| menu-bar% : class? | ||
superclass: object%  | ||
  | 
A menu-bar% object is created for a particular
 frame% object. A frame can have at most one menu bar;
 an exn:fail:contract exception is raised when a new menu bar is created for a frame that
 already has a menu bar.
  | ||||||||||||
| → (is-a?/c menu-bar%) | ||||||||||||
| parent : (or/c (is-a?/c frame%) (one-of/c 'root)) | ||||||||||||
  | 
Creates a menu bar in the specified frame. The menu bar is initially
 empty. If 'root is supplied as parent, the
 menu bar becomes active only when no other frames are shown. A
 'root parent is allowed only when
 current-eventspace-has-menu-root? returns #t, and
 only if no such menu bar has been created before, otherwise
 an exn:fail:contract exception is raised.
The demand-callback procedure is called by the default on-demand method with the object itself.
Enables or disables the menu bar (i.e., all of its menus).  Each
 menu’s is-enabled? method returns
 #f only if the menu is specifically disabled (in addition to
 the menu bar).
Returns the menu bar’s frame.
| (send a-menu-bar is-enabled?) → boolean? | 
Returns #t if the menu bar is enabled, #f otherwise.