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:
