weird key behavior

From: Jan Biel (jan.biel_at_tu-clausthal.de)
Date: 06/29/04 

Date: Tue, 29 Jun 2004 16:29:21 +0200

I have a problem and it's really driving me insane!

I gave the code below, but first the problem description:

It's quite simple:
I have a JFrame with a KeyListener.
Everytime someone hits the CTRL or ALT key the program is supposed to type
either "CONTROL" or "ALT".

But somehow the KeyListener does not always fire and I have no idea why.

When the program starts I can hit CTRL as much as I want and get the desired
result
When I hit ALT once I cannot get any CTRL registered.
When I hit ALT a second time, nothing happens
But after that, CTRL hits register every time
When I hit ALT again, no CTRL hits register
and so on.

It seems as if hitting alt would lock up the KeyEventListener until I hit
ALT again.

If I keep hitting ALT, the following happens:
ALT -> returns "ALT"
ALT -> nothing happens
ALT -> returns "ALT"
ALT -> nothing happens

and so on. Seems to me like some "on-off" switch. I'm really confused :(

=============================

Here's the code:

public class MyFrame extends JFrame implements KeyListener
{
  public MyFrame()
  {
    this.setVisible(true);
    this.setSize(100, 100);
    this.addKeyListener(this);
  }

public void keyPressed(KeyEvent arg0)
{
    if (arg0.isControlDown())
        System.out.println("CONTROL");
    if (arg0.isAltDown())
        System.out.println("ALT");
}

public void keyReleased(KeyEvent arg0)
{}

public void keyTyped(KeyEvent arg0)
{}

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