notifyItemInserted() not working when inserting first item at zero index

Question

I am trying to insert an item in recycler view at first position i.e, 0 index as below

 try {
       commentList.add(new Comment(
          Preferences.getProfileImageUrl(),
             "",                                       
               Preferences.getUserName(DONApplication.getInstance()),
               String.valueOf(Preferences.getUserId(DONApplication.getInstance())),
               response.getString("comment_id"),
               commentText
       ));
       commentAdapter.notifyItemInserted(commentList.size() - 1);                                      
     } catch (Exception e) {
         e.printStackTrace();                    
       }

but its not showing at all but when I close the window and open it again it gets visible. I don't know why it is happening. Can someone help me?

use `commentAdapter.notifyDataSetChanged()` instead of `commentAdapter.notifyItemInserted()` — Anand Savjani, Mar 30 '17 at 10:15
read http://stackoverflow.com/questions/33789345/whats-better-notifydatasetchanged-or-notifyitemchanged-in-loop — IntelliJ Amiya, Mar 30 '17 at 10:24
@AnandSavjani, that's basically the most inefficient way to update RecyclerView as per Android Docs. — Farid, Jan 01 '20 at 10:28

score 17 · Accepted Answer · answered Oct 30 '17 at 16:25

After waisting hours - this is what I found. Item 0 was added to the list and the screen was already showing items that were previously 0-9 now displayed the items 1-10.

you need to scroll programmatically to position 0 in order to see the newly added item.

I used

public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    this.recyclerView = recyclerView;
    super.onAttachedToRecyclerView(recyclerView);
}

to get a reference to the recyclerView that is attached to the adapter(In my case I know that there is only one possible recyclerView, the javadoc states that there could be multiple ones)

after adding item at position 0, I checked if the first visible item was 0 (I don't want to scroll if the user already scrolled down)

private void restoreScrollPositionAfterAdAdded() {
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    if (layoutManager != null) {
        int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();

        if (firstVisibleItemPosition == 0){
            layoutManager.scrollToPosition(0);
        }
    }
}

notifyItemInserted() not working when inserting first item at zero index

1 Answers1