public class GamePanel extends JPanel 
{
    MainFrame mainFrame;
    
    private Image background = ImageUtil.getImage("images/background.jpg");
    
    public GamePanel(MainFrame mainFrame) {
        this.mainFrame = mainFrame;
//        this.setPreferredSize(new Dimension())
    }
    
    public void paint(Graphics g) {
        g.drawImage(this.background, 0, 0, this.getWidth(), 
                this.getHeight() , null);
        Piece currentPiece = this.mainFrame.getCurrentPiece();
        ImageUtil.paintPiece(g, currentPiece);
        Square[][] squares = this.mainFrame.getSquares();
        if (squares == null) return;
        for (int i = 0; i < squares.length; i++) {
            for (int j = 0; j < squares[i].length; j++) {
                Square s = squares[i][j];
                if (s != null) {
                    g.drawImage(s.getImage(), s.getBeginX(), s.getBeginY(), this);
                }
            }
        }
    }

}