gistfile1.java

 @Override
    public void onActivityCreated( Bundle savedInstanceState ) {
        super.onActivityCreated( savedInstanceState );
        mainActivity = (MainActivity) getActivity();
        buttonStart.setOnClickListener( new OnClickListener() {

            @Override
            public void onClick( View v ) {
                onStart( v );
            }
        } );
        buttonStop.setOnClickListener( new OnClickListener() {

            @Override
            public void onClick( View v ) {
                onStop( v );
            }
        } );
    }