector2(128, 128),
                 ComboIndex = 1,
-            }), null));
+            })));
         }
 
         private HitCircle prepareObject(HitCircle circle)

osu.Game.Rulesets.Osu.Tests/TestSceneSliderApplication.cs

@@ -57,7 +57,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                     new Vector2(300, 0),
                 }),
                 RepeatCount = 1
-            }), null));
+            })));
         }
 
         [Test]

osu.Game.Rulesets.Osu.Tests/TestSceneSpinnerApplication.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 Position = new Vector2(256, 192),
                 ComboIndex = 1,
                 Duration = 1000,
-            }), null));
+            })));
 
             AddAssert("rotation is reset", () => dho.Result.RateAdjustedRotation == 0);
         }

osu.Game.Rulesets.Osu.Tests/TestSceneSpinnerRotation.cs

@@ -21,6 +21,7 @@ using osu.Game.Rulesets.Osu.UI;
 using osu.Game.Rulesets.Replays;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Scoring;
+using osu.Game.Screens.Play;
 using osu.Game.Storyboards;
 using osu.Game.Tests.Visual;
 using osuTK;
@@ -193,7 +194,7 @@ namespace osu.Game.Rulesets.Osu.Tests
 
             addSeekStep(0);
 
-            AddStep("adjust track rate", () => Player.GameplayClockContainer.UserPlaybackRate.Value = rate);
+            AddStep("adjust track rate", () => ((MasterGameplayClockContainer)Player.GameplayClockContainer).UserPlaybackRate.Value = rate);
 
             addSeekStep(1000);
             AddAssert("progress almost same", () => Precision.AlmostEquals(expectedProgress, drawableSpinner.Progress, 0.05));

osu.Game.Rulesets.Osu/Edit/Checks/CheckOffscreenObjects.cs

@@ -31,9 +31,9 @@ namespace osu.Game.Rulesets.Osu.Edit.Checks
             new IssueTemplateOffscreenSlider(this)
         };
 
-        public IEnumerable<Issue> Run(IBeatmap beatmap)
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, IWorkingBeatmap workingBeatmap)
         {
-            foreach (var hitobject in beatmap.HitObjects)
+            foreach (var hitobject in playableBeatmap.HitObjects)
             {
                 switch (hitobject)
                 {

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

@@ -3,8 +3,11 @@
 
 using System.Collections.Generic;
 using System.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Objects.Drawables;
@@ -27,8 +30,16 @@ namespace osu.Game.Rulesets.Osu.Edit
 
         private class OsuEditPlayfield : OsuPlayfield
         {
+            private Bindable<bool> hitAnimations;
+
             protected override GameplayCursorContainer CreateCursor() => null;
 
+            [BackgroundDependencyLoader]
+            private void load(OsuConfigManager config)
+            {
+                hitAnimations = config.GetBindable<bool>(OsuSetting.EditorHitAnimations);
+            }
+
             protected override void OnNewDrawableHitObject(DrawableHitObject d)
             {
                 d.ApplyCustomUpdateState += updateState;
@@ -42,7 +53,7 @@ namespace osu.Game.Rulesets.Osu.Edit
 
             private void updateState(DrawableHitObject hitObject, ArmedState state)
             {
-                if (state == ArmedState.Idle)
+                if (state == ArmedState.Idle || hitAnimations.Value)
                     return;
 
                 // adjust the visuals of certain object types to make them stay on screen for longer than usual.
@@ -58,8 +69,17 @@ namespace osu.Game.Rulesets.Osu.Edit
 
                     case DrawableHitCircle circle: // also handles slider heads
                         circle.ApproachCircle
-                              .FadeOutFromOne(editor_hit_object_fade_out_extension)
+                              .FadeOutFromOne(editor_hit_object_fade_out_extension * 4)
                               .Expire();
+
+                        circle.ApproachCircle.ScaleTo(1.1f, 300, Easing.OutQuint);
+
+                        var circlePieceDrawable = circle.CirclePiece.Drawable;
+
+                        // clear any explode animation logic.
+                        circlePieceDrawable.ApplyTransformsAt(circle.HitStateUpdateTime, true);
+                        circlePieceDrawable.ClearTransformsAfter(circle.HitStateUpdateTime, true);
+
                         break;
                 }
 
@@ -71,7 +91,7 @@ namespace osu.Game.Rulesets.Osu.Edit
 
                 hitObject.RemoveTransform(existing);
 
-                using (hitObject.BeginAbsoluteSequence(existing.StartTime))
+                using (hitObject.BeginAbsoluteSequence(hitObject.HitStateUpdateTime))
                     hitObject.FadeOut(editor_hit_object_fade_out_extension).Expire();
             }
         }

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

@@ -17,6 +17,9 @@ namespace osu.Game.Rulesets.Osu.Edit
             new CheckOffscreenObjects()
         };
 
-        public IEnumerable<Issue> Run(IBeatmap beatmap) => checks.SelectMany(check => check.Run(beatmap));
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, WorkingBeatmap workingBeatmap)
+        {
+            return checks.SelectMany(check => check.Run(playableBeatmap, workingBeatmap));
+        }
     }
 }

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

@@ -1,25 +1,30 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions;
 using osu.Framework.Graphics;
 using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Osu.Objects.Drawables;
 using osu.Game.Rulesets.Osu.UI;
 using osu.Game.Rulesets.UI;
 using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModBarrelRoll : Mod, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>
+    public class OsuModBarrelRoll : Mod, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>, IApplicableToDrawableHitObjects
     {
+        private float currentRotation;
+
         [SettingSource("Roll speed", "Rotations per minute")]
         public BindableNumber<double> SpinSpeed { get; } = new BindableDouble(0.5)
         {
             MinValue = 0.02,
-            MaxValue = 4,
+            MaxValue = 12,
             Precision = 0.01,
         };
 
@@ -35,7 +40,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
         public void Update(Playfield playfield)
         {
-            playfield.Rotation = (Direction.Value == RotationDirection.CounterClockwise ? -1 : 1) * 360 * (float)(playfield.Time.Current / 60000 * SpinSpeed.Value);
+            playfield.Rotation = currentRotation = (Direction.Value == RotationDirection.Counterclockwise ? -1 : 1) * 360 * (float)(playfield.Time.Current / 60000 * SpinSpeed.Value);
         }
 
         public void ApplyToDrawableRuleset(DrawableRuleset<OsuHitObject> drawableRuleset)
@@ -43,5 +48,21 @@ namespace osu.Game.Rulesets.Osu.Mods
             // scale the playfield to allow all hitobjects to stay within the visible region.
             drawableRuleset.Playfield.Scale = new Vector2(OsuPlayfield.BASE_SIZE.Y / OsuPlayfield.BASE_SIZE.X);
         }
+
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+            foreach (var d in drawables)
+            {
+                d.OnUpdate += _ =>
+                {
+                    switch (d)
+                    {
+                        case DrawableHitCircle circle:
+                            circle.CirclePiece.Rotation = -currentRotation;
+                            break;
+                    }
+                };
+            }
+        }
     }
 }

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

@@ -4,7 +4,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Bindables;
-using osu.Framework.Graphics.Sprites;
 using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -16,22 +15,8 @@ using osu.Game.Rulesets.UI;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModClassic : Mod, IApplicableToHitObject, IApplicableToDrawableHitObjects, IApplicableToDrawableRuleset<OsuHitObject>
+    public class OsuModClassic : ModClassic, IApplicableToHitObject, IApplicableToDrawableHitObjects, IApplicableToDrawableRuleset<OsuHitObject>
     {
-        public override string Name => "Classic";
-
-        public override string Acronym => "CL";
-
-        public override double ScoreMultiplier => 1;
-
-        public override IconUsage? Icon => FontAwesome.Solid.History;
-
-        public override string Description => "Feeling nostalgic?";
-
-        public override bool Ranked => false;
-
-        public override ModType Type => ModType.Conversion;
-
         [SettingSource("No slider head accuracy requirement", "Scores sliders proportionally to the number of ticks hit.")]
         public Bindable<bool> NoSliderHeadAccuracy { get; } = new BindableBool(true);
 

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

@@ -34,9 +34,9 @@ namespace osu.Game.Rulesets.Osu.Mods
             var osuObject = (OsuHitObject)drawable.HitObject;
             Vector2 origin = drawable.Position;
 
-            // Wiggle the repeat points with the slider instead of independently.
+            // Wiggle the repeat points and the tail with the slider instead of independently.
             // Also fixes an issue with repeat points being positioned incorrectly.
-            if (osuObject is SliderRepeat)
+            if (osuObject is SliderRepeat || osuObject is SliderTailCircle)
                 return;
 
             Random objRand = new Random((int)osuObject.StartTime);

osu.Game.Rulesets.Osu/Objects/Drawables/DrawableHitCircle.cs

@@ -66,7 +66,11 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
                                 return true;
                             },
                         },
-                        CirclePiece = new SkinnableDrawable(new OsuSkinComponent(CirclePieceComponent), _ => new MainCirclePiece()),
+                        CirclePiece = new SkinnableDrawable(new OsuSkinComponent(CirclePieceComponent), _ => new MainCirclePiece())
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                        },
                         ApproachCircle = new ApproachCircle
                         {
                             Alpha = 0,
@@ -178,6 +182,8 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
             // todo: temporary / arbitrary, used for lifetime optimisation.
             this.Delay(800).FadeOut();
 
+            (CirclePiece.Drawable as IMainCirclePiece)?.Animate(state);
+
             switch (state)
             {
                 case ArmedState.Idle:

osu.Game.Rulesets.Osu/Skinning/Default/IMainCirclePiece.cs

@@ -0,0 +1,17 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Osu.Objects.Drawables;
+
+namespace osu.Game.Rulesets.Osu.Skinning.Default
+{
+    public interface IMainCirclePiece
+    {
+        /// <summary>
+        /// Begins animating this <see cref="IMainCirclePiece"/>.
+        /// </summary>
+        /// <param name="state">The <see cref="ArmedState"/> of the related <see cref="DrawableHitCircle"/>.</param>
+        void Animate(ArmedState state);
+    }
+}

osu.Game.Rulesets.Osu/Skinning/Default/MainCirclePiece.cs

@@ -13,7 +13,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Rulesets.Osu.Skinning.Default
 {
-    public class MainCirclePiece : CompositeDrawable
+    public class MainCirclePiece : CompositeDrawable, IMainCirclePiece
     {
         private readonly CirclePiece circle;
         private readonly RingPiece ring;
@@ -67,12 +67,9 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
             }, true);
 
             indexInCurrentCombo.BindValueChanged(index => number.Text = (index.NewValue + 1).ToString(), true);
-
-            drawableObject.ApplyCustomUpdateState += updateState;
-            updateState(drawableObject, drawableObject.State.Value);
         }
 
-        private void updateState(DrawableHitObject drawableObject, ArmedState state)
+        public void Animate(ArmedState state)
         {
             using (BeginAbsoluteSequence(drawableObject.StateUpdateTime))
                 glow.FadeOut(400);

osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyMainCirclePiece.cs

@@ -12,6 +12,7 @@ using osu.Game.Graphics.Sprites;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.Objects.Drawables;
+using osu.Game.Rulesets.Osu.Skinning.Default;
 using osu.Game.Skinning;
 using osuTK;
 using osuTK.Graphics;
@@ -19,7 +20,7 @@ using static osu.Game.Skinning.LegacySkinConfiguration;
 
 namespace osu.Game.Rulesets.Osu.Skinning.Legacy
 {
-    public class LegacyMainCirclePiece : CompositeDrawable
+    public class LegacyMainCirclePiece : CompositeDrawable, IMainCirclePiece
     {
         private readonly string priorityLookup;
         private readonly bool hasNumber;
@@ -138,12 +139,9 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
             accentColour.BindValueChanged(colour => hitCircleSprite.Colour = LegacyColourCompatibility.DisallowZeroAlpha(colour.NewValue), true);
             if (hasNumber)
                 indexInCurrentCombo.BindValueChanged(index => hitCircleText.Text = (index.NewValue + 1).ToString(), true);
-
-            drawableObject.ApplyCustomUpdateState += updateState;
-            updateState(drawableObject, drawableObject.State.Value);
         }
 
-        private void updateState(DrawableHitObject drawableObject, ArmedState state)
+        public void Animate(ArmedState state)
         {
             const double legacy_fade_duration = 240;
 

osu.Game.Rulesets.Osu/UI/OsuResumeOverlay.cs

@@ -42,7 +42,7 @@ namespace osu.Game.Rulesets.Osu.UI
             base.PopIn();
 
             GameplayCursor.ActiveCursor.Hide();
-            cursorScaleContainer.MoveTo(GameplayCursor.ActiveCursor.Position);
+            cursorScaleContainer.Position = ToLocalSpace(GameplayCursor.ActiveCursor.ScreenSpaceDrawQuad.Centre);
             clickToResumeCursor.Appear();
 
             if (localCursorContainer == null)

