/*
 * Move the system caret. (We maintain one, even though it's
 * invisible, for the benefit of blind people: apparently some
 * helper software tracks the system caret, so we should arrange to
 * have one.)
 */
void sys_cursor(int x, int y) {
    if (has_focus)
    SetCaretPos(x * font_width, y * font_height);
	SetCaretPos(x * font_width, y * font_height);
}

/*
 * Draw a line of text in the window, at given character
 * coordinates, in given attributes.
 *
 * We are allowed to fiddle with the contents of `text'.