menu_driver()

NAME

menu_driver() - command-processing loop of the menu system

SYNOPSIS 

#include <menu.h>


int menu_driver(MENU *menu, int c);

DESCRIPTION

Once a menu has been posted (displayed), you should funnel input events to it through menu_driver(3). This routine has two major input cases; either the input is a menu navigation request or it's a printable ASCII character. The menu driver requests are as follows:

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 down a page.
REQ_SCR_UPAGE Scroll up 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/deselect an item.
REQ_CLEAR_PATTERN Clear the menu pattern buffer.
REQ_BACK_PATTERN Delete the previous character from the pattern buffer.
REQ_NEXT_MATCH Move to the next item matching the pattern match.
REQ_PREV_MATCH Move to the previous item matching the pattern match.

If the second argument is a printable ASCII character, the code appends it to the pattern buffer and attempts to move to the next item matching the new pattern. If there is no such match, menu_driver(3) returns E_NO_MATCH and deletes the appended character from the buffer.

If the second argument is one of the above pre-defined requests, the corresponding action is performed.

If the second argument is neither printable ASCII nor one of the above pre-defined menu requests, the driver assumes it is an application-specific command and returns E_UNKNOWN_COMMAND. Application-defined commands should be defined relative to MAX_COMMAND, the maximum value of these pre-defined requests.

RETURN VALUE

menu_driver(3) return one of the following error codes:

E_OK
The routine succeeded.
E_SYSTEM_ERROR
System error occurred (see errno
E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
E_BAD_STATE
Routine was called from an initialization or termination function.
E_NOT_POSTED
The menu has not been posted.
E_UNKNOWN_COMMAND
The menu driver code saw an unknown request code.
E_NO_MATCH
Character failed to match.
E_REQUEST_DENIED
The menu driver could not process the request.

SEE ALSO

curses(3)

menus(3).

NOTES

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

PORTABILITY

These routines emulate the System V menu library. They were not supported on Version 7 or BSD versions.