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

@@ -18,7 +18,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
             {
                 StartTime = 400,
                 Major = true
-            }), null));
+            })));
             AddHitObject(barLine);
             RemoveHitObject(barLine);
 
@@ -26,7 +26,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
             {
                 StartTime = 200,
                 Major = false
-            }), null));
+            })));
             AddHitObject(barLine);
         }
     }

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

@@ -20,7 +20,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
                 Duration = 500,
                 IsStrong = false,
                 TickRate = 2
-            }), null));
+            })));
 
             AddHitObject(drumRoll);
             RemoveHitObject(drumRoll);
@@ -31,7 +31,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
                 Duration = 400,
                 IsStrong = true,
                 TickRate = 16
-            }), null));
+            })));
 
             AddHitObject(drumRoll);
         }

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

@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
                 Type = HitType.Rim,
                 IsStrong = false,
                 StartTime = 300
-            }), null));
+            })));
 
             AddHitObject(hit);
             RemoveHitObject(hit);
@@ -29,7 +29,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
                 Type = HitType.Centre,
                 IsStrong = true,
                 StartTime = 500
-            }), null));
+            })));
 
             AddHitObject(hit);
         }

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

@@ -0,0 +1,11 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Mods;
+
+namespace osu.Game.Rulesets.Taiko.Mods
+{
+    public class TaikoModClassic : ModClassic
+    {
+    }
+}

osu.Game.Rulesets.Taiko/TaikoRuleset.cs

@@ -135,6 +135,7 @@ namespace osu.Game.Rulesets.Taiko
                     {
                         new TaikoModRandom(),
                         new TaikoModDifficultyAdjust(),
+                        new TaikoModClassic(),
                     };
 
                 case ModType.Automation:

osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapEncoderTest.cs

@@ -168,6 +168,8 @@ namespace osu.Game.Tests.Beatmaps.Formats
             protected override Texture GetBackground() => throw new NotImplementedException();
 
             protected override Track GetBeatmapTrack() => throw new NotImplementedException();
+
+            public override Stream GetStream(string storagePath) => throw new NotImplementedException();
         }
     }
 }

osu.Game.Tests/Editing/Checks/CheckAudioQualityTest.cs

@@ -0,0 +1,114 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Linq;
+using Moq;
+using NUnit.Framework;
+using osu.Framework.Audio.Track;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks;
+using osu.Game.Rulesets.Objects;
+
+namespace osu.Game.Tests.Editing.Checks
+{
+    [TestFixture]
+    public class CheckAudioQualityTest
+    {
+        private CheckAudioQuality check;
+        private IBeatmap beatmap;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckAudioQuality();
+            beatmap = new Beatmap<HitObject>
+            {
+                BeatmapInfo = new BeatmapInfo
+                {
+                    Metadata = new BeatmapMetadata { AudioFile = "abc123.jpg" }
+                }
+            };
+        }
+
+        [Test]
+        public void TestMissing()
+        {
+            // While this is a problem, it is out of scope for this check and is caught by a different one.
+            beatmap.Metadata.AudioFile = null;
+
+            var mock = new Mock<IWorkingBeatmap>();
+            mock.SetupGet(w => w.Beatmap).Returns(beatmap);
+            mock.SetupGet(w => w.Track).Returns((Track)null);
+
+            Assert.That(check.Run(beatmap, mock.Object), Is.Empty);
+        }
+
+        [Test]
+        public void TestAcceptable()
+        {
+            var mock = getMockWorkingBeatmap(192);
+
+            Assert.That(check.Run(beatmap, mock.Object), Is.Empty);
+        }
+
+        [Test]
+        public void TestNullBitrate()
+        {
+            var mock = getMockWorkingBeatmap(null);
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckAudioQuality.IssueTemplateNoBitrate);
+        }
+
+        [Test]
+        public void TestZeroBitrate()
+        {
+            var mock = getMockWorkingBeatmap(0);
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckAudioQuality.IssueTemplateNoBitrate);
+        }
+
+        [Test]
+        public void TestTooHighBitrate()
+        {
+            var mock = getMockWorkingBeatmap(320);
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckAudioQuality.IssueTemplateTooHighBitrate);
+        }
+
+        [Test]
+        public void TestTooLowBitrate()
+        {
+            var mock = getMockWorkingBeatmap(64);
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckAudioQuality.IssueTemplateTooLowBitrate);
+        }
+
+        /// <summary>
+        /// Returns the mock of the working beatmap with the given audio properties.
+        /// </summary>
+        /// <param name="audioBitrate">The bitrate of the audio file the beatmap uses.</param>
+        private Mock<IWorkingBeatmap> getMockWorkingBeatmap(int? audioBitrate)
+        {
+            var mockTrack = new Mock<Track>();
+            mockTrack.SetupGet(t => t.Bitrate).Returns(audioBitrate);
+
+            var mockWorkingBeatmap = new Mock<IWorkingBeatmap>();
+            mockWorkingBeatmap.SetupGet(w => w.Beatmap).Returns(beatmap);
+            mockWorkingBeatmap.SetupGet(w => w.Track).Returns(mockTrack.Object);
+
+            return mockWorkingBeatmap;
+        }
+    }
+}

osu.Game.Tests/Editing/Checks/CheckBackgroundQualityTest.cs

@@ -0,0 +1,130 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using JetBrains.Annotations;
+using Moq;
+using NUnit.Framework;
+using osu.Framework.Graphics.Textures;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks;
+using osu.Game.Rulesets.Objects;
+using FileInfo = osu.Game.IO.FileInfo;
+
+namespace osu.Game.Tests.Editing.Checks
+{
+    [TestFixture]
+    public class CheckBackgroundQualityTest
+    {
+        private CheckBackgroundQuality check;
+        private IBeatmap beatmap;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckBackgroundQuality();
+            beatmap = new Beatmap<HitObject>
+            {
+                BeatmapInfo = new BeatmapInfo
+                {
+                    Metadata = new BeatmapMetadata { BackgroundFile = "abc123.jpg" },
+                    BeatmapSet = new BeatmapSetInfo
+                    {
+                        Files = new List<BeatmapSetFileInfo>(new[]
+                        {
+                            new BeatmapSetFileInfo
+                            {
+                                Filename = "abc123.jpg",
+                                FileInfo = new FileInfo
+                                {
+                                    Hash = "abcdef"
+                                }
+                            }
+                        })
+                    }
+                }
+            };
+        }
+
+        [Test]
+        public void TestMissing()
+        {
+            // While this is a problem, it is out of scope for this check and is caught by a different one.
+            beatmap.Metadata.BackgroundFile = null;
+            var mock = getMockWorkingBeatmap(null, System.Array.Empty<byte>());
+
+            Assert.That(check.Run(beatmap, mock.Object), Is.Empty);
+        }
+
+        [Test]
+        public void TestAcceptable()
+        {
+            var mock = getMockWorkingBeatmap(new Texture(1920, 1080));
+
+            Assert.That(check.Run(beatmap, mock.Object), Is.Empty);
+        }
+
+        [Test]
+        public void TestTooHighResolution()
+        {
+            var mock = getMockWorkingBeatmap(new Texture(3840, 2160));
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckBackgroundQuality.IssueTemplateTooHighResolution);
+        }
+
+        [Test]
+        public void TestLowResolution()
+        {
+            var mock = getMockWorkingBeatmap(new Texture(640, 480));
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckBackgroundQuality.IssueTemplateLowResolution);
+        }
+
+        [Test]
+        public void TestTooLowResolution()
+        {
+            var mock = getMockWorkingBeatmap(new Texture(100, 100));
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckBackgroundQuality.IssueTemplateTooLowResolution);
+        }
+
+        [Test]
+        public void TestTooUncompressed()
+        {
+            var mock = getMockWorkingBeatmap(new Texture(1920, 1080), new byte[1024 * 1024 * 3]);
+
+            var issues = check.Run(beatmap, mock.Object).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.Single().Template is CheckBackgroundQuality.IssueTemplateTooUncompressed);
+        }
+
+        /// <summary>
+        /// Returns the mock of the working beatmap with the given background and filesize.
+        /// </summary>
+        /// <param name="background">The texture of the background.</param>
+        /// <param name="fileBytes">The bytes that represent the background file.</param>
+        private Mock<IWorkingBeatmap> getMockWorkingBeatmap(Texture background, [CanBeNull] byte[] fileBytes = null)
+        {
+            var stream = new MemoryStream(fileBytes ?? new byte[1024 * 1024]);
+
+            var mock = new Mock<IWorkingBeatmap>();
+            mock.SetupGet(w => w.Beatmap).Returns(beatmap);
+            mock.SetupGet(w => w.Background).Returns(background);
+            mock.Setup(w => w.GetStream(It.IsAny<string>())).Returns(stream);
+
+            return mock;
+        }
+    }
+}

osu.Game.Tests/Editing/Checks/CheckFilePresenceTest.cs

@@ -5,21 +5,23 @@ using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using osu.Game.Beatmaps;
+using osu.Game.IO;
 using osu.Game.Rulesets.Edit.Checks;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Tests.Beatmaps;
 
 namespace osu.Game.Tests.Editing.Checks
 {
     [TestFixture]
-    public class CheckBackgroundTest
+    public class CheckFilePresenceTest
     {
-        private CheckBackground check;
+        private CheckBackgroundPresence check;
         private IBeatmap beatmap;
 
         [SetUp]
         public void Setup()
         {
-            check = new CheckBackground();
+            check = new CheckBackgroundPresence();
             beatmap = new Beatmap<HitObject>
             {
                 BeatmapInfo = new BeatmapInfo
@@ -29,7 +31,11 @@ namespace osu.Game.Tests.Editing.Checks
                     {
                         Files = new List<BeatmapSetFileInfo>(new[]
                         {
-                            new BeatmapSetFileInfo { Filename = "abc123.jpg" }
+                            new BeatmapSetFileInfo
+                            {
+                                Filename = "abc123.jpg",
+                                FileInfo = new FileInfo { Hash = "abcdef" }
+                            }
                         })
                     }
                 }
@@ -39,7 +45,7 @@ namespace osu.Game.Tests.Editing.Checks
         [Test]
         public void TestBackgroundSetAndInFiles()
         {
-            Assert.That(check.Run(beatmap), Is.Empty);
+            Assert.That(check.Run(beatmap, new TestWorkingBeatmap(beatmap)), Is.Empty);
         }
 
         [Test]
@@ -47,10 +53,10 @@ namespace osu.Game.Tests.Editing.Checks
         {
             beatmap.BeatmapInfo.BeatmapSet.Files.Clear();
 
-            var issues = check.Run(beatmap).ToList();
+            var issues = check.Run(beatmap, new TestWorkingBeatmap(beatmap)).ToList();
 
             Assert.That(issues, Has.Count.EqualTo(1));
-            Assert.That(issues.Single().Template is CheckBackground.IssueTemplateDoesNotExist);
+            Assert.That(issues.Single().Template is CheckFilePresence.IssueTemplateDoesNotExist);
         }
 
         [Test]
@@ -58,10 +64,10 @@ namespace osu.Game.Tests.Editing.Checks
         {
             beatmap.Metadata.BackgroundFile = null;
 
-            var issues = check.Run(beatmap).ToList();
+            var issues = check.Run(beatmap, new TestWorkingBeatmap(beatmap)).ToList();
 
             Assert.That(issues, Has.Count.EqualTo(1));
-            Assert.That(issues.Single().Template is CheckBackground.IssueTemplateNoneSet);
+            Assert.That(issues.Single().Template is CheckFilePresence.IssueTemplateNoneSet);
         }
     }
 }

osu.Game.Tests/Gameplay/TestSceneGameplayClockContainer.cs

@@ -1,32 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using NUnit.Framework;
-using osu.Framework.Testing;
-using osu.Game.Rulesets.Osu;
-using osu.Game.Screens.Play;
-using osu.Game.Tests.Visual;
-
-namespace osu.Game.Tests.Gameplay
-{
-    [HeadlessTest]
-    public class TestSceneGameplayClockContainer : OsuTestScene
-    {
-        [Test]
-        public void TestStartThenElapsedTime()
-        {
-            GameplayClockContainer gcc = null;
-
-            AddStep("create container", () =>
-            {
-                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
-                working.LoadTrack();
-
-                Add(gcc = new GameplayClockContainer(working, 0));
-            });
-
-            AddStep("start track", () => gcc.Start());
-            AddUntilStep("elapsed greater than zero", () => gcc.GameplayClock.ElapsedFrameTime > 0);
-        }
-    }
-}

osu.Game.Tests/Gameplay/TestSceneMasterGameplayClockContainer.cs

@@ -0,0 +1,58 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Testing;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Screens.Play;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.Gameplay
+{
+    [HeadlessTest]
+    public class TestSceneMasterGameplayClockContainer : OsuTestScene
+    {
+        [Test]
+        public void TestStartThenElapsedTime()
+        {
+            GameplayClockContainer gcc = null;
+
+            AddStep("create container", () =>
+            {
+                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
+                working.LoadTrack();
+
+                Add(gcc = new MasterGameplayClockContainer(working, 0));
+            });
+
+            AddStep("start clock", () => gcc.Start());
+            AddUntilStep("elapsed greater than zero", () => gcc.GameplayClock.ElapsedFrameTime > 0);
+        }
+
+        [Test]
+        public void TestElapseThenReset()
+        {
+            GameplayClockContainer gcc = null;
+
+            AddStep("create container", () =>
+            {
+                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
+                working.LoadTrack();
+
+                Add(gcc = new MasterGameplayClockContainer(working, 0));
+            });
+
+            AddStep("start clock", () => gcc.Start());
+            AddUntilStep("current time greater 2000", () => gcc.GameplayClock.CurrentTime > 2000);
+
+            double timeAtReset = 0;
+            AddStep("reset clock", () =>
+            {
+                timeAtReset = gcc.GameplayClock.CurrentTime;
+                gcc.Reset();
+            });
+
+            AddAssert("current time < time at reset", () => gcc.GameplayClock.CurrentTime < timeAtReset);
+        }
+    }
+}

osu.Game.Tests/Gameplay/TestSceneStoryboardSamples.cs

@@ -20,6 +20,7 @@ using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Mods;
+using osu.Game.Rulesets.UI;
 using osu.Game.Screens.Play;
 using osu.Game.Skinning;
 using osu.Game.Storyboards;
@@ -67,17 +68,47 @@ namespace osu.Game.Tests.Gameplay
                 var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
                 working.LoadTrack();
 
