public void ShowPreferencePanel(Foundation.NSObject sender) { // Is preference controller null? if (preferenceController == null) { preferenceController = new PreferenceController(); Preference prefWindow = preferenceController.Window; nfloat x, y; if (NSApplication.SharedApplication.MainWindow != null) { x = NSApplication.SharedApplication.MainWindow.Frame.X + NSApplication.SharedApplication.MainWindow.Frame.Width + 20; y = NSApplication.SharedApplication.MainWindow.Frame.Y; } else { x = 100; y = 500; } prefWindow.SetFrame(new CGRect(x, y, prefWindow.Frame.Width, prefWindow.Frame.Height), false); } Console.WriteLine("Showing {0}", preferenceController); preferenceController.ShowWindow(this); }