class Adapter(_data: List<String>?) : HFEAdapter<String>(_data) {
    override fun getItemView(inflater: LayoutInflater, parent: ViewGroup): ViewHolder {

        return ViewHolder(inflater.inflate(R.layout.row, parent,false))

    }

    override fun onBindViewHolder(holder: android.support.v7.widget.RecyclerView.ViewHolder, position: Int) {
        when (holder) {
            is ViewHolder -> {
                holder.tv.text = getItem(position) //required

            }
            else -> {
            }

        }
    }


    class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {

        var tv: TextView = view.findViewById(R.id.tv)

    }
}

class MainActivity : AppCompatActivity() {
    private lateinit var hfeRecyclerView: HFERecyclerView
    private val listString: MutableList<String> = ArrayList()

    private lateinit var adapter: Adapter

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        hfeRecyclerView = findViewById(R.id.recycler)

        val mLayoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)

        hfeRecyclerView.layoutManager = mLayoutManager
        hfeRecyclerView.itemAnimator = DefaultItemAnimator()

        hfeRecyclerView.emptyView = findViewById(R.id.empty_view)
        for (i in 1..20)
            listString.add("hii $i")

        adapter = Adapter(listString)
        hfeRecyclerView.adapter = adapter

        hfeRecyclerView.setFooter(LayoutInflater.from(this).inflate(R.layout.footer,hfeRecyclerView, false))
        hfeRecyclerView.setHeader(LayoutInflater.from(this).inflate(R.layout.header,hfeRecyclerView, false))

    }
}

hfeRecyclerView.setFooter(view)

hfeRecyclerView.setHeader(view)

hfeRecyclerView.emtyView = view