-                Add(gameplayContainer = new GameplayClockContainer(working, 0));
+                Add(gameplayContainer = new MasterGameplayClockContainer(working, 0)
-
-                gameplayContainer.Add(sample = new DrawableStoryboardSample(new StoryboardSampleInfo(string.Empty, 0, 1))
                 {
-                    Clock = gameplayContainer.GameplayClock
+                    IsPaused = { Value = true },
+                    Child = new FrameStabilityContainer
+                    {
+                        Child = sample = new DrawableStoryboardSample(new StoryboardSampleInfo(string.Empty, 0, 1))
+                    }
+                });
+            });
+
+            AddStep("reset clock", () => gameplayContainer.Start());
+
+            AddUntilStep("sample played", () => sample.RequestedPlaying);
+            AddUntilStep("sample has lifetime end", () => sample.LifetimeEnd < double.MaxValue);
+        }
+
+        [Test]
+        public void TestSampleHasLifetimeEndWithInitialClockTime()
+        {
+            GameplayClockContainer gameplayContainer = null;
+            DrawableStoryboardSample sample = null;
+
+            AddStep("create container", () =>
+            {
+                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
+                working.LoadTrack();
+
+                Add(gameplayContainer = new MasterGameplayClockContainer(working, 1000, true)
+                {
+                    IsPaused = { Value = true },
+                    Child = new FrameStabilityContainer
+                    {
+                        Child = sample = new DrawableStoryboardSample(new StoryboardSampleInfo(string.Empty, 0, 1))
+                    }
                 });
             });
 
             AddStep("start time", () => gameplayContainer.Start());
 
-            AddUntilStep("sample playback succeeded", () => sample.LifetimeEnd < double.MaxValue);
+            AddUntilStep("sample not played", () => !sample.RequestedPlaying);
+            AddUntilStep("sample has lifetime end", () => sample.LifetimeEnd < double.MaxValue);
         }
 
         [TestCase(typeof(OsuModDoubleTime), 1.5)]
@@ -114,7 +145,7 @@ namespace osu.Game.Tests.Gameplay
 
                 var beatmapSkinSourceContainer = new BeatmapSkinProvidingContainer(Beatmap.Value.Skin);
 
-                Add(gameplayContainer = new GameplayClockContainer(Beatmap.Value, 0)
+                Add(gameplayContainer = new MasterGameplayClockContainer(Beatmap.Value, 0)
                 {
                     Child = beatmapSkinSourceContainer
                 });

osu.Game.Tests/NonVisual/Multiplayer/StatefulMultiplayerClientTest.cs

@@ -41,6 +41,32 @@ namespace osu.Game.Tests.NonVisual.Multiplayer
             checkPlayingUserCount(0);
         }
 
+        [Test]
+        public void TestPlayingUsersUpdatedOnJoin()
+        {
+            AddStep("leave room", () => Client.LeaveRoom());
+            AddUntilStep("wait for room part", () => Client.Room == null);
+
+            AddStep("create room initially in gameplay", () =>
+            {
+                Room.RoomID.Value = null;
+                Client.RoomSetupAction = room =>
+                {
+                    room.State = MultiplayerRoomState.Playing;
+                    room.Users.Add(new MultiplayerRoomUser(55)
+                    {
+                        User = new User { Id = 55 },
+                        State = MultiplayerUserState.Playing
+                    });
+                };
+
+                RoomManager.CreateRoom(Room);
+            });
+
+            AddUntilStep("wait for room join", () => Client.Room != null);
+            checkPlayingUserCount(1);
+        }
+
         private void checkPlayingUserCount(int expectedCount)
             => AddAssert($"{"user".ToQuantity(expectedCount)} playing", () => Client.CurrentMatchPlayingUserIds.Count == expectedCount);
 

osu.Game.Tests/NonVisual/SessionStaticsTest.cs

@@ -0,0 +1,47 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Game.Configuration;
+using osu.Game.Input;
+
+namespace osu.Game.Tests.NonVisual
+{
+    [TestFixture]
+    public class SessionStaticsTest
+    {
+        private SessionStatics sessionStatics;
+        private IdleTracker sessionIdleTracker;
+
+        [SetUp]
+        public void SetUp()
+        {
+            sessionStatics = new SessionStatics();
+            sessionIdleTracker = new GameIdleTracker(1000);
+
+            sessionStatics.SetValue(Static.LoginOverlayDisplayed, true);
+            sessionStatics.SetValue(Static.MutedAudioNotificationShownOnce, true);
+            sessionStatics.SetValue(Static.LowBatteryNotificationShownOnce, true);
+            sessionStatics.SetValue(Static.LastHoverSoundPlaybackTime, (double?)1d);
+
+            sessionIdleTracker.IsIdle.BindValueChanged(e =>
+            {
+                if (e.NewValue)
+                    sessionStatics.ResetValues();
+            });
+        }
+
+        [Test]
+        [Timeout(2000)]
+        public void TestSessionStaticsReset()
+        {
+            sessionIdleTracker.IsIdle.BindValueChanged(e =>
+            {
+                Assert.IsTrue(sessionStatics.GetBindable<bool>(Static.LoginOverlayDisplayed).IsDefault);
+                Assert.IsTrue(sessionStatics.GetBindable<bool>(Static.MutedAudioNotificationShownOnce).IsDefault);
+                Assert.IsTrue(sessionStatics.GetBindable<bool>(Static.LowBatteryNotificationShownOnce).IsDefault);
+                Assert.IsTrue(sessionStatics.GetBindable<double?>(Static.LastHoverSoundPlaybackTime).IsDefault);
+            });
+        }
+    }
+}

osu.Game.Tests/Visual/Components/TestSceneIdleTracker.cs

@@ -81,6 +81,13 @@ namespace osu.Game.Tests.Visual.Components
         [Test]
         public void TestMovement()
         {
+            checkIdleStatus(1, false);
+            checkIdleStatus(2, false);
+            checkIdleStatus(3, false);
+            checkIdleStatus(4, false);
+
+            waitForAllIdle();
+
             AddStep("move to top right", () => InputManager.MoveMouseTo(box2));
 
             checkIdleStatus(1, true);
@@ -102,6 +109,8 @@ namespace osu.Game.Tests.Visual.Components
         [Test]
         public void TestTimings()
         {
+            waitForAllIdle();
+
             AddStep("move to centre", () => InputManager.MoveMouseTo(Content));
 
             checkIdleStatus(1, false);
@@ -140,7 +149,7 @@ namespace osu.Game.Tests.Visual.Components
 
         private void waitForAllIdle()
         {
-            AddUntilStep("Wait for all idle", () => box1.IsIdle && box2.IsIdle && box3.IsIdle && box4.IsIdle);
+            AddUntilStep("wait for all idle", () => box1.IsIdle && box2.IsIdle && box3.IsIdle && box4.IsIdle);
         }
 
         private class IdleTrackingBox : CompositeDrawable
@@ -149,7 +158,7 @@ namespace osu.Game.Tests.Visual.Components
 
             public bool IsIdle => idleTracker.IsIdle.Value;
 
-            public IdleTrackingBox(double timeToIdle)
+            public IdleTrackingBox(int timeToIdle)
             {
                 Box box;
 
@@ -158,7 +167,7 @@ namespace osu.Game.Tests.Visual.Components
 
                 InternalChildren = new Drawable[]
                 {
-                    idleTracker = new IdleTracker(timeToIdle),
+                    idleTracker = new GameIdleTracker(timeToIdle),
                     box = new Box
                     {
                         Colour = Color4.White,

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

@@ -3,12 +3,16 @@
 
 using System.Linq;
 using NUnit.Framework;
+using osu.Framework.Testing;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets;
+using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Screens.Edit.Compose.Components;
+using osu.Game.Screens.Edit.Compose.Components.Timeline;
 using osu.Game.Tests.Beatmaps;
 using osuTK;
 
@@ -110,8 +114,9 @@ namespace osu.Game.Tests.Visual.Editing
             AddAssert("duration matches", () => ((Spinner)EditorBeatmap.HitObjects.Single()).Duration == 5000);
         }
 
-        [Test]
+        [TestCase(false)]
-        public void TestCopyPaste()
+        [TestCase(true)]
+        public void TestCopyPaste(bool deselectAfterCopy)
         {
             var addedObject = new HitCircle { StartTime = 1000 };
 
@@ -123,11 +128,22 @@ namespace osu.Game.Tests.Visual.Editing
 
             AddStep("move forward in time", () => EditorClock.Seek(2000));
 
+            if (deselectAfterCopy)
+            {
+                AddStep("deselect", () => EditorBeatmap.SelectedHitObjects.Clear());
+
+                AddUntilStep("timeline selection box is not visible", () => Editor.ChildrenOfType<Timeline>().First().ChildrenOfType<SelectionHandler>().First().Alpha == 0);
+                AddUntilStep("composer selection box is not visible", () => Editor.ChildrenOfType<HitObjectComposer>().First().ChildrenOfType<SelectionHandler>().First().Alpha == 0);
+            }
+
             AddStep("paste hitobject", () => Editor.Paste());
 
             AddAssert("are two objects", () => EditorBeatmap.HitObjects.Count == 2);
 
             AddAssert("new object selected", () => EditorBeatmap.SelectedHitObjects.Single().StartTime == 2000);
+
+            AddUntilStep("timeline selection box is visible", () => Editor.ChildrenOfType<Timeline>().First().ChildrenOfType<SelectionHandler>().First().Alpha > 0);
+            AddUntilStep("composer selection box is visible", () => Editor.ChildrenOfType<HitObjectComposer>().First().ChildrenOfType<SelectionHandler>().First().Alpha > 0);
         }
 
         [Test]

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

@@ -12,6 +12,7 @@ using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components;
+using osu.Game.Rulesets.Osu.UI;
 using osu.Game.Tests.Beatmaps;
 using osu.Game.Screens.Edit.Compose.Components;
 using osuTK;
@@ -41,6 +42,28 @@ namespace osu.Game.Tests.Visual.Editing
             });
         }
 
+        [Test]
+        public void TestNudgeSelection()
+        {
+            HitCircle[] addedObjects = null;
+
+            AddStep("add hitobjects", () => EditorBeatmap.AddRange(addedObjects = new[]
+            {
+                new HitCircle { StartTime = 100 },
+                new HitCircle { StartTime = 200, Position = new Vector2(50) },
+                new HitCircle { StartTime = 300, Position = new Vector2(100) },
+                new HitCircle { StartTime = 400, Position = new Vector2(150) },
+            }));
+
+            AddStep("select objects", () => EditorBeatmap.SelectedHitObjects.AddRange(addedObjects));
+
+            AddStep("nudge forwards", () => InputManager.Key(Key.K));
+            AddAssert("objects moved forwards in time", () => addedObjects[0].StartTime > 100);
+
+            AddStep("nudge backwards", () => InputManager.Key(Key.J));
+            AddAssert("objects reverted to original position", () => addedObjects[0].StartTime == 100);
+        }
+
         [Test]
         public void TestBasicSelect()
         {
@@ -156,9 +179,35 @@ namespace osu.Game.Tests.Visual.Editing
         }
 
