example RecyclerView Adapter using view type

BaseRecyclerAdapter.kt

abstract class BaseRecyclerAdapter<Item, ViewBinding : ViewDataBinding>(
    callBack: DiffUtil.ItemCallback<Item>
) : ListAdapter<Item, BaseViewHolder<ViewBinding>>(
    AsyncDifferConfig.Builder<Item>(callBack)
        .setBackgroundThreadExecutor(Executors.newSingleThreadExecutor())
        .build()
) {

    override fun submitList(list: List<Item>?) {
        super.submitList(ArrayList<Item>(list ?: listOf()))
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<ViewBinding> {
        return BaseViewHolder(
            DataBindingUtil.inflate<ViewBinding>(
            LayoutInflater.from(parent.context),
            getLayoutRes(viewType),
            parent, false
        ).apply {
            bindFirstTime(this)
        })
    }

    override fun onBindViewHolder(holder: BaseViewHolder<ViewBinding>, position: Int) {
        try {
            val item: Item = getItem(position)
            holder.binding.setVariable(BR.item, item)
            bindView(holder.binding, item, position)
        } catch (e: IndexOutOfBoundsException) {
            bind(holder.binding, position)
        }
        holder.binding.executePendingBindings()
    }

    /**
     * get layout res based on view type
     */
    protected abstract fun getLayoutRes(viewType: Int): Int

    /**
     * override if need
     * bind first time
     * use for set item onClickListener, something only set one time
     */
    protected open fun bindFirstTime(binding: ViewBinding) {}

    /**
     * override if need
     * bind view
     */
    protected open fun bindView(binding: ViewBinding, item: Item, position: Int) {}

    protected open fun bind(binding: ViewBinding, position: Int) {}
}

open class BaseViewHolder<ViewBinding : ViewDataBinding> constructor(
    val binding: ViewBinding
) : RecyclerView.ViewHolder(binding.root)

EventDetailAdapter.kt

class EventDetailAdapter(
    private val headerViewModel: EventDetailHeaderViewModel
) : BaseRecyclerAdapter<Any?, ViewDataBinding>(eventDetailDiffCallback) {

    companion object {
        const val TYPE_INFO = 1
        const val TYPE_MY_DISCUSSION = 2
        const val TYPE_DISCUSSIONS = 3
    }

    override fun getLayoutRes(viewType: Int): Int {
        return when (viewType) {
            TYPE_INFO -> R.layout.section_event_detail_info
            TYPE_MY_DISCUSSION -> R.layout.item_my_discussion
            else -> R.layout.item_discussion
        }
    }

    override fun getItemViewType(position: Int): Int {
        return when (position) {
            0 -> TYPE_INFO
            1 -> TYPE_MY_DISCUSSION
            else -> TYPE_DISCUSSIONS
        }
    }

    override fun onBindViewHolder(holder: BaseViewHolder<ViewDataBinding>, position: Int) {
        when (position) {
            0 -> holder.binding.setVariable(BR.headerViewModel, headerViewModel)
        }
        super.onBindViewHolder(holder, position)
    }
}

val eventDetailDiffCallback = object : DiffUtil.ItemCallback<Any?>() {
    override fun areItemsTheSame(oldItem: Any, newItem: Any): Boolean {
        return when (oldItem) {
            is Event -> oldItem == newItem
            else -> true
        }
    }

    override fun areContentsTheSame(oldItem: Any, newItem: Any): Boolean {
        return when (oldItem) {
            is Event -> (oldItem as Event) == newItem
            else -> true
        }
    }

}