How to find the item that shows up on top of the RecyclerView while scrolling

Question

I have been looking for a proper API for what I need to do and I am all but certain that there has to be an API. But I am not finding it.

Here is my problem:

I am displaying an ArrayList inside a recycler view. What I need is to know what item in the ArrayList is showing at the top of the recycler view as I scroll up and down. Here is how I set up my recycler view (nothing special):

private ArrayList<Transaction> filteredTransactions = new ArrayList<>();
...            

recyclerView = view.findViewById(R.id.feed_recycle_view);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager((getActivity()));
        adapter = new FeedAdapter(filteredTransactions);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setAdapter(adapter);

I came across

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
}

that provides the listener I need, but I can't figure out how to get the item that appears on top of the view from it.

Thanks in advance

I think it will help you. https://stackoverflow.com/questions/48687976/how-to-find-the-position-of-current-visible-item-in-recyclerview — mrtcnkryln, Jan 28 '20 at 06:00

score 1 · Answer 1 · answered Jan 28 '20 at 05:58

You can use the following methods of the LinearLayoutManager

int findFirstVisibleItemPosition();
int findFirstCompletelyVisibleItemPosition();
int findLastVisibleItemPosition();
int findLastCompletelyVisibleItemPosition();

Read the official document

score 1 · Accepted Answer · answered Jan 28 '20 at 06:03

findFirstCompletelyVisibleItemPosition() will return the adapter position of the first fully visible view.

You can do it like this:

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int itemPoition = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstCompletelyVisibleItemPosition();

                // Get the item from the list
                mList.get(itemPoition)

            }

score 0 · Answer 3 · answered Jan 28 '20 at 05:58

There are some methods which are available in Linear Layout manager like

findFirstCompletelyVisibleItemPosition()

int findFirstVisibleItemPosition()

int findLastCompletelyVisibleItemPosition()

findLastVisibleItemPosition()

Go through the documentation it will surely help you.

How to find the item that shows up on top of the RecyclerView while scrolling

3 Answers3