libcurses/screen/wbkgd.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*LINTLIBRARY*/

#include    <sys/types.h>
#include    "curses_inc.h"

/* Change the background of a window.  nbkgd :  new background. */

int
wbkgd(WINDOW *win, chtype nbkgd)
{
    short   maxx;
    int x, y;
    chtype  *wcp, obkgda, obkgdc, nbkgda,
        nbkgdc, acolor, c;
    short   *begch, *endch;

    /* if 'nbkgd' contains color information, but this is not a color   */
    /* terminal, erase that information.                */

    if ((nbkgd & A_COLOR) && (cur_term->_pairs_tbl == NULL))
        nbkgd &= ~A_COLOR;

    if (nbkgd == win->_bkgd)
        return (OK);

    obkgdc = _CHAR(win->_bkgd);
    obkgda = _ATTR(win->_bkgd);

    nbkgdc = _CHAR(nbkgd);
    nbkgda = _ATTR(nbkgd);

    /* switch byte order if necessary */
    if (ISCBIT(nbkgdc))
        nbkgdc = _CHAR((RBYTE(nbkgdc) << 8) | (LBYTE(nbkgdc)|MBIT)) |
            CBIT;
    c = RBYTE(nbkgdc);
    if ((nbkgdc < ' ' || nbkgdc == _CTRL('?')) ||
        _curs_scrwidth[TYPE(c)] > 1)
        nbkgdc = obkgdc;
    nbkgd = (nbkgdc & ~CBIT) | nbkgda;

    win->_bkgd = nbkgd;

    /* delete the old background from the attribute field and replace    */
    /* it with the new background.  Note: if the same attribute was */
    /* first set by wbkgd() and then by wattron(), or vice versa, it */
    /* will be deleted, so the effect of wattron() will be lost.     */
    /* This applies to both video and color attributes.      */

    if ((acolor = (win->_attrs & A_COLOR)) != 0) {
        if (acolor == (obkgda & A_COLOR)) {
            win->_attrs = _ATTR((win->_attrs & ~obkgda) | nbkgda);
        } else {
            win->_attrs = _ATTR((win->_attrs &
                (~obkgda | A_COLOR)) | (nbkgda & ~A_COLOR));
        }
    } else
        win->_attrs = _ATTR((win->_attrs & ~obkgda) | nbkgda);

    maxx = win->_maxx - 1;
    begch = win->_firstch;
    endch = win->_lastch;
    for (y = win->_maxy-1; y >= 0; --y, ++begch, ++endch) {
        for (x = maxx, wcp = win->_y[y]; x-- >= 0; ++wcp) {
            if ((c = _CHAR(*wcp)) == obkgdc)
                c = nbkgdc;
            if ((acolor = (*wcp & A_COLOR)) != 0) {
                if (acolor == (obkgda & A_COLOR))
                    *wcp = c | _ATTR((*wcp & ~obkgda) |
                        nbkgda);
                else
                    *wcp = c | _ATTR((*wcp & (~obkgda |
                        A_COLOR)) | (nbkgda & ~A_COLOR));
            } else
                *wcp = c | _ATTR((*wcp & ~obkgda) | nbkgda);
        }
        *begch = 0;
        *endch = maxx;
    }

    win->_flags |= _WINCHANGED;
    if (win->_sync)
        wsyncup(win);

    return (win->_immed ? wrefresh(win) : OK);
}