Key Event not working - java

Question

I'm working through some tutorials but have been stuck on keyEvents for days. I'm sure it's to do with how I'm implementing it as I cant even get a print statement.

Here's my troubling snippet

static class Keyboard extends JPanel {

public Keyboard() {
   addKeyListener(new KeyAdapter() {

       public void keyPressed(KeyEvent e) {
            // TODO Auto-generated method stub
            System.out.println("pressed");
            switch (e.getKeyCode()) {
            case KeyEvent.VK_DOWN: 
                y += 10;break;
            case KeyEvent.VK_UP:
                y -= 10;break;
            case KeyEvent.VK_LEFT:
                x -= 10;break;
            case KeyEvent.VK_RIGHT:
                x += 10;break;
            }
            repaint();
        }
    });
}
}

and here's the full code. Its just a simple awt demonstration where you can move and enlarge a circle with existing buttons.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ShapeTest1 extends JFrame {

   private JButton enlarge = new JButton("enlarge"); 
   private JButton up = new JButton("up"); 
   private JButton right = new JButton("right"); 
   private JButton down = new JButton("down"); 
   private JButton left = new JButton("left"); 
   BoardPanel bp;
   public ShapeTest1()
   {
  bp = new BoardPanel();

  // Create a separate panel and add all the buttons 
  JPanel panel = new JPanel();
  panel.add(enlarge); 
  panel.add(up); 
  panel.add(right); 
  panel.add(down); 
  panel.add(left); 

 // add Action listeners to all button events
 enlarge.addActionListener(bp);
  up.addActionListener(bp);
  down.addActionListener(bp);
  left.addActionListener(bp);
  right.addActionListener(bp);

 // add panels to frame
 add (bp, BorderLayout.CENTER);             
  add (panel,BorderLayout.SOUTH);
}      

public static void main(String args[]) throws Exception
{
   ShapeTest1 shape = new ShapeTest1();
   shape.setTitle("Draw Shape");
   shape.setSize(700,700);
   shape.setLocationRelativeTo(null);  // center the frame
   shape.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   shape.setVisible(true);
}
}

class BoardPanel extends JPanel implements ActionListener {

private Graphics gr;
protected static int x;
protected static int y;
protected int radius = 50;

public BoardPanel()
{
  x = 300;
  y = 300;
  radius = 50;

}

/* responds to various button clicked messages */ 
public void actionPerformed(ActionEvent e)
{
 if (e.getActionCommand().compareTo("enlarge") == 0)
    radius += 10;
 else if (e.getActionCommand().compareTo("left") == 0)
    x -= 10;
 else if (e.getActionCommand().compareTo("right") == 0)
    x += 10;
 else if (e.getActionCommand().compareTo("up") == 0)
    y -= 10;
 else if (e.getActionCommand().compareTo("down") == 0)
    y += 10;
  repaint();
}

static class Keyboard extends JPanel {

public Keyboard() {
   addKeyListener(new KeyAdapter() {

       public void keyPressed(KeyEvent e) {
            // TODO Auto-generated method stub
            System.out.println("pressed");
            switch (e.getKeyCode()) {
            case KeyEvent.VK_DOWN: 
                y += 10;break;
            case KeyEvent.VK_UP:
                y -= 10;break;
            case KeyEvent.VK_LEFT:
                x -= 10;break;
            case KeyEvent.VK_RIGHT:
                x += 10;break;
            }
            repaint();
        }
    });
}
}

/* Redraws the board and the pieces
 * Called initially and in response to repaint()
 */
protected void paintComponent(Graphics gr)
{
    super.paintComponent(gr);
    gr.fillOval(x-radius, y-radius, 2*radius, 2*radius);
}   
}

Any help would be much appreciated.

Answer 1

You don't appear to be calling new Keyboard() anywhere in your code, so the listener is never created or registered. From the design I'd imagine you were intending to use this panel with the buttons on it, so change the type of your panel like so:

// Create a separate panel and add all the buttons 
JPanel panel = new Keyboard();