/*
 * allocate space for and set up defaults for a new window
 *
 * 1/26/81 (Berkeley) %W
 */

# include	"curses.ext"

short	*calloc();

static WINDOW	*makenew();

# undef		nl	/* don't need it here, and it interferes	*/

WINDOW *
newwin(num_lines, num_cols, begy, begx)
int	num_lines, num_cols, begy, begx;
{
    reg WINDOW	*win;
    reg char	*sp;
    reg int		i, by, bx, nl, nc;

    by = begy;
    bx = begx;
    nl = num_lines;
    nc = num_cols;

    if(nl > LINES || nc > COLS || nl+by > LINES || nc+bx > COLS)
		return(ERR);

    if (nl == 0)
	nl = LINES - by;
    if (nc == 0)
	nc = COLS - bx;
    if ((win = makenew(nl, nc, by, bx)) == NULL)
	return ERR;
    for (i = 0; i < nl; i++)
	if ((win->_y[i] = (char *) calloc(nc, sizeof (char))) == NULL) {
	    reg int		j;

	    for (j = 0; j < i; j++)
		cfree(win->_y[j]);
	    cfree(win->_firstch);
	    cfree(win->_lastch);
	    cfree(win->_y);
	    cfree(win);
	    return ERR;
	}
	else
	    for (sp = win->_y[i]; sp < win->_y[i] + nc; )
		*sp++ = ' ';
    return win;
}

WINDOW *
subwin(orig, num_lines, num_cols, begy, begx)
reg WINDOW	*orig;
int		num_lines, num_cols, begy, begx; 
{

    reg int		i;
    reg WINDOW	*win;
    reg int		by, bx, nl, nc;
    reg int		j, k;

    by = begy;
    bx = begx;
    nl = num_lines;
    nc = num_cols;

    /*
    	 * make sure window fits inside the original one
    	 */
# ifdef	DEBUG
    fprintf(outf, "SUBWIN(%0.2o, %d, %d, %d, %d)\n", orig, nl, nc, by, bx);
# endif
    if (by < orig->_begy || bx < orig->_begx
        || by - orig->_begy + nl > orig->_maxy
        || bx - orig->_begx + nc > orig->_maxx) {
	return ERR;
    }
    if (nl == 0)
	nl = orig->_maxy - orig->_begy - by;
    if (nc == 0)
	nc = orig->_maxx - orig->_begx - bx;
    if ((win = makenew(nl, nc, by, bx)) == NULL) {
	return ERR;
    }
    j = by - orig->_begy;
    k = bx - orig->_begx;
    for (i = 0; i < nl; i++)
	win->_y[i] = &orig->_y[j++][k];
    win->_flags = _SUBWIN;
    return win;
}

/*
 *	This routine sets up a window buffer and returns a pointer to it.
 */
static WINDOW *
makenew(num_lines, num_cols, begy, begx)
int	num_lines, num_cols, begy, begx; 
{

    reg int		i;
    reg WINDOW	*win;
    reg int		by, bx, nl, nc;

    by = begy;
    bx = begx;
    nl = num_lines;
    nc = num_cols;

# ifdef	DEBUG
    fprintf(outf, "MAKENEW(%d, %d, %d, %d)\n", nl, nc, by, bx);
# endif
    if ((win = (WINDOW *) calloc(1,sizeof (WINDOW))) == NULL)
	return NULL;
# ifdef DEBUG
    fprintf(outf, "MAKENEW: nl = %d\n", nl);
# endif
    if ((win->_y = (char **) calloc(nl, sizeof (char *))) == NULL) {
	cfree(win);
	return (WINDOW *) NULL;
    }
    if ((win->_firstch = calloc(nl, sizeof (short))) == NULL) {
	cfree(win);
	cfree(win->_y);
    }
    if ((win->_lastch = calloc(nl, sizeof (short))) == NULL) {
	cfree(win);
	cfree(win->_y);
	cfree(win->_firstch);
    }
# ifdef DEBUG
    fprintf(outf, "MAKENEW: nc = %d\n", nc);
# endif
    win->_cury = win->_curx = 0;
    win->_clear = (nl == LINES && nc == COLS);
    win->_maxy = nl;
    win->_maxx = nc;
    win->_begy = by;
    win->_begx = bx;
    win->_scroll = win->_leave = FALSE;
    for (i = 0; i < nl; i++)
	win->_firstch[i] = win->_lastch[i] = _NOCHANGE;
    if (bx + nc == COLS) {
	win->_flags |= _ENDLINE;
	if (bx == 0 && nl == LINES && by == 0)
	    win->_flags |= _FULLWIN;
	if (by + nl == LINES)
	    win->_flags |= _SCROLLWIN;
    }
# ifdef DEBUG
    fprintf(outf, "MAKENEW: win->_clear = %d\n", win->_clear);
    fprintf(outf, "MAKENEW: win->_leave = %d\n", win->_leave);
    fprintf(outf, "MAKENEW: win->_scroll = %d\n", win->_scroll);
    fprintf(outf, "MAKENEW: win->_flags = %0.2o\n", win->_flags);
    fprintf(outf, "MAKENEW: win->_maxy = %d\n", win->_maxy);
    fprintf(outf, "MAKENEW: win->_maxx = %d\n", win->_maxx);
    fprintf(outf, "MAKENEW: win->_begy = %d\n", win->_begy);
    fprintf(outf, "MAKENEW: win->_begx = %d\n", win->_begx);
# endif
    return win;
}
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