1/* $OpenBSD: lib_erase.c,v 1.4 2023/10/17 09:52:08 nicm Exp $ */
2
3/****************************************************************************
4 * Copyright 2020,2022 Thomas E. Dickey                                     *
5 * Copyright 1998-2009,2016 Free Software Foundation, Inc.                  *
6 *                                                                          *
7 * Permission is hereby granted, free of charge, to any person obtaining a  *
8 * copy of this software and associated documentation files (the            *
9 * "Software"), to deal in the Software without restriction, including      *
10 * without limitation the rights to use, copy, modify, merge, publish,      *
11 * distribute, distribute with modifications, sublicense, and/or sell       *
12 * copies of the Software, and to permit persons to whom the Software is    *
13 * furnished to do so, subject to the following conditions:                 *
14 *                                                                          *
15 * The above copyright notice and this permission notice shall be included  *
16 * in all copies or substantial portions of the Software.                   *
17 *                                                                          *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
21 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
24 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
25 *                                                                          *
26 * Except as contained in this notice, the name(s) of the above copyright   *
27 * holders shall not be used in advertising or otherwise to promote the     *
28 * sale, use or other dealings in this Software without prior written       *
29 * authorization.                                                           *
30 ****************************************************************************/
31
32/****************************************************************************
33 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
34 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
35 *     and: Thomas E. Dickey                        1996-on                 *
36 ****************************************************************************/
37
38/*
39**	lib_erase.c
40**
41**	The routine werase().
42**
43*/
44
45#include <curses.priv.h>
46
47MODULE_ID("$Id: lib_erase.c,v 1.4 2023/10/17 09:52:08 nicm Exp $")
48
49NCURSES_EXPORT(int)
50werase(WINDOW *win)
51{
52    int code = ERR;
53    NCURSES_CH_T *start;
54
55    T((T_CALLED("werase(%p)"), (void *) win));
56
57    if (win) {
58	NCURSES_CH_T blank;
59	NCURSES_CH_T *sp;
60	int y;
61
62	blank = win->_nc_bkgd;
63	for (y = 0; y <= win->_maxy; y++) {
64	    NCURSES_CH_T *end;
65
66	    start = win->_line[y].text;
67	    end = &start[win->_maxx];
68
69	    /*
70	     * If this is a derived window, we have to handle the case where
71	     * a multicolumn character extends into the window that we are
72	     * erasing.
73	     */
74	    if_WIDEC({
75		if (isWidecExt(start[0])) {
76		    int x = (win->_parent != 0) ? (win->_begx) : 0;
77		    while (x-- > 0) {
78			if (isWidecBase(start[-1])) {
79			    --start;
80			    break;
81			}
82			--start;
83		    }
84		}
85	    });
86
87	    for (sp = start; sp <= end; sp++)
88		*sp = blank;
89
90	    win->_line[y].firstchar = 0;
91	    win->_line[y].lastchar = win->_maxx;
92	}
93	win->_curx = win->_cury = 0;
94	win->_flags &= ~_WRAPPED;
95	_nc_synchook(win);
96	code = OK;
97    }
98    returnCode(code);
99}
100