activity.java

FloatingActionButton FAB = (FloatingActionButton) v.findViewById(R.id.fab);
FAB.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(getActivity(), AddAlarmActivity.class);
        getActivity().startActivityForResult(intent, Constants.ADD_ALARM_REQUEST);
    }
});