ux: use transparent tab separator pen

Signed-off-by: leo <[email protected]>

Author: love-linger

src/Views/LauncherTabBar.axaml.cs

@@ -5,6 +5,7 @@
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Media;
+using Avalonia.Styling;
 
 namespace SourceGit.Views
 {
@@ -69,7 +70,7 @@ public override void Render(DrawingContext context)
 
             var selectedIdx = LauncherTabsList.SelectedIndex;
             var count = LauncherTabsList.ItemCount;
-            var separatorPen = new Pen(this.FindResource("Brush.FG2") as IBrush);
+            var separatorPen = new Pen(new SolidColorBrush(ActualThemeVariant == ThemeVariant.Dark ? Colors.White : Colors.Black, 0.2));
             var separatorY = (height - 18) * 0.5 + 1;
 
             if (!IsScrollerVisible && selectedIdx > 0)
@@ -152,6 +153,14 @@ public override void Render(DrawingContext context)
             context.DrawGeometry(fill, stroke, geo);
         }
 
+        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+        {
+            base.OnPropertyChanged(change);
+
+            if (change.Property.Name == nameof(ActualThemeVariant))
+                InvalidateVisual();
+        }
+
         private void ScrollTabs(object _, PointerWheelEventArgs e)
         {
             if (!e.KeyModifiers.HasFlag(KeyModifiers.Shift))