RecyclerView is creating ViewHolders for all items at once

Question

I have main RecyclerView which contains other RecyclerViews (let's call them subRecyclerViews). The number of subRecyclerViews is based on the data received from server. The problem is, that whenever a subRecyclerView is about to become visible, it creates ViewHolders for all its items at once (instead of creating ViewHolders only for visible items).

In my MainRecyclerViewAdapter onBindViewHolder() method I call

subRecyclerViewAdapter.setData(data);
subRecyclerView.notifyDataSetChanged();

which results in a lag, because the subRecyclerView is calling onCreateViewHolder() and onBindViewHolder() methods for all its items.

The version of RecyclerView I use is

com.android.support:recyclerview-v7:25.1.1

The question is, is there a way to tell subRecyclerView that it doesn't need to create ViewHolders for the items, that are not yet visible? Also, is this a bug in RecyclerView or am I doing something wrong?

Answer 1

A solution these days instead of using 'subRecyclerViews' is to use one recyclerView with a ConcatAdapter

val firstAdapter: FirstAdapter
val secondAdapter: SecondAdapter
val thirdAdapter: ThirdAdapter
val concatAdapter = ConcatAdapter(firstAdapter, secondAdapter, 
     thirdAdapter)
recyclerView.adapter = concatAdapter