class HogeFragment : Fragment() {

    private var listener: OnHogeFragmentListener? = null

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val fragmentView = inflater.inflate(R.layout.fragment_hoge, container, false)
        val addFragment = fragmentView.findViewById<Button>(R.id.addFragment)
        addFragment.setOnClickListener {
            addFragment()
        }
        return fragmentView
    }

    fun addFragment() {
        listener?.onHogeFragmentAddFragment()
    }

    override fun onAttach(context: Context) {
        super.onAttach(context)
        if (context is OnHogeFragmentListener) {
            listener = context
        } else {
            throw RuntimeException("$context must implement OnHogeFragmentListener")
        }
    }

    override fun onDetach() {
        super.onDetach()
        listener = null
    }

    interface OnHogeFragmentListener {
        fun onHogeFragmentAddFragment()
    }

}