xref: /netbsd-src/lib/libcurses/erase.c (revision 6348e3f32a4431b45d07e1da16fd7b12725a45e7)
1 /*	$NetBSD: erase.c,v 1.38 2024/12/23 02:58:03 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[] = "@(#)erase.c	8.2 (Berkeley) 5/4/94";
36 #else
37 __RCSID("$NetBSD: erase.c,v 1.38 2024/12/23 02:58:03 blymn Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #include <stdlib.h>
42 
43 #include "curses.h"
44 #include "curses_private.h"
45 
46 #ifndef _CURSES_USE_MACROS
47 
48 /*
49  * erase --
50  *	Erases everything on stdscr.
51  */
52 int
53 erase(void)
54 {
55 	return werase(stdscr);
56 }
57 
58 #endif
59 
60 /*
61  * werase --
62  *	Erases everything on the window.
63  */
64 int
65 werase(WINDOW *win)
66 {
67 	int     y;
68 	__LDATA *sp, *end, *start;
69 	wchar_t	bch;
70 	attr_t	battr;
71 
72 	__CTRACE(__CTRACE_ERASE, "werase: (%p)\n", win);
73 
74 	if (__predict_false(win == NULL))
75 		return ERR;
76 
77 	bch = win->bch;
78 	if (win != curscr)
79 		battr = win->battr & __ATTRIBUTES;
80 	else
81 		battr = 0;
82 
83 	for (y = 0; y < win->maxy; y++) {
84 		start = win->alines[y]->line;
85 		end = &start[win->maxx];
86 		for (sp = start; sp < end; sp++) {
87 			if (!(__NEED_ERASE(sp, bch, battr)))
88 				continue;
89 
90 			sp->ch = bch;
91 			sp->cflags |= CA_BACKGROUND;
92 			sp->cflags &= ~CA_CONTINUATION;
93 			sp->attr = battr | (sp->attr & __ALTCHARSET);
94 #ifdef HAVE_WCHAR
95 			if (_cursesi_copy_nsp(win->bnsp, sp) == ERR)
96 				return ERR;
97 			sp->wcols = 1;
98 #endif
99 		}
100 	}
101 
102 	/*
103 	 * Mark the whole window as changed in case we have overlapping
104 	 * windows - this will result in the (intended) clearing of the
105 	 * screen over the area covered by the window. */
106 	__touchwin(win, 0);
107 	wmove(win, 0, 0);
108 	return OK;
109 }
110