A widget used for holding items in menus.
The GtkMenuItem is the fundamental building block
of all menus. These widgets are responsible for holding valid children
that will make up the menu. Their function is to correctly handle
highlighting, alignment, events and the addition of sub-menus.
Since this widget derives itself from GtkBin, it
can hold any valid child widget, although only a few may aid in the
creation of menus.
Emitted when the menu item is activated.
Emitted when the menu item is activated and has a submenu.
Emitted when the size allocation is changed.
Emitted when a size change request is made.