|
MENUS(3) |
Library Functions Manual |
MENUS(3) |
NAME
menus — menu library
LIBRARY
Curses Menu Library (libmenu, -lmenu)
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.
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.