xref: /netbsd-src/lib/libcurses/scroll.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: scroll.c,v 1.24 2017/02/10 06:25:28 blymn 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 1.24 2017/02/10 06:25:28 blymn 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 
52 	return wscrl(win, 1);
53 }
54 
55 #ifndef _CURSES_USE_MACROS
56 
57 /*
58  * scrl --
59  *	Scroll stdscr n lines - up if n is positive, down if n is negative.
60  */
61 int
62 scrl(int nlines)
63 {
64 
65 	return wscrl(stdscr, nlines);
66 }
67 
68 /*
69  * setscrreg --
70  *	Set the top and bottom of the scrolling region for stdscr.
71  */
72 int
73 setscrreg(int top, int bottom)
74 {
75 
76 	return wsetscrreg(stdscr, top, bottom);
77 }
78 
79 #endif
80 
81 /*
82  * wscrl --
83  *	Scroll a window n lines - up if n is positive, down if n is negative.
84  */
85 int
86 wscrl(WINDOW *win, int nlines)
87 {
88 	int     oy, ox;
89 
90 #ifdef DEBUG
91 	__CTRACE(__CTRACE_WINDOW, "wscrl: (%p) lines=%d\n", win, nlines);
92 #endif
93 
94 	if (!(win->flags & __SCROLLOK))
95 		return ERR;
96 	if (!nlines)
97 		return OK;
98 
99 	getyx(win, oy, ox);
100 #ifdef DEBUG
101 	__CTRACE(__CTRACE_WINDOW, "wscrl: y=%d\n", oy);
102 #endif
103 	wmove(win, win->scr_t, 0);
104 	winsdelln(win, 0 - nlines);
105 	wmove(win, oy, ox);
106 
107 	if (win == curscr) {
108 		__cputchar('\n');
109 		if (!__NONL)
110 			win->curx = 0;
111 #ifdef DEBUG
112 		__CTRACE(__CTRACE_WINDOW, "scroll: win == curscr\n");
113 #endif
114 	}
115 	return OK;
116 }
117 
118 /*
119  * wsetscrreg --
120  *	Set the top and bottom of the scrolling region for win.
121  */
122 int
123 wsetscrreg(WINDOW *win, int top, int bottom)
124 {
125 	if (top < 0 || bottom >= win->maxy || bottom - top < 1)
126 		return ERR;
127 	win->scr_t = top;
128 	win->scr_b = bottom;
129 	return OK;
130 }
131 
132 /*
133  * has_ic --
134  *	Does the terminal have insert- and delete-character?
135  */
136 bool
137 has_ic(void)
138 {
139 
140 	if (insert_character != NULL && delete_character != NULL)
141 		return true;
142 	else
143 		return false;
144 }
145 
146 /*
147  * has_ic --
148  *	Does the terminal have insert- and delete-line?
149  */
150 bool
151 has_il(void)
152 {
153 	if (insert_line !=NULL && delete_line != NULL)
154 		return true;
155 	else
156 		return false;
157 }
158