release/src/router/libncurses/ncurses/base/lib_erase.c

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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 1.17 2009/10/24 22:32:29 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)"), (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 }