Communication between TabActivity and the embedded activity

Question

I am trying to figure out the best practice of communication between a TabActivity and the child activity embedded in this TabActivity.

In my TabActivity, there is a

Answer 1

Seems fine. A couple of notes:
- I see no reason for synchronization.
- I'd replace

ChildActivity.s_childActivity.changeUI();

with

if(ChildActivity.s_childActivity != null){
    ChildActivity.s_childActivity.changeUI();
}

or even

try{
    ChildActivity.s_childActivity.changeUI();
} catch(Exception e){
    //log
}

for added paranoid safety. :)