Question

Is it possible to install filter for events for all controls placed in some container?

For example I have a panel where two buttons live and one panel with two text boxes, I want to be able to receive all events that go to these controls (buttons and text boxes).

UPD
There are four controls:

JPanel mainPanel = new JPanel(new BorderLayout());
JButton b1 = new JButton();
JButton b2 = new JButton();
mainPanel.add(b1, BorderLayout.WEST);
mainPanel.add(b2, BorderLayout.EAST);

JPanel childPanel = new JPanel(new FlowLayout());
JTextField txt1 = new JTextField();
JTextField txt2 = new JTextField();
childPanel.add(txt1);
childPanel.add(txt2);
mainPanel.add(childPanel, BorderLayout.SOUTH);

EventDispatchingMachine.attachEventListener(mainPanel, listener);

where listener receives all events that go to b1, b2, txt1, txt2. Ideally every event that could be processed via listener on specific control (e.g. b1.addActionListener(asd)) I want to receive in listener.

Answer 1

In jdk7 you can use JLayer to decorate any component with listeners:

    LayerUI<JComponent> ui = new LayerUI<JComponent>() {

        @Override
        protected void processMouseEvent(MouseEvent e, JLayer<? extends JComponent> l) {
             System.out.println(e.getSource().getClass() + " at " + e.getPoint());
        } 
    };
    JLayer<JComponent> layer = new JLayer<JComponent>(mainPanel, ui);
    layer.setLayerEventMask(AWTEvent.MOUSE_EVENT_MASK );   

(for jdk6, there’s the project JXLayer which supports the same)

Edit

on second reading of the question, the answer could be “not possible”: event != event. You can (via a LayerUI or manually AWTEventListener) register to receive all events that are globally dispatched. You cannot hook into “locally” dispatched events, as f.i. actionEvents which are simply used as parameters to a known callback method which is called directly by the sender.