xref: /netbsd-src/lib/libcurses/scroll.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: scroll.c,v 1.16 2001/05/17 19:04:01 jdc 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)scroll.c	8.3 (Berkeley) 5/4/94";
40 #else
41 __RCSID("$NetBSD: scroll.c,v 1.16 2001/05/17 19:04:01 jdc Exp $");
42 #endif
43 #endif				/* not lint */
44 
45 #include "curses.h"
46 #include "curses_private.h"
47 
48 /*
49  * scroll --
50  *	Scroll the window up a line.
51  */
52 int
53 scroll(WINDOW *win)
54 {
55 	return(wscrl(win, 1));
56 }
57 
58 #ifndef _CURSES_USE_MACROS
59 
60 /*
61  * scrl --
62  *	Scroll stdscr n lines - up if n is positive, down if n is negative.
63  */
64 int
65 scrl(int lines)
66 {
67 	return wscrl(stdscr, lines);
68 }
69 
70 /*
71  * setscrreg --
72  *	Set the top and bottom of the scrolling region for stdscr.
73  */
74 int
75 setscrreg(int top, int bottom)
76 {
77 	return wsetscrreg(stdscr, top, bottom);
78 }
79 
80 #endif
81 
82 /*
83  * wscrl --
84  *	Scroll a window n lines - up if n is positive, down if n is negative.
85  */
86 int
87 wscrl(WINDOW *win, int lines)
88 {
89 	int     oy, ox;
90 
91 #ifdef DEBUG
92 	__CTRACE("wscrl: (%0.2o) lines=%d\n", win, lines);
93 #endif
94 
95 	if (!(win->flags & __SCROLLOK))
96 		return (ERR);
97 	if (!lines)
98 		return (OK);
99 
100 	getyx(win, oy, ox);
101 #ifdef DEBUG
102 	__CTRACE("wscrl: y=%d\n", oy);
103 #endif
104 	if (oy < win->scr_t || oy > win->scr_b)
105 		/* Outside scrolling region */
106 		wmove(win, 0, 0);
107 	else
108 		/* Inside scrolling region */
109 		wmove(win, win->scr_t, 0);
110 	winsdelln(win, 0 - lines);
111 	wmove(win, oy, ox);
112 
113 	if (win == curscr) {
114 		__cputchar('\n');
115 		if (!__NONL)
116 			win->curx = 0;
117 #ifdef DEBUG
118 		__CTRACE("scroll: win == curscr\n");
119 #endif
120 	}
121 	return (OK);
122 }
123 
124 /*
125  * wsetscrreg --
126  *	Set the top and bottom of the scrolling region for win.
127  */
128 int
129 wsetscrreg(WINDOW *win, int top, int bottom)
130 {
131 	if (top < 0 || bottom >= win->maxy || bottom - top < 1)
132 		return (ERR);
133 	win->scr_t = top;
134 	win->scr_b = bottom;
135 	return (OK);
136 }
137 
138 /*
139  * has_ic --
140  *	Does the terminal have insert- and delete-character?
141  */
142 bool
143 has_ic(void)
144 {
145 	if (__tc_ic !=NULL && __tc_dc != NULL)
146 		return (TRUE);
147 	else
148 		return (FALSE);
149 }
150 
151 /*
152  * has_ic --
153  *	Does the terminal have insert- and delete-line?
154  */
155 bool
156 has_il(void)
157 {
158 	if (__tc_al !=NULL && __tc_dl != NULL)
159 		return (TRUE);
160 	else
161 		return (FALSE);
162 }
163