center()
Sets the window’s location to the center of the screen.
Declaration
func center()Discussion
The window is placed exactly in the center horizontally and somewhat above center vertically. Such a placement carries a certain visual immediacy and importance. This method doesn’t put the window onscreen, however; use makeKeyAndOrderFront(_:) to do that.
You typically use this method to place a window—most likely an alert dialog—where the user can’t miss it. This method is invoked automatically when a panel is placed on the screen by the runModal(for:) method of the NSApplication class.