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erase.c revision 1.17 
      1 /*	$NetBSD: erase.c,v 1.17 2003/08/07 16:44:21 agc 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 1.17 2003/08/07 16:44:21 agc Exp $");
     38 #endif
     39 #endif				/* not lint */
     40 
     41 #include "curses.h"
     42 #include "curses_private.h"
     43 
     44 #ifndef _CURSES_USE_MACROS
     45 
     46 /*
     47  * erase --
     48  *	Erases everything on stdscr.
     49  */
     50 int
     51 erase(void)
     52 {
     53 	return werase(stdscr);
     54 }
     55 
     56 #endif
     57 
     58 /*
     59  * werase --
     60  *	Erases everything on the window.
     61  */
     62 int
     63 werase(WINDOW *win)
     64 {
     65 
     66 	int     minx, y;
     67 	__LDATA *sp, *end, *start, *maxx;
     68 
     69 #ifdef DEBUG
     70 	__CTRACE("werase: (%p)\n", win);
     71 #endif
     72 #ifdef __GNUC__
     73 	maxx = NULL;		/* XXX gcc -Wuninitialized */
     74 #endif
     75 	for (y = 0; y < win->maxy; y++) {
     76 		minx = -1;
     77 		start = win->lines[y]->line;
     78 		end = &start[win->maxx];
     79 		for (sp = start; sp < end; sp++)
     80 			if (sp->ch != ' ' || sp->attr != 0 ||
     81 			    sp->bch != win->bch || sp->battr != win->battr) {
     82 				maxx = sp;
     83 				if (minx == -1)
     84 					minx = sp - start;
     85 				sp->ch = ' ';
     86 				sp->bch = win->bch;
     87 				sp->attr = 0;
     88 				sp->battr = win->battr;
     89 			}
     90 		if (minx != -1)
     91 			__touchline(win, y, minx, maxx - win->lines[y]->line);
     92 	}
     93 	wmove(win, 0, 0);
     94 	return (OK);
     95 }
     96