sumeetph

//Return cached view holder for particular position
    private val viewCacheExtension = object : ViewCacheExtension() {
        override fun getViewForPositionAndType(
            recycler: Recycler,
            position: Int,
            type: Int
        ): View? {
            val cachedItemId = getItemId(position)
            if (cachedViewHolderTypes.contains(type) && cachedItemId != NO_CACHED_ITEM_ID
                && cachedItems.containsKey(cachedItemId)

sumeetph

 //Saving the cached item once it goes out of screen
    override fun onViewDetachedFromWindow(holder: ViewHolder) {
        if (cachedViewHolderTypes.contains(holder.itemViewType)) {
            val pos = holder.bindingAdapterPosition
            Timber.d("onViewDetached called for position : $pos")
            if (pos > -1) {
                holder.setIsRecyclable(false)
                cachedItems[getCachedItemId(pos)] = holder
            }

sumeetph

override fun onChanged() {
            Timber.d("items added or moved")
            if (cachedItems.isEmpty())
                return

            val iterator: MutableIterator<String> = cachedItems.keys.iterator()

            val newItemsIds = mutableSetOf<String>()

            for (newIndex in 0 until itemCount) {

sumeetph

 override fun onItemRangeRemoved(positionStart: Int, itemCount: Int) {
            Timber.d("On Item range removed  called for adapter observer")
            if (cachedItems.isEmpty())
                return
            val iterator: MutableIterator<String> = cachedItems.keys.iterator()

            while (iterator.hasNext()) {
                val cachedItemId = iterator.next()
                val index = cachedItems[cachedItemId]?.bindingAdapterPosition ?: -1
                if (index != -1 && positionStart <= index && index < positionStart + itemCount) {

sumeetph

import android.view.View
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.RecyclerView.*
import timber.log.Timber
import java.util.HashSet
import java.util.concurrent.ConcurrentHashMap

/**
 * Created by Sumeet on 24,January,2022