@Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (mActivatedPosition != ListView.INVALID_POSITION) {
            // Serialize and persist the activated item position.
            outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
        }
    }
Mandatory empty constructor for the fragment manager to instantiate the
fragment (e.g. upon screen orientation changes).
Example/src/com/tonicartos/stickygridheadersexample/ItemListFragment.java