.\"***************************************************************************
.\" Copyright (c) 1998-2005,2006 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: curs_overlay.3x,v 1.14 2006/02/25 21:49:19 tom Exp $
.TH curs_overlay 3X ""
.na
.hy 0
.SH NAME
\fBoverlay\fR,
\fBoverwrite\fR,
\fBcopywin\fR - overlay and manipulate overlapped \fBcurses\fR windows
.ad
.hy
.SH SYNOPSIS
\fB#include <curses.h>\fR
.sp
\fBint overlay(const WINDOW *srcwin, WINDOW *dstwin);\fR
.br
\fBint overwrite(const WINDOW *srcwin, WINDOW *dstwin);\fR
.br
\fBint copywin(const WINDOW *srcwin, WINDOW *dstwin, int sminrow,\fR
      \fBint smincol, int dminrow, int dmincol, int dmaxrow,\fR
      \fBint dmaxcol, int overlay);\fR
.SH DESCRIPTION
The \fBoverlay\fR and \fBoverwrite\fR routines overlay \fIsrcwin\fR on
top of \fIdstwin\fR.  \fIscrwin\fR and \fIdstwin\fR are not required
to be the same size; only text where the two windows overlap is
copied.  The difference is that \fBoverlay\fR is non-destructive
(blanks are not copied) whereas \fBoverwrite\fR is destructive.
.PP
The \fBcopywin\fR routine provides a finer granularity of control over the
\fBoverlay\fR and \fBoverwrite\fR routines.  Like in the \fBprefresh\fR
routine, a rectangle is specified in the destination window, (\fIdminrow\fR,
\fIdmincol\fR) and (\fIdmaxrow\fR, \fIdmaxcol\fR), and the upper-left-corner
coordinates of the source window, (\fIsminrow\fR, \fIsmincol\fR).  If the
argument \fIoverlay\fR is \fBtrue\fR, then copying is non-destructive, as in
\fBoverlay\fR.
.SH RETURN VALUE
Routines that return an integer return \fBERR\fR upon failure, and \fBOK\fR
(SVr4 only specifies "an integer value other than \fBERR\fR") upon successful
completion.
.PP
X/Open defines no error conditions.
In this implementation,
\fBcopywin\fP,
\fBoverlay\fP and \fBoverwrite\fP return an error
if either of the window pointers are null, or
if some part of the window would be placed off-screen.
.SH NOTES
Note that \fBoverlay\fR and \fBoverwrite\fR may be macros.
.SH PORTABILITY
The XSI Curses standard, Issue 4 describes these functions (adding the const
qualifiers).  It further specifies their behavior in the presence of characters
with multibyte renditions (not yet supported in this implementation).
.SH SEE ALSO
\fBcurses\fR(3X), \fBcurs_pad\fR(3X), \fBcurs_refresh\fR(3X)
.\"#
.\"# The following sets edit modes for GNU EMACS
.\"# Local Variables:
.\"# mode:nroff
.\"# fill-column:79
.\"# End: