/*      $NetBSD: scroll.c,v 1.29 2024/12/23 02:58:04 blymn Exp $        */

/*
 * Copyright (c) 1981, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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 <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)scroll.c    8.3 (Berkeley) 5/4/94";
#else
__RCSID("$NetBSD: scroll.c,v 1.29 2024/12/23 02:58:04 blymn Exp $");
#endif
#endif                          /* not lint */

#include "curses.h"
#include "curses_private.h"

/*
 * scroll --
 *      Scroll the window up a line.
 */
int
scroll(WINDOW *win)
{

        return wscrl(win, 1);
}

#ifndef _CURSES_USE_MACROS

/*
 * scrl --
 *      Scroll stdscr n lines - up if n is positive, down if n is negative.
 */
int
scrl(int nlines)
{

        return wscrl(stdscr, nlines);
}

/*
 * setscrreg --
 *      Set the top and bottom of the scrolling region for stdscr.
 */
int
setscrreg(int top, int bottom)
{

        return wsetscrreg(stdscr, top, bottom);
}

/*
 * getscrreg --
 *      Get the top and bottom of the scrolling region for stdscr.
 */
int
getscrreg(int *top, int *bottom)
{

        return wgetscrreg(stdscr, top, bottom);
}

#endif

/*
 * wscrl --
 *      Scroll a window n lines - up if n is positive, down if n is negative.
 */
int
wscrl(WINDOW *win, int nlines)
{
        int     oy, ox;

        __CTRACE(__CTRACE_WINDOW, "wscrl: (%p) lines=%d\n", win, nlines);

        if (__predict_false(win == NULL))
                return ERR;

        if (!(win->flags & __SCROLLOK))
                return ERR;
        if (!nlines)
                return OK;

        getyx(win, oy, ox);
        __CTRACE(__CTRACE_WINDOW, "wscrl: y=%d\n", oy);
        wmove(win, win->scr_t, 1);
        winsdelln(win, 0 - nlines);
        wmove(win, oy, ox);

        if (win == curscr) {
                __cputchar('\n');
                if (!__NONL)
                        win->curx = 0;
                __CTRACE(__CTRACE_WINDOW, "scroll: win == curscr\n");
        }
        return OK;
}

/*
 * wsetscrreg --
 *      Set the top and bottom of the scrolling region for win.
 */
int
wsetscrreg(WINDOW *win, int top, int bottom)
{
        if (__predict_false(win == NULL))
                return ERR;

        if (top < 0 || bottom >= win->maxy || bottom - top < 1)
                return ERR;
        win->scr_t = top;
        win->scr_b = bottom;
        return OK;
}

/*
 * wgetscrreg --
 *      Get the top and bottom of the scrolling region for win.
 */
int
wgetscrreg(WINDOW *win, int *top, int *bottom)
{
        if (__predict_false(win == NULL))
                return ERR;

        *top = win->scr_t;
        *bottom = win->scr_b;
        return OK;
}

/*
 * has_ic --
 *      Does the terminal have insert- and delete-character?
 */
bool
has_ic(void)
{

        if (insert_character != NULL && delete_character != NULL)
                return true;
        else
                return false;
}

/*
 * has_ic --
 *      Does the terminal have insert- and delete-line?
 */
bool
has_il(void)
{
        if (insert_line !=NULL && delete_line != NULL)
                return true;
        else
                return false;
}