How to access views directly with ViewPager2

TL;DR:

You can use

(viewPager2.getChildAt(0) as RecyclerView)

to access the internal RecyclerView used inside the ViewPager2 for now, and you can call findViewHolderForAdapterPosition() or findViewHolderForItemId() as usual.

Explanation:

I had a custom view implementing a ViewPager which could, in some cases, modify the inner views without having to recompute all of them for a small change.

This is not possible to do as such anymore, as the internal implementation is a bit different. As you know, ViewPager2 now uses a RecyclerView.Adapter to handle the paged views, but how is it used internally?

Internals:

If we look at the children of an initialized ViewPager2, we can see there is only one, a RecyclerViewImpl. RecyclerViewImpl is a new internal class used to manage the ViewPager2 internally, bringing a lot of benefits that ReyclerViews have to ViewPager. Unfortunately, this class is private and therefore inaccessible outside of ViewPager2. So we're stuck?

Nope! RecyclerViewImpl inherits from RecyclerView, and it should be enough in most cases, and thankfully in ours, to use.

Solution:

So then we can use:

(viewPager2.getChildAt(0) as RecyclerView)

to access the internal RecyclerView.

We can quickly wrap that in a Kotlin extension function to hide the complexity and simplify the use:

fun ViewPager2.findViewHolderForAdapterPosition(position: Int): RecyclerView.ViewHolder? {
    return (getChildAt(0) as RecyclerView).findViewHolderForAdapterPosition(position)
}

You can adapt to something that suits your needs better of course, like for example directly returning the ViewHolder.itemView.

⚠️ Warning : This relies on internal implementation, which could change at any time without warning. For now this is the only way that I found to access the underlying views, but a feature request is open here.