production version - first attempt

[unix-history] / usr / src / usr.bin / window / wwinsline.c

#ifndef lint
static  char *sccsid = "@(#)wwinsline.c 3.3 83/08/18";
#endif

#include "ww.h"

wwinsline(w, line)
register struct ww *w;
int line;
{
       register i;
       register union ww_char **cpp, **cqq;
       register union ww_char *cp;
       int srow, erow;
       char deleted;
       int visible;

       /*
        * Scroll first.
        */
       if ((srow = line - w->ww_scroll) < 0) {
               srow = 0;
               visible = 0;
       } else
               visible = 1;
       if ((erow = w->ww_nline - w->ww_scroll - 1) >= w->ww_w.nr)
               erow = w->ww_w.nr - 1;
       deleted = wwscroll1(w, srow, erow, -1, visible);

       /*
        * Fix the buffer.
        * But leave clearing the last line for wwclreol().
        */
       cpp = &w->ww_buf[w->ww_nline];
       cqq = cpp - 1;
       cp = *cqq;
       for (i = w->ww_nline - line - 1; --i >= 0;)
               *--cpp = *--cqq;
       *cqq = cp;

       /*
        * Now clear the last line.
        */
       if (visible)
               wwclreol1(w, line, 0, deleted);
       else
               for (i = w->ww_w.nc; --i >= 0;)
                       cp++->c_w = ' ';
}