MouseListener on JFrame

Question

I want to be notified of mouse events (specifically the mouse entered and exited events) on my JFrame. But when i add a mouselistener to it i get the events on the borders of the frame not the entire frame with it's contents.

Any ideas as to why?

EDIT : Or at least do you have an alternative? I want a "gloabal" way to catch mouse events on the JFrame. Maybe a mouselistener is not the answer.

Answer 1

You can get all events and check if their source is a component in the JFrame.

See Toolkit.addAWTEventListener

Answer 2

There is an invisible component that overlays the whole GUI, the "glass pane". You can attach your listeners to that. Example:

JFrame frame = new JFrame();
Component glassPane = frame.getGlassPane();
glassPane.addMouseListener(myListener);

If you want your intercepted events to pass through to the underlying components, you can redispatch them. For example:

public void mouseMoved(MouseEvent e) {
    redispatchMouseEvent(e, false);
}

Answer 3

Because the contents ( probably a JPanel ) are "shadowing" and consuming the events and they don't reach the JFrame.

What you can do is to add the same listener to all the children. There should be a better way though.

Answer 4

An alternative to AWTEventListener is to push an EventQueue. This has the advantage that applets and WebStart application can do this.