Question

I’m writing a XMPP Client using SMACK.

So when I want to update my contactList – the ListAdapter.notifyDataSetChanged requires to be run in the UI thread, but obviously the SMACK Library uses Multithreading on the RosterListener (which in fact is a good thing). But here is the problem: to run s.th. in the UI thread, I need a valid context.

But how do I get it? Passing the Context of the Activity down to the register function of the RosterListener was the first that came to mind – but I have some functions in different classes there before I even get to the register function, and I don’t really like it to pass the context over and over again until it finally reaches its destination, where it will be used.

I guess, I’m not the only one, who has encountered this problem, so how would you solve it?

Maybe a Singleton, just to save this one Context (in my opinion an even less favourable idea…)
Or is maybe my whole design flawed?
Is there a possibility to get the UI thread from anywhere?

Bottom line: I don’t really have a clue how to handle it, at the moment I’m passing the context as argument through multiple functions, but is there a better way to do it.

Thanks for any help.

Answer 1

Put XMPP code into Service and then send broadcasts. Interested Activities can simply register for those broadcasts. That way you’ll never again worry about UI thread and availability of Activity context.