KeyClicked from KeyListener is not responding

[Zayaan Khan]

I am making a game which develops on top of the original Snake game. The problem is that when the user snake hits a purple apple or the wall or it's own snake body, the game ends. To restart the game, I have initialized the user to press SPACE in order to restart and it is not responding on press. This was working before I made changes to the drawWalls() method but I have tried backtracking to the source of the bug but I have had no luck so far. I know I should be using KeyBindings instead of KeyListener but I need to specifically use KeyListener for this project. Any help will be appreciated. Also if an MCVE needs to be created I would like advice on how to condense this to do so.

I have also provided images of both in game and when the user needs to press SPACE to restart to where it will navigate to. I have taken out some code to attempt to simplify the post.

Code:

public class Panel extends JPanel implements ActionListener, ChangeListener {
    Panel() {
        super();

        exitButton = new JButton("Exit");
        exitButton.setFont(new Font("Monaco", Font.PLAIN, 20));
        exitButton.setBounds((SCREEN_WIDTH / 2 ) + 50, (SCREEN_HEIGHT / 2) + 200, 200, 50);
        exitButton.setFocusable(false);
        exitButton.setVisible(true);
        exitButton.setEnabled(true);

        // slider
        slider = new JSlider(JSlider.CENTER, 0, 10, 1);
        slider.setPreferredSize(new Dimension(400, 200));
        slider.setPaintTicks(true);
        slider.setMinorTickSpacing(1);
        slider.setPaintTrack(true);
        slider.setMajorTickSpacing(1);
        slider.setPaintLabels(true);
        slider.setFont(new Font("Monaco", Font.PLAIN, 15));
        // slider.setOrientation(SwingConstants.VERTICAL); // sets slider vertically
        slider.addChangeListener(this);

        // lobels and buttons on slider
        sliderLabel = new JLabel();
        sliderLabel.setPreferredSize(new Dimension(450, 50));
        sliderLabel.setForeground(Color.BLACK);
        sliderLabel.setBackground(Color.WHITE);
        sliderLabel.setOpaque(true);
        sliderLabel.setHorizontalAlignment(JLabel.CENTER);
        sliderLabel.setVerticalAlignment((JLabel.CENTER));
        sliderLabel.setVisible(true);


        confirmButton = new JButton();
        confirmButton.setFont(new Font("Monaco", Font.PLAIN, 20));
        confirmButton.setBounds(100, 200, 100, 100);
        confirmButton.setText("Generate");
        confirmButton.setFocusable(false);
        confirmButton.setHorizontalAlignment(JLabel.CENTER);
        confirmButton.setVerticalAlignment(JLabel.CENTER);
        confirmButton.setForeground(Color.BLACK);
        confirmButton.setBackground(Color.LIGHT_GRAY);
        confirmButton.setBorder(BorderFactory.createEtchedBorder());

        confirmButton.setVisible(true);
        confirmButton.setEnabled(true);


        random = new Random();
        this.setPreferredSize(dimension);
        this.setBackground(Color.BLACK);
        this.setOpaque(true);

        this.setFocusable(true);
        this.addKeyListener(new MyKeyAdapter());
        this.addKeyListener(new KeyClicked());

        this.add(slider);
        confirmButton.addActionListener(this);
        this.add(confirmButton);
        this.add(sliderLabel);
        sliderLabel.setFont(new Font("Monaco", Font.PLAIN, 25));
        sliderLabel.setText("Generate " + slider.getValue() + " apples");

        // wall image
        wallImgBuff = null;
        try {
            wallImgBuff = ImageIO.read(new File("C:\\Users\\zayaa\\OneDrive\\Documents\\Zayaan\\Java\\SnakeRevamp\\SnakeRevamp\\src\\assets\\wallHorizontal.jpg")); // loading image
        }
        catch (IOException e) {
            e.printStackTrace();
            System.out.println("Image not processed");
        }

        vWallImgBuff = null;
        try {
            vWallImgBuff = ImageIO.read(new File("C:\\Users\\zayaa\\OneDrive\\Documents\\Zayaan\\Java\\SnakeRevamp\\SnakeRevamp\\src\\assets\\wallVertical.jpg"));
        }
        catch (IOException e) {
            e.printStackTrace();
            System.out.println("Image not processed");
        }


        this.setVisible(true);
    }

    public void startGame() {
        running = true;
        slider.setVisible(false);
        sliderLabel.setVisible(false);
        confirmButton.setVisible(false);
        exitButton.setVisible(false);
        newApple();
        requestFocus();
        requestFocusInWindow();

        drawWalls();

        timer = new Timer(DELAY, this);
        timer.start();

        this.setLayout(null);
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        draw(g);

