A Boolean value that indicates the behavior of the button’s menu.
- macOS 10.0+
When the value of this property is
true, the menu behaves like a pull-down menu; when the value is
false, it behaves like a pop-up menu. If you use this property to change the menu type from a pop-up menu to a pull-down menu, and the cell alters the state of its selected items, the state of the currently selected item is set to
off before the menu type is changed.