GoodsAdapter.kt

class GoodsAdapter (dataSet: MutableList<Good>, val callback: Callback) : AbstractArrayAdapter<Good, GoodsAdapter.BaseHolder>(dataSet) {

    interface Callback {
        fun onNormalGoodClick(data: Good)
        fun onSaleGoodClick(data: Good)
    }

    enum class Type(val value: Int) {
        NORMAL(1),
        SALE(2)
    }

    private val normalCellLayout = R.layout.normal_item
    private val saleCellLayout = R.layout.sale_item

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseHolder {
        val inflater = LayoutInflater.from(parent.context)
        val itemView: View
        var dataHolder: BaseHolder? = null
        when(viewType) {
            Type.NORMAL.value -> {
                itemView  = inflater.inflate(normalCellLayout, parent, false)
                dataHolder = NormalGoodHolder(itemView, callback)
            }
            Type.SALE.value -> {
                itemView  = inflater.inflate(saleCellLayout, parent, false)
                dataHolder = SaleGoodHolder(itemView, callback)
            }
        }
        return dataHolder!!
    }

    override fun getItemViewType(position: Int): Int {
        if(getItemAtPosition(position).saleAmount > 0) {
            return Type.SALE.value
        }
        return Type.NORMAL.value
    }

    override fun onBindViewHolder(holder: BaseHolder, position: Int) {
        holder.bindData(getItemAtPosition(position))
    }

    abstract class BaseHolder(itemView: View, protected var callback: Callback) : RecyclerView.ViewHolder(itemView) {
        protected var unbinder: Unbinder? = null
        protected lateinit var data: Good
        abstract fun bindData(data: Good)
    }

    class SaleGoodHolder(itemView: View, callback: Callback) : BaseHolder(itemView, callback) {

        @BindView(R.id.sale_item_name)
        lateinit var name: TextView

        @BindView(R.id.sale_item_sale_amount)
        lateinit var saleAmount: TextView

        @BindView(R.id.sale_item_price)
        lateinit var price: TextView

        init {
            unbinder = ButterKnife.bind(this, itemView)
        }

        override fun bindData(data: Good) {
            this.data = data

            name.text = data.name
            saleAmount.text = "${data.saleAmount}"
            price.text = "${data.calculatePrice()}"

            itemView.setOnClickListener {
                callback.onSaleGoodClick(data)
            }
        }
    }

    class NormalGoodHolder(itemView: View, callback: Callback) : BaseHolder(itemView, callback) {

        @BindView(R.id.normal_item_name)
        lateinit var name: TextView

        @BindView(R.id.normal_item_price)
        lateinit var price: TextView

        init {
            unbinder = ButterKnife.bind(this, itemView)
        }

        override fun bindData(data: Good) {
            this.data = data

            name.text = data.name
            price.text = "${data.price}"

            itemView.setOnClickListener {
                callback.onNormalGoodClick(data)
            }
        }
    }
}