BaseAdapter.kt

BaseAdapter.kt

class BaseAdapter<T : Any>(
    private val layoutResId: Int,
    areContentsTheSame: (T, T) -> Boolean,
    areItemsTheSame: (T, T) -> Boolean = { old, new -> old == new },
    private val onBind: (View, T) -> Unit,
    private val onViewCreated: (View, position: () -> Pair<Int, T>) -> Unit,
) : ListAdapter<T, RecyclerView.ViewHolder>(
    GenericDiffCallback(
        areContentsTheSame,
        areItemsTheSame,
    )
) {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(layoutResId, parent, false)
        return ViewHolder(itemView)
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val item = getItem(position)
        onBind(holder.itemView, item)
    }

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        init {
            try {
                onViewCreated(itemView, ::item)
            } catch (e: Exception) {
                Timber.e(e.stackTraceToString())
            }
        }

        fun item(): Pair<Int, T> {
            val absoluteAdapterPosition = absoluteAdapterPosition
            return Pair(absoluteAdapterPosition, getItem(absoluteAdapterPosition))
        }

    }


    private class GenericDiffCallback<T : Any>(
        private val areContentsSame: (T, T) -> Boolean,
        private val areItemsSame: (T, T) -> Boolean,
    ) : DiffUtil.ItemCallback<T>() {
        override fun areContentsTheSame(oldItem: T, newItem: T): Boolean {
            return areContentsSame(oldItem, newItem)
        }

        override fun areItemsTheSame(oldItem: T, newItem: T): Boolean {
            return areItemsSame(oldItem, newItem)
        }
    }

}