1/****************************************************************************
2 * Copyright (c) 1998-2005,2009 Free Software Foundation, Inc.              *
3 *                                                                          *
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5 * copy of this software and associated documentation files (the            *
6 * "Software"), to deal in the Software without restriction, including      *
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9 * copies of the Software, and to permit persons to whom the Software is    *
10 * furnished to do so, subject to the following conditions:                 *
11 *                                                                          *
12 * The above copyright notice and this permission notice shall be included  *
13 * in all copies or substantial portions of the Software.                   *
14 *                                                                          *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
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22 *                                                                          *
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28
29/****************************************************************************
30 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32 *     and: Thomas E. Dickey                        1996-on                 *
33 ****************************************************************************/
34
35/*
36**	lib_erase.c
37**
38**	The routine werase().
39**
40*/
41
42#include <curses.priv.h>
43
44MODULE_ID("$Id: lib_erase.c,v 1.17 2009/10/24 22:32:29 tom Exp $")
45
46NCURSES_EXPORT(int)
47werase(WINDOW *win)
48{
49    int code = ERR;
50    int y;
51    NCURSES_CH_T blank;
52    NCURSES_CH_T *sp, *end, *start;
53
54    T((T_CALLED("werase(%p)"), (void *) win));
55
56    if (win) {
57	blank = win->_nc_bkgd;
58	for (y = 0; y <= win->_maxy; y++) {
59	    start = win->_line[y].text;
60	    end = &start[win->_maxx];
61
62	    /*
63	     * If this is a derived window, we have to handle the case where
64	     * a multicolumn character extends into the window that we are
65	     * erasing.
66	     */
67	    if_WIDEC({
68		if (isWidecExt(start[0])) {
69		    int x = (win->_parent != 0) ? (win->_begx) : 0;
70		    while (x-- > 0) {
71			if (isWidecBase(start[-1])) {
72			    --start;
73			    break;
74			}
75			--start;
76		    }
77		}
78	    });
79
80	    for (sp = start; sp <= end; sp++)
81		*sp = blank;
82
83	    win->_line[y].firstchar = 0;
84	    win->_line[y].lastchar = win->_maxx;
85	}
86	win->_curx = win->_cury = 0;
87	win->_flags &= ~_WRAPPED;
88	_nc_synchook(win);
89	code = OK;
90    }
91    returnCode(code);
92}
93