问KeyBindings在JApplet中无法正常工作

EN

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.ImageIcon;
import javax.swing.InputMap;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.KeyStroke;

public class GameTest extends JApplet {

//    private PAPITest papi;
    private TestPane panel;
    private boolean inMenu = true;
    private ImageIcon ii;
    private Image image;

    public void init() {
// Don't need any of this, this will still focus from our control pane
//        setFocusable(true);
//        requestFocusInWindow();
//        requestFocus();
        setLayout(new BorderLayout());
        ii = new ImageIcon("Ball Jump.png");
        image = ii.getImage();
//        papi = new PAPITest();
        panel = new TestPane();
        add(panel);
        // Useless, the size of applet is actually normally defined by the html tags
//        setSize(600, 600);
//        setVisible(true);
    }

//    This is a very bad idea
//    This is not double buffered and you are over painting the applets
//    content.  Use a CardLayout and a series of JPanels to provide this
//    functionality or the Glass Pane...
//    You MUST call super.paint!!
//    public void paint(Graphics g) {
//        if (inMenu == true) {
//            Graphics2D g2D = (Graphics2D) g;
//            g2D.drawImage(image, 0, 0, this);
//            repaint();
//        }
//    }

    public class TestPane extends JPanel {

        public TestPane() {
            InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
            ActionMap am = getActionMap();

            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, false), "pressed");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, true), "released");

            am.put("pressed", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    System.out.println("Space Pressed");
                    if (inMenu == true) {
                        inMenu = false;
//                        Removing the panel will remove the key binings...
//                        remove(panel);

//                        Don't have this code...
//                        Set size will have no effect as the layout manager
//                        apply it's own sizing based on the components
//                        preferred size...
//                        papi.setSize(600, 600);
//                        papi.setAlive(true);
//                        This seems a bit pointless, cause you just removed the "panel"
//                        which this now been added to...
//                        add(papi);

//                        Why call this when you've just removed it??
//                        setVisible(true);
                    }

//                    if (papi.isAlive() != true) {
//                        remove(papi);
//                        papi = new PAPITest();
//                        papi.setSize(600, 600);
//                        add(papi);
//                        setVisible(true);
//                        repaint();
//                    }
                }
            });

            am.put("released", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    System.out.println("Space Released");
                    if (inMenu == true) {
                        inMenu = false;
//                        remove(panel);
//                        papi.setSize(600, 600);
//                        papi.setAlive(true);
//                        add(papi);
//                        setVisible(true);
                    }

//                    if (papi.isAlive() != true) {
//                        remove(papi);
//                        papi = new PAPITest();
//                        papi.setSize(600, 600);
//                        add(papi);
//                        setVisible(true);
//                        repaint();
//                    }
                }
            });

            setFocusable(true);
            requestFocusInWindow();
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(600, 600);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2D = (Graphics2D) g;
//            Don't have the image...
//            g2D.drawImage(image, 0, 0, this);
            repaint();
        }
    }
}

public void paint(Graphics g){
    if(inMenu == true){
        Graphics2D g2D = (Graphics2D) g;
        g2D.drawImage(image, 0, 0, this);
        repaint();
    }
}