From 23913b726a26839f5f33871743e18762d35b6e7b Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 11 Nov 2024 17:41:10 +0900
Subject: [PATCH 1/2] Allow customising `ScrollContainer`'s scrollbar mapping

For use in osu!.
---
 osu.Framework/Graphics/Containers/ScrollContainer.cs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/osu.Framework/Graphics/Containers/ScrollContainer.cs b/osu.Framework/Graphics/Containers/ScrollContainer.cs
index eae4c968ee..e838aa683f 100644
--- a/osu.Framework/Graphics/Containers/ScrollContainer.cs
+++ b/osu.Framework/Graphics/Containers/ScrollContainer.cs
@@ -409,7 +409,7 @@ protected override bool OnScroll(ScrollEvent e)
             return true;
         }
 
-        private void onScrollbarMovement(float value) => OnUserScroll(Clamp(fromScrollbarPosition(value)), false);
+        private void onScrollbarMovement(float value) => OnUserScroll(Clamp(FromScrollbarPosition(value)), false);
 
         /// <summary>
         /// Immediately offsets the current and target scroll position.
@@ -576,12 +576,12 @@ protected override void UpdateAfterChildren()
 
             if (ScrollDirection == Direction.Horizontal)
             {
-                Scrollbar.X = toScrollbarPosition(Current);
+                Scrollbar.X = ToScrollbarPosition(Current);
                 ScrollContent.X = -Current + ScrollableExtent * ScrollContent.RelativeAnchorPosition.X;
             }
             else
             {
-                Scrollbar.Y = toScrollbarPosition(Current);
+                Scrollbar.Y = ToScrollbarPosition(Current);
                 ScrollContent.Y = -Current + ScrollableExtent * ScrollContent.RelativeAnchorPosition.Y;
             }
         }
@@ -591,7 +591,7 @@ protected override void UpdateAfterChildren()
         /// </summary>
         /// <param name="scrollPosition">The absolute scroll position (e.g. <see cref="Current"/>).</param>
         /// <returns>The scrollbar position.</returns>
-        private float toScrollbarPosition(float scrollPosition)
+        protected virtual float ToScrollbarPosition(float scrollPosition)
         {
             if (Precision.AlmostEquals(0, ScrollableExtent))
                 return 0;
@@ -604,7 +604,7 @@ private float toScrollbarPosition(float scrollPosition)
         /// </summary>
         /// <param name="scrollbarPosition">The scrollbar position.</param>
         /// <returns>The absolute scroll position.</returns>
-        private float fromScrollbarPosition(float scrollbarPosition)
+        protected virtual float FromScrollbarPosition(float scrollbarPosition)
         {
             if (Precision.AlmostEquals(0, ScrollbarMovementExtent))
                 return 0;

From 3bab44a584201ace24508a6d6a2177412110ba7f Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 11 Nov 2024 19:08:52 +0900
Subject: [PATCH 2/2] Make `ScrollbarMovementExtent` `protected`

---
 osu.Framework/Graphics/Containers/ScrollContainer.cs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/osu.Framework/Graphics/Containers/ScrollContainer.cs b/osu.Framework/Graphics/Containers/ScrollContainer.cs
index e838aa683f..dbd89fed1c 100644
--- a/osu.Framework/Graphics/Containers/ScrollContainer.cs
+++ b/osu.Framework/Graphics/Containers/ScrollContainer.cs
@@ -136,7 +136,10 @@ public bool ScrollbarOverlapsContent
         /// <summary>
         /// The maximum distance that the scrollbar can move in the scroll direction.
         /// </summary>
-        public float ScrollbarMovementExtent => Math.Max(DisplayableContent - Scrollbar.DrawSize[ScrollDim], 0);
+        /// <remarks>
+        /// May not be accurate to actual display of scrollbar if <see cref="ToScrollbarPosition"/> or <see cref="FromScrollbarPosition"/> are overridden.
+        /// </remarks>
+        protected float ScrollbarMovementExtent => Math.Max(DisplayableContent - Scrollbar.DrawSize[ScrollDim], 0);
 
         /// <summary>
         /// Clamp a value to the available scroll range.