Hi,

I've been trying to listen to the Tab and Enter keys in Java Frame, so that I cna perform a custom action:


now I'm using the following methodology:

I add a keylistenter to the frame, and in the keyPressed function I write:

But When I fire up the applicaiton and press Tab, the dialog box is never displayed, and the control just moves to the next control.

When I display the getKeyCode() in the console, no matter what key I press I always get a '0'. Whereas getKeyChar() displays the characters and number nicely but does not show anything for Enter or Tab.

So how do I trap the key press on Tab and Enter button

Can you post your code, I can't get a frame to have a keylistener

I tried this but nothing gets printed out:

public MyFrame extends JFrame implements KeyListener {
public MyFrame() {
addKeyListener(this);
/* rest of code */
}

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

@Jamie Barrow

Their are three functions you have to implement:
KeyPressed, keyTyped and keyReleased

I also tried putting the code in keyTyped, but it still doesnt trap Tab and Enter keys

I know about implementing all functions, laziness made me leave them out

Can you post your code? Did you also implement KeyListener? Did you add like I did, coz my program didn't even do anything!

The following code does trap enter key but not tab key. Since the tab key is used to switch between components, something must be listening for it already and must handle the keyEvent and not pass it on. So something higher up in Swings hierarchy. Dont ask me what though

public class MyFrame extends JFrame implements KeyListener {
public static void main(String args[]) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MyFrame();
}
});
}

public MyFrame() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addKeyListener(this);
pack();
setVisible(true);
}

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

public void keyPressed(KeyEvent e) {
System.out.println(e);
if (e.getKeyCode() == 10) {
//Enter pressed
JOptionPane.showMessageDialog(this, "Enter pressed");
}
}

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

Ok I figured out how to trap the TAB key:

This is what you need to do:

component.setFocusTraversalKeysEnabled(false)

After disabling setFocusTraversalKeysEnabled, you will be able to trap the TAB key, but you must handle the focus traversal yourself in the code

Actually, the whole idea of "hijacking" the tab key is probably wrong. Please consider how you might be able to "work within the system" by CUSTOMIZING the EXISTING Swing mechanisms, instead of re-writing your own.

If you can do this, you will have a MUCH better, more responsive user interface that gives the end-user a MUCH more pleasant experience,

Please look at the following:
http://java.sun.com/docs/books/tutorial/uiswing/misc/focus.html#customFocusTraversal

IMHO .. PSM