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.\" $Id: menu_hook.3x,v 1.30 2023/11/25 13:58:47 tom Exp $
.TH hook 3MENU 2023-11-25 "ncurses 6.4" "Library calls"
.SH NAME
\fBmenu_hook\fP \-
set hooks for automatic invocation by applications
.SH SYNOPSIS
.nf
\fB#include <menu.h>
.PP
\fBint set_item_init(MENU *\fImenu\fP, Menu_Hook \fIfunc\fP);
\fBMenu_Hook item_init(const MENU *\fImenu\fP);
.PP
\fBint set_item_term(MENU *\fImenu\fP, Menu_Hook \fIfunc\fP);
\fBMenu_Hook item_term(const MENU *\fImenu\fP);
.PP
\fBint set_menu_init(MENU *\fImenu\fP, Menu_Hook \fIfunc\fP);
\fBMenu_Hook menu_init(const MENU *\fImenu\fP);
.PP
\fBint set_menu_term(MENU *\fImenu\fP, Menu_Hook \fIfunc\fP);
\fBMenu_Hook menu_term(const MENU *\fImenu\fP);
.fi
.SH DESCRIPTION
These functions make it possible to set hook functions to be called at various
points in the automatic processing of input event codes by \fBmenu_driver\fP.
.PP
The function \fBset_item_init\fP sets a hook to be called at menu-post time and
each time the selected item changes (after the change).
\fBitem_init\fP
returns the current item init hook, if any (\fBNULL\fP if there is no such
hook).
.PP
The function \fBset_item_term\fP sets a hook to be called at menu-unpost time
and each time the selected item changes (before the change).
\fBitem_term\fP
returns the current item term hook, if any (\fBNULL\fP if there is no such
hook).
.PP
The function \fBset_menu_init\fP sets a hook to be called at menu-post time and
just after the top row on the menu changes once it is posted.
\fBmenu_init\fP
returns the current menu init hook, if any (\fBNULL\fP if there is no such
hook).
.PP
The function \fBset_menu_term\fP sets a hook to be called at menu-unpost time
and just before the top row on the menu changes once it is posted.
\fBmenu_term\fP returns the current menu term hook, if any (\fBNULL\fP if there
is no such hook).
.SH RETURN VALUE
Routines that return pointers return \fBNULL\fP on error.
Other routines
return one of the following:
.TP 5
.B E_OK
The routine succeeded.
.TP 5
.B E_SYSTEM_ERROR
System error occurred (see \fBerrno\fP(3)).
.SH PORTABILITY
These routines emulate the System V menu library.
They were not supported on
Version 7 or BSD versions.
.SH AUTHORS
Juergen Pfeifer.
Manual pages and adaptation for new curses by Eric
S. Raymond.
.SH SEE ALSO
\fB\%ncurses\fP(3NCURSES),
\fB\%menu\fP(3MENU)