/**
 * Create and update adapter that can set list of user
 */
private void setListUser(){

    if(getListAdapter()==null){
        // init adapter
        adapter=new UserArrayAdapter(getActivity(),
                friends);
        setListAdapter(adapter);
    }
    else
    {
        //update adapter
        adapter.notifyDataSetChanged();
    }
}

public boolean onQueryTextSubmit(String newText) {
        ListUser lt = (ListUser)
                getSupportFragmentManager().findFragmentById(R.id.listuser_fragment);
        if (lt != null) {
            lt.refreshList(newText);
        }

public void refreshList(String toSearch){
    friends= SearchUser(toSearch, this.getActivity().getApplication());
    setListUser();
}