fix: hightlight not working the first time clicking the first line (#448)

Author: love-linger

src/Views/Blame.axaml.cs

@@ -233,6 +233,7 @@ public Models.BlameData BlameData
             TextArea.LeftMargins.Add(new VerticalSeperatorMargin(this));
             TextArea.LeftMargins.Add(new CommitInfoMargin(this) { Margin = new Thickness(8, 0) });
             TextArea.LeftMargins.Add(new VerticalSeperatorMargin(this));
+            TextArea.Caret.PositionChanged += OnTextAreaCaretPositionChanged;
             TextArea.LayoutUpdated += OnTextAreaLayoutUpdated;
             TextArea.PointerWheelChanged += OnTextAreaPointerWheelChanged;
             TextArea.TextView.ContextRequested += OnTextViewContextRequested;
@@ -279,7 +280,9 @@ protected override void OnUnloaded(RoutedEventArgs e)
             base.OnUnloaded(e);
 
             TextArea.LeftMargins.Clear();
+            TextArea.Caret.PositionChanged -= OnTextAreaCaretPositionChanged;
             TextArea.LayoutUpdated -= OnTextAreaLayoutUpdated;
+            TextArea.PointerWheelChanged -= OnTextAreaPointerWheelChanged;
             TextArea.TextView.ContextRequested -= OnTextViewContextRequested;
             TextArea.TextView.VisualLinesChanged -= OnTextViewVisualLinesChanged;
 
@@ -312,7 +315,7 @@ protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs chang
             }
         }
 
-        private void OnTextAreaLayoutUpdated(object sender, EventArgs e)
+        private void OnTextAreaCaretPositionChanged(object sender, EventArgs e)
         {
             if (!TextArea.IsFocused)
                 return;
@@ -325,6 +328,12 @@ private void OnTextAreaLayoutUpdated(object sender, EventArgs e)
             InvalidateVisual();
         }
 
+        private void OnTextAreaLayoutUpdated(object sender, EventArgs e)
+        {
+            if (TextArea.IsFocused)
+                InvalidateVisual();
+        }
+
         private void OnTextAreaPointerWheelChanged(object sender, PointerWheelEventArgs e)
         {
             if (!TextArea.IsFocused && !string.IsNullOrEmpty(_highlight))