@Override
    public void paint(Graphics g) {
        if( environment != null ){
            Reversi reversi = (Reversi)environment;
            if( reversi.board != null )
               reversi.board.draw(g, DRAW_AREA_SIZE, MARGIN);
            if( reversi.clock != null ){
                if( reversi.clock.white_turn()){
                   g.fillOval( 10, DRAW_AREA_SIZE+10, 10, 10);
                }else{
                   g.fillOval( 210, DRAW_AREA_SIZE+10, 10, 10);
                }
                g.drawString("White:"+reversi.clock.white_time_string(), 20, DRAW_AREA_SIZE+20);
                g.drawString("Black:"+reversi.clock.black_time_string(), 230, DRAW_AREA_SIZE+20);
            }
        }
    }