         [Test]
-        public void TestQuickDeleteRemovesObject()
+        public void TestQuickDeleteRemovesObjectInPlacement()
         {
-            var addedObject = new HitCircle { StartTime = 1000 };
+            var addedObject = new HitCircle
+            {
+                StartTime = 0,
+                Position = OsuPlayfield.BASE_SIZE * 0.5f
+            };
+
+            AddStep("add hitobject", () => EditorBeatmap.Add(addedObject));
+
+            AddStep("enter placement mode", () => InputManager.PressKey(Key.Number2));
+
+            moveMouseToObject(() => addedObject);
+
+            AddStep("hold shift", () => InputManager.PressKey(Key.ShiftLeft));
+            AddStep("right click", () => InputManager.Click(MouseButton.Right));
+            AddStep("release shift", () => InputManager.ReleaseKey(Key.ShiftLeft));
+
+            AddAssert("no hitobjects in beatmap", () => EditorBeatmap.HitObjects.Count == 0);
+        }
+
+        [Test]
+        public void TestQuickDeleteRemovesObjectInSelection()
+        {
+            var addedObject = new HitCircle
+            {
+                StartTime = 0,
+                Position = OsuPlayfield.BASE_SIZE * 0.5f
+            };
 
             AddStep("add hitobject", () => EditorBeatmap.Add(addedObject));
 

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

@@ -130,9 +130,9 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             public double GameplayClockTime => GameplayClockContainer.GameplayClock.CurrentTime;
 
-            protected override void UpdateAfterChildren()
+            protected override void Update()
             {
-                base.UpdateAfterChildren();
+                base.Update();
 
                 if (!FirstFrameClockTime.HasValue)
                 {

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

@@ -118,8 +118,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestBasic()
         {
             AddStep("move to center", () => InputManager.MoveMouseTo(recordingManager.ScreenSpaceDrawQuad.Centre));
-            AddUntilStep("one frame recorded", () => replay.Frames.Count == 1);
+            AddUntilStep("at least one frame recorded", () => replay.Frames.Count > 0);
-            AddAssert("position matches", () => playbackManager.ChildrenOfType<Box>().First().Position == recordingManager.ChildrenOfType<Box>().First().Position);
+            AddUntilStep("position matches", () => playbackManager.ChildrenOfType<Box>().First().Position == recordingManager.ChildrenOfType<Box>().First().Position);
         }
 
         [Test]
@@ -139,14 +139,16 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestLimitedFrameRate()
         {
             ScheduledDelegate moveFunction = null;
+            int initialFrameCount = 0;
 
             AddStep("lower rate", () => recorder.RecordFrameRate = 2);
+            AddStep("count frames", () => initialFrameCount = replay.Frames.Count);
             AddStep("move to center", () => InputManager.MoveMouseTo(recordingManager.ScreenSpaceDrawQuad.Centre));
             AddStep("much move", () => moveFunction = Scheduler.AddDelayed(() =>
                 InputManager.MoveMouseTo(InputManager.CurrentState.Mouse.Position + new Vector2(-1, 0)), 10, true));
             AddWaitStep("move", 10);
             AddStep("stop move", () => moveFunction.Cancel());
-            AddAssert("less than 10 frames recorded", () => replay.Frames.Count < 10);
+            AddAssert("less than 10 frames recorded", () => replay.Frames.Count - initialFrameCount < 10);
         }
 
         [Test]

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

@@ -33,7 +33,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             var working = CreateWorkingBeatmap(CreateBeatmap(new OsuRuleset().RulesetInfo));
             working.LoadTrack();
 
-            Child = gameplayClockContainer = new GameplayClockContainer(working, 0)
+            Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0)
             {
                 RelativeSizeAxes = Axes.Both,
                 Children = new Drawable[]
@@ -80,7 +80,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("move mouse", () => InputManager.MoveMouseTo(skip.ScreenSpaceDrawQuad.Centre));
             AddStep("click", () =>
             {
-                increment = skip_time - gameplayClock.CurrentTime - GameplayClockContainer.MINIMUM_SKIP_TIME / 2;
+                increment = skip_time - gameplayClock.CurrentTime - MasterGameplayClockContainer.MINIMUM_SKIP_TIME / 2;
                 InputManager.Click(MouseButton.Left);
             });
             AddStep("click", () => InputManager.Click(MouseButton.Left));

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

@@ -288,7 +288,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             public override void WatchUser(int userId)
             {
-                if (sentState)
+                if (!PlayingUsers.Contains(userId) && sentState)
                 {
                     // usually the server would do this.
                     sendState(beatmapId);

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

@@ -83,6 +83,28 @@ namespace osu.Game.Tests.Visual.Online
             };
         });
 
+        [Test]
+        public void TestSystemMessageOrdering()
+        {
+            var standardMessage = new Message(messageIdSequence++)
+            {
+                Sender = admin,
+                Content = "I am a wang!"
+            };
+
+            var infoMessage1 = new InfoMessage($"the system is calling {messageIdSequence++}");
+            var infoMessage2 = new InfoMessage($"the system is calling {messageIdSequence++}");
+
+            AddStep("message from admin", () => testChannel.AddNewMessages(standardMessage));
+            AddStep("message from system", () => testChannel.AddNewMessages(infoMessage1));
+            AddStep("message from system", () => testChannel.AddNewMessages(infoMessage2));
+
+            AddAssert("message order is correct", () => testChannel.Messages.Count == 3
+                                                        && testChannel.Messages[0] == standardMessage
+                                                        && testChannel.Messages[1] == infoMessage1
+                                                        && testChannel.Messages[2] == infoMessage2);
+        }
+
         [Test]
         public void TestManyMessages()
         {

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

@@ -0,0 +1,70 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Utils;
+using osu.Game.Graphics.UserInterfaceV2;
+using osuTK.Graphics;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    public class TestSceneLabelledColourPalette : OsuTestScene
+    {
+        private LabelledColourPalette component;
+
+        [Test]
+        public void TestPalette([Values] bool hasDescription)
+        {
+            createColourPalette(hasDescription);
+
+            AddRepeatStep("add random colour", () => component.Colours.Add(randomColour()), 4);
+
+            AddStep("set custom prefix", () => component.ColourNamePrefix = "Combo");
+
+            AddRepeatStep("remove random colour", () =>
+            {
+                if (component.Colours.Count > 0)
+                    component.Colours.RemoveAt(RNG.Next(component.Colours.Count));
+            }, 8);
+        }
+
+        private void createColourPalette(bool hasDescription = false)
+        {
+            AddStep("create component", () =>
+            {
+                Child = new Container
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    Width = 500,
+                    AutoSizeAxes = Axes.Y,
+                    Child = component = new LabelledColourPalette
+                    {
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        ColourNamePrefix = "My colour #"
+                    }
+                };
+
+                component.Label = "a sample component";
+                component.Description = hasDescription ? "this text describes the component" : string.Empty;
+
+                component.Colours.AddRange(new[]
+                {
+                    Color4.DarkRed,
+                    Color4.Aquamarine,
+                    Color4.Goldenrod,
+                    Color4.Gainsboro
+                });
+            });
+        }
+
+        private Color4 randomColour() => new Color4(
+            RNG.NextSingle(),
+            RNG.NextSingle(),
+            RNG.NextSingle(),
+            1);
+    }
+}

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

@@ -167,7 +167,7 @@ namespace osu.Game.Tests.Visual.UserInterface
                 GetModButton(mod).SelectNext(1);
 
             public void SetModSettingsWidth(float newWidth) =>
-                ModSettingsContainer.Width = newWidth;
+                ModSettingsContainer.Parent.Width = newWidth;
         }
 
         public class TestRulesetInfo : RulesetInfo

osu.Game.Tests/WaveformTestBeatmap.cs

@@ -52,6 +52,8 @@ namespace osu.Game.Tests
 
         protected override Waveform GetWaveform() => new Waveform(trackStore.GetStream(firstAudioFile));
 
+        public override Stream GetStream(string storagePath) => null;
+
         protected override Track GetBeatmapTrack() => trackStore.Get(firstAudioFile);
 
         private string firstAudioFile

osu.Game/Beatmaps/BeatmapManager.cs

@@ -526,6 +526,7 @@ namespace osu.Game.Beatmaps
             protected override IBeatmap GetBeatmap() => beatmap;
             protected override Texture GetBackground() => null;
             protected override Track GetBeatmapTrack() => null;
+            public override Stream GetStream(string storagePath) => null;
         }
     }
 

osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs

@@ -3,7 +3,7 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
+using System.IO;
 using osu.Framework.Audio.Track;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Logging;
@@ -36,7 +36,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    using (var stream = new LineBufferedReader(resources.Files.GetStream(getPathForFile(BeatmapInfo.Path))))
+                    using (var stream = new LineBufferedReader(GetStream(BeatmapSetInfo.GetPathForFile(BeatmapInfo.Path))))
                         return Decoder.GetDecoder<Beatmap>(stream).Decode(stream);
                 }
                 catch (Exception e)
@@ -46,8 +46,6 @@ namespace osu.Game.Beatmaps
                 }
             }
 
-            private string getPathForFile(string filename) => BeatmapSetInfo.Files.SingleOrDefault(f => string.Equals(f.Filename, filename, StringComparison.OrdinalIgnoreCase))?.FileInfo.StoragePath;
-
             protected override bool BackgroundStillValid(Texture b) => false; // bypass lazy logic. we want to return a new background each time for refcounting purposes.
 
             protected override Texture GetBackground()
@@ -57,7 +55,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    return resources.LargeTextureStore.Get(getPathForFile(Metadata.BackgroundFile));
+                    return resources.LargeTextureStore.Get(BeatmapSetInfo.GetPathForFile(Metadata.BackgroundFile));
                 }
                 catch (Exception e)
                 {
@@ -73,7 +71,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    return resources.Tracks.Get(getPathForFile(Metadata.AudioFile));
+                    return resources.Tracks.Get(BeatmapSetInfo.GetPathForFile(Metadata.AudioFile));
                 }
                 catch (Exception e)
                 {
@@ -89,7 +87,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    var trackData = resources.Files.GetStream(getPathForFile(Metadata.AudioFile));
+                    var trackData = GetStream(BeatmapSetInfo.GetPathForFile(Metadata.AudioFile));
                     return trackData == null ? null : new Waveform(trackData);
                 }
                 catch (Exception e)
@@ -105,7 +103,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    using (var stream = new LineBufferedReader(resources.Files.GetStream(getPathForFile(BeatmapInfo.Path))))
+                    using (var stream = new LineBufferedReader(GetStream(BeatmapSetInfo.GetPathForFile(BeatmapInfo.Path))))
                     {
                         var decoder = Decoder.GetDecoder<Storyboard>(stream);
 
@@ -114,7 +112,7 @@ namespace osu.Game.Beatmaps
                             storyboard = decoder.Decode(stream);
                         else
                         {
-                            using (var secondaryStream = new LineBufferedReader(resources.Files.GetStream(getPathForFile(BeatmapSetInfo.StoryboardFile))))
+                            using (var secondaryStream = new LineBufferedReader(GetStream(BeatmapSetInfo.GetPathForFile(BeatmapSetInfo.StoryboardFile))))
                                 storyboard = decoder.Decode(stream, secondaryStream);
                         }
                     }
@@ -142,6 +140,8 @@ namespace osu.Game.Beatmaps
                     return null;
                 }
             }
+
+            public override Stream GetStream(string storagePath) => resources.Files.GetStream(storagePath);
         }
     }
 }

osu.Game/Beatmaps/BeatmapSetInfo.cs

@@ -59,6 +59,13 @@ namespace osu.Game.Beatmaps
 
         public string StoryboardFile => Files?.Find(f => f.Filename.EndsWith(".osb", StringComparison.OrdinalIgnoreCase))?.Filename;
 
+        /// <summary>
+        /// Returns the storage path for the file in this beatmapset with the given filename, if any exists, otherwise null.
+        /// The path returned is relative to the user file storage.
+        /// </summary>
+        /// <param name="filename">The name of the file to get the storage path of.</param>
+        public string GetPathForFile(string filename) => Files?.SingleOrDefault(f => string.Equals(f.Filename, filename, StringComparison.OrdinalIgnoreCase))?.FileInfo.StoragePath;
+
         public List<BeatmapSetFileInfo> Files { get; set; }
 
         public override string ToString() => Metadata?.ToString() ?? base.ToString();

osu.Game/Beatmaps/DummyWorkingBeatmap.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Threading;
 using JetBrains.Annotations;
 using osu.Framework.Audio;
@@ -48,6 +49,8 @@ namespace osu.Game.Beatmaps
 
         protected override Track GetBeatmapTrack() => GetVirtualTrack();
 
+        public override Stream GetStream(string storagePath) => null;
+
         private class DummyRulesetInfo : RulesetInfo
         {
             public override Ruleset CreateInstance() => new DummyRuleset();

osu.Game/Beatmaps/IWorkingBeatmap.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using osu.Framework.Audio.Track;
 using osu.Framework.Graphics.Textures;
 using osu.Game.Rulesets;
@@ -41,6 +42,11 @@ namespace osu.Game.Beatmaps
         /// </summary>
         ISkin Skin { get; }
 
