Replace EntryCrossedBoundary with more useful RemoveRewoundEntry property

It can be used for dynamically added entries.

osu.Game.Rulesets.Taiko/UI/DrumRollHitContainer.cs

@@ -1,9 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Performance;
-using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Taiko.Objects.Drawables;
 using osu.Game.Rulesets.UI.Scrolling;
 
@@ -11,6 +8,11 @@ namespace osu.Game.Rulesets.Taiko.UI
 {
     internal class DrumRollHitContainer : ScrollingHitObjectContainer
     {
+        // TODO: this usage is buggy.
+        // Because `LifetimeStart` is set based on scrolling, lifetime is not same as the time when the object is created.
+        // If the `Update` override is removed, it breaks in an obscure way.
+        protected override bool RemoveRewoundEntry => true;
+
         protected override void Update()
         {
             base.Update();
@@ -23,14 +25,5 @@ namespace osu.Game.Rulesets.Taiko.UI
                     Remove(flyingHit);
             }
         }
-
-        protected override void OnChildLifetimeBoundaryCrossed(LifetimeBoundaryCrossedEvent e)
-        {
-            base.OnChildLifetimeBoundaryCrossed(e);
-
-            // ensure all old hits are removed on becoming alive (may miss being in the AliveInternalChildren list above).
-            if (e.Kind == LifetimeBoundaryKind.Start && e.Direction == LifetimeBoundaryCrossingDirection.Backward)
-                Remove((DrawableHitObject)e.Child);
-        }
     }
 }

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

@@ -39,6 +39,12 @@ namespace osu.Game.Rulesets.Objects.Pooling
         /// </remarks>
         public IEnumerable<(TEntry Entry, TDrawable Drawable)> AliveEntries => aliveDrawableMap.Select(x => (x.Key, x.Value));
 
+        /// <summary>
+        /// Whether to remove an entry when clock goes backward and crossed its <see cref="LifetimeEntry.LifetimeStart"/>.
+        /// Used when entries are dynamically added at its <see cref="LifetimeEntry.LifetimeStart"/> to prevent duplicated entries.
+        /// </summary>
+        protected virtual bool RemoveRewoundEntry => false;
+
         /// <summary>
         /// The amount of time prior to the current time within which entries should be considered alive.
         /// </summary>
@@ -130,11 +136,10 @@ namespace osu.Game.Rulesets.Objects.Pooling
         /// </remarks>
         protected virtual void RemoveDrawable(TEntry entry, TDrawable drawable) => RemoveInternal(drawable);
 
-        private void entryCrossedBoundary(LifetimeEntry lifetimeEntry, LifetimeBoundaryKind kind, LifetimeBoundaryCrossingDirection direction) =>
+        private void entryCrossedBoundary(LifetimeEntry lifetimeEntry, LifetimeBoundaryKind kind, LifetimeBoundaryCrossingDirection direction)
-            OnEntryCrossedBoundary((TEntry)lifetimeEntry, kind, direction);
-
-        protected virtual void OnEntryCrossedBoundary(TEntry entry, LifetimeBoundaryKind kind, LifetimeBoundaryCrossingDirection direction)
         {
+            if (RemoveRewoundEntry && kind == LifetimeBoundaryKind.Start && direction == LifetimeBoundaryCrossingDirection.Backward)
+                Remove((TEntry)lifetimeEntry);
         }
 
         /// <summary>

osu.Game/Rulesets/UI/HitObjectContainer.cs

@@ -9,8 +9,6 @@ using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.TypeExtensions;
 using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Performance;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
@@ -159,16 +157,6 @@ namespace osu.Game.Rulesets.UI
 
         public int IndexOf(DrawableHitObject hitObject) => IndexOfInternal(hitObject);
 
-        protected override void OnEntryCrossedBoundary(HitObjectLifetimeEntry entry, LifetimeBoundaryKind kind, LifetimeBoundaryCrossingDirection direction)
-        {
-            if (nonPooledDrawableMap.TryGetValue(entry, out var drawable))
-                OnChildLifetimeBoundaryCrossed(new LifetimeBoundaryCrossedEvent(drawable, kind, direction));
-        }
-
-        protected virtual void OnChildLifetimeBoundaryCrossed(LifetimeBoundaryCrossedEvent e)
-        {
-        }
-
         #endregion
 
         /// <summary>