Re: KeyListener not working

From:

Radoslaw Jocz <rmjocz@poczta.onet.pl>

Newsgroups:

comp.lang.java.help

Date:

Mon, 31 Dec 2007 20:54:14 +0000

Message-ID:

<flbktn$js4$1@news.onet.pl>

Hello, probably you forgot about set component focus

requestFocusInWindow
--------------------
public boolean requestFocusInWindow()Requests that this Component gets
the input focus. Refer to Component.requestFocusInWindow() for a
complete description of this method.
If you would like more information on focus, see How to Use the Focus
Subsystem, a section in The Java Tutorial.

Justin wrote:

I'm just messing around, getting ready to write a game for fun and
can't get this KeyListener to work. I am really not sure why. The
code below should run without modification. Thanks.

package javaapplication1;

import javax.swing.JPanel;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;

public class Board extends JPanel implements KeyListener{

    private final int BOARD_WIDTH = 12;
    private final int BOARD_HEIGHT = 20;
    private final int BLOCK_SIZE = 10;
    //private Piece pieceBoard[][] = new Piece[BOARD_WIDTH]
[BOARD_HEIGHT];

    public Board() {
        setPreferredSize(new java.awt.Dimension(BOARD_WIDTH *
BLOCK_SIZE, BOARD_HEIGHT * BLOCK_SIZE));
        setSize(getPreferredSize());
        setBackground(java.awt.Color.WHITE);
        setLayout(null);

        addKeyListener(this);
        addKeyListener(new KeyListener(){

            public void keyTyped(KeyEvent e) {
                System.out.println("key event");
            }

            public void keyPressed(KeyEvent e) {
                System.out.println("key event");
            }

            public void keyReleased(KeyEvent e) {
                System.out.println("key event");
            }

        });

        System.out.println(getKeyListeners());
    }

    public static void main (String args[]){
        javax.swing.JFrame frame = new javax.swing.JFrame();
        frame.setBounds(10, 10, 200, 300);
        java.awt.Container c = frame.getContentPane();
        c.add(new Board());

frame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public void keyTyped(KeyEvent e) {
        System.out.println("key event");
    }

    public void keyPressed(KeyEvent e) {
        System.out.println("key event");
    }

    public void keyReleased(KeyEvent e) {
        System.out.println("key event");
    }
}