I'm implementing an endless data loading for a RecyclerView. When software detects that last item is going to be shown, it downloads new items and call to the loadMoreData() function but new dataset is not showing.
When I called notifyDataSetChanged() so nothing to be happened.
I have only one solution that is refresh the view is to set again the adapter but problem is that the recyclerview returns to the first position then again recyclerview scrolled up from the first position to last position.
RecyclerViewActivity.java
RecyclerView rv;
DatabaseHelpr databaseHelpr;
RVAdapter adapter;
LocationFinder locationfinder;
Location currentLocation;
ArrayList<ServiceModel> childList, list;
private int MainService_ID, city_id;
String url2;
ActionBar actionBar;
JSONArray items = null;
Utility utility;
Double lat, longi;
LinearLayoutManager llm;
int counter=0;
ProgressBar progressBar;
private static final String TAG_ITEMS = "items";
private static final String TAG_LOCALITY = "Locality";
private static final String TAG_BUSINESS_ID = "Business_Id";
private static final String TAG_LONGITUDE = "Longitude";
private static final String TAG_BUSINESS_NAME = "Business_Name";
private static final String TAG_LATITUDE = "Latitude";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recyclerview_activity);
list = new ArrayList<>();
utility = new Utility(this);
llm = new LinearLayoutManager(this);
Bundle bundle=getIntent().getExtras();
MainService_ID=bundle.getInt("service_id");
String mainService_Name = bundle.getString("service_name");
city_id = bundle.getInt("city_id");
lat= bundle.getDouble("lat");
longi=bundle.getDouble("longi");
rv=(RecyclerView)findViewById(R.id.rv);
rv.setLayoutManager(llm);
actionBar = getSupportActionBar();
assert actionBar != null;
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setTitle(mainService_Name);
//Here city_id = 8, lat = 18.552954, longi = 73.897200, counter=0, MainService_ID = 5
String url="https://servicedata2-dot-indiacomapi.appspot.com/_ah/api/servicedata/v1/ServiceData?city_id=";
url2 =url+city_id+"&lat="+lat+"&lng="+longi+"&roll="+counter+"&service_id="+MainService_ID;
AsyncHttpClient client = new AsyncHttpClient();
progressBar=(ProgressBar) findViewById(R.id.progressBar1);
progressBar.setVisibility(View.VISIBLE);
client.get(url2, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
// called when response HTTP status is "200 OK"
String s = new String(response);
try {
JSONObject jsonObj = new JSONObject(s);
// Getting JSON Array node
items = jsonObj.getJSONArray(TAG_ITEMS);
// looping through All Contacts
for (int i = 0; i < items.length(); i++) {
JSONObject c = items.getJSONObject(i);
String locality = c.getString(TAG_LOCALITY);
String business_Id = c.getString(TAG_BUSINESS_ID);
String longitude = c.getString(TAG_LONGITUDE);
String latitude = c.getString(TAG_LATITUDE);
String business_Name = c.getString(TAG_BUSINESS_NAME);
locationfinder = new LocationFinder(RecyclerViewActivity.this);
// check if GPS enabled
if (locationfinder.canGetLocation()) {
double lat = locationfinder.getLatitude();
double longi = locationfinder.getLongitude();
currentLocation = new Location("");
currentLocation.setLatitude(lat);
currentLocation.setLongitude(longi);
} else {
locationfinder.showSettingsAlert();
}
Location savedLocation = new Location("databaseLocation");
savedLocation.setLatitude(Double.parseDouble(latitude));
savedLocation.setLongitude(Double.parseDouble(longitude));
Double difference = currentLocation.distanceTo(savedLocation) * (0.001);
difference = Double.parseDouble(new DecimalFormat("##.##").format(difference));
String newDifference = String.valueOf(difference) + " km";
ServiceModel serviceModel = new ServiceModel(business_Id, business_Name, newDifference, locality);
list.add(serviceModel);
}
} catch (JSONException e) {
e.printStackTrace();
}
progressBar.setVisibility(View.GONE);
adapter = new RVAdapter(RecyclerViewActivity.this, list);
rv.setAdapter(adapter);
rv.addOnScrollListener(new EndlessRecyclerOnScrollListener(llm) {
@Override
public void onLoadMore(int current_page) {
// counter= counter+1;
loadMoreData();
}
});
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
// called when response HTTP status is "4XX" (eg. 401, 403, 404)
//Toast.makeText(getApplicationContext(),""+statusCode,Toast.LENGTH_LONG).show();
}
});
}
private void loadMoreData() {
counter= counter+1;
//Here city_id = 8, lat = 18.552954, longi = 73.897200, counter=1, MainService_ID = 5
String url="https://servicedata2-dot-indiacomapi.appspot.com/_ah/api/servicedata/v1/ServiceData?city_id=";
url2 =url+city_id+"&lat="+lat+"&lng="+longi+"&roll="+counter+"&service_id="+MainService_ID;
AsyncHttpClient client = new AsyncHttpClient();
progressBar=(ProgressBar) findViewById(R.id.progressBar1);
progressBar.setVisibility(View.VISIBLE);
client.get(url2, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
// called when response HTTP status is "200 OK"
String s = new String(response);
try {
JSONObject jsonObj = new JSONObject(s);
// Getting JSON Array node
items = jsonObj.getJSONArray(TAG_ITEMS);
// looping through All Contacts
for (int i = 0; i < items.length(); i++) {
JSONObject c = items.getJSONObject(i);
String locality = c.getString(TAG_LOCALITY);
String business_Id = c.getString(TAG_BUSINESS_ID);
String longitude = c.getString(TAG_LONGITUDE);
String latitude = c.getString(TAG_LATITUDE);
String business_Name = c.getString(TAG_BUSINESS_NAME);
locationfinder = new LocationFinder(RecyclerViewActivity.this);
// check if GPS enabled
if (locationfinder.canGetLocation()) {
double lat = locationfinder.getLatitude();
double longi = locationfinder.getLongitude();
currentLocation = new Location("");
currentLocation.setLatitude(lat);
currentLocation.setLongitude(longi);
} else {
locationfinder.showSettingsAlert();
}
Location savedLocation = new Location("databaseLocation");
savedLocation.setLatitude(Double.parseDouble(latitude));
savedLocation.setLongitude(Double.parseDouble(longitude));
Double difference = currentLocation.distanceTo(savedLocation) * (0.001);
difference = Double.parseDouble(new DecimalFormat("##.##").format(difference));
String newDifference = String.valueOf(difference) + " km";
ServiceModel serviceModel = new ServiceModel(business_Id, business_Name, newDifference, locality);
list.add(serviceModel);
}
} catch (JSONException e) {
e.printStackTrace();
}
progressBar.setVisibility(View.GONE);
//adapter = new RVAdapter(RecyclerViewActivity.this, list);
//rv.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
}
});
Toast.makeText(this, "Net is present", Toast.LENGTH_SHORT).show();
}
}
RVAdapter.java
public class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder>{
private final LayoutInflater mInflater;
List<ServiceModel> persons ;
private Context mContext;
public RVAdapter(Context context,List<ServiceModel> persons){
this.mInflater = LayoutInflater.from(context);
this.persons = new ArrayList<>(persons);
this.mContext = context;
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
@Override
public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item, viewGroup, false);
PersonViewHolder pvh = new PersonViewHolder(v);
return pvh;
}
@Override
public void onBindViewHolder(PersonViewHolder personViewHolder, int i) {
ServiceModel person = persons.get(i);
personViewHolder.businessName.setOnClickListener(clickListener);
personViewHