There are four basic objects in the CAPI model: interfaces , menus , panes and layouts .
Everything that the CAPI displays is contained within an interface (an instance of the class
). When an interface is displayed a window appears containing all the menus and panes you have specified for it.
An interface can contain a number of menus which are collected together on a menu bar. Each menu on the menu bar can contain menu items or other menus. Items can be grouped together visually and functionally inside
. Menus, menu items, and menu components are, respectively, instances of the classes
Panes are window objects such as buttons and lists. They can be positioned anywhere in an interface. The CAPI provides many different kinds of pane class, among them
The positions of panes are controlled by a layout, which allows objects to be collected together and positioned either regularly (with instances of the classes
) or arbitrarily using a
. Layouts themselves can be laid out by other layouts -- for example, a row of buttons can be laid out above a list by placing both the
and the list in a
CAPI User Guide (Macintosh version) - 30 Aug 2011