    }


    public void drawWalls() {

        wallImgLabel_horizontal = new JLabel(new ImageIcon(wallImgBuff.getScaledInstance(wallImgBuff.getWidth() - 140, wallImgBuff.getHeight()  - 30, Image.SCALE_FAST)));
        wallImgLabel_horizontal.setBounds(0, 0 , wallImgBuff.getWidth() - 140, wallImgBuff.getHeight()  - 30);
        this.add(wallImgLabel_horizontal);

        wallImgLabel_horizontal2 = new JLabel(new ImageIcon(wallImgBuff.getScaledInstance(wallImgBuff.getWidth() - 140, wallImgBuff.getHeight() + 30, Image.SCALE_FAST)));
        wallImgLabel_horizontal2.setBounds(0, SCREEN_HEIGHT - 5, wallImgBuff.getWidth() - 140, wallImgBuff.getHeight() + 30);
        this.add(wallImgLabel_horizontal2);

        // vertical walls
        wallImgLabel_vertical = new JLabel(new ImageIcon(vWallImgBuff.getScaledInstance(vWallImgBuff.getWidth() - 20 , vWallImgBuff.getHeight(), Image.SCALE_FAST))); // bug at - 30 (at 0)
        wallImgLabel_vertical.setBounds(1, 0, vWallImgBuff.getWidth() - 20 , vWallImgBuff.getHeight());
        this.add(wallImgLabel_vertical);

        wallImgLabel_vertical2 = new JLabel(new ImageIcon(vWallImgBuff.getScaledInstance(vWallImgBuff.getWidth() + 250, vWallImgBuff.getHeight(), Image.SCALE_FAST)));
        wallImgLabel_vertical2.setBounds(SCREEN_WIDTH - 25, 0, vWallImgBuff.getWidth() + 250, vWallImgBuff.getHeight());
        this.add(wallImgLabel_vertical2);

    }


    public void gameOver(Graphics g) {
        // game over text
        g.setColor(Color.RED);
        g.setFont(new Font("Ink Free", Font.BOLD, 75));
        FontMetrics fontMetrics0 = getFontMetrics(g.getFont());
        g.drawString("Game Over!", (SCREEN_WIDTH - fontMetrics0.stringWidth("Game Over")) / 2 , 200); // center text

        g.setColor(Color.RED);
        g.setFont(new Font("Ink Free", Font.BOLD, 30));
        FontMetrics fontMetrics1 = getFontMetrics(g.getFont()); // getFont() uses font specified
        g.drawString("Apples Eaten: " + applesEaten, + (SCREEN_WIDTH - fontMetrics1.stringWidth("Apples Eaten: " + applesEaten)) / 2, 300);

        g.setColor(Color.WHITE);
        g.setFont(new Font("Interstate", Font.BOLD, 30));
        g.drawString("collect the  ", 150, SCREEN_HEIGHT / 2 + 50);
        g.setColor(Color.RED);
        g.drawString("RED", (SCREEN_WIDTH / 2) + 10 , SCREEN_HEIGHT / 2 + 50);
        g.setColor(Color.WHITE);
        g.drawString("apples!", (SCREEN_WIDTH / 2) + 80, SCREEN_HEIGHT / 2 + 50);

        g.setColor(new Color(195, 20, 230));
        g.setFont(new Font("Interstate", Font.BOLD, 30));
        g.drawString("Don't hit the walls!", 130 , SCREEN_HEIGHT / 2 + 100);
        g.drawString("or the PURPLE APPLES!", 130 , SCREEN_HEIGHT / 2 + 150);

        g.setColor(Color.WHITE);
        g.setFont(new Font("Interstate", Font.BOLD, 30));
        g.drawString("Press SPACE to restart", 130 , SCREEN_HEIGHT / 2 + 220);

