A CAPI interface.
The generic function
interface-menu-groups is called when an embedded document sets the menu bar of its containing interface. It is called when an embedded object uses the
IOleInPlaceFrame::InsertMenus method to add menus from the interface to its own composite menu, which is used as the menubar while the embedded object is active.
The menu bar for the embedded document includes three groups of menus that are supplied by the container (file-group, view-group, windows-group).
interface-menu-groups is used to define these groups of menus.
interface-menu-groups should return a list of length 3. Each element is a list of menus. In this list, each item is either a menu object, or a cons. When it is a cons, the car is a menu object and the cdr is a string, which overrides the the title of the menu.
CAPI User Guide and Reference Manual (Unix version) - 3 Aug 2017