CQ: set drag area in TabBar

Author: XTorLukas

src/Files.App/UserControls/TabBar/TabBar.xaml.cs

@@ -67,8 +67,6 @@ public GridLength TitleBarWidth
 
 		public static event EventHandler<TabBarItem?>? SelectedTabItemChanged;
 
-		public event EventHandler<SizeChangedEventArgs>? TabControlAreaSizeChanged;
-
 		// Constructor
 
 		public TabBar()
@@ -96,9 +94,6 @@ public TabBar()
 			};
 		}
 
-		private void BaseTabBar_Loaded(object sender, RoutedEventArgs e)
-			=> MainWindow.Instance.AppWindow.Changed += (_, _) => MainWindow.Instance.RaiseSetTitleBarDragRegion(SetTitleBarDragRegion);
-
 		private void TabView_TabItemsChanged(TabView sender, Windows.Foundation.Collections.IVectorChangedEventArgs args)
 		{
 			if (args.CollectionChange == Windows.Foundation.Collections.CollectionChange.ItemRemoved)
@@ -383,17 +378,9 @@ private void TabViewItem_Loaded(object sender, RoutedEventArgs e)
 		}
 
 		private void DragAreaRectangle_Loaded(object sender, RoutedEventArgs e)
-		{
-			var width = HorizontalTabView.ActualWidth - TabBarAddNewTabButton.Width - TitleBarWidth.Value;
-			var height = HorizontalTabView.ActualHeight;
-			HorizontalTabView.Measure(new(width >= 0 ? width : 0, height >= 0 ? height : 0));
-
-			MainWindow.Instance.RaiseSetTitleBarDragRegion(SetTitleBarDragRegion);
-			SizeChanged += (s, e) => TabControlAreaSizeChanged?.Invoke(s, e);
-			DragArea.SizeChanged += (s, e) => TabControlAreaSizeChanged?.Invoke(s, e);
-		}
+			=> HorizontalTabView.Measure(new(HorizontalTabView.ActualWidth - TabBarAddNewTabButton.Width - TitleBarWidth.Value, HorizontalTabView.ActualHeight));
 
-		private int SetTitleBarDragRegion(InputNonClientPointerSource source, SizeInt32 size, double scaleFactor, Func<UIElement, RectInt32?, RectInt32> getScaledRect)
+		public int SetTitleBarDragRegion(InputNonClientPointerSource source, SizeInt32 size, double scaleFactor, Func<UIElement, RectInt32?, RectInt32> getScaledRect)
 		{
 			var height = (int)ActualHeight;
 			var width = (int)(ActualWidth - DragArea.ActualWidth);

src/Files.App/Views/MainPage.xaml.cs

@@ -125,10 +125,14 @@ private void UserSettingsService_OnSettingChangedEvent(object? sender, SettingCh
 		}
 
 		private void HorizontalMultitaskingControl_Loaded(object sender, RoutedEventArgs e)
-			=> TabControl.TabControlAreaSizeChanged += TabControlArea_SizeChanged;
+		{
+			TabControl.SizeChanged += TabControlArea_SizeChanged;
+			TabControl.DragArea.SizeChanged += TabControlArea_SizeChanged;
+		}
 
 		private void TabControlArea_SizeChanged(object sender, SizeChangedEventArgs e)
 		{
+			MainWindow.Instance.RaiseSetTitleBarDragRegion(TabControl.SetTitleBarDragRegion);
 			if (ViewModel.MultitaskingControl is not TabBar)
 			{
 				ViewModel.MultitaskingControl = TabControl;
@@ -274,6 +278,8 @@ protected override void OnLostFocus(RoutedEventArgs e)
 
 		private void Page_Loaded(object sender, RoutedEventArgs e)
 		{
+			MainWindow.Instance.AppWindow.Changed += (_, _) => MainWindow.Instance.RaiseSetTitleBarDragRegion(TabControl.SetTitleBarDragRegion);
+
 			// Defers the status bar loading until after the page has loaded to improve startup perf
 			FindName(nameof(StatusBar));
 			FindName(nameof(InnerNavigationToolbar));