BooksAdapter with multiple item types

BooksAdapter.kt

class BooksAdapter : DataBindingAdapter<Listable>(DiffCallback()) {

    class DiffCallback : DiffUtil.ItemCallback<Listable>() {
        // your DiffCallback implementation
    }

    override fun getItemViewType(position: Int) = if (getItem(position) is Book) {
        R.layout.item_book
    } else {
        R.layout.item_section
    }
}