MouseListener/KeyListener not working (JPanel)

Question

I\'m doing a little project that involves the mouse and key listeners in JPanel. Unfortunately, none of the methods are called when I use the mouse/keyboard. I have worked

Answer 1

Try this instead:

 panel.addKeyListener(this);
 panel.addMouseListener(this);

You have to add the listeners to every component you want to listen to.

Answer 2

Have a look at Java KeyListener for JFrame is being unresponsive?.

You need to register your KeyListener and MouseListener for every JComponent you want to listen to:

public Hello() {
    addKeyListener(this);
    addMouseListener(this);
    panel.addKeyListener(this);
    panel.addMouseListener(this);
    frame.addKeyListener(this);
    frame.addMouseListener(this);
}

Edit:
Key and mouse events are only fired from the JComponent which has focus at the time. Because of this there seems to be a consensus that KeyBindings may be favorable to KeyListeners. The two have their applications, however, and so there is no hard and fast rule here. Have a read of 'How to Write a Key Listener' and 'How to Write a Key Binding' and you'll get the gist.

Answer 3

Better to avoid using KeyListeners with JPanel, use KeyBindings instead. JPanel cannot gain focus so cannot interact with KeyEvents. Using KeyBindings, you can map an Action to a KeyStroke even when a component doesn't have focus.