+        /// <summary>
+        /// Retrieves the <see cref="Track"/> which this <see cref="WorkingBeatmap"/> has loaded.
+        /// </summary>
+        Track Track { get; }
+
         /// <summary>
         /// Constructs a playable <see cref="IBeatmap"/> from <see cref="Beatmap"/> using the applicable converters for a specific <see cref="RulesetInfo"/>.
         /// <para>
@@ -67,5 +73,11 @@ namespace osu.Game.Beatmaps
         /// </remarks>
         /// <returns>A fresh track instance, which will also be available via <see cref="Track"/>.</returns>
         Track LoadTrack();
+
+        /// <summary>
+        /// Returns the stream of the file from the given storage path.
+        /// </summary>
+        /// <param name="storagePath">The storage path to the file.</param>
+        Stream GetStream(string storagePath);
     }
 }

osu.Game/Beatmaps/Timing/TimeSignatures.cs

@@ -1,11 +1,16 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.ComponentModel;
+
 namespace osu.Game.Beatmaps.Timing
 {
     public enum TimeSignatures
     {
+        [Description("4/4")]
         SimpleQuadruple = 4,
+
+        [Description("3/4")]
         SimpleTriple = 3
     }
 }

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -326,6 +327,8 @@ namespace osu.Game.Beatmaps
         protected virtual ISkin GetSkin() => new DefaultSkin();
         private readonly RecyclableLazy<ISkin> skin;
 
+        public abstract Stream GetStream(string storagePath);
+
         public class RecyclableLazy<T>
         {
             private Lazy<T> lazy;

osu.Game/Configuration/OsuConfigManager.cs

@@ -143,6 +143,7 @@ namespace osu.Game.Configuration
             SetDefault(OsuSetting.DiscordRichPresence, DiscordRichPresenceMode.Full);
 
             SetDefault(OsuSetting.EditorWaveformOpacity, 0.25f);
+            SetDefault(OsuSetting.EditorHitAnimations, false);
         }
 
         public OsuConfigManager(Storage storage)
@@ -266,6 +267,7 @@ namespace osu.Game.Configuration
         GameplayDisableWinKey,
         SeasonalBackgroundMode,
         EditorWaveformOpacity,
+        EditorHitAnimations,
         DiscordRichPresence,
         AutomaticallyDownloadWhenSpectating,
         ShowOnlineExplicitContent,

osu.Game/Configuration/SessionStatics.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Bindables;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Overlays;
@@ -12,14 +13,18 @@ namespace osu.Game.Configuration
     /// </summary>
     public class SessionStatics : InMemoryConfigManager<Static>
     {
-        protected override void InitialiseDefaults()
+        protected override void InitialiseDefaults() => ResetValues();
+
+        public void ResetValues()
         {
-            SetDefault(Static.LoginOverlayDisplayed, false);
+            ensureDefault(SetDefault(Static.LoginOverlayDisplayed, false));
-            SetDefault(Static.MutedAudioNotificationShownOnce, false);
+            ensureDefault(SetDefault(Static.MutedAudioNotificationShownOnce, false));
-            SetDefault(Static.LowBatteryNotificationShownOnce, false);
+            ensureDefault(SetDefault(Static.LowBatteryNotificationShownOnce, false));
-            SetDefault(Static.LastHoverSoundPlaybackTime, (double?)null);
+            ensureDefault(SetDefault(Static.LastHoverSoundPlaybackTime, (double?)null));
-            SetDefault<APISeasonalBackgrounds>(Static.SeasonalBackgrounds, null);
+            ensureDefault(SetDefault<APISeasonalBackgrounds>(Static.SeasonalBackgrounds, null));
         }
+
+        private void ensureDefault<T>(Bindable<T> bindable) => bindable.SetDefault();
     }
 
     public enum Static

osu.Game/Graphics/OsuColour.cs

@@ -94,6 +94,18 @@ namespace osu.Game.Graphics
             }
         }
 
+        /// <summary>
+        /// Returns a foreground text colour that is supposed to contrast well with
+        /// the supplied <paramref name="backgroundColour"/>.
+        /// </summary>
+        public static Color4 ForegroundTextColourFor(Color4 backgroundColour)
+        {
+            // formula taken from the RGB->YIQ conversions: https://en.wikipedia.org/wiki/YIQ
+            // brightness here is equivalent to the Y component in the above colour model, which is a rough estimate of lightness.
+            float brightness = 0.299f * backgroundColour.R + 0.587f * backgroundColour.G + 0.114f * backgroundColour.B;
+            return Gray(brightness > 0.5f ? 0.2f : 0.9f);
+        }
+
         // See https://github.com/ppy/osu-web/blob/master/resources/assets/less/colors.less
         public readonly Color4 PurpleLighter = Color4Extensions.FromHex(@"eeeeff");
         public readonly Color4 PurpleLight = Color4Extensions.FromHex(@"aa88ff");

osu.Game/Graphics/UserInterface/DownloadButton.cs

@@ -27,7 +27,7 @@ namespace osu.Game.Graphics.UserInterface
         [BackgroundDependencyLoader]
         private void load()
         {
-            AddInternal(checkmark = new SpriteIcon
+            Add(checkmark = new SpriteIcon
             {
                 Anchor = Anchor.Centre,
                 Origin = Anchor.Centre,

osu.Game/Graphics/UserInterfaceV2/ColourDisplay.cs

@@ -0,0 +1,107 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.UserInterface;
+using osu.Framework.Localisation;
+using osu.Game.Graphics.Sprites;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Graphics.UserInterfaceV2
+{
+    /// <summary>
+    /// A component which displays a colour along with related description text.
+    /// </summary>
+    public class ColourDisplay : CompositeDrawable, IHasCurrentValue<Color4>
+    {
+        private readonly BindableWithCurrent<Color4> current = new BindableWithCurrent<Color4>();
+
+        private Box fill;
+        private OsuSpriteText colourHexCode;
+        private OsuSpriteText colourName;
+
+        public Bindable<Color4> Current
+        {
+            get => current.Current;
+            set => current.Current = value;
+        }
+
+        private LocalisableString name;
+
+        public LocalisableString ColourName
+        {
+            get => name;
+            set
+            {
+                if (name == value)
+                    return;
+
+                name = value;
+
+                colourName.Text = name;
+            }
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            AutoSizeAxes = Axes.Y;
+            Width = 100;
+
+            InternalChild = new FillFlowContainer
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y,
+                Direction = FillDirection.Vertical,
+                Spacing = new Vector2(0, 10),
+                Children = new Drawable[]
+                {
+                    new CircularContainer
+                    {
+                        RelativeSizeAxes = Axes.X,
+                        Height = 100,
+                        Masking = true,
+                        Children = new Drawable[]
+                        {
+                            fill = new Box
+                            {
+                                RelativeSizeAxes = Axes.Both
+                            },
+                            colourHexCode = new OsuSpriteText
+                            {
+                                Anchor = Anchor.Centre,
+                                Origin = Anchor.Centre,
+                                Font = OsuFont.Default.With(size: 12)
+                            }
+                        }
+                    },
+                    colourName = new OsuSpriteText
+                    {
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopCentre
+                    }
+                }
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            current.BindValueChanged(_ => updateColour(), true);
+        }
+
+        private void updateColour()
+        {
+            fill.Colour = current.Value;
+            colourHexCode.Text = current.Value.ToHex();
+            colourHexCode.Colour = OsuColour.ForegroundTextColourFor(current.Value);
+        }
+    }
+}

osu.Game/Graphics/UserInterfaceV2/ColourPalette.cs

@@ -0,0 +1,119 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics.Sprites;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Graphics.UserInterfaceV2
+{
+    /// <summary>
+    /// A component which displays a collection of colours in individual <see cref="ColourDisplay"/>s.
+    /// </summary>
+    public class ColourPalette : CompositeDrawable
+    {
+        public BindableList<Color4> Colours { get; } = new BindableList<Color4>();
+
+        private string colourNamePrefix = "Colour";
+
+        public string ColourNamePrefix
+        {
+            get => colourNamePrefix;
+            set
+            {
+                if (colourNamePrefix == value)
+                    return;
+
+                colourNamePrefix = value;
+
+                if (IsLoaded)
+                    reindexItems();
+            }
+        }
+
+        private FillFlowContainer<ColourDisplay> palette;
+        private Container placeholder;
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChildren = new Drawable[]
+            {
+                palette = new FillFlowContainer<ColourDisplay>
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Spacing = new Vector2(10),
+                    Direction = FillDirection.Full
+                },
+                placeholder = new Container
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Child = new OsuSpriteText
+                    {
+                        Anchor = Anchor.CentreRight,
+                        Origin = Anchor.CentreRight,
+                        Text = "(none)",
+                        Font = OsuFont.Default.With(weight: FontWeight.Bold)
+                    }
+                }
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Colours.BindCollectionChanged((_, __) => updatePalette(), true);
+            FinishTransforms(true);
+        }
+
+        private const int fade_duration = 200;
+
+        private void updatePalette()
+        {
+            palette.Clear();
+
+            if (Colours.Any())
+            {
+                palette.FadeIn(fade_duration, Easing.OutQuint);
+                placeholder.FadeOut(fade_duration, Easing.OutQuint);
+            }
+            else
+            {
+                palette.FadeOut(fade_duration, Easing.OutQuint);
+                placeholder.FadeIn(fade_duration, Easing.OutQuint);
+            }
+
+            foreach (var item in Colours)
+            {
+                palette.Add(new ColourDisplay
+                {
+                    Current = { Value = item }
+                });
+            }
+
+            reindexItems();
+        }
+
+        private void reindexItems()
+        {
+            int index = 1;
+
+            foreach (var colour in palette)
+            {
+                colour.ColourName = $"{colourNamePrefix} {index}";
+                index += 1;
+            }
+        }
+    }
+}

osu.Game/Graphics/UserInterfaceV2/LabelledColourPalette.cs

@@ -0,0 +1,26 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Bindables;
+using osuTK.Graphics;
+
+namespace osu.Game.Graphics.UserInterfaceV2
+{
+    public class LabelledColourPalette : LabelledDrawable<ColourPalette>
+    {
+        public LabelledColourPalette()
+            : base(true)
+        {
+        }
+
+        public BindableList<Color4> Colours => Component.Colours;
+
+        public string ColourNamePrefix
+        {
+            get => Component.ColourNamePrefix;
+            set => Component.ColourNamePrefix = value;
+        }
+
+        protected override ColourPalette CreateComponent() => new ColourPalette();
+    }
+}

osu.Game/Input/Bindings/GlobalActionContainer.cs

@@ -71,6 +71,8 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(new[] { InputKey.F3 }, GlobalAction.EditorTimingMode),
             new KeyBinding(new[] { InputKey.F4 }, GlobalAction.EditorSetupMode),
             new KeyBinding(new[] { InputKey.Control, InputKey.Shift, InputKey.A }, GlobalAction.EditorVerifyMode),
+            new KeyBinding(new[] { InputKey.J }, GlobalAction.EditorNudgeLeft),
+            new KeyBinding(new[] { InputKey.K }, GlobalAction.EditorNudgeRight),
         };
 
         public IEnumerable<KeyBinding> InGameKeyBindings => new[]
@@ -251,5 +253,11 @@ namespace osu.Game.Input.Bindings
 
         [Description("Verify mode")]
         EditorVerifyMode,
+
+        [Description("Nudge selection left")]
+        EditorNudgeLeft,
+
+        [Description("Nudge selection right")]
+        EditorNudgeRight
     }
 }

osu.Game/Input/IdleTracker.cs

@@ -42,6 +42,12 @@ namespace osu.Game.Input
             RelativeSizeAxes = Axes.Both;
         }
 
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            updateLastInteractionTime();
+        }
+
         protected override void Update()
         {
             base.Update();

osu.Game/Online/Chat/InfoMessage.cs

@@ -8,10 +8,8 @@ namespace osu.Game.Online.Chat
 {
     public class InfoMessage : LocalMessage
     {
-        private static int infoID = -1;
-
         public InfoMessage(string message)
-            : base(infoID--)
+            : base(null)
         {
             Timestamp = DateTimeOffset.Now;
             Content = message;

osu.Game/Online/Chat/Message.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Online.Chat
             return Id.Value.CompareTo(other.Id.Value);
         }
 
-        public virtual bool Equals(Message other) => Id == other?.Id;
+        public virtual bool Equals(Message other) => Id.HasValue && Id == other?.Id;
 
         // ReSharper disable once ImpureMethodCallOnReadonlyValueField
         public override int GetHashCode() => Id.GetHashCode();

osu.Game/Online/Multiplayer/StatefulMultiplayerClient.cs

@@ -144,6 +144,8 @@ namespace osu.Game.Online.Multiplayer
                     Room = joinedRoom;
                     apiRoom = room;
                     defaultPlaylistItemId = apiRoom.Playlist.FirstOrDefault()?.ID ?? 0;
+                    foreach (var user in joinedRoom.Users)
+                        updateUserPlayingState(user.UserID, user.State);
                 }, cancellationSource.Token).ConfigureAwait(false);
 
                 // Update room settings.

osu.Game/Online/Spectator/SpectatorStreamingClient.cs

@@ -47,6 +47,8 @@ namespace osu.Game.Online.Spectator
 
         private readonly BindableList<int> playingUsers = new BindableList<int>();
 
