/*      $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;
}