Why doesnt the keylistener react CardLayout's panel as other listeners in the code do successfully?

Question

I wrote a keylistener to that would switch from a screensaver JPanel back to the main screen and added it to the screensaver JPanel creation method however it is not firing on key press and nothing is happening.

Anyone have any idea what is happening?

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import static javax.swing.SwingUtilities.invokeLater;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class layoutdemo {
    JPanel cards; // panel that uses CardLayout
    CardLayout clo;
    final static String WELCOMEPANEL = "Card with welcome message";
    final static String SCREENSAVERPANEL = "Card with screensaver";
    final static String ENTERPINPANEL = "Card with PIN input"; // not implemented yet
    final static String[] FILEARRAY = new String[]      {"/cardlayouttest/newpackage/btc-zg.jpg","/cardlayouttest/newpackage/pic2.jpeg"};
    static layoutdemo ldm = null;
    private static int INDEX = 0;
    private JLabel screenImage;
    private Timer changeTimer;
    public void addComponenttoPane(Container pane){ //method for adding CardLayout and components to JFrame
    cards = new JPanel(new CardLayout());
    cards.add(welcomePanel(),WELCOMEPANEL);
    cards.add(screensaverPanel(),SCREENSAVERPANEL);
    pane.add(cards,BorderLayout.CENTER);
}
public JPanel welcomePanel(){ //method for creating the "Welcome" panel
    JPanel welcomePanel;
    welcomePanel = new JPanel();
    JLabel welcomeLabel = new JLabel("Dobrodošli na depozitni bankomat!",SwingConstants.CENTER);
    JLabel instructionLabel = new JLabel("Molim vas ubacite karticu u utor sa desne strane",SwingConstants.CENTER);
    instructionLabel.setFont(new Font(instructionLabel.getFont().getFontName(),Font.PLAIN,28));
    welcomeLabel.setFont(new Font(instructionLabel.getFont().getFontName(),Font.PLAIN,28));
    welcomePanel.setLayout(new GridLayout(0,1));
    welcomePanel.add(welcomeLabel);
    welcomePanel.add(instructionLabel);

    return welcomePanel;
}
public JPanel screensaverPanel(){ // method for creating the "Screensaver" panel
    JPanel screensaverPanel;
    screensaverPanel = new JPanel();
    screenImage = new JLabel();
    screenImage.setIcon(new ImageIcon(getClass().getResource("/cardlayouttest/newpackage/btc-zg.jpg")));
    screensaverPanel.add(screenImage);
    screensaverPanel.addKeyListener(stopScreensaver());
    screensaverPanel.setFocusable(true);
    return screensaverPanel;
}
private static layoutdemo createAndShowGUI(){ // method for creating and showing the GUI
    JFrame frame1 = new JFrame("layoutdemowithswitch");
    frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    layoutdemo ldm = new layoutdemo();
    ldm.addComponenttoPane(frame1);
    frame1.pack();
    frame1.setVisible(true);
    frame1.getGraphicsConfiguration().getDevice().setFullScreenWindow(frame1);
    ldm.clo = (CardLayout) ldm.cards.getLayout();
    ldm.clo.show(ldm.cards, WELCOMEPANEL);
    return ldm;
}
public ActionListener timeoutPanelListener(Timer timer){ //listener for main screen timeout - returns to ads
    ActionListener timeout = new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            CardLayout cl = (CardLayout) cards.getLayout();
            cl.show(cards, SCREENSAVERPANEL);
            timer.stop();
            changeTimer = new Timer(5000,changeImageListener(screenImage));
            changeTimer.start();

        }
    };
    return timeout;
}
    public ActionListener changeImageListener(JLabel image){ //listener for changing images in Screensaver
    ActionListener change = new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            image.setIcon(new ImageIcon(getClass().getResource(FILEARRAY[INDEX])));
            INDEX++;
            if (INDEX >= FILEARRAY.length) INDEX = 0;

        }
    };
    return change;
}
public KeyListener stopScreensaver(){
    KeyListener key = new KeyListener() {

        @Override
        public void keyTyped(KeyEvent e) {
            CardLayout cl = (CardLayout) cards.getLayout();
            cl.show(cards, WELCOMEPANEL);
            Timer timer2 = new Timer(10000,null);
            ActionListener timeout = ldm.timeoutPanelListener(timer2);
            timer2.addActionListener(timeout);
            timer2.start();
            System.out.println("key typed");
        }

        @Override
        public void keyPressed(KeyEvent e) {

        }

        @Override
        public void keyReleased(KeyEvent e) {
            CardLayout cl = (CardLayout) cards.getLayout();
            cl.show(cards, WELCOMEPANEL);
            Timer timer2 = new Timer(10000,null);
            timer2.start();
            ActionListener timeout = ldm.timeoutPanelListener(timer2);
        }
    };
    return key;
    }

   public static void main(String[] args) throws ClassNotFoundException, IllegalAccessException, InstantiationException, UnsupportedLookAndFeelException{
   UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
   invokeLater(new Runnable(){
       @Override
       public void run(){
           ldm = createAndShowGUI();      
           Timer timer = new Timer(5000,null);
           ActionListener timeout = ldm.timeoutPanelListener(timer);
           timer.addActionListener(timeout);
           timer.start();       
       }
   });
   }
}

Answer 1

When using CardLayout focus is not placed on the panel when the card is switched. Since the panel doesn't have focus it can't receive KeyEvents.

So first you need to make the panel focusable.

Secondly, you need to give the panel focus when it is made visible. Check out Card Layout Focus . This is a class extends CardLayout and gives the panel focus when it is made visible.