.\"	$NetBSD: form_page.3,v 1.10 2010/03/22 21:58:31 joerg Exp $
.\"
.\" Copyright (c) 1999
.\"	Brett Lymn - blymn@baea.com.au, brett_lymn@yahoo.com.au
.\"
.\" This code is donated to The NetBSD Foundation by the author.
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.Dd January 1, 2001
.Dt FORM_PAGE 3
.Os
.Sh NAME
.Nm current_field ,
.Nm field_index ,
.Nm form_page ,
.Nm form_max_page ,
.Nm set_current_field ,
.Nm set_form_page
.Nd form library
.Sh LIBRARY
.Lb libform
.Sh SYNOPSIS
.In form.h
.Ft FIELD *
.Fn current_field "FORM *form"
.Ft int
.Fn field_index "FIELD *field"
.Ft int
.Fn form_page "FORM *form"
.Ft int
.Fn form_max_page "FORM *form"
.Ft int
.Fn set_current_field "FORM *form" "FIELD *field"
.Ft int
.Fn set_form_page "FORM *form" "int page"
.Sh DESCRIPTION
The
.Fn current_field
returns a pointer to the structure for the field that is currently
active on the page.
If there is an error,
.Fn current_field
will return
.Dv NULL .
Calling
.Fn field_index
will return the index of the given field in the form field array.
The
current page the form is on can be determined by using
.Fn form_page ,
the current page of a form can be programmatically set by calling
.Fn set_form_page .
The maximum page number for a form can be found by
calling the function
.Fn form_max_page
but note that this function is a
.Nx
extension and must not be used in portable forms library programs.
The current field on the form may be set by calling
.Fn set_current_field
which will set the current field to the one given.
.Sh RETURN VALUES
Functions returning pointers will return
.Dv NULL
if an error is detected.
The functions that return an int will return one of the following
error values:
.Pp
.Bl -tag -width E_UNKNOWN_COMMAND -compact
.It Er E_OK
The function was successful.
.It Er E_BAD_ARGUMENT
The function was passed a bad argument.
.It Er E_NOT_CONNECTED
The given field is not associated with a form.
.It Er E_BAD_STATE
The function was called from within an init or term function.
.It Er E_INVALID_FIELD
The field given is not part of the given form.
.El
.Sh SEE ALSO
.Xr curses 3 ,
.Xr forms 3
.Sh NOTES
The header
.In form.h
automatically includes both
.In curses.h
and
.In eti.h .
.Pp
The
.Nm form_max_page
is a
.Nx
extension and should not be used in portable applications.