BindingActivity.kt

private val adapter by lazy {
    DataBindingAdapter<NormalUiModel>(
        bindingVariableId = BR.item,
        variables = mapOf(BR.onNormalListener to onNormalListener),
        object : DiffUtil.ItemCallback<BindingItem<NormalUiModel>>() {
            override fun areItemsTheSame(
                oldItem: BindingItem<NormalUiModel>, newItem: BindingItem<NormalUiModel>
            ) = oldItem.item.id == newItem.item.id

            override fun areContentsTheSame(
                oldItem: BindingItem<NormalUiModel>, newItem: BindingItem<NormalUiModel>
            ) = oldItem == newItem
        })
}

override fun onCreate(savedInstanceState: Bundle?) {

    binding.recyclerView.adapter = adapter

    viewModel.uiModels.observe(this) { uiModels ->
        adapter.submitList(
            uiModels.map {
                when (it) {
                    is NormalUiModel.Monitor -> it.toBindingItem(R.layout.item_normal_monitor)
                    is NormalUiModel.Mouse -> it.toBindingItem(R.layout.item_normal_mouse)
                    is NormalUiModel.Phone -> it.toBindingItem(R.layout.item_normal_phone)
                }
            }
        )
    }
}