From what I understand, you need to handle 2 states:

1. LOADING – When the search button is clicked and you are getting your data from Api Or Db.
2. LOADED – When the data is fetched, and set in the adapter of the recyclerview.

   // In loading state,clear data, hide recyclerview and show progressbar
   public void showLoadingState() {
      pb_Search.setVisibility( View.VISIBLE );
      rv_items.setVisbility(View.GONE);
      // Clear your adapter here, otherwise old content will
      // show when you do 2 searches in a row.
   }

   // In loaded state, show recyclerview and hide progressbar
   public void showLoadedState() {
      pb_Search.setVisibility( View.GONE );
      rv_items.setVisbility(View.VISIBLE);
   }

I created an EditText that is used in order to search.

Once the user click the search button I show a ProgressBar until the RecyclerView is loaded by doing this:

et_Search.setOnEditorActionListener( (v, actionId, event) -> {
    if (actionId == EditorInfo.IME_ACTION_SEARCH) {

        InputMethodManager imm =(InputMethodManager) getSystemService( Context.INPUT_METHOD_SERVICE);
        View view = this.getCurrentFocus();
        imm.hideSoftInputFromWindow( view.getWindowToken(), 0);

        pb_Search.setVisibility( View.VISIBLE );

        query = et_Search.getText().toString();

        fetchAddItems(query);

        return true;
    }
    return false;
} );

Where:

private void fetchAddItems(String query) {

    B_client = new ItemClient();
    B_client.getItems( query, new JsonHttpResponseHandler() {
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
            List<Item> Items;
            try {
                JSONArray items;
                if (response != null) {
                    items = response.getJSONArray( "items" );
                    Items = Item.fromJson( items );

                    AddItemsAdapter = new AddItemAdapter(Items, listenerAdd);
                    rv_Items.setAdapter(AddItemsAdapter);

                    rv_Items.getViewTreeObserver()
                        .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                            @Override
                            public void onGlobalLayout() {
                                pb_Search.setVisibility( View.GONE );
                            }
                        });

                }
            } catch (JSONException ignored) {

            }
        }
    } );

}

Everything works ok.

The problem is in the case where the user performs two searches in a row.

In this case, the RecyclerView is already filled from the first search, and therefore the ProgressBar won’t show.

Is there a way to do what I want in both cases when the RecyclerView is filled/updated?

Thank you

SOLUTION:

What solved my problem is removing the listener and using this:

rv_Items.getViewTreeObserver()
    .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            rv_Items.setVisibility( View.VISIBLE );
            pb_Search.setVisibility( View.GONE );
            rv_Items.getViewTreeObserver().removeOnGlobalLayoutListener(this);
        }
    });