Thread: keyListener keyPressed not working

I'm working on a project at school and for some reason can't figure out why my keyListener isn't working. The project is in the CVM(Controller View Model) design.

here is the view code:

import javax.swing.JFrame;
import java.awt.Graphics;
import javax.swing.JPanel;
import java.util.ArrayList;
 
public class View extends JFrame {
    private Controller controller;
    private class MyPanel extends JPanel {
        MyPanel(Controller c) {
            addKeyListener(c);
            addMouseListener(c);
 
        }
        public void paintComponent(Graphics g) {
            controller.update(g);
            revalidate();
        }
    }
    public View(Controller c) throws Exception{
        controller = c;
        setTitle("Assignment 4");
        setSize(1200, 800);
        getContentPane().add(new MyPanel(c));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
}

here is the Controller:

import java.awt.Graphics;
import java.io.IOException;
import java.awt.event.KeyEvent;
import java.awt.event.MouseListener;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
 
class Controller implements MouseListener, KeyListener
{
    private Model model;
    private View view;
    Controller() throws IOException, Exception {
        view = new View(this);
        model = new Model(view.getWidth(), view.getHeight());
        view.requestFocus();
    }
    public void update(Graphics g) {
        if (model != null) {
            model.update(g);
        }
    }    
    public Model getModel() { return model; }
 
    public void mousePressed(MouseEvent e) {
        model.forward();
        view.repaint();
    }
    public void mouseReleased(MouseEvent e) {    }
    public void mouseEntered(MouseEvent e) {    }
    public void mouseExited(MouseEvent e) {    }
    public void mouseClicked(MouseEvent e) {    }
 
    public void keyPressed(KeyEvent e) {
        char s = e.getKeyChar();
        if(s == 'r' || s == 'R') {
            model.initialize();
        }
    }
    public void keyTyped(KeyEvent e) {    }
    public void keyReleased(KeyEvent e) {    }   
    public static void main(String[] args) throws Exception {
        //  Use the following line to determine which directory your program
        //  is being executed from, since that is where the image files will
        //  need to be.
        //System.out.println("cwd=" + System.getProperty("user.dir"));
        new Controller();
    }
}

Here is the Model:

import java.awt.Graphics;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Random;
import java.util.Iterator;
 
class Model
{
    private ArrayList<Sprite> sprites;
    private int width;
    private int height;
    Random r;
 
    Model(int w, int h) throws IOException {
        sprites = new ArrayList<Sprite>();
        width = w;
        height = h;
        r = new Random();
        initialize();
    }    
    public ArrayList<Sprite> getSpriteList() { return sprites; }
    public void initialize() {
        if((sprites != null)&&(!sprites.isEmpty())) {
            Iterator<Sprite> iter = sprites.iterator();
            while(iter.hasNext())
                sprites.remove(iter);
        }
        for (int i=0; i<50; i++) {
            int newX = r.nextInt(width-50);
            int newY = r.nextInt(height-50);
            if (i%2==0) {
                sprites.add(new Razorback(newX, newY, width, height));
            } else {
                sprites.add(new Opponent(newX, newY, width, height));
            }
        }
    }
    public void update(Graphics g) {
        for (Sprite sprite : sprites) {
            sprite.update(g);
        }
    }
    public void forward() {
    	Iterator<Sprite> iter1 = sprites.iterator();
    	while(iter1.hasNext()){
    		Sprite obj1 = iter1.next();
    		if(obj1.shouldRemove()) {
                iter1.remove();
    		}
    	}
        for (Sprite s : sprites) {
            s.move();
            Iterator<Sprite> iter2 = sprites.iterator();
            while(iter2.hasNext()) {
                Sprite obj2 = iter2.next();
                if(s.overlaps(obj2))
                {
                    if((s instanceof Razorback)&&(obj2 instanceof Opponent)){
                        obj2.hit();
                    }
                    else if((s instanceof Opponent)&&(obj2 instanceof Razorback)){
                        s.hit();
                    }
                }
            }
        }
    }
}

When a key is pressed the model is suppose to be re initialized. Any Idea why the keyListener keyPressed handler is not working?

Debug your code. Place print statements in the keyPressed method to ensure it is actually being called.
Try resizing the GUI. If you see changes after that it usually indicates a painting problem.

Does the MyPanel object have the focus?

I've tried but not sure if I was setting it right

Post the code showing where you are trying.

Does the View object get the focus? Add a focus listener to see if it gets and keeps the focus by printing out messages when it gets the focus and when it loses the focus.
What object has the key listener and what object has the focus? It needs to be the same object.

How do I request the focus for the MyPanel class

Get a reference to the object and use that to call the method.

Also you should read the tutorial about focus:
http://docs.oracle.com/javase/tutori...isc/focus.html

Where is the MyPanel object created? Use the reference to the object that is created there to call that object's methods. Or do it in the constructor.

Can the MyPanel object get the focus? Not all components can. You may need to call a method that makes it possible for the MyPanel object to get the focus. It's explained in the tutorial page I linked to in the Making a Custom Component Focusable section.

If you want a reference to the MyPanel object you should use an assignment statement with the new operator. Then use that reference to call the methods and to pass the reference to the add() method.

Or call the methods in the MyPanel's constructor.

Did you see this from post#12

Can the MyPanel object get the focus? Not all components can. You may need to call a method that makes it possible for the MyPanel object to get the focus. It's explained in the tutorial page I linked to in the Making a Custom Component Focusable section.

For debugging you should add a call to the println() method to print a message to show that the keyPressed() method was called.

Is the MyPanel object able to get the focus? See the doc at the link.

Adding a key listener to a component that can get the focus will work.
Adding a key listener to a component that is not configured to take the focus won't work until that component's method is called to allow it to get the focus.

I guess you found another component that can get the focus instead of using MyPanel.