1 CAPI Reference Entries

menu-object

Class

Summary

The classmenu-object is the superclass of all menu objects, and provides functionality for handling generic aspects of menus, menu components and menu items.

Superclasses

callbacks

Subclasses

titled-menu-object

Slots

enabled

Ifnil, the menu object is disabled, and cannot be selected.

popup-callback

Callback before the menu appears.

enabled-function

Returns non-nil if the menu is enabled.

enabled-slot

The object is enabled if the slot is non-nil.

callback

The selection callback for the object.

callback-data-function

A function to return data for the callback.

Accessors

menu-object-enabled menu-popup-callback

Description

When the menu object is about to appear on the screen, the CAPI does the following:

: 1. Thepopup-callback (if there is one) is called with the menu object and it is allowed to make arbitrary changes to that object.
: 2. The enabled function (if there is one) is called with the interface, and it should return non-nil if the menu object is enabled.
: 3. The menu containing the object appears with all of the changes made.

Note thatenabled-slot is a short-hand means of creating anenabled-function which checks the value of a slot in the menu object's interface.

The callbackinitarg is placed in theselection-callback,extend-callback andretract-callback slots unless these are given explicitly, and so will get called when the menu object is selected or deselected. Thecallback-data-function is a function that is called with no arguments and the value it returns is used as the data to the callbacks.

Example

(capi:contain (make-instance
               'capi:menu-item
               :text "Press Me"
               :enabled-function #'(lambda (item)
                                     (eq (random 2)
                                     1))))

See also
: menu
menu-item
menu-component