class ListFragment : Fragment() {

    private lateinit var books : Array<Book>

    private lateinit var recyclerView: RecyclerView
    private lateinit var viewAdapter: RecyclerView.Adapter<*>
    private lateinit var viewManager: RecyclerView.LayoutManager
    private lateinit var listener: BookOnClickListener

    companion object {
        fun newInstance(book : Array<Book>) : ListFragment{
            val myFragment = ListFragment()

            val args = Bundle()
            args.putParcelableArray("books", book)
            myFragment.arguments = (args)

            return myFragment
        }
    }

    override fun onAttach(context: Context?) {
        super.onAttach(context)
        listener= context as BookOnClickListener
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {

        val view = inflater.inflate(R.layout.list_fragment, container, false)

        books = arguments?.getParcelableArray("books") as Array<Book>

        viewManager = LinearLayoutManager(context)

        viewAdapter = BookListAdapter(books, listener::onClick)
        recyclerView = view.findViewById<RecyclerView>(R.id.recyclerView).apply {
            // use this setting to improve performance if you know that changes
            // in content do not change the layout size of the RecyclerView
            setHasFixedSize(true)

            // use a linear layout manager
            layoutManager = viewManager

            // specify an viewAdapter (see also next example)
            adapter = viewAdapter
        }

        return view
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
    }

    interface BookOnClickListener {
        fun onClick(book: Book)
    }

}