menu_driver(3X)

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. 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 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 drive asumes 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 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(3X), menus(3x).

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.

AUTHORS
Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond.