Ensures un associed both old parent dialog and new if it was already shownmore-window-fixes

1 files changed, 10 insertions, 2 deletions

diff --git a/Xwt.XamMac/Xwt.Mac/WindowFrameBackend.cs b/Xwt.XamMac/Xwt.Mac/WindowFrameBackend.cs
index f96b4ce7..ae43d353 100644
--- a/Xwt.XamMac/Xwt.Mac/WindowFrameBackend.cs
+++ b/Xwt.XamMac/Xwt.Mac/WindowFrameBackend.cs
@@ -336,8 +336,16 @@ namespace Xwt.Mac
 				Window.StyleMask &= ~NSWindowStyle.Miniaturizable;
 
 			//we try to get the native object from the parameter if not we fallback into the real parent
-			NSWindow nParent = (ApplicationContext.Toolkit.GetNativeWindow(parent) as NSWindow) ?? Window.ParentWindow;
-			if (nParent != Window.ParentWindow) {
+			if (ApplicationContext.Toolkit.GetNativeWindow(parent) is NSWindow nParent && nParent != Window.ParentWindow)
+            {
+				// remove from the previous parent
+				if (Window.ParentWindow != null)
+					Window.ParentWindow.RemoveChildWindow(Window);
+
+				// new parent has any associed window we remove it
+				if (nParent.ParentWindow != null)
+					nParent.ParentWindow.RemoveChildWindow(nParent);
+
 				Window.ParentWindow = nParent;
 			}
 		}