ScrollStateHolder

Persists scroll state for nested RecyclerViews.

1. Call saveScrollState in RecyclerView.Adapter.onViewRecycled to save the scroll position.

2. Call restoreScrollState in RecyclerView.Adapter.onBindViewHolder after changing the adapter's contents to restore the scroll position

In fragment or activity override fun onSaveInstanceState(outState: Bundle) { super.onSaveInstanceState(outState) if (::scrollStateHolder.isInitialized) scrollStateHolder.onSaveInstanceState(outState) }

private lateinit var scrollStateHolder: ScrollStateHolder override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) scrollStateHolder = ScrollStateHolder(savedInstanceState) }