feat: drag MessageBox.

src/Ursa/Controls/MessageBox/MessageBoxWindow.cs

@@ -31,7 +31,8 @@ public class MessageBoxWindow: Window
 
     protected override Type StyleKeyOverride => typeof(MessageBoxWindow);
 
-    public static readonly StyledProperty<MessageBoxIcon> MessageIconProperty = AvaloniaProperty.Register<MessageBoxWindow, MessageBoxIcon>(
+    public static readonly StyledProperty<MessageBoxIcon> MessageIconProperty =
+        AvaloniaProperty.Register<MessageBoxWindow, MessageBoxIcon>(
             nameof(MessageIcon));
 
     public MessageBoxIcon MessageIcon
@@ -57,22 +58,27 @@ public class MessageBoxWindow: Window
         {
             _closeButton.Click -= OnCloseButtonClick;
         }
+
         if (_yesButton != null)
         {
             _yesButton.Click -= OnYesButtonClick;
         }
+
         if (_noButton != null)
         {
             _noButton.Click -= OnNoButtonClick;
         }
+
         if (_okButton != null)
         {
             _okButton.Click -= OnOKButtonClick;
         }
+
         if (_cancelButton != null)
         {
             _cancelButton.Click -= OnCancelButtonClick;
         }
+
         _yesButton = e.NameScope.Find<Button>(PART_YesButton);
         _noButton = e.NameScope.Find<Button>(PART_NoButton);
         _okButton = e.NameScope.Find<Button>(PART_OKButton);
@@ -82,22 +88,27 @@ public class MessageBoxWindow: Window
         {
             _closeButton.Click += OnCloseButtonClick;
         }
+
         if (_yesButton is not null)
         {
             _yesButton.Click += OnYesButtonClick;
         }
+
         if (_noButton is not null)
         {
             _noButton.Click += OnNoButtonClick;
         }
+
         if (_okButton is not null)
         {
             _okButton.Click += OnOKButtonClick;
         }
+
         if (_cancelButton is not null)
         {
             _cancelButton.Click += OnCancelButtonClick;
         }
+
         SetButtonVisibility();
     }
 
@@ -143,6 +154,7 @@ public class MessageBoxWindow: Window
         {
             Close(MessageBoxResult.OK);
         }
+
         Close(MessageBoxResult.Cancel);
     }
 
@@ -174,4 +186,12 @@ public class MessageBoxWindow: Window
             Close(MessageBoxResult.OK);
         }
     }
+
+    protected override void OnPointerPressed(PointerPressedEventArgs e)
+    {
+        if (TopLevel.GetTopLevel(this) is Window toplevel)
+        {
+            toplevel.BeginMoveDrag(e);
+        }
+    }
 }