Add callbacks to EventBus

[smetarom]

I would appreciate a feature, where I can add additional functionality to EventBus. My main goal is to extend logging and debugging capabilities of EventBus.

My proposal is to create callbacks, which are overwritten in the child class. As at is now, I have to do logging before I call EventBus.post and it creates code duplication.

The simple example:

EventBus eventBus = new EventBus() {
@OverRide
protected void onEventPosted(Object event) {
// do some logging
}
};

I added onRegister, onUnregister, onEventPosted, and onNoSubscriberRegistered callbacks to corresponding methods.

[kluever]

We're unlikely to add new features to com.google.common.eventbus in the near future (and will in fact be recommending alternatives).