xref: /netbsd-src/lib/libcurses/scroll.c (revision c34236556bea94afcaca1782d7d228301edc3ea0)
1 /*	$NetBSD: scroll.c,v 1.23 2017/01/06 13:53:18 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 1.23 2017/01/06 13:53:18 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 
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 	if (oy < win->scr_t || oy > win->scr_b)
104 		/* Outside scrolling region */
105 		wmove(win, 0, 0);
106 	else
107 		/* Inside scrolling region */
108 		wmove(win, win->scr_t, 0);
109 	winsdelln(win, 0 - nlines);
110 	wmove(win, oy, ox);
111 
112 	if (win == curscr) {
113 		__cputchar('\n');
114 		if (!__NONL)
115 			win->curx = 0;
116 #ifdef DEBUG
117 		__CTRACE(__CTRACE_WINDOW, "scroll: win == curscr\n");
118 #endif
119 	}
120 	return OK;
121 }
122 
123 /*
124  * wsetscrreg --
125  *	Set the top and bottom of the scrolling region for win.
126  */
127 int
128 wsetscrreg(WINDOW *win, int top, int bottom)
129 {
130 	if (top < 0 || bottom >= win->maxy || bottom - top < 1)
131 		return ERR;
132 	win->scr_t = top;
133 	win->scr_b = bottom;
134 	return OK;
135 }
136 
137 /*
138  * has_ic --
139  *	Does the terminal have insert- and delete-character?
140  */
141 bool
142 has_ic(void)
143 {
144 
145 	if (insert_character != NULL && delete_character != 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 (insert_line !=NULL && delete_line != NULL)
159 		return true;
160 	else
161 		return false;
162 }
163