+        private readonly Dictionary<int, SpectatorState> playingUserStates = new Dictionary<int, SpectatorState>();
+
         [CanBeNull]
         private IBeatmap currentBeatmap;
 
@@ -69,7 +71,7 @@ namespace osu.Game.Online.Spectator
         public event Action<int, FrameDataBundle> OnNewFrames;
 
         /// <summary>
-        /// Called whenever a user starts a play session.
+        /// Called whenever a user starts a play session, or immediately if the user is being watched and currently in a play session.
         /// </summary>
         public event Action<int, SpectatorState> OnUserBeganPlaying;
 
@@ -123,7 +125,11 @@ namespace osu.Game.Online.Spectator
                     }
                     else
                     {
-                        playingUsers.Clear();
+                        lock (userLock)
+                        {
+                            playingUsers.Clear();
+                            playingUserStates.Clear();
+                        }
                     }
                 }, true);
             }
@@ -131,8 +137,13 @@ namespace osu.Game.Online.Spectator
 
         Task ISpectatorClient.UserBeganPlaying(int userId, SpectatorState state)
         {
-            if (!playingUsers.Contains(userId))
+            lock (userLock)
-                playingUsers.Add(userId);
+            {
+                if (!playingUsers.Contains(userId))
+                    playingUsers.Add(userId);
+
+                playingUserStates[userId] = state;
+            }
 
             OnUserBeganPlaying?.Invoke(userId, state);
 
@@ -141,7 +152,11 @@ namespace osu.Game.Online.Spectator
 
         Task ISpectatorClient.UserFinishedPlaying(int userId, SpectatorState state)
         {
-            playingUsers.Remove(userId);
+            lock (userLock)
+            {
+                playingUsers.Remove(userId);
+                playingUserStates.Remove(userId);
+            }
 
             OnUserFinishedPlaying?.Invoke(userId, state);
 
@@ -268,5 +283,37 @@ namespace osu.Game.Online.Spectator
 
             lastSendTime = Time.Current;
         }
+
+        /// <summary>
+        /// Attempts to retrieve the <see cref="SpectatorState"/> for a currently-playing user.
+        /// </summary>
+        /// <param name="userId">The user.</param>
+        /// <param name="state">The current <see cref="SpectatorState"/> for the user, if they're playing. <c>null</c> if the user is not playing.</param>
+        /// <returns><c>true</c> if successful (the user is playing), <c>false</c> otherwise.</returns>
+        public bool TryGetPlayingUserState(int userId, out SpectatorState state)
+        {
+            lock (userLock)
+                return playingUserStates.TryGetValue(userId, out state);
+        }
+
+        /// <summary>
+        /// Bind an action to <see cref="OnUserBeganPlaying"/> with the option of running the bound action once immediately.
+        /// </summary>
+        /// <param name="callback">The action to perform when a user begins playing.</param>
+        /// <param name="runOnceImmediately">Whether the action provided in <paramref name="callback"/> should be run once immediately for all users currently playing.</param>
+        public void BindUserBeganPlaying(Action<int, SpectatorState> callback, bool runOnceImmediately = false)
+        {
+            // The lock is taken before the event is subscribed to to prevent doubling of events.
+            lock (userLock)
+            {
+                OnUserBeganPlaying += callback;
+
+                if (!runOnceImmediately)
+                    return;
+
+                foreach (var (userId, state) in playingUserStates)
+                    callback(userId, state);
+            }
+        }
     }
 }

osu.Game/OsuGame.cs

@@ -577,6 +577,15 @@ namespace osu.Game
 
             dependencies.CacheAs(idleTracker = new GameIdleTracker(6000));
 
+            var sessionIdleTracker = new GameIdleTracker(300000);
+            sessionIdleTracker.IsIdle.BindValueChanged(idle =>
+            {
+                if (idle.NewValue)
+                    SessionStatics.ResetValues();
+            });
+
+            Add(sessionIdleTracker);
+
             AddRange(new Drawable[]
             {
                 new VolumeControlReceptor

osu.Game/OsuGameBase.cs

@@ -61,6 +61,8 @@ namespace osu.Game
 
         protected OsuConfigManager LocalConfig;
 
+        protected SessionStatics SessionStatics { get; private set; }
+
         protected BeatmapManager BeatmapManager;
 
         protected ScoreManager ScoreManager;
@@ -289,7 +291,7 @@ namespace osu.Game
             if (powerStatus != null)
                 dependencies.CacheAs(powerStatus);
 
-            dependencies.Cache(new SessionStatics());
+            dependencies.Cache(SessionStatics = new SessionStatics());
             dependencies.Cache(new OsuColour());
 
             RegisterImportHandler(BeatmapManager);

osu.Game/Overlays/Mods/ModSelectOverlay.cs

@@ -245,15 +245,21 @@ namespace osu.Game.Overlays.Mods
                                             },
                                         }
                                     },
-                                    ModSettingsContainer = new ModSettingsContainer
+                                    new Container
                                     {
                                         RelativeSizeAxes = Axes.Both,
                                         Anchor = Anchor.BottomRight,
                                         Origin = Anchor.BottomRight,
-                                        Width = 0.3f,
-                                        Alpha = 0,
                                         Padding = new MarginPadding(30),
-                                        SelectedMods = { BindTarget = SelectedMods },
+                                        Width = 0.3f,
+                                        Children = new Drawable[]
+                                        {
+                                            ModSettingsContainer = new ModSettingsContainer
+                                            {
+                                                Alpha = 0,
+                                                SelectedMods = { BindTarget = SelectedMods },
+                                            },
+                                        }
                                     },
                                 }
                             },

osu.Game/Overlays/Settings/Sections/Input/TabletAreaSelection.cs

@@ -129,9 +129,10 @@ namespace osu.Game.Overlays.Settings.Sections.Input
             rotation.BindTo(handler.Rotation);
             rotation.BindValueChanged(val =>
             {
+                tabletContainer.RotateTo(-val.NewValue, 800, Easing.OutQuint);
                 usableAreaContainer.RotateTo(val.NewValue, 100, Easing.OutQuint)
                                    .OnComplete(_ => checkBounds()); // required as we are using SSDQ.
-            });
+            }, true);
 
             tablet.BindTo(handler.Tablet);
             tablet.BindValueChanged(_ => Scheduler.AddOnce(updateTabletDetails));
@@ -183,8 +184,10 @@ namespace osu.Game.Overlays.Settings.Sections.Input
             if (!(tablet.Value?.Size is Vector2 size))
                 return;
 
-            float fitX = size.X / (DrawWidth - Padding.Left - Padding.Right);
+            float maxDimension = size.LengthFast;
-            float fitY = size.Y / DrawHeight;
+
+            float fitX = maxDimension / (DrawWidth - Padding.Left - Padding.Right);
+            float fitY = maxDimension / DrawHeight;
 
             float adjust = MathF.Max(fitX, fitY);
 

osu.Game/Overlays/Toolbar/ToolbarRulesetSelector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Effects;
@@ -13,6 +14,8 @@ using osu.Framework.Input.Events;
 using osuTK.Input;
 using System.Linq;
 using osu.Framework.Allocation;
+using osu.Framework.Audio;
+using osu.Framework.Audio.Sample;
 
 namespace osu.Game.Overlays.Toolbar
 {
@@ -20,6 +23,8 @@ namespace osu.Game.Overlays.Toolbar
     {
         protected Drawable ModeButtonLine { get; private set; }
 
+        private readonly Dictionary<string, Sample> selectionSamples = new Dictionary<string, Sample>();
+
         public ToolbarRulesetSelector()
         {
             RelativeSizeAxes = Axes.Y;
@@ -27,7 +32,7 @@ namespace osu.Game.Overlays.Toolbar
         }
 
         [BackgroundDependencyLoader]
-        private void load()
+        private void load(AudioManager audio)
         {
             AddRangeInternal(new[]
             {
@@ -54,6 +59,9 @@ namespace osu.Game.Overlays.Toolbar
                     }
                 }
             });
+
+            foreach (var ruleset in Rulesets.AvailableRulesets)
+                selectionSamples[ruleset.ShortName] = audio.Samples.Get($"UI/ruleset-select-{ruleset.ShortName}");
         }
 
         protected override void LoadComplete()
@@ -72,6 +80,10 @@ namespace osu.Game.Overlays.Toolbar
             if (SelectedTab != null)
             {
                 ModeButtonLine.MoveToX(SelectedTab.DrawPosition.X, !hasInitialPosition ? 0 : 200, Easing.OutQuint);
+
+                if (hasInitialPosition)
+                    selectionSamples[SelectedTab.Value.ShortName]?.Play();
+
                 hasInitialPosition = true;
             }
         });

osu.Game/Overlays/Volume/VolumeControlReceptor.cs

@@ -44,6 +44,9 @@ namespace osu.Game.Overlays.Volume
 
         protected override bool OnScroll(ScrollEvent e)
         {
+            if (e.ScrollDelta.Y == 0)
+                return false;
+
             // forward any unhandled mouse scroll events to the volume control.
             ScrollActionRequested?.Invoke(GlobalAction.IncreaseVolume, e.ScrollDelta.Y, e.IsPrecise);
             return true;

osu.Game/Overlays/Volume/VolumeMeter.cs

@@ -245,6 +245,9 @@ namespace osu.Game.Overlays.Volume
 
         private void adjust(double delta, bool isPrecise)
         {
+            if (delta == 0)
+                return;
+
             // every adjust increment increases the rate at which adjustments happen up to a cutoff.
             // this debounce will reset on inactivity.
             accelerationDebounce?.Cancel();

osu.Game/Rulesets/Edit/BeatmapVerifier.cs

@@ -16,9 +16,18 @@ namespace osu.Game.Rulesets.Edit
     {
         private readonly List<ICheck> checks = new List<ICheck>
         {
-            new CheckBackground(),
+            // Resources
+            new CheckBackgroundPresence(),
+            new CheckBackgroundQuality(),
+
+            // Audio
+            new CheckAudioPresence(),
+            new CheckAudioQuality()
         };
 
-        public IEnumerable<Issue> Run(IBeatmap beatmap) => checks.SelectMany(check => check.Run(beatmap));
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, WorkingBeatmap workingBeatmap)
+        {
+            return checks.SelectMany(check => check.Run(playableBeatmap, workingBeatmap));
+        }
     }
 }

osu.Game/Rulesets/Edit/Checks/CheckAudioPresence.cs

@@ -0,0 +1,15 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public class CheckAudioPresence : CheckFilePresence
+    {
+        protected override CheckCategory Category => CheckCategory.Audio;
+        protected override string TypeOfFile => "audio";
+        protected override string GetFilename(IBeatmap playableBeatmap) => playableBeatmap.Metadata?.AudioFile;
+    }
+}

osu.Game/Rulesets/Edit/Checks/CheckAudioQuality.cs

@@ -0,0 +1,75 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public class CheckAudioQuality : ICheck
+    {
+        // This is a requirement as stated in the Ranking Criteria.
+        // See https://osu.ppy.sh/wiki/en/Ranking_Criteria#rules.4
+        private const int max_bitrate = 192;
+
+        // "A song's audio file /.../ must be of reasonable quality. Try to find the highest quality source file available"
+        // There not existing a version with a bitrate of 128 kbps or higher is extremely rare.
+        private const int min_bitrate = 128;
+
+        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Audio, "Too high or low audio bitrate");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateTooHighBitrate(this),
+            new IssueTemplateTooLowBitrate(this),
+            new IssueTemplateNoBitrate(this)
+        };
+
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, IWorkingBeatmap workingBeatmap)
+        {
+            var audioFile = playableBeatmap.Metadata?.AudioFile;
+            if (audioFile == null)
+                yield break;
+
+            var track = workingBeatmap.Track;
+
+            if (track?.Bitrate == null || track.Bitrate.Value == 0)
+                yield return new IssueTemplateNoBitrate(this).Create();
+            else if (track.Bitrate.Value > max_bitrate)
+                yield return new IssueTemplateTooHighBitrate(this).Create(track.Bitrate.Value);
+            else if (track.Bitrate.Value < min_bitrate)
+                yield return new IssueTemplateTooLowBitrate(this).Create(track.Bitrate.Value);
+        }
+
+        public class IssueTemplateTooHighBitrate : IssueTemplate
+        {
+            public IssueTemplateTooHighBitrate(ICheck check)
+                : base(check, IssueType.Problem, "The audio bitrate ({0} kbps) exceeds {1} kbps.")
+            {
+            }
+
+            public Issue Create(int bitrate) => new Issue(this, bitrate, max_bitrate);
+        }
+
+        public class IssueTemplateTooLowBitrate : IssueTemplate
+        {
+            public IssueTemplateTooLowBitrate(ICheck check)
+                : base(check, IssueType.Problem, "The audio bitrate ({0} kbps) is lower than {1} kbps.")
+            {
+            }
+
+            public Issue Create(int bitrate) => new Issue(this, bitrate, min_bitrate);
+        }
+
+        public class IssueTemplateNoBitrate : IssueTemplate
+        {
+            public IssueTemplateNoBitrate(ICheck check)
+                : base(check, IssueType.Error, "The audio bitrate could not be retrieved.")
+            {
+            }
+
+            public Issue Create() => new Issue(this);
+        }
+    }
+}

