Activity and EventHandler confusion

Hi,

 I am using Activity classes and event handlers as follows and I am not sure if my understanding is correct. Hence the post.

1. I understand that Activity instances are disposable but view instances are not. 

2. As a result of a place change, my ActivityMapper creates a new Activity instance:

           if (place instanceof LoginPlace)

              return new LoginActivity((LoginPlace) place, clientFactory);

Question: While it is true that Activity is supposed to be disposable, is it really a good idea to create a new instance instead of reusing an existing one? I.e. is it better to just do clientFactory.getHomeActivity()?

3. In the constructor of my activity, I add event handlers. For example:

clientFactory.getEventBus().addHandler(LoginEvent.TYPE, new LoginEventHandler(){

public void onEvent(LoginEvent event) {

System.out.print("Got login event "+event.getLoggedInUser()+" "+event.getFailureMessage());

if(!event.isAuthenticated()){

Window.alert(event.getFailureMessage());

}

}

}); 

Now, as per the JavaDoc documentation of Activity, 

Any handlers attached to the provided event bus will be de-registered when the activity is stopped, so activities will rarely need to hold on to the HandlerRegistration instances returned byEventBus.addHandler(com.google.gwt.event.shared.GwtEvent.Type, H).

So, what I understand is that in the mayStop() method of my activity, I don't have to do anything wrt the event handler. If the user goes back to the same activity again, a new Activity instance will be created and a new handler will be registered (since that code is in the constructor). The old registration is automatically cleaned up.

I just want to confirm this because it seems asymmetric. In general, if I register an event handler explicitly it is my responsibility to un-register it. But here it is being cleaned up automatically. 

This ties back to the previous question that if the handler is being removed automatically, then I have no option but to create another instance of Activity (or at least re-register the handler),

Could some one please let me know how am I doing?

thank you,

Andy.

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