1 /****************************************************************************
2  * Copyright (c) 1998,2000,2001 Free Software Foundation, Inc.              *
3  *                                                                          *
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5  * copy of this software and associated documentation files (the            *
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10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
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14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
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22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
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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 
44 MODULE_ID("$Id: lib_erase.c,v 1.16 2005/10/30 00:36:36 tom Exp $")
45 
46 NCURSES_EXPORT(int)
47 werase(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)"), 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