Access Fragment in Activity?

Question

I have one main activity with 2 fragments. Both fragments have a ListView. I want to update the list in MainActivity. Is there any way to access fr

Answer 1

You could do the following with Otto event bus:

public class UpdateListEvent {
    private int fragmentState;

    public UpdateListEvent(int fragmentState) {
        this.fragmentState = fragmentState;
    }
}

public class MainActivity extends ActionBarActivity {
    ...
    public void updatelist() {
       SingletonBus.INSTANCE.getBus().post(new UpdateListEvent(fragmentState));
    }
}

public class FragmentA extends Fragment {
    @Override
    public void onResume() {
        super.onResume();
        SingletonBus.INSTANCE.getBus().register(this);
    }

    @Override
    public void onPause() {
        SingletonBus.INSTANCE.getBus().unregister(this);
        super.onPause();
    }

    @Subscribe
    public void onUpdateListEvent(UpdateListEvent e) {
        if(e.getFragmentState() == 0) { //is this even necessary?
            this.adapter.notifyDataSetChanged();
        }
    }
}

public class FragmentB extends Fragment {
    @Override
    public void onResume() {
        super.onResume();
        SingletonBus.INSTANCE.getBus().register(this);
    }

    @Override
    public void onPause() {
        SingletonBus.INSTANCE.getBus().unregister(this);
        super.onPause();
    }

    @Subscribe
    public void onUpdateListEvent(UpdateListEvent e) {
        if(e.getFragmentState() != 0) { //is this even necessary?
             this.adapter.notifyDataSetChanged();
        }
    }
}

And a revised version of the Singleton Bus

public enum SingletonBus {
    INSTANCE;

    private static String TAG = SingletonBus.class.getSimpleName();

    private Bus bus;

    private volatile boolean paused;

    private final Vector