gtk:check-menu-item-active (object)

object -- a gtk:check-menu-item widget
is-active -- a boolean value indicating whether the check box is active

Accessor of the active slot of the gtk:check-menu-item class. The gtk:check-menu-item-active returns whether the check menu item is active. The (setf gtk:check-menu-item-active) function sets the active state of the menu item's check box.