Use hit object pooling for JuiceStream.

- Use `Clear(false)` to not dispose pooled children.
- Don't set nested DHO `Origin`.
- Simplify the layout (remove custom `Origin`).

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

@@ -136,7 +136,7 @@ namespace osu.Game.Rulesets.Catch.Tests
             if (juice.NestedHitObjects.Last() is CatchHitObject tail)
                 tail.LastInCombo = true; // usually the (Catch)BeatmapProcessor would do this for us when necessary
 
-            addToPlayfield(new DrawableJuiceStream(juice, drawableRuleset.CreateDrawableRepresentation));
+            addToPlayfield(new DrawableJuiceStream(juice));
         }
 
         private void spawnBananas(bool hit = false)

osu.Game.Rulesets.Catch/Objects/Drawables/DrawableJuiceStream.cs

@@ -1,37 +1,33 @@
 // 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 JetBrains.Annotations;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
-using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
-using osuTK;
 
 namespace osu.Game.Rulesets.Catch.Objects.Drawables
 {
     public class DrawableJuiceStream : DrawableCatchHitObject
     {
-        private readonly Func<CatchHitObject, DrawableHitObject<CatchHitObject>> createDrawableRepresentation;
         private readonly Container dropletContainer;
 
-        public override Vector2 OriginPosition => base.OriginPosition - new Vector2(0, CatchHitObject.OBJECT_RADIUS);
+        public DrawableJuiceStream()
+            : this(null)
+        {
+        }
 
-        public DrawableJuiceStream(JuiceStream s, Func<CatchHitObject, DrawableHitObject<CatchHitObject>> createDrawableRepresentation = null)
+        public DrawableJuiceStream([CanBeNull] JuiceStream s)
             : base(s)
         {
-            this.createDrawableRepresentation = createDrawableRepresentation;
             RelativeSizeAxes = Axes.X;
             Origin = Anchor.BottomLeft;
-            X = 0;
 
             AddInternal(dropletContainer = new Container { RelativeSizeAxes = Axes.Both, });
         }
 
         protected override void AddNestedHitObject(DrawableHitObject hitObject)
         {
-            hitObject.Origin = Anchor.BottomCentre;
-
             base.AddNestedHitObject(hitObject);
             dropletContainer.Add(hitObject);
         }
@@ -39,18 +35,7 @@ namespace osu.Game.Rulesets.Catch.Objects.Drawables
         protected override void ClearNestedHitObjects()
         {
             base.ClearNestedHitObjects();
-            dropletContainer.Clear();
+            dropletContainer.Clear(false);
-        }
-
-        protected override DrawableHitObject CreateNestedHitObject(HitObject hitObject)
-        {
-            switch (hitObject)
-            {
-                case CatchHitObject catchObject:
-                    return createDrawableRepresentation?.Invoke(catchObject);
-            }
-
-            throw new ArgumentException($"{nameof(hitObject)} must be of type {nameof(CatchHitObject)}.");
         }
     }
 }

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

@@ -64,6 +64,7 @@ namespace osu.Game.Rulesets.Catch.UI
             RegisterPool<TinyDroplet, DrawableTinyDroplet>(1);
             RegisterPool<Fruit, DrawableFruit>(1);
             RegisterPool<Banana, DrawableBanana>(1);
+            RegisterPool<JuiceStream, DrawableJuiceStream>(1);
         }
 
         protected override void LoadComplete()

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

@@ -44,9 +44,6 @@ namespace osu.Game.Rulesets.Catch.UI
         {
             switch (h)
             {
-                case JuiceStream stream:
-                    return new DrawableJuiceStream(stream, CreateDrawableRepresentation);
-
                 case BananaShower shower:
                     return new DrawableBananaShower(shower, CreateDrawableRepresentation);
             }