A Boolean value indicating whether the button displays a pull-down or pop-up menu.
- macOS 10.0+
When the value of this property is
YES, the button displays a pull-down menu; otherwise, it displays a pop-up menu. This property does not affect the contents of the menu; it affects only the style of the menu.
When changing the menu type to a pull-down menu, if the menu was a pop-up menu and the cell alters the state of its selected items, this method sets the state of the currently selected item to
NSState before changing the menu type.