        // button

        exitButton.addActionListener(this);
        this.add(exitButton);
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        if (running) {
            move();
            checkApple();
            checkCollisions();
        }
        repaint();
        if (e.getSource() == retryButton) {
            //   System.out.println("you clicked try again...");
            restart();
        } else if (e.getSource() == exitButton) {
            System.exit(0);
        } else if (e.getSource() == confirmButton) {
            if (confirmButton.getModel().isArmed()) {
                startGame();

            } else {
                running = false;
            }
        }
    }


    public void restart() {
        this.remove(new JFrame());
        this.remove(new Panel());
        SwingUtilities.updateComponentTreeUI(this);
        Panel game = new Panel();
        this.add(game);
        game.grabFocus();         // trigger refocus on new panel*/
        exitButton.setVisible(false);
        repaint();
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        sliderLabel.setText("Generate " + slider.getValue() + " apples");

    }
    public class KeyClicked extends KeyAdapter {
        @Override
        public void keyPressed(KeyEvent e) {

            if (e.getKeyCode() == KeyEvent.VK_SPACE) {
                restart();
                requestFocus();
                requestFocusInWindow();
                repaint();
            }
        }
    }
}

[Rob Camick]

Don't use a KeyListener. It can only respond to events when a component has focus.

Instead you can use Key Bindings. You can configure key bindings to work even when a component doesn't have focus.

[Norm Radder]

Small note: Panel is the name of a java class:  java.awt.Panel
Using the same name as one in the Java SE packages can be confusing.

[Zayaan Khan]

I have said that I need to use KeyListener. Can you provide help based on those guidelines?

[Norm Radder]

Can you post the code with the main method so the code can be executed for testing?

[Zayaan Khan]

My program features other files apart from Panel.java hence you may view the entire project on my github. The link is here: https://github.com/zkhan122/snakeboost

[Norm Radder]

How are you debugging the code?  Add some print statements to the code so you know when the Space bar is pressed.
What is the code supposed to do when Space is pressed?

[Paul Clapham]

Zayaan Khan wrote:I have said that I need to use KeyListener.

But you didn't say why.

[Norm Radder]

The code has lots of bugs that need to be found and fixed.

Note: The existing listener is called when buttons are pressed.

[Campbell Ritchie]

Afraid it also has design problems, like using only one action listener, and extending display classes.

[Zayaan Khan]

When space is pressed, it show the user the screen with the slider so they can choose the number of bad apples and play again. I will attempt to further debug this

[Zayaan Khan]

By buttons, are you referring to JButton or keypad key buttons? And yes there are several bugs which need to be fixed, I will try to debug them.

[Norm Radder]

Start by defining the detailed steps that the restart method needs to do.
Currently it looks like it is trying to startup a new instance of the Panel class.  However it does not stop the timer or remove the listeners that are associated with the old instance of the Panel class.  Leaving them will probably be a problem.
Can the code be tailored to use the existing Panel class vs creating a new instance?   What variables need to be reset?

[Zayaan Khan]

Yes I believe that the bug lies in the restart() method as my KeyClicked class which extends the KeyAdapter interface is actually working which I have tested through print statements and I am getting feedback in the console (I have attached an image to show this for further understanding) but I am still not too sure if it is a problem of refocusing on components and how I can fix this as although the actual KeyClicked interface is working, on click it does not restart the game. Further help will be appreciated.

[Norm Radder]

KeyClicked class which extends the KeyAdapter interface is actually working

Yes that is not the problem.  

on click it does not restart the game.

The restart method needs to be rewritten.
Did you read my last post?

Start by defining the detailed steps that the restart method needs to do.
Currently it looks like it is trying to startup a new instance of the Panel class.  However it does not stop the timer or remove the listeners that are associated with the old instance of the Panel class.  Leaving them will probably be a problem.
Can the code be tailored to use the existing Panel class vs creating a new instance?   What variables need to be reset?

Look at continuing to use the current instance of the Panel class.  Define a method to reset whatever variables need to changed to restart the game at the  beginning.