lib/libcurses/scroll.c

   1 /*      $NetBSD: scroll.c,v 1.22 2010/02/03 15:34:40 roy Exp $  */
   2
   3 /*
   4  * Copyright (c) 1981, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)scroll.c    8.3 (Berkeley) 5/4/94";
  36 #else
  37 __RCSID("$NetBSD: scroll.c,v 1.22 2010/02/03 15:34:40 roy Exp $");
  38 #endif
  39 #endif                          /* not lint */
  40
  41 #include "curses.h"
  42 #include "curses_private.h"
  43
  44 /*
  45  * scroll --
  46  *      Scroll the window up a line.
  47  */
  48 int
  49 scroll(WINDOW *win)
  50 {
  51         return(wscrl(win, 1));
  52 }
  53
  54 #ifndef _CURSES_USE_MACROS
  55
  56 /*
  57  * scrl --
  58  *      Scroll stdscr n lines - up if n is positive, down if n is negative.
  59  */
  60 int
  61 scrl(int nlines)
  62 {
  63         return wscrl(stdscr, nlines);
  64 }
  65
  66 /*
  67  * setscrreg --
  68  *      Set the top and bottom of the scrolling region for stdscr.
  69  */
  70 int
  71 setscrreg(int top, int bottom)
  72 {
  73         return wsetscrreg(stdscr, top, bottom);
  74 }
  75
  76 #endif
  77
  78 /*
  79  * wscrl --
  80  *      Scroll a window n lines - up if n is positive, down if n is negative.
  81  */
  82 int
  83 wscrl(WINDOW *win, int nlines)
  84 {
  85         int     oy, ox;
  86
  87 #ifdef DEBUG
  88         __CTRACE(__CTRACE_WINDOW, "wscrl: (%p) lines=%d\n", win, nlines);
  89 #endif
  90
  91         if (!(win->flags & __SCROLLOK))
  92                 return (ERR);
  93         if (!nlines)
  94                 return (OK);
  95
  96         getyx(win, oy, ox);
  97 #ifdef DEBUG
  98         __CTRACE(__CTRACE_WINDOW, "wscrl: y=%d\n", oy);
  99 #endif
 100         if (oy < win->scr_t || oy > win->scr_b)
 101                 /* Outside scrolling region */
 102                 wmove(win, 0, 0);
 103         else
 104                 /* Inside scrolling region */
 105                 wmove(win, win->scr_t, 0);
 106         winsdelln(win, 0 - nlines);
 107         wmove(win, oy, ox);
 108
 109         if (win == curscr) {
 110                 __cputchar('\n');
 111                 if (!__NONL)
 112                         win->curx = 0;
 113 #ifdef DEBUG
 114                 __CTRACE(__CTRACE_WINDOW, "scroll: win == curscr\n");
 115 #endif
 116         }
 117         return (OK);
 118 }
 119
 120 /*
 121  * wsetscrreg --
 122  *      Set the top and bottom of the scrolling region for win.
 123  */
 124 int
 125 wsetscrreg(WINDOW *win, int top, int bottom)
 126 {
 127         if (top < 0 || bottom >= win->maxy || bottom - top < 1)
 128                 return (ERR);
 129         win->scr_t = top;
 130         win->scr_b = bottom;
 131         return (OK);
 132 }
 133
 134 /*
 135  * has_ic --
 136  *      Does the terminal have insert- and delete-character?
 137  */
 138 bool
 139 has_ic(void)
 140 {
 141         if (insert_character != NULL && delete_character != NULL)
 142                 return (TRUE);
 143         else
 144                 return (FALSE);
 145 }
 146
 147 /*
 148  * has_ic --
 149  *      Does the terminal have insert- and delete-line?
 150  */
 151 bool
 152 has_il(void)
 153 {
 154         if (insert_line !=NULL && delete_line != NULL)
 155                 return (TRUE);
 156         else
 157                 return (FALSE);
 158 }