The menu property of type gtk:menu-tool-button (Read / Write) The dropdown menu.
Details
The gtk:menu-tool-button widget is a gtk:tool-item that
contains a button and a small additional button with an arrow.
When clicked, the arrow button pops up a dropdown menu.
The gtk:menu-tool-button implementation of the gtk:buildable
interface supports adding a menu by specifying "menu" as the "type" attribute of a <child> element.
The signal is emitted before the menu is shown. It can be used to populate the menu on demand, using the gtk:menu-tool-button-menu function.
Note that even if you populate the menu dynamically in this way, you must set an empty menu on the gtk:menu-tool-button widget beforehand,
since the arrow is made insensitive if the menu is not set.