NAME

menu_driver - command processor for the menus subsystem

SYNOPSIS

#include <menu.h>

int menu_driver(MENU *menu, int c);

DESCRIPTION

menu_driver is the workhorse of the menus subsystem. It checks to determine whether the character c is a menu request or data. If c is a request, the menu driver executes the request and reports the result. If c is data (a printable ASCII character), it enters the data into the pattern buffer and tries to find a matching item. If no match is found, the menu driver deletes the character from the pattern buffer and returns E_NO_MATCH. If the character is not recognized, the menu driver assumes it is an application-defined command and returns E_UNKNOWN_COMMAND.

Menu driver requests:
REQ_LEFT_ITEM     Move left to an item.
REQ_RIGHT_ITEM    Move right to an item.
REQ_UP_ITEM       Move up to an item.
REQ_DOWN_ITEM     Move down to an item.

REQ_SCR_ULINE     Scroll up a line.
REQ_SCR_DLINE     Scroll down a line.
REQ_SCR_DPAGE     Scroll up a page.
REQ_SCR_UPAGE     Scroll down a page.
REQ_FIRST_ITEM    Move to the first item.
REQ_LAST_ITEM     Move to the last item.
REQ_NEXT_ITEM     Move to the next item.
REQ_PREV_ITEM     Move to the previous item.

REQ_TOGGLE_ITEM   Select/de-select an item.
REQ_CLEAR_PATTERN Clear the menu pattern buffer.
REQ_BACK_PATTERN  Delete the previous character from pattern buffer.
REQ_NEXT_MATCH    Move the next matching item.
REQ_PREV_MATCH    Move to the previous matching item.

RETURN VALUE

menu_driver returns one of the following:
E_OK              - The routine returned successfully.
E_SYSTEM_ERROR    - System error.
E_BAD_ARGUMENT    - An incorrect argument was passed to the routine.
E_BAD_STATE       - The routine was called from an initialization or
                    termination function.
E_NOT_POSTED      - The menu has not been posted.

E_UNKNOWN_COMMAND - An  unknown  request  was  passed  to  the  menu
                    driver.
E_NO_MATCH        - The character failed to match.
E_NOT_SELECTABLE  - The item cannot be selected.
E_REQUEST_DENIED  - The menu driver could not process the request.

NOTES

Application defined commands should be defined relative to (greater than) MAX_COMMAND, the maximum value of a request listed above.

The header file <menu.h> automatically includes the header files <eti.h> and <curses.h>.

SEE ALSO

curses(3X), menus(3X).