MENUS(3)

NAME
menus - menu library

LIBRARY
libmenu

SYNOPSIS
#include <menu.h>

DESCRIPTION
The menus library provides a terminal independent menu system using the curses(3) library. Before using the menus functions the terminal must be set up by curses(3) using the initscr() function or similar. Programs using menus functions must be linked with the curses(3) library.

The menus library provides facilities for defining menu items, placing a menu on the terminal screen, assign pre- and post-change operations and setting the attributes of both the menu and its items.

  Defining default attributes for menus and items
The menus library allows any settable attribute or option of both the menu and item objects to be defined such that any new menu or item automatically inherits the value as default. Setting the default value will not affect any item or menu that has already been created but will be applied to subsequent objects. To set the default attribute or option the set routine is passed a NULL pointer in the item or menu parameter when calling the set routine. The current default value can be retrieved by calling the get routine with a NULL pointer for the item or menu parameter.

function name
    manual page name
current_item
    menu_item_current(3)
free_item
    menu_item_new(3)
free_menu
    menu_new(3)
item_count
    menu_items(3)
item_description
    menu_item_name(3)
item_index
    menu_item_current(3)
item_init
    menu_hook(3)
item_name
    menu_item_name(3)
item_opts
    menu_item_opts(3)
item_opts_off
    menu_item_opts(3)
item_opts_on
    menu_item_opts(3)
item_selected
    menu_item_value(3)
item_term
    menu_hook(3)
item_userptr
    menu_item_userptr(3)
item_value
    menu_item_value(3)
item_visible
    menu_item_visible(3)
menu_back
    menu_attributes(3)
menu_driver
    menu_driver(3)
menu_fore
    menu_attributes(3)
menu_format
    menu_format(3)
menu_grey
    menu_attributes(3)
menu_init
    menu_hook(3)
menu_items
    menu_items(3)
menu_mark
    menu_mark(3)
menu_opts
    menu_opts(3)
menu_opts_off
    menu_opts(3)
menu_opts_on
    menu_opts(3)
menu_pad
    menu_attributes(3)
menu_pattern
    menu_pattern(3)
menu_sub
    menu_win(3)
menu_term
    menu_hook(3)
menu_unmark
    menu_mark(3)
menu_userptr
    menu_userptr(3)
men_win
    menu_win(3)
new_item
    menu_item_new(3)
new_menu
    menu_new(3)
pos_menu_cursor
    menu_cursor(3)
post_menu
    menu_post(3)
scale_menu
    menu_win(3)
set_current_item
    menu_item_current(3)
set_item_init
    menu_hook(3)
set_item_opts
    menu_item_opts(3)
set_item_term
    menu_hook(3)
set_item_userptr
    menu_item_userptr(3)
set_item_value
    menu_item_value(3)
set_menu_back
    menu_attributes(3)
set_menu_fore
    menu_attributes(3)
set_menu_format
    menu_format(3)
set_menu_grey
    menu_attributes(3)
set_menu_init
    menu_hook(3)
set_menu_items
    menu_items(3)
set_menu_mark
    menu_mark(3)
set_menu_opts
    menu_opts(3)
set_menu_pad
    menu_attributes(3)
set_menu_pattern
    menu_pattern(3)
set_menu_sub
    menu_win(3)
set_menu_term
    menu_hook(3)
set_menu_unmark
    menu_mark(3)
set_menu_userptr
    menu_userptr(3)
set_menu_win
    menu_win(3)
set_top_row
    menu_item_current(3)
top_row
    menu_item_current(3)
unpost_menu
    menu_post(3)

RETURN VALUES
Any function returning a string pointer will return NULL if an error occurs. Functions returning an integer will return one of the following:

E_OK
    The function was successful.
E_SYSTEM_ERROR
    There was a system error during the call.
E_BAD_ARGUMENT
    One or more of the arguments passed to the function was incorrect.
E_POSTED
    The menu is already posted.
E_CONNECTED
    An item was already connected to a menu.
E_BAD_STATE
    The function was called from within an initialization or termination routine.
E_NO_ROOM
    The menu does not fit within the subwindow.
E_NOT_POSTED
    The menu is not posted.
E_UNKNOWN_COMMAND
    The menu driver does not recognize the request passed to it.
E_NO_MATCH
    The character search failed to find a match.
E_NOT_SELECTABLE
    The item could not be selected.
E_NOT_CONNECTED
    The item is not connected to a menu.
E_REQUEST_DENIED
    The menu driver could not process the request.

SEE ALSO
curses(3), menu_attributes(3), menu_cursor(3), menu_driver(3), menu_format(3), menu_hook(3), menu_item_current(3), menu_item_name(3), menu_item_new(3), menu_item_opts(3), menu_item_userptr(3), menu_item_value(3), menu_item_visible(3), menu_items(3), menu_mark(3), menu_new(3), menu_opts(3), menu_pattern(3), menu_post(3), menu_userptr(3), menu_win(3)

NOTES
This implementation of the menus library does depart in behaviour subtly from the original AT & T implementation. Some of the more notable departures are:

unmark
    The original implementation did not have a marker for an unmarked field the mark was only displayed next to a field when it had been marked using the REQ_TOGGLE_ITEM. In this implementation a separate marker can be used to indicate an unmarked item. This can be set using set_menu_unmark function. There is no requirement for the mark and unmark strings to be the same length. Room will be left for the longest of the two. The unmark string is optional, if it is not set then menus defaults to the old behaviour.
item marking
    In the original implementation the current item was considered selected and hence had the mark string displayed next to it. This implementation does not do this because the Author considers the effect too confusing. Especially in the case of a multiple selection menu because there was no way to tell if the current item is selected or not without shifting off of it. Since the current item is displayed using the foreground attribute it was deemed unnecessary to also display the mark string against the current item.

The option O_RADIO and the function item_selected() are NetBSD extensions and must not be used in portable code.