Add test

osu.Game.Tests/Editing/TestSceneHitObjectContainerEventQueue.cs

@@ -0,0 +1,168 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.UI;
+using osu.Game.Screens.Edit.Compose;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.Editing
+{
+    public class TestSceneHitObjectContainerEventQueue : OsuTestScene
+    {
+        private readonly TestHitObject testObj = new TestHitObject();
+
+        private TestPlayfield playfield1;
+        private TestPlayfield playfield2;
+        private TestDrawable intermediateDrawable;
+        private HitObjectContainerEventQueue eventQueue;
+
+        private HitObject beganUsage;
+        private HitObject finishedUsage;
+        private HitObject transferredUsage;
+
+        [SetUp]
+        public void Setup() => Schedule(() =>
+        {
+            reset();
+
+            if (eventQueue != null)
+            {
+                eventQueue.HitObjectUsageBegan -= onHitObjectUsageBegan;
+                eventQueue.HitObjectUsageFinished -= onHitObjectUsageFinished;
+                eventQueue.HitObjectUsageTransferred -= onHitObjectUsageTransferred;
+            }
+
+            var topPlayfield = new TestPlayfield();
+            topPlayfield.AddNested(playfield1 = new TestPlayfield());
+            topPlayfield.AddNested(playfield2 = new TestPlayfield());
+
+            eventQueue = new HitObjectContainerEventQueue(topPlayfield);
+            eventQueue.HitObjectUsageBegan += onHitObjectUsageBegan;
+            eventQueue.HitObjectUsageFinished += onHitObjectUsageFinished;
+            eventQueue.HitObjectUsageTransferred += onHitObjectUsageTransferred;
+
+            Children = new Drawable[]
+            {
+                topPlayfield,
+                intermediateDrawable = new TestDrawable(),
+                eventQueue
+            };
+        });
+
+        private void onHitObjectUsageBegan(HitObject obj) => beganUsage = obj;
+
+        private void onHitObjectUsageFinished(HitObject obj) => finishedUsage = obj;
+
+        private void onHitObjectUsageTransferred(HitObject obj, DrawableHitObject drawableObj) => transferredUsage = obj;
+
+        [Test]
+        public void TestUsageBeganAfterAdd()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addCheckStep(began: true);
+        }
+
+        [Test]
+        public void TestUsageFinishedAfterRemove()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("remove hitobject", () => playfield1.Remove(testObj));
+            addCheckStep(finished: true);
+        }
+
+        [Test]
+        public void TestUsageTransferredWhenMovedBetweenPlayfields()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("transfer hitobject to other playfield", () =>
+            {
+                playfield1.Remove(testObj);
+                playfield2.Add(testObj);
+            });
+
+            addCheckStep(transferred: true);
+        }
+
+        [Test]
+        public void TestRemoveImmediatelyAfterUsageBegan()
+        {
+            AddStep("add hitobject and schedule removal", () =>
+            {
+                playfield1.Add(testObj);
+                intermediateDrawable.Schedule(() => playfield1.Remove(testObj));
+            });
+
+            addCheckStep();
+        }
+
+        [Test]
+        public void TestRemoveImmediatelyAfterTransferred()
+        {
+            AddStep("add hitobject", () => playfield1.Add(testObj));
+            addResetStep();
+            AddStep("transfer hitobject to other playfield and schedule removal", () =>
+            {
+                playfield1.Remove(testObj);
+                playfield2.Add(testObj);
+                intermediateDrawable.Schedule(() => playfield2.Remove(testObj));
+            });
+
+            addCheckStep(finished: true);
+        }
+
+        private void addResetStep() => AddStep("reset", reset);
+
+        private void reset()
+        {
+            beganUsage = null;
+            finishedUsage = null;
+            transferredUsage = null;
+        }
+
+        private void addCheckStep(bool began = false, bool finished = false, bool transferred = false)
+            => AddAssert($"began = {began}, finished = {finished}, transferred = {transferred}",
+                () => (beganUsage == testObj) == began && (finishedUsage == testObj) == finished && (transferredUsage == testObj) == transferred);
+
+        private class TestPlayfield : Playfield
+        {
+            public TestPlayfield()
+            {
+                RegisterPool<TestHitObject, TestDrawableHitObject>(1);
+            }
+
+            public new void AddNested(Playfield playfield)
+            {
+                AddInternal(playfield);
+                base.AddNested(playfield);
+            }
+
+            protected override HitObjectLifetimeEntry CreateLifetimeEntry(HitObject hitObject)
+            {
+                var entry = base.CreateLifetimeEntry(hitObject);
+                entry.KeepAlive = true;
+                return entry;
+            }
+        }
+
+        private class TestHitObject : HitObject
+        {
+            public override string ToString() => "TestHitObject";
+        }
+
+        private class TestDrawableHitObject : DrawableHitObject
+        {
+        }
+
+        private class TestDrawable : Drawable
+        {
+            public new void Schedule(Action action) => base.Schedule(action);
+        }
+    }
+}

osu.Game/Rulesets/UI/Playfield.cs

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