'\" t
+.\"***************************************************************************
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 1998-2010,2017 Free Software Foundation, Inc. *
+.\" *
+.\" Permission is hereby granted, free of charge, to any person obtaining a *
+.\" copy of this software and associated documentation files (the *
+.\" "Software"), to deal in the Software without restriction, including *
+.\" without limitation the rights to use, copy, modify, merge, publish, *
+.\" distribute, distribute with modifications, sublicense, and/or sell *
+.\" copies of the Software, and to permit persons to whom the Software is *
+.\" furnished to do so, subject to the following conditions: *
+.\" *
+.\" The above copyright notice and this permission notice shall be included *
+.\" in all copies or substantial portions of the Software. *
+.\" *
+.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+.\" *
+.\" Except as contained in this notice, the name(s) of the above copyright *
+.\" holders shall not be used in advertising or otherwise to promote the *
+.\" sale, use or other dealings in this Software without prior written *
+.\" authorization. *
+.\"***************************************************************************
+.\"
+.\" $Id: form_field_buffer.3x,v 1.26 2020/03/28 19:06:28 tom Exp $
.TH form_field_buffer 3X ""
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
.SH NAME
-\fBform_field_buffer\fR - field buffer control
+\fBform_field_buffer\fR \- field buffer control
.SH SYNOPSIS
\fB#include <form.h>\fR
-.br
+.sp
int set_field_buffer(FIELD *field, int buf, const char *value);
.br
char *field_buffer(const FIELD *field, int buffer);
.br
.SH DESCRIPTION
The function \fBset_field_buffer\fR sets the numbered buffer of the given field
-to contain a given string. Buffer 0 is the displayed value of the field; other
-numbered buffers may be allocated by applications through the \fBnbuf\fR
-argument of (see \fBform_field_new\fR(3X)) but are not manipulated by the forms
-library. The function \fBfield_buffer\fR returns the foreground attribute.
-
-The function \fBset_field_status\fR sets the associated status flag of
-\fIfield\fR; \fBfield_status\fR gets the current value. The status flag
+to contain a given string:
+.RS 3
+.bP
+Buffer 0 is the displayed value of the field.
+.bP
+Other numbered buffers may be allocated by applications through the \fBnbuf\fR
+argument of (see \fBform_field_new\fR(3X))
+but are not manipulated by the forms library.
+.RE
+.PP
+The function \fBfield_buffer\fR returns a pointer to
+the contents of the given numbered buffer:
+.RS 3
+.bP
+The buffer contents always have the same length,
+and are padded with trailing spaces
+as needed to ensure this length is the same.
+.bP
+The buffer may contain leading spaces, depending on how it was set.
+.bP
+The buffer contents are set with \fBset_field_buffer\fP,
+or as a side effect of any editing operations on the corresponding field.
+.bP
+Editing operations are based on the \fIwindow\fP which displays the field,
+rather than a \fIstring\fP.
+The window contains only printable characters, and is filled with blanks.
+If you want the raw data, you must write your
+own routine that copies the value out of the buffer and removes the leading
+and trailing spaces.
+.bP
+Because editing operations change the content of the buffer to
+correspond to the window, you should not rely on using buffers
+for long-term storage of form data.
+.RE
+.PP
+The function \fBset_field_status\fR sets the associated status flag of
+\fIfield\fR; \fBfield_status\fR gets the current value.
+The status flag
is set to a nonzero value whenever the field changes.
-
+.PP
The function \fBset_max_field\fR sets the maximum size for a dynamic field.
An argument of 0 turns off any maximum size threshold for that field.
.SH RETURN VALUE
The \fBfield_buffer\fR function returns NULL on error.
-
+It sets \fBerrno\fP according to their success:
+.TP 5
+.B E_OK
+The routine succeeded.
+.TP 5
+.B E_BAD_ARGUMENT
+Routine detected an incorrect or out-of-range argument.
+.PP
The \fBfield_status\fR function returns \fBTRUE\fR or \fBFALSE\fR.
-
+.PP
The remaining routines return one of the following:
.TP 5
-\fBE_OK\fR
+.B E_OK
The routine succeeded.
.TP 5
-\fBE_SYSTEM_ERROR\fR
-System error occurred (see \fBerrno\fR).
+.B E_SYSTEM_ERROR
+System error occurred (see \fBerrno\fR(3)).
.TP 5
-\fBE_BAD_ARGUMENT\fR
+.B E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
.SH SEE ALSO
-\fBcurses\fR(3X) and 3X pages whose names begin "form_" for detailed
+\fBcurses\fR(3X) and related pages whose names begin \*(``form_\*('' for detailed
descriptions of the entry points.
.SH NOTES
The header file \fB<form.h>\fR automatically includes the header file
+.PP
+When configured for wide characters, \fBfield_buffer\fP returns a pointer
+to temporary storage (allocated and freed by the library).
+The application should not attempt to modify the data.
+It will be freed on the next call to \fBfield_buffer\fP to return the
+same buffer.
\fB<curses.h>\fR.
.SH PORTABILITY
-These routines emulate the System V forms library. They were not supported on
+These routines emulate the System V forms library.
+They were not supported on
Version 7 or BSD versions.
+.PP
+The \fBset_max_field\fP function checks for an ncurses extension
+\fBO_INPUT_FIELD\fP which allows a dynamic field to shrink if the new
+limit is smaller than the current field size.
.SH AUTHORS
-Juergen Pfeifer. Manual pages and adaptation for new curses by Eric
-S. Raymond.
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+Juergen Pfeifer.
+Manual pages and adaptation for new curses by Eric S. Raymond.
projects / ncurses.git / blobdiff