How Eventbug actually works

Question

Eventbug is a add-on for Firebug (yes, add-on for add-on), which is aimed to track all events assigned to DOM elements.

The question is - how it actually works? Since, generally speaking, there is no way, at least as far as I know, to get the list of attached events in W3C event model.

Can somebody who already explored this issue tell me something about the basic idea underneath. Is it redefining addEventListener in global scope or something?

Answer 1

It is using nsIEventListenerService which is an internal API available to Firefox add-ons. In fact, it has been introduced specifically for Firebug, see bug 448602.