java - ボタンを表示するためにマウスをボタンの上に置く必要があるのはなぜですか?

Question

ここで問題が発生しました。ボタンとテキストフィールドの上にマウスを置いて表示しようとすると、背景画像を追加するまでボタンが正常に機能していました。マウスがクリックしているかどうかに関係なく、ラベルも機能しませんか? クラスへのコードは次のとおりです。

public class launcher extends JFrame{
    private static final long serialVersionUID = 1L;

     protected JPanel window = new JPanel();
     protected JFrame f = new JFrame("stackoverflow");

    private Rectangle rAncient, rMedieval, rModern, rFuture, rFinancial, rUpdate;
    private JButton ancient, medieval, modern, future, financial, update;
    private JLabel time, name;
    private JTextField tName;


     protected int width = 600;
     protected int height = 400;
     protected int button_width = 80;
     protected int button_height = 40;


    public launcher(int id) throws IOException{
        try{
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e){
            e.printStackTrace();
        }
        setTitle("Choose your Path");
        setSize(new Dimension(width, height));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        getContentPane().add(window);
        setLocationRelativeTo(null);
        setResizable(false);
        setVisible(true);
        window.setLayout(null);
        if(id==0){
        drawButtons();
    }
        repaint();
    }
    private void drawButtons(){
        ancient = new JButton("Ancient");
        rAncient = new Rectangle(140, 150, 70, 40);
        ancient.setBounds(rAncient);
        window.add(ancient);

        medieval = new JButton("Medieval");
        rMedieval = new Rectangle(220, 150, 80, 40);
        medieval.setBounds(rMedieval);
        window.add(medieval);

        modern = new JButton("Modern");
        rModern = new Rectangle(310, 150, 70, 40);
        modern.setBounds(rModern);
        window.add(modern);

        future = new JButton("Future");
        rFuture = new Rectangle(350, 150, 70, 40);
        future.setBounds(rFuture);
        window.add(future);

        financial = new JButton("Financial");
        rFinancial = new Rectangle(390, 150, 70, 40);
        future.setBounds(rFinancial);
        window.add(financial);

        update = new JButton("Update");
        rUpdate = new Rectangle(250, 300, 100, 50);
        update.setBounds(rUpdate);
        window.add(update);

        time = new JLabel("Choose your desired time period");
        time.setBounds(220, 90, 200, 50);
        window.add(time);

        name = new JLabel("Name: ");
        name.setBounds(210, 220, 200, 50);
        window.add(name);

        tName = new JTextField();
        tName.setBounds(250, 235, 150, 20);
        window.add(tName);
        tName.setText("Bob");

          ancient.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Starting in Ancient mode...");
            }
          });

          medieval.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Starting in Medieval mode...");
            }
          });

          modern.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Starting in Modern mode...");
            }
          });

          future.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Starting in Future mode...");
            }
          });

          financial.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Starting in Financial mode...");
            }
          });

          update.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent a){
                System.out.println("Opening browser to http://ubergamesproductions.weebly.com/adventure");
                try{
                    String URL ="http://ubergamesproductions.weebly.com/adventure";
                    java.awt.Desktop.getDesktop().browse(java.net.URI.create(URL));
                }catch(Exception e){
                    JOptionPane.showMessageDialog(null, e.getMessage());
                }
            }
          });
    }
    public static void main(String[] args)throws IOException{
    new launcher(0);
    }
      private Image backgroundImage = ImageIO.read(new File("C:/Users/Samuels Laptop/Dropbox/Java/Questor/Launcher_UGP.png"));
      public void paint(Graphics g) { 
        super.paint(g);
        g.drawImage(backgroundImage, 0, 0, null);
      }
};