osu.Game/Rulesets/Edit/Checks/CheckBackground.cs

@@ -1,61 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using System.Collections.Generic;
-using System.Linq;
-using osu.Game.Beatmaps;
-using osu.Game.Rulesets.Edit.Checks.Components;
-
-namespace osu.Game.Rulesets.Edit.Checks
-{
-    public class CheckBackground : ICheck
-    {
-        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Resources, "Missing background");
-
-        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
-        {
-            new IssueTemplateNoneSet(this),
-            new IssueTemplateDoesNotExist(this)
-        };
-
-        public IEnumerable<Issue> Run(IBeatmap beatmap)
-        {
-            if (beatmap.Metadata.BackgroundFile == null)
-            {
-                yield return new IssueTemplateNoneSet(this).Create();
-
-                yield break;
-            }
-
-            // If the background is set, also make sure it still exists.
-
-            var set = beatmap.BeatmapInfo.BeatmapSet;
-            var file = set.Files.FirstOrDefault(f => f.Filename == beatmap.Metadata.BackgroundFile);
-
-            if (file != null)
-                yield break;
-
-            yield return new IssueTemplateDoesNotExist(this).Create(beatmap.Metadata.BackgroundFile);
-        }
-
-        public class IssueTemplateNoneSet : IssueTemplate
-        {
-            public IssueTemplateNoneSet(ICheck check)
-                : base(check, IssueType.Problem, "No background has been set.")
-            {
-            }
-
-            public Issue Create() => new Issue(this);
-        }
-
-        public class IssueTemplateDoesNotExist : IssueTemplate
-        {
-            public IssueTemplateDoesNotExist(ICheck check)
-                : base(check, IssueType.Problem, "The background file \"{0}\" does not exist.")
-            {
-            }
-
-            public Issue Create(string filename) => new Issue(this, filename);
-        }
-    }
-}

osu.Game/Rulesets/Edit/Checks/CheckBackgroundPresence.cs

@@ -0,0 +1,15 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public class CheckBackgroundPresence : CheckFilePresence
+    {
+        protected override CheckCategory Category => CheckCategory.Resources;
+        protected override string TypeOfFile => "background";
+        protected override string GetFilename(IBeatmap playableBeatmap) => playableBeatmap.Metadata?.BackgroundFile;
+    }
+}

osu.Game/Rulesets/Edit/Checks/CheckBackgroundQuality.cs

@@ -0,0 +1,98 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public class CheckBackgroundQuality : ICheck
+    {
+        // These are the requirements as stated in the Ranking Criteria.
+        // See https://osu.ppy.sh/wiki/en/Ranking_Criteria#rules.5
+        private const int min_width = 160;
+        private const int max_width = 2560;
+        private const int min_height = 120;
+        private const int max_height = 1440;
+        private const double max_filesize_mb = 2.5d;
+
+        // It's usually possible to find a higher resolution of the same image if lower than these.
+        private const int low_width = 960;
+        private const int low_height = 540;
+
+        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Resources, "Too high or low background resolution");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateTooHighResolution(this),
+            new IssueTemplateTooLowResolution(this),
+            new IssueTemplateTooUncompressed(this)
+        };
+
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, IWorkingBeatmap workingBeatmap)
+        {
+            var backgroundFile = playableBeatmap.Metadata?.BackgroundFile;
+            if (backgroundFile == null)
+                yield break;
+
+            var texture = workingBeatmap.Background;
+            if (texture == null)
+                yield break;
+
+            if (texture.Width > max_width || texture.Height > max_height)
+                yield return new IssueTemplateTooHighResolution(this).Create(texture.Width, texture.Height);
+
+            if (texture.Width < min_width || texture.Height < min_height)
+                yield return new IssueTemplateTooLowResolution(this).Create(texture.Width, texture.Height);
+            else if (texture.Width < low_width || texture.Height < low_height)
+                yield return new IssueTemplateLowResolution(this).Create(texture.Width, texture.Height);
+
+            string storagePath = playableBeatmap.BeatmapInfo.BeatmapSet.GetPathForFile(backgroundFile);
+            double filesizeMb = workingBeatmap.GetStream(storagePath).Length / (1024d * 1024d);
+
+            if (filesizeMb > max_filesize_mb)
+                yield return new IssueTemplateTooUncompressed(this).Create(filesizeMb);
+        }
+
+        public class IssueTemplateTooHighResolution : IssueTemplate
+        {
+            public IssueTemplateTooHighResolution(ICheck check)
+                : base(check, IssueType.Problem, "The background resolution ({0} x {1}) exceeds {2} x {3}.")
+            {
+            }
+
+            public Issue Create(double width, double height) => new Issue(this, width, height, max_width, max_height);
+        }
+
+        public class IssueTemplateTooLowResolution : IssueTemplate
+        {
+            public IssueTemplateTooLowResolution(ICheck check)
+                : base(check, IssueType.Problem, "The background resolution ({0} x {1}) is lower than {2} x {3}.")
+            {
+            }
+
+            public Issue Create(double width, double height) => new Issue(this, width, height, min_width, min_height);
+        }
+
+        public class IssueTemplateLowResolution : IssueTemplate
+        {
+            public IssueTemplateLowResolution(ICheck check)
+                : base(check, IssueType.Warning, "The background resolution ({0} x {1}) is lower than {2} x {3}.")
+            {
+            }
+
+            public Issue Create(double width, double height) => new Issue(this, width, height, low_width, low_height);
+        }
+
+        public class IssueTemplateTooUncompressed : IssueTemplate
+        {
+            public IssueTemplateTooUncompressed(ICheck check)
+                : base(check, IssueType.Problem, "The background filesize ({0:0.##} MB) exceeds {1} MB.")
+            {
+            }
+
+            public Issue Create(double actualMb) => new Issue(this, actualMb, max_filesize_mb);
+        }
+    }
+}

osu.Game/Rulesets/Edit/Checks/CheckFilePresence.cs

@@ -0,0 +1,63 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public abstract class CheckFilePresence : ICheck
+    {
+        protected abstract CheckCategory Category { get; }
+        protected abstract string TypeOfFile { get; }
+        protected abstract string GetFilename(IBeatmap playableBeatmap);
+
+        public CheckMetadata Metadata => new CheckMetadata(Category, $"Missing {TypeOfFile}");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateNoneSet(this),
+            new IssueTemplateDoesNotExist(this)
+        };
+
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, IWorkingBeatmap workingBeatmap)
+        {
+            var filename = GetFilename(playableBeatmap);
+
+            if (filename == null)
+            {
+                yield return new IssueTemplateNoneSet(this).Create(TypeOfFile);
+
+                yield break;
+            }
+
+            // If the file is set, also make sure it still exists.
+            var storagePath = playableBeatmap.BeatmapInfo.BeatmapSet.GetPathForFile(filename);
+            if (storagePath != null)
+                yield break;
+
+            yield return new IssueTemplateDoesNotExist(this).Create(TypeOfFile, filename);
+        }
+
+        public class IssueTemplateNoneSet : IssueTemplate
+        {
+            public IssueTemplateNoneSet(ICheck check)
+                : base(check, IssueType.Problem, "No {0} has been set.")
+            {
+            }
+
+            public Issue Create(string typeOfFile) => new Issue(this, typeOfFile);
+        }
+
+        public class IssueTemplateDoesNotExist : IssueTemplate
+        {
+            public IssueTemplateDoesNotExist(ICheck check)
+                : base(check, IssueType.Problem, "The {0} file \"{1}\" does not exist.")
+            {
+            }
+
+            public Issue Create(string typeOfFile, string filename) => new Issue(this, typeOfFile, filename);
+        }
+    }
+}

osu.Game/Rulesets/Edit/Checks/Components/ICheck.cs

@@ -24,7 +24,8 @@ namespace osu.Game.Rulesets.Edit.Checks.Components
         /// <summary>
         /// Runs this check and returns any issues detected for the provided beatmap.
         /// </summary>
-        /// <param name="beatmap">The beatmap to run the check on.</param>
+        /// <param name="playableBeatmap">The playable beatmap of the beatmap to run the check on.</param>
-        public IEnumerable<Issue> Run(IBeatmap beatmap);
+        /// <param name="workingBeatmap">The working beatmap of the beatmap to run the check on.</param>
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, IWorkingBeatmap workingBeatmap);
     }
 }

osu.Game/Rulesets/Edit/IBeatmapVerifier.cs

@@ -12,6 +12,6 @@ namespace osu.Game.Rulesets.Edit
     /// </summary>
     public interface IBeatmapVerifier
     {
-        public IEnumerable<Issue> Run(IBeatmap beatmap);
+        public IEnumerable<Issue> Run(IBeatmap playableBeatmap, WorkingBeatmap workingBeatmap);
     }
 }

osu.Game/Rulesets/Edit/PlacementBlueprint.cs

@@ -14,6 +14,7 @@ using osu.Game.Rulesets.Objects;
 using osu.Game.Screens.Edit;
 using osu.Game.Screens.Edit.Compose;
 using osuTK;
+using osuTK.Input;
 
 namespace osu.Game.Rulesets.Edit
 {
@@ -128,8 +129,11 @@ namespace osu.Game.Rulesets.Edit
                 case DoubleClickEvent _:
                     return false;
 
-                case MouseButtonEvent _:
+                case MouseButtonEvent mouse:
-                    return true;
+                    // placement blueprints should generally block mouse from reaching underlying components (ie. performing clicks on interface buttons).
+                    // for now, the one exception we want to allow is when using a non-main mouse button when shift is pressed, which is used to trigger object deletion
+                    // while in placement mode.
+                    return mouse.Button == MouseButton.Left || !mouse.ShiftPressed;
 
                 default:
                     return false;

osu.Game/Rulesets/Mods/ModClassic.cs

@@ -0,0 +1,24 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics.Sprites;
+
+namespace osu.Game.Rulesets.Mods
+{
+    public abstract class ModClassic : Mod
+    {
+        public override string Name => "Classic";
+
+        public override string Acronym => "CL";
+
+        public override double ScoreMultiplier => 1;
+
+        public override IconUsage? Icon => FontAwesome.Solid.History;
+
+        public override string Description => "Feeling nostalgic?";
+
+        public override bool Ranked => false;
+
+        public override ModType Type => ModType.Conversion;
+    }
+}

osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
@@ -39,7 +40,7 @@ namespace osu.Game.Rulesets.Objects.Drawables
         /// <summary>
         /// The <see cref="HitObject"/> currently represented by this <see cref="DrawableHitObject"/>.
         /// </summary>
-        public HitObject HitObject { get; private set; }
+        public HitObject HitObject => lifetimeEntry?.HitObject;
 
         /// <summary>
         /// The parenting <see cref="DrawableHitObject"/>, if any.
@@ -108,7 +109,7 @@ namespace osu.Game.Rulesets.Objects.Drawables
         /// <summary>
         /// The scoring result of this <see cref="DrawableHitObject"/>.
         /// </summary>
-        public JudgementResult Result { get; private set; }
+        public JudgementResult Result => lifetimeEntry?.Result;
 
         /// <summary>
         /// The relative X position of this hit object for sample playback balance adjustment.
@@ -141,13 +142,14 @@ namespace osu.Game.Rulesets.Objects.Drawables
         public IBindable<ArmedState> State => state;
 
         /// <summary>
-        /// Whether <see cref="HitObject"/> is currently applied.
+        /// Whether a <see cref="HitObjectLifetimeEntry"/> is currently applied.
         /// </summary>
-        private bool hasHitObjectApplied;
+        private bool hasEntryApplied;
 
         /// <summary>
         /// The <see cref="HitObjectLifetimeEntry"/> controlling the lifetime of the currently-attached <see cref="HitObject"/>.
         /// </summary>
+        /// <remarks>Even if it is not null, it may not be fully applied until loaded (<see cref="hasEntryApplied"/> is false).</remarks>
         [CanBeNull]
         private HitObjectLifetimeEntry lifetimeEntry;
 
@@ -164,11 +166,15 @@ namespace osu.Game.Rulesets.Objects.Drawables
         /// </summary>
         /// <param name="initialHitObject">
         /// The <see cref="HitObject"/> to be initially applied to this <see cref="DrawableHitObject"/>.
-        /// If <c>null</c>, a hitobject is expected to be later applied via <see cref="Apply"/> (or automatically via pooling).
+        /// If <c>null</c>, a hitobject is expected to be later applied via <see cref="Apply(osu.Game.Rulesets.Objects.HitObjectLifetimeEntry)"/> (or automatically via pooling).
         /// </param>
         protected DrawableHitObject([CanBeNull] HitObject initialHitObject = null)
         {
-            HitObject = initialHitObject;
+            if (initialHitObject != null)
+            {
+                lifetimeEntry = new SyntheticHitObjectEntry(initialHitObject);
+                ensureEntryHasResult();
+            }
         }
 
