xref: /netbsd-src/lib/libcurses/scroll.c (revision 6348e3f32a4431b45d07e1da16fd7b12725a45e7)
1 /*	$NetBSD: scroll.c,v 1.29 2024/12/23 02:58:04 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 1.29 2024/12/23 02:58:04 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 /*
80  * getscrreg --
81  *	Get the top and bottom of the scrolling region for stdscr.
82  */
83 int
84 getscrreg(int *top, int *bottom)
85 {
86 
87 	return wgetscrreg(stdscr, top, bottom);
88 }
89 
90 #endif
91 
92 /*
93  * wscrl --
94  *	Scroll a window n lines - up if n is positive, down if n is negative.
95  */
96 int
97 wscrl(WINDOW *win, int nlines)
98 {
99 	int     oy, ox;
100 
101 	__CTRACE(__CTRACE_WINDOW, "wscrl: (%p) lines=%d\n", win, nlines);
102 
103 	if (__predict_false(win == NULL))
104 		return ERR;
105 
106 	if (!(win->flags & __SCROLLOK))
107 		return ERR;
108 	if (!nlines)
109 		return OK;
110 
111 	getyx(win, oy, ox);
112 	__CTRACE(__CTRACE_WINDOW, "wscrl: y=%d\n", oy);
113 	wmove(win, win->scr_t, 1);
114 	winsdelln(win, 0 - nlines);
115 	wmove(win, oy, ox);
116 
117 	if (win == curscr) {
118 		__cputchar('\n');
119 		if (!__NONL)
120 			win->curx = 0;
121 		__CTRACE(__CTRACE_WINDOW, "scroll: win == curscr\n");
122 	}
123 	return OK;
124 }
125 
126 /*
127  * wsetscrreg --
128  *	Set the top and bottom of the scrolling region for win.
129  */
130 int
131 wsetscrreg(WINDOW *win, int top, int bottom)
132 {
133 	if (__predict_false(win == NULL))
134 		return ERR;
135 
136 	if (top < 0 || bottom >= win->maxy || bottom - top < 1)
137 		return ERR;
138 	win->scr_t = top;
139 	win->scr_b = bottom;
140 	return OK;
141 }
142 
143 /*
144  * wgetscrreg --
145  *	Get the top and bottom of the scrolling region for win.
146  */
147 int
148 wgetscrreg(WINDOW *win, int *top, int *bottom)
149 {
150 	if (__predict_false(win == NULL))
151 		return ERR;
152 
153 	*top = win->scr_t;
154 	*bottom = win->scr_b;
155 	return OK;
156 }
157 
158 /*
159  * has_ic --
160  *	Does the terminal have insert- and delete-character?
161  */
162 bool
163 has_ic(void)
164 {
165 
166 	if (insert_character != NULL && delete_character != NULL)
167 		return true;
168 	else
169 		return false;
170 }
171 
172 /*
173  * has_ic --
174  *	Does the terminal have insert- and delete-line?
175  */
176 bool
177 has_il(void)
178 {
179 	if (insert_line !=NULL && delete_line != NULL)
180 		return true;
181 	else
182 		return false;
183 }
184