From f0c56cadac897b87bf937bbe2d0c4e80cc1f0eb9 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 22 Jan 2025 18:47:48 +0900
Subject: [PATCH] Change the method of finding a drawable representation of
 items to be on-demand

---
 osu.Game/Screens/SelectV2/BeatmapCarousel.cs | 11 +++++-----
 osu.Game/Screens/SelectV2/Carousel.cs        | 22 ++++++++++++++------
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/osu.Game/Screens/SelectV2/BeatmapCarousel.cs b/osu.Game/Screens/SelectV2/BeatmapCarousel.cs
index 45fd7e0a2edd..7e8a3397febb 100644
--- a/osu.Game/Screens/SelectV2/BeatmapCarousel.cs
+++ b/osu.Game/Screens/SelectV2/BeatmapCarousel.cs
@@ -70,9 +70,9 @@ protected override void HandleItemDeselected(List<CarouselItem> allItems, Carous
             }
         }
 
-        protected override void HandleItemSelected(List<CarouselItem> allItems, CarouselItem item, Drawable? drawableItem)
+        protected override void HandleItemSelected(List<CarouselItem> allItems, CarouselItem item)
         {
-            base.HandleItemSelected(allItems, item, drawableItem);
+            base.HandleItemSelected(allItems, item);
 
             // Selecting a set isn't valid – let's re-select the first difficulty.
             if (item.Model is BeatmapSetInfo setInfo)
@@ -92,11 +92,12 @@ protected override void HandleItemSelected(List<CarouselItem> allItems, Carousel
             UpdateYPositions(allItems, VisibleHalfHeight, SpacingBetweenPanels);
         }
 
-        protected override void HandleItemActivated(CarouselItem item, Drawable? drawableItem)
+        protected override void HandleItemActivated(CarouselItem item)
         {
-            base.HandleItemActivated(item, drawableItem);
+            base.HandleItemActivated(item);
 
-            if (drawableItem is BeatmapCarouselPanel drawable)
+            // TODO: maybe this should be handled by the panel itself?
+            if (GetMaterialisedDrawableForItem(item) is BeatmapCarouselPanel drawable)
                 drawable.FlashFromActivation();
         }
 
diff --git a/osu.Game/Screens/SelectV2/Carousel.cs b/osu.Game/Screens/SelectV2/Carousel.cs
index 392f1e33dc87..1fade4189b2b 100644
--- a/osu.Game/Screens/SelectV2/Carousel.cs
+++ b/osu.Game/Screens/SelectV2/Carousel.cs
@@ -120,7 +120,7 @@ public void ActivateSelection()
                 return;
             }
 
-            HandleItemActivated(currentSelectionCarouselItem, scroll.Panels.SingleOrDefault(p => ((ICarouselPanel)p).Item == currentSelectionCarouselItem));
+            HandleItemActivated(currentSelectionCarouselItem);
         }
 
         #endregion
@@ -171,6 +171,17 @@ public void ActivateSelection()
         /// <returns>A <see cref="CarouselItem"/> representing the model.</returns>
         protected abstract CarouselItem CreateCarouselItemForModel(T model);
 
+        /// <summary>
+        /// Given a <see cref="CarouselItem"/>, find a drawable representation if it is currently displayed in the carousel.
+        /// </summary>
+        /// <remarks>
+        /// This will only return a drawable if it is "on-screen".
+        /// </remarks>
+        /// <param name="item">The item to find a related drawable representation.</param>
+        /// <returns>The drawable representation if it exists.</returns>
+        protected Drawable? GetMaterialisedDrawableForItem(CarouselItem item) =>
+            scroll.Panels.SingleOrDefault(p => ((ICarouselPanel)p).Item == currentSelectionCarouselItem);
+
         /// <summary>
         /// Called when an item is "activated".
         /// </summary>
@@ -180,22 +191,21 @@ public void ActivateSelection()
         /// - Start gameplay on a beatmap difficulty.
         /// </remarks>
         /// <param name="item">The carousel item which was activated.</param>
-        /// <param name="drawableItem">The drawable representation of the item, if manifested.</param>
-        protected virtual void HandleItemActivated(CarouselItem item, Drawable? drawableItem)
+        protected virtual void HandleItemActivated(CarouselItem item)
         {
         }
 
         /// <summary>
         /// Called when an item is "deselected".
         /// </summary>
-        protected virtual void HandleItemDeselected(List<CarouselItem> carouselItems, CarouselItem carouselItem)
+        protected virtual void HandleItemDeselected(List<CarouselItem> allItems, CarouselItem item)
         {
         }
 
         /// <summary>
         /// Called when an item is "selected".
         /// </summary>
-        protected virtual void HandleItemSelected(List<CarouselItem> allItems, CarouselItem item, Drawable? drawableItem)
+        protected virtual void HandleItemSelected(List<CarouselItem> allItems, CarouselItem item)
         {
         }
 
@@ -458,7 +468,7 @@ private void updateSelection()
                         if (currentSelectionCarouselItem != null)
                             HandleItemDeselected(displayedCarouselItems, currentSelectionCarouselItem);
                         currentSelectionCarouselItem = item;
-                        HandleItemSelected(displayedCarouselItems, item, scroll.Panels.SingleOrDefault(p => ((ICarouselPanel)p).Item == currentSelectionCarouselItem));
+                        HandleItemSelected(displayedCarouselItems, item);
                     }
                 }
             }