UserAdapter.kt

class UserAdapter : RecyclerView.Adapter<UserAdapter.UserViewHolder> {
        
        var users: List<User> = emptyList()
            set(value) {
                field = value
                notifyDataSetChanged()
            }

       // This keeps track of the currently selected position
       var selectedPosition by Delegates.observable(-1) { property, oldPos, newPos ->
            if (newPos in items.indices) {
                notifyItemChanged(oldPos)
                notifyItemChanged(newPos)
           }
       }

        override fun onCreateViewHolder(parent: ViewGroup, viewType:   Int): UserViewHolder {
            val layoutInflater = LayoutInflater.from(parent.context)
            val viewBinding: ViewListItemBinding =
                        DataBindingUtil.inflate(layoutInflater,R.layout.view_list_item, parent, false)
        return UserViewHolder(viewBinding)
        }

       override fun getItemCount(): Int = users.size

       override fun onBindViewHolder(holder: UserViewHolder, position: Int) {
        if (position in users.indices){
            holder.bind(items[position], position == selectedPosition)
            holder.itemView.setOnClickListener { selectedPosition = position }
        }
    }

    inner class UserViewHolder(private val viewBinding: ViewListItemBinding) :
        RecyclerView.ViewHolder(viewBinding.root) {

        fun bind(user: User, selected: Boolean) {
            with(event) {
                viewBinding.tvUserName.text = name
                viewBinding.tvAddress.text = address
                viewBinding.tvAge.text = "$age"
                viewBinding.btnChecked.isChecked = selected
            }
        }
    }
}