Remove IndexOf overhead

peppy · Jan 22, 2025 · 0a15bbd · 0a15bbd
1 parent ee7972b
commit 0a15bbd
Showing 1 changed file with 25 additions and 17 deletions.
diff --git a/osu.Game/Screens/SelectV2/Carousel.cs b/osu.Game/Screens/SelectV2/Carousel.cs
@@ -332,33 +332,43 @@ private bool selectNext(int direction, bool isGroupSelection)
             if (displayedCarouselItems == null || displayedCarouselItems.Count == 0)
                 return false;
 
-            CarouselItem? originalItem = currentKeyboardSelection.CarouselItem;
+            CarouselItem? originalSelection = currentKeyboardSelection.CarouselItem;
+            int currentSelectionIndex = currentKeyboardSelection.Index ?? -1;
 
             // To keep things simple, let's first handle the cases where there's no selection yet.
             // Once we've confirmed that the first or last isn't valid, we can handle everything
             // using the same process.
-            if (originalItem == null)
+            if (originalSelection == null || currentSelectionIndex < 0)
             {
-                originalItem = direction > 0
-                    ? displayedCarouselItems.First()
-                    : displayedCarouselItems.Last();
+                if (direction > 0)
+                {
+                    originalSelection = displayedCarouselItems.First();
+                    currentSelectionIndex = 0;
+                }
+                else
+                {
+                    originalSelection = displayedCarouselItems.Last();
+                    currentSelectionIndex = displayedCarouselItems.Count - 1;
+                }
 
-                if (isValidItem(originalItem))
+                if (isValidItem(originalSelection))
                 {
-                    performSelection(originalItem);
+                    performSelection(originalSelection);
                     return true;
                 }
             }
 
+            Debug.Assert(originalSelection != null);
+            Debug.Assert(currentSelectionIndex >= 0);
+
             // As a special case, if the user has a different keyboard selection and requests
             // group selection, first transfer the keyboard selection.
-            if (isGroupSelection && currentSelection.CarouselItem != originalItem)
+            if (isGroupSelection && currentSelection.CarouselItem != originalSelection)
             {
-                setSelection(originalItem.Model);
+                setSelection(originalSelection.Model);
                 return true;
             }
 
-            int currentSelectionIndex = displayedCarouselItems.IndexOf(originalItem);
             int newSelectionIndex = currentSelectionIndex;
 
             // As a second special case, if we're group selecting backwards and the current selection isn't
@@ -369,17 +379,15 @@ private bool selectNext(int direction, bool isGroupSelection)
                     newSelectionIndex--;
             }
 
-            Debug.Assert(currentSelectionIndex >= 0);
-
             CarouselItem newItem;
 
-            while ((newItem = selectNextPanel()) != originalItem)
+            while ((newItem = selectNextPanel()) != originalSelection)
             {
                 if (isValidItem(newItem))
                     break;
             }
 
-            if (newItem == originalItem)
+            if (newItem == originalSelection)
                 return false;
 
             performSelection(newItem);
@@ -480,7 +488,7 @@ private void updateSelection()
                 {
                     double? previousYPosition = currentKeyboardSelection?.YPosition;
 
-                    currentKeyboardSelection = new Selection(item.Model, item, item.CarouselYPosition);
+                    currentKeyboardSelection = new Selection(item.Model, item, item.CarouselYPosition, i);
 
                     if (previousYPosition != null && previousYPosition != item.CarouselYPosition)
                     {
@@ -490,7 +498,7 @@ private void updateSelection()
                 }
 
                 if (isSelected)
-                    currentSelection = new Selection(item.Model, item, item.CarouselYPosition);
+                    currentSelection = new Selection(item.Model, item, item.CarouselYPosition, i);
 
                 item.CarouselYPosition = yPos;
 
@@ -666,7 +674,7 @@ private static void expirePanelImmediately(Drawable panel)
 
         #region Internal helper classes
 
-        private record Selection(object? Model = null, CarouselItem? CarouselItem = null, double? YPosition = null);
+        private record Selection(object? Model = null, CarouselItem? CarouselItem = null, double? YPosition = null, int? Index = null);
 
         private record DisplayRange(int First, int Last);