Apps Interfragment communication null pointer on view loading

[SergF]

Hi, guys,
as you could guess another one newbee question here
It should be quite routine thing for seasoned developer, but I'm not that guy.
just trying to grasp the recommended/usual way to do this thing.
So the question is next:
Let's say we have one activity and two fragments, looking like this:

fragment 1:

/**
* Created by ... on 11/9/2015.
*/
public class MyDetailFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View view=inflater.inflate(R.layout.details_layout, container, false);
return view;
}
public void show(){
TextView view=(TextView)getActivity().findViewById(R.id.detail_text);
view.setText(Long.toString(System.currentTimeMillis()));
}

}

fragment 2:

/**
* Created by ... on 11/9/2015.
*/
public class MyListFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, final ViewGroup container, Bundle savedInstanceState){
View view=inflater.inflate(R.layout.list_layout, container, false);
Button button=(Button)view.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MyListFragmentListener fragmentListener=(MyListFragmentListener)getActivity();
fragmentListener.updateDetails();
}
});
return view;
}
interface MyListFragmentListener{
void updateDetails();
}

}

activity:

public class Main extends Activity implements MyListFragment.MyListFragmentListener{
    MyDetailFragment details;
    MyListFragment list;
    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);
        list=new MyListFragment();
        details=new MyDetailFragment();
        FragmentTransaction ft=getFragmentManager().beginTransaction();
        ft.add(R.id.list_container, list, "LIST");
        if(getResources().getBoolean(R.bool.dual_pane)){

            Log.d("test", "dual_pane is true");
            FrameLayout listFrame=(FrameLayout)findViewById(R.id.list_container);
            LinearLayout.LayoutParams params=new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT);
            listFrame.setLayoutParams(params);
            ft.add(R.id.detail_container, details, "DETAILS").commit();

        }else{
            Log.d("test","dual_pane is false");
            ft.commit();
        }
    }

    @Override
    public void updateDetails(){

        if(getResources().getBoolean(R.bool.dual_pane)) {

            details.show();
        }else{
            FragmentTransaction ftr=getFragmentManager().beginTransaction();
            ftr.replace(R.id.list_container, details).addToBackStack(null).commit();
           //if uncomment section below, it works, but looks wrong...
           // Runnable r = new Runnable() {
           //     @Override
           //     public void run(){
                    details.show(); //<-- put your code in here.
           //     }
           // };
           // android.os.Handler handler=new android.os.Handler();
           // handler.postDelayed(r, 3000);

        }
    }
}

It should show two fragments and display currentTimeMillis() in fragment 1, after click on button in fragment 2 in landscape mode, and replace fragment 2 with fragment 1, displaying the same currentTimeMillis() in fragment 1 in portrait mode.

It works well in landscape, and kind of work in portrait, but
take a look at this mess in the end of activity code, if uncomment this thing with delaying to run details.show() method - it works, but such solution looks wrong...

If thing commented (like in current listing) it crushes in portrait because of NullPointerException in this string of fragment 1:

TextView view=(TextView)getActivity().findViewById(R.id.detail_text);

So the question: Is there recommended/common solution for such task, that looks less terrible?
Sorry, for newbee question...

 

[SergF]

sorry, got appropriate solution, question closed
Thank you, guys.