smoothScrollToPosition does not work in nested RecyclerView

Question

I have a recyclerView and each of it's item is a recyclerView. I want scroll to custom position of inner recyclerView at specific condition. I used this code at innerRecyclerView but it didn't work:

innerRecyclerView.smoothScrollToPosition(position);

and this:

innerRecyclerView.scrollToPosition(position);

and this one:

layoutManager.scrollToPositionWithOffset(position, offset);

Now I have two question:

1) Is it possible scroll to custom position of inner recyclerView?

2) If that is possible, how?

Here is initialize main recyclerView:

LinearLayoutManager layoutManager = new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false);
        adapter = new FreightsListRVAdapter(new FreightListCallBack(), new FreightListVHFactory());
        rvFreightsList.setLayoutManager(layoutManager);
        rvFreightsList.setItemViewCacheSize(30);
        rvFreightsList.setNestedScrollingEnabled(true);
        rvFreightsList.setAdapter(adapter);

Here is initialize innerRecyclerview:

LinearLayoutManager layoutManager = new LinearLayoutManager(itemView.getContext(), RecyclerView.VERTICAL, false);
        layoutManager.setItemPrefetchEnabled(true);
        layoutManager.setInitialPrefetchItemCount(7);
        rvFreights.setNestedScrollingEnabled(false);
        rvFreights.setLayoutManager(layoutManager);
        rvFreights.setItemViewCacheSize(20);

        adapter = new FreightsRVAdapter(new FreightCallBack(), new FreightSingleVHFactory());
        rvFreights.setAdapter(adapter);

Here is my main recyclerView adapter:

public class FreightsListRVAdapter extends ListAdapter<FreightListModel, FreightListVH> {

    private final FreightListVHFactory mFactory;
    private final PublishSubject<FreightListVHAction> mClickUserPS = PublishSubject.create();

    @Inject
    public FreightsListRVAdapter(@NonNull FreightListCallBack diffCallback, FreightListVHFactory factory) {
        super(diffCallback);
        mFactory = factory;
    }

    @NonNull
    @Override
    public FreightListVH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return mFactory.create(parent);
    }

    @Override
    public void onBindViewHolder(@NonNull FreightListVH holder, int position) {
        holder.getVM().setObject(getItem(position));
        holder.bind();
        holder.itemOnClick(mClickUserPS);

    }

    public PublishSubject<FreightListVHAction> getmClickUserPS() {
        return mClickUserPS;
    }
}

Here is layout of each row of mainRecyclerView:

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:descendantFocusability="blocksDescendants"
    android:orientation="vertical">

    <androidx.appcompat.widget.AppCompatTextView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/txtDescription"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingLeft="10dp"
        android:paddingTop="5dp"
        android:paddingRight="10dp"
        android:textColor="#992C2C2C"
        android:textSize="11sp"
        app:fontFamily="@font/iransans"
        tools:ignore="HardcodedText,SmallSp" />

    <androidx.appcompat.widget.AppCompatTextView
        android:id="@+id/txtDate"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_marginLeft="15dp"
        android:layout_marginRight="15dp"
        android:layout_marginBottom="15dp"
        android:gravity="right"
        android:textColor="#2C2C2C"
        android:textSize="20sp"
        app:fontFamily="@font/iransans_medium"
        tools:ignore="RtlHardcoded"/>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvFreights"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:overScrollMode="never"
        android:scrollbars="none" />
</androidx.appcompat.widget.LinearLayoutCompat>

You need to store a reference of inner RecylerView in some Arraylist (as outer one is dynamic) and later on you can scroll using that reference. Don't forget to push reference in `onBindMethod` of outer RecylerView — Firdous nath, Feb 25 '19 at 14:04
not sure if this will work in your case: https://stackoverflow.com/questions/52083678/nestedscrollviews-smoothscrollto-behaves-weird — user1506104, Mar 13 '19 at 18:16
Have you tried this [solution](https://stackoverflow.com/questions/11431832/android-smoothscrolltoposition-not-working-correctly) — Abid Khan, Mar 18 '19 at 12:38
And you should also try `layoutManager.smoothScrollToPosition(recyclerView, new RecyclerView.State(), position);` if the setSelectionMethod doesn't works for you. — Abid Khan, Mar 18 '19 at 12:59
It is possible to scroll an inner `RecyclerView` and it is quite straight forward, you just get the inner recycler view instance and call the scrollToPosition method on it. However as you've said you haven't found any luck doing so. Can you instead show how you are getting the inner `RecyclerView`? I recommend `mainRecyclerView.findViewHolderForPosition()` This will return `LinearLayoutCompat`, however you can then use `findByViewId(R.id.rvFreights)` on it to get the `RecyclerView`. — Abbas, Mar 18 '19 at 13:01
all recycler are vertical, this is bad for performance, the nested recycler will draw all items on initialization... layout manager will no be able to scroll to nested scroll position, the best way is to merge on 1 recycler. If it's too hard to do, you can try this. You have to use the nested scrollView and retrieve the ViewHolder using findViewHolderForAdapterPosition. with the viewholder.itemView, use layoutManager, getDecoratedBoundsWithMargins to get Y bound, after that, on main recycler layout manager call scrollToPositionWithOffset, with position in main recycler and Y as offset. — Anis BEN NSIR, Mar 19 '19 at 18:00

score 1 · Answer 1 · answered Apr 01 '21 at 10:35

In Kotlin-androidX recyclerview solution

val parentViewHolder = parentRecyclerView?.findViewHolderForAdapterPosition(parentPosition) as? ParentViewHolder?

var childY = 0F
if (parentViewHolder != null)
  childY = parentViewHolder.childRecyclerView?.getChildAt(lastPosition)?.y ?: 0F
parentRecyclerView.scrollBy(0, childY.toInt())

PrentViewHolder.kt

class PrentViewHolder(
    view: InflateBinding
): RecyclerView.ViewHolder(view.root) {
    var recyclerView: RecyclerView? = null

    fun populateData(data: Data) {
        viewDataBinding.recyclerview.adapter = adapter
        recyclerView = viewDataBinding.recyclerview
    }
}

score 0 · Answer 2 · answered Mar 20 '19 at 06:15

0

Can you please try this:

 float y = recyclerView.getY() + recyclerView.getChildAt(selectedPosition).getY();    
 mainRecyclerview.smoothScrollTo(0, (int) y);

answered Mar 20 '19 at 06:15

Jiten Basnet

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smoothScrollToPosition does not work in nested RecyclerView

2 Answers2