/*      @(#)wwdelline.c 8.1 (Berkeley) 6/6/93   */
/*      $NetBSD: wwdelline.c,v 1.6 2003/08/07 11:17:38 agc Exp $        */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Edward Wang at The University of California, Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "ww.h"

void
wwdelline(struct ww *w, int row)
{
        int i;
        union ww_char **cpp, **cqq;
        union ww_char *cp;
        int row1, row2;
        char deleted;
        int visible;

        /*
         * Scroll first.
         */
        if ((row1 = row) < w->ww_i.t) {
                row1 = w->ww_i.t;
        }
        if ((row2 = w->ww_b.b) > w->ww_i.b) {
                row2 = w->ww_i.b;
                visible = 0;
        } else
                visible = 1;
        deleted = wwscroll1(w, row1, row2, 1, visible);

        /*
         * Fix the buffer.
         * But leave clearing the last line for wwclreol().
         */
        cpp = &w->ww_buf[row];
        cqq = cpp + 1;
        cp = *cpp;
        for (i = w->ww_b.b - row; --i > 0;)
                *cpp++ = *cqq++;
        *cpp = cp;

        /*
         * Now clear the last line.
         */
        if (visible)
                wwclreol1(w, w->ww_b.b - 1, w->ww_b.l, deleted);
        else {
                cp += w->ww_b.l;
                for (i = w->ww_b.nc; --i >= 0;)
                        cp++->c_w = ' ';
        }
}