menu_hook(3X) | menu_hook(3X) |
NAME
menu_hook - set hooks for automatic invocation by applicationsSYNOPSIS
#include <menu.h>DESCRIPTION
These functions make it possible to set hook functions to be called at various points in the automatic processing of input event codes by menu_driver.The function set_item_init sets a hook to be called at menu-post time and each time the selected item changes (after the change). item_init returns the current item init hook, if any ( NULL if there is no such hook).
The function set_item_term sets a hook to be called at menu-unpost time and each time the selected item changes (before the change). item_term returns the current item term hook, if any ( NULL if there is no such hook).
The function set_menu_init sets a hook to be called at menu-post time and just after the top row on the menu changes once it is posted. menu_init returns the current menu init hook, if any ( NULL if there is no such hook).
The function set_menu_term sets a hook to be called at menu-unpost time and just before the top row on the menu changes once it is posted. menu_term returns the current menu term hook, if any ( NULL if there is no such hook).
RETURN VALUE
Routines that return pointers return NULL on error. Other routines return one of the following:- E_OK
- The routine succeeded.
- E_SYSTEM_ERROR
- System error occurred (see errno).