         [BackgroundDependencyLoader]
@@ -184,8 +190,8 @@ namespace osu.Game.Rulesets.Objects.Drawables
         {
             base.LoadAsyncComplete();
 
-            if (HitObject != null)
+            if (lifetimeEntry != null && !hasEntryApplied)
-                Apply(HitObject, lifetimeEntry);
+                Apply(lifetimeEntry);
         }
 
         protected override void LoadComplete()
@@ -198,37 +204,47 @@ namespace osu.Game.Rulesets.Objects.Drawables
         }
 
         /// <summary>
-        /// Applies a new <see cref="HitObject"/> to be represented by this <see cref="DrawableHitObject"/>.
+        /// Applies a hit object to be represented by this <see cref="DrawableHitObject"/>.
         /// </summary>
-        /// <param name="hitObject">The <see cref="HitObject"/> to apply.</param>
+        [Obsolete("Use either overload of Apply that takes a single argument of type HitObject or HitObjectLifetimeEntry")]
-        /// <param name="lifetimeEntry">The <see cref="HitObjectLifetimeEntry"/> controlling the lifetime of <paramref name="hitObject"/>.</param>
         public void Apply([NotNull] HitObject hitObject, [CanBeNull] HitObjectLifetimeEntry lifetimeEntry)
+        {
+            if (lifetimeEntry != null)
+                Apply(lifetimeEntry);
+            else
+                Apply(hitObject);
+        }
+
+        /// <summary>
+        /// Applies a new <see cref="HitObject"/> to be represented by this <see cref="DrawableHitObject"/>.
+        /// A new <see cref="HitObjectLifetimeEntry"/> is automatically created and applied to this <see cref="DrawableHitObject"/>.
+        /// </summary>
+        public void Apply([NotNull] HitObject hitObject)
+        {
+            if (hitObject == null)
+                throw new ArgumentNullException($"Cannot apply a null {nameof(HitObject)}.");
+
+            Apply(new SyntheticHitObjectEntry(hitObject));
+        }
+
+        /// <summary>
+        /// Applies a new <see cref="HitObjectLifetimeEntry"/> to be represented by this <see cref="DrawableHitObject"/>.
+        /// </summary>
+        public void Apply([NotNull] HitObjectLifetimeEntry newEntry)
         {
             free();
 
-            HitObject = hitObject ?? throw new InvalidOperationException($"Cannot apply a null {nameof(HitObject)}.");
+            lifetimeEntry = newEntry;
 
-            this.lifetimeEntry = lifetimeEntry;
+            // LifetimeStart is already computed using HitObjectLifetimeEntry's InitialLifetimeOffset.
+            // We override this with DHO's InitialLifetimeOffset for a non-pooled DHO.
+            if (newEntry is SyntheticHitObjectEntry)
+                lifetimeEntry.LifetimeStart = HitObject.StartTime - InitialLifetimeOffset;
 
-            if (lifetimeEntry != null)
+            LifetimeStart = lifetimeEntry.LifetimeStart;
-            {
+            LifetimeEnd = lifetimeEntry.LifetimeEnd;
-                // Transfer lifetime from the entry.
-                LifetimeStart = lifetimeEntry.LifetimeStart;
-                LifetimeEnd = lifetimeEntry.LifetimeEnd;
 
-                // Copy any existing result from the entry (required for rewind / judgement revert).
+            ensureEntryHasResult();
-                Result = lifetimeEntry.Result;
-            }
-            else
-                LifetimeStart = HitObject.StartTime - InitialLifetimeOffset;
-
-            // Ensure this DHO has a result.
-            Result ??= CreateResult(HitObject.CreateJudgement())
-                       ?? throw new InvalidOperationException($"{GetType().ReadableName()} must provide a {nameof(JudgementResult)} through {nameof(CreateResult)}.");
-
-            // Copy back the result to the entry for potential future retrieval.
-            if (lifetimeEntry != null)
-                lifetimeEntry.Result = Result;
 
             foreach (var h in HitObject.NestedHitObjects)
             {
@@ -278,16 +294,15 @@ namespace osu.Game.Rulesets.Objects.Drawables
                     updateState(ArmedState.Idle, true);
             }
 
-            hasHitObjectApplied = true;
+            hasEntryApplied = true;
         }
 
         /// <summary>
-        /// Removes the currently applied <see cref="HitObject"/>
+        /// Removes the currently applied <see cref="lifetimeEntry"/>
         /// </summary>
         private void free()
         {
-            if (!hasHitObjectApplied)
+            if (!hasEntryApplied) return;
-                return;
 
             StartTimeBindable.UnbindFrom(HitObject.StartTimeBindable);
             if (HitObject is IHasComboInformation combo)
@@ -319,14 +334,12 @@ namespace osu.Game.Rulesets.Objects.Drawables
 
             OnFree();
 
-            HitObject = null;
             ParentHitObject = null;
-            Result = null;
             lifetimeEntry = null;
 
             clearExistingStateTransforms();
 
-            hasHitObjectApplied = false;
+            hasEntryApplied = false;
         }
 
         protected sealed override void FreeAfterUse()
@@ -385,7 +398,9 @@ namespace osu.Game.Rulesets.Objects.Drawables
 
         private void onDefaultsApplied(HitObject hitObject)
         {
-            Apply(hitObject, lifetimeEntry);
+            Debug.Assert(lifetimeEntry != null);
+            Apply(lifetimeEntry);
+
             DefaultsApplied?.Invoke(this);
         }
 
@@ -783,6 +798,13 @@ namespace osu.Game.Rulesets.Objects.Drawables
         /// <param name="judgement">The <see cref="Judgement"/> that provides the scoring information.</param>
         protected virtual JudgementResult CreateResult(Judgement judgement) => new JudgementResult(HitObject, judgement);
 
+        private void ensureEntryHasResult()
+        {
+            Debug.Assert(lifetimeEntry != null);
+            lifetimeEntry.Result ??= CreateResult(HitObject.CreateJudgement())
+                                     ?? throw new InvalidOperationException($"{GetType().ReadableName()} must provide a {nameof(JudgementResult)} through {nameof(CreateResult)}.");
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);

osu.Game/Rulesets/Objects/SyntheticHitObjectEntry.cs

@@ -0,0 +1,19 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Objects.Drawables;
+
+namespace osu.Game.Rulesets.Objects
+{
+    /// <summary>
+    /// Created for a <see cref="DrawableHitObject"/> when only <see cref="HitObject"/> is given
+    /// to make sure a <see cref="DrawableHitObject"/> is always associated with a <see cref="HitObjectLifetimeEntry"/>.
+    /// </summary>
+    internal class SyntheticHitObjectEntry : HitObjectLifetimeEntry
+    {
+        public SyntheticHitObjectEntry(HitObject hitObject)
+            : base(hitObject)
+        {
+        }
+    }
+}

osu.Game/Rulesets/UI/Playfield.cs

@@ -362,7 +362,7 @@ namespace osu.Game.Rulesets.UI
                     lifetimeEntryMap[hitObject] = entry = CreateLifetimeEntry(hitObject);
 
                 dho.ParentHitObject = parent;
-                dho.Apply(hitObject, entry);
+                dho.Apply(entry);
             });
         }
 

osu.Game/Rulesets/UI/ReplayRecorder.cs

@@ -58,6 +58,12 @@ namespace osu.Game.Rulesets.UI
             spectatorStreaming?.EndPlaying();
         }
 
+        protected override void Update()
+        {
+            base.Update();
+            recordFrame(false);
+        }
+
         protected override bool OnMouseMove(MouseMoveEvent e)
         {
             recordFrame(false);

osu.Game/Scoring/ScoreInfo.cs

@@ -65,14 +65,21 @@ namespace osu.Game.Scoring
         {
             get
             {
+                var rulesetInstance = Ruleset?.CreateInstance();
+                if (rulesetInstance == null)
+                    return mods ?? Array.Empty<Mod>();
+
+                Mod[] scoreMods = Array.Empty<Mod>();
+
                 if (mods != null)
-                    return mods;
+                    scoreMods = mods;
+                else if (localAPIMods != null)
+                    scoreMods = apiMods.Select(m => m.ToMod(rulesetInstance)).ToArray();
 
-                if (localAPIMods == null)
+                if (IsLegacyScore)
-                    return Array.Empty<Mod>();
+                    scoreMods = scoreMods.Append(rulesetInstance.GetAllMods().OfType<ModClassic>().Single()).ToArray();
 
-                var rulesetInstance = Ruleset.CreateInstance();
+                return scoreMods;
-                return apiMods.Select(m => m.ToMod(rulesetInstance)).ToArray();
             }
             set
             {

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

@@ -519,7 +519,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 // Apply the start time at the newly snapped-to position
                 double offset = result.Time.Value - movementBlueprints.First().HitObject.StartTime;
 
-                Beatmap.PerformOnSelection(obj => obj.StartTime += offset);
+                if (offset != 0)
+                    Beatmap.PerformOnSelection(obj => obj.StartTime += offset);
             }
 
             return true;

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

@@ -33,10 +33,14 @@ namespace osu.Game.Screens.Edit.Compose.Components
     /// </summary>
     public class SelectionHandler : CompositeDrawable, IKeyBindingHandler<PlatformAction>, IHasContextMenu
     {
+        /// <summary>
+        /// The currently selected blueprints.
+        /// Should be used when operations are dealing directly with the visible blueprints.
+        /// For more general selection operations, use <see cref="osu.Game.Screens.Edit.EditorBeatmap.SelectedHitObjects"/> instead.
+        /// </summary>
         public IEnumerable<SelectionBlueprint> SelectedBlueprints => selectedBlueprints;
-        private readonly List<SelectionBlueprint> selectedBlueprints;
 
-        public int SelectedCount => selectedBlueprints.Count;
+        private readonly List<SelectionBlueprint> selectedBlueprints;
 
         private Drawable content;
 
@@ -295,7 +299,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// </summary>
         private void updateVisibility()
         {
-            int count = selectedBlueprints.Count;
+            int count = EditorBeatmap.SelectedHitObjects.Count;
 
             selectionDetailsText.Text = count > 0 ? count.ToString() : string.Empty;
 

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

@@ -12,9 +12,11 @@ using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Primitives;
 using osu.Framework.Graphics.Shapes;
+using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
 using osu.Framework.Utils;
 using osu.Game.Graphics;
+using osu.Game.Input.Bindings;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Screens.Edit.Components.Timelines.Summary.Parts;
@@ -237,10 +239,48 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             }
         }
 
-        internal class TimelineSelectionHandler : SelectionHandler
+        internal class TimelineSelectionHandler : SelectionHandler, IKeyBindingHandler<GlobalAction>
         {
             // for now we always allow movement. snapping is provided by the Timeline's "distance" snap implementation
             public override bool HandleMovement(MoveSelectionEvent moveEvent) => true;
+
+            public bool OnPressed(GlobalAction action)
+            {
+                switch (action)
+                {
+                    case GlobalAction.EditorNudgeLeft:
+                        nudgeSelection(-1);
+                        return true;
+
+                    case GlobalAction.EditorNudgeRight:
+                        nudgeSelection(1);
+                        return true;
+                }
+
+                return false;
+            }
+
+            public void OnReleased(GlobalAction action)
+            {
+            }
+
+            /// <summary>
+            /// Nudge the current selection by the specified multiple of beat divisor lengths,
+            /// based on the timing at the first object in the selection.
+            /// </summary>
+            /// <param name="amount">The direction and count of beat divisor lengths to adjust.</param>
+            private void nudgeSelection(int amount)
+            {
+                var selected = EditorBeatmap.SelectedHitObjects;
+
+                if (selected.Count == 0)
+                    return;
+
+                var timingPoint = EditorBeatmap.ControlPointInfo.TimingPointAt(selected.First().StartTime);
+                double adjustment = timingPoint.BeatLength / EditorBeatmap.BeatDivisor * amount;
+
+                EditorBeatmap.PerformOnSelection(h => h.StartTime += adjustment);
+            }
         }
 
         private class TimelineDragBox : DragBox

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

@@ -158,10 +158,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 circle.Colour = comboColour;
 
             var col = circle.Colour.TopLeft.Linear;
-            float brightness = col.R + col.G + col.B;
+            colouredComponents.Colour = OsuColour.ForegroundTextColourFor(col);
-
-            // decide the combo index colour based on brightness?
-            colouredComponents.Colour = OsuColour.Gray(brightness > 0.5f ? 0.2f : 0.9f);
         }
 
         protected override void Update()

osu.Game/Screens/Edit/Editor.cs

@@ -224,9 +224,10 @@ namespace osu.Game.Screens.Edit
                                 },
                                 new MenuItem("View")
                                 {
-                                    Items = new[]
+                                    Items = new MenuItem[]
                                     {
-                                        new WaveformOpacityMenu(config)
+                                        new WaveformOpacityMenuItem(config.GetBindable<float>(OsuSetting.EditorWaveformOpacity)),
+                                        new HitAnimationsMenuItem(config.GetBindable<bool>(OsuSetting.EditorHitAnimations))
                                     }
                                 }
                             }