enhance: use Parent instead of find TextDiffView first before find first ThemedTextDiffPresenter

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/TextDiffView.axaml.cs

@@ -11,6 +11,7 @@
 using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Avalonia.LogicalTree;
 using Avalonia.Media;
 using Avalonia.Threading;
 using Avalonia.VisualTree;
@@ -1405,7 +1406,9 @@ protected override void OnPointerPressed(PointerPressedEventArgs e)
                 return;
 
             var line = Math.Max(1, Math.Min(total, (int)Math.Ceiling(pressedY * total / height)));
-            this.FindAncestorOfType<TextDiffView>()?.ScrollToLine(line);
+            if (this.Parent is Control parent)
+                parent.FindLogicalDescendantOfType<ThemedTextDiffPresenter>()?.ScrollToLine(line);
+
             e.Handled = true;
         }
 
@@ -1458,11 +1461,6 @@ public TextDiffView()
             InitializeComponent();
         }
 
-        public void ScrollToLine(int line)
-        {
-            this.FindDescendantOfType<ThemedTextDiffPresenter>()?.ScrollToLine(line);
-        }
-
         protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
         {
             base.OnPropertyChanged(change);