MenuButton.setPopup
void setPopup(gtk.widget.Widget menu = null)Sets the #GtkMenu that will be popped up when the menu_button is clicked, or null to dissociate any existing menu and disable the button.
If #GtkMenuButton:menu-model or #GtkMenuButton:popover are set, those objects are dissociated from the menu_button, and those properties are set to null.
Parameters
menu | a #GtkMenu, or null to unset and disable the button |