Follow lazer to refactor the scale change.

see:
https://github.com/ppy/osu/pull/26643/files

Author: andy840119

osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Content/Components/Lyrics/Blueprints/RubyBlueprintContainer.cs

@@ -7,6 +7,7 @@
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Primitives;
 using osu.Framework.Logging;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Karaoke.Edit.ChangeHandlers.Lyrics;
@@ -45,18 +46,9 @@ protected partial class RubyTagSelectionHandler : LyricPropertySelectionHandler<
         [Resolved]
         private IPreviewLyricPositionProvider previewLyricPositionProvider { get; set; } = null!;
 
-        private float deltaScaleSize;
-
-        protected override void OnSelectionChanged()
-        {
-            base.OnSelectionChanged();
-
-            // only select one ruby tag can let user drag to change start and end index.
-            ScaleHandler.CanScaleX.Value = SelectedItems.Count == 1;
-
-            // should clear delta size before change start/end index.
-            deltaScaleSize = 0;
-        }
+        // need to implement this because blueprint container support change the x scale.
+        public override SelectionScaleHandler CreateScaleHandler()
+            => new RubyTagSelectionScaleHandler();
 
         #region User Input Handling
 
@@ -96,41 +88,126 @@ void setRubyTagShifting(IEnumerable<RubyTag> rubyTags, int offset)
                 => rubyTagsChangeHandler.ShiftingIndex(rubyTags, offset);
         }
 
-        public override bool HandleScale(Vector2 scale, Anchor anchor)
+        private int? calculateNewIndex(RubyTag rubyTag, float offset, Anchor anchor)
         {
-            deltaScaleSize += scale.X;
+            // get real left-side and right-side position
+            var rect = previewLyricPositionProvider.GetRubyTagByPosition(rubyTag);
 
-            // this feature only works if only select one ruby tag.
-            var selectedRubyTag = SelectedItems.FirstOrDefault();
-            if (selectedRubyTag == null)
-                return false;
+            // todo: need to think about how to handle the case if the text-tag already out of the range of the text.
+            if (rect == null)
+                throw new InvalidOperationException($"{nameof(rubyTag)} not in the range of the text.");
 
             switch (anchor)
             {
                 case Anchor.CentreLeft:
-                    int? newStartIndex = calculateNewIndex(selectedRubyTag, deltaScaleSize, anchor);
-                    if (newStartIndex == null || !RubyTagUtils.ValidNewStartIndex(selectedRubyTag, newStartIndex.Value))
-                        return false;
-
-                    setRubyTagIndex(selectedRubyTag, newStartIndex, null);
-                    return true;
+                    var leftPosition = rect.Value.BottomLeft + new Vector2(offset, 0);
+                    return previewLyricPositionProvider.GetCharIndexByPosition(leftPosition);
 
                 case Anchor.CentreRight:
-                    int? newEndIndex = calculateNewIndex(selectedRubyTag, deltaScaleSize, anchor);
-                    if (newEndIndex == null || !RubyTagUtils.ValidNewEndIndex(selectedRubyTag, newEndIndex.Value))
-                        return false;
-
-                    setRubyTagIndex(selectedRubyTag, null, newEndIndex);
-                    return true;
+                    var rightPosition = rect.Value.BottomRight + new Vector2(offset, 0);
+                    return previewLyricPositionProvider.GetCharIndexByPosition(rightPosition);
 
                 default:
-                    return false;
+                    throw new ArgumentOutOfRangeException(nameof(anchor));
             }
+        }
+
+        #endregion
+
+        protected override void DeleteItems(IEnumerable<RubyTag> items)
+            => rubyTagsChangeHandler.RemoveRange(items);
+    }
+
+    private partial class RubyTagSelectionScaleHandler : SelectionScaleHandler
+    {
+        [Resolved]
+        private IPreviewLyricPositionProvider previewLyricPositionProvider { get; set; } = null!;
+
+        [Resolved]
+        private ILyricRubyTagsChangeHandler rubyTagsChangeHandler { get; set; } = null!;
+
+        private BindableList<RubyTag> selectedItems { get; } = new();
+
+        [BackgroundDependencyLoader]
+        private void load(IEditRubyModeState editRubyModeState)
+        {
+            selectedItems.BindTo(editRubyModeState.SelectedItems);
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            selectedItems.CollectionChanged += (_, __) => updateState();
+            updateState();
+        }
+
+        private void updateState()
+        {
+            // only select one ruby tag can let user drag to change start and end index.
+            CanScaleX.Value = selectedItems.Count == 1;
+        }
+
+        public override void Begin()
+        {
+            base.Begin();
+
+            var selectedItemsRect = selectedItems
+                                    .Select(x => previewLyricPositionProvider.GetRubyTagByPosition(x))
+                                    .Where(rect => rect != null)
+                                    .OfType<RectangleF>();
+
+            var rect = selectedItemsRect.Aggregate(new RectangleF(), RectangleF.Union);
+
+            // Update the quad
+            OriginalSurroundingQuad = Quad.FromRectangle(rect);
+        }
+
+        public override void Update(Vector2 scale, Vector2? origin = null, Axes adjustAxis = Axes.Both, float axisRotation = 0)
+        {
+            // this feature only works if only select one ruby tag.
+            var selectedRubyTag = selectedItems.FirstOrDefault();
+            if (selectedRubyTag == null)
+                return;
+
+            if (adjustAxis != Axes.X)
+                throw new InvalidOperationException("Only can adjust x axes");
+
+            if (origin == null || OriginalSurroundingQuad == null)
+                return;
+
+            float offset = OriginalSurroundingQuad.Value.Width * (scale.X - 1);
+
+            if (origin.Value.X > OriginalSurroundingQuad.Value.Centre.X)
+            {
+                int? newStartIndex = calculateNewIndex(selectedRubyTag, -offset, Anchor.CentreLeft);
+                if (newStartIndex == null || !RubyTagUtils.ValidNewStartIndex(selectedRubyTag, newStartIndex.Value))
+                    return;
+
+                setRubyTagIndex(selectedRubyTag, newStartIndex, null);
+            }
+            else
+            {
+                int? newEndIndex = calculateNewIndex(selectedRubyTag, offset, Anchor.CentreRight);
+                if (newEndIndex == null || !RubyTagUtils.ValidNewEndIndex(selectedRubyTag, newEndIndex.Value))
+                    return;
+
+                setRubyTagIndex(selectedRubyTag, null, newEndIndex);
+            }
+
+            return;
 
             void setRubyTagIndex(RubyTag rubyTag, int? startPosition, int? endPosition)
                 => rubyTagsChangeHandler.SetIndex(rubyTag, startPosition, endPosition);
         }
 
+        public override void Commit()
+        {
+            base.Commit();
+
+            OriginalSurroundingQuad = null;
+        }
+
         private int? calculateNewIndex(RubyTag rubyTag, float offset, Anchor anchor)
         {
             // get real left-side and right-side position
@@ -154,10 +231,5 @@ void setRubyTagIndex(RubyTag rubyTag, int? startPosition, int? endPosition)
                     throw new ArgumentOutOfRangeException(nameof(anchor));
             }
         }
-
-        #endregion
-
-        protected override void DeleteItems(IEnumerable<RubyTag> items)
-            => rubyTagsChangeHandler.RemoveRange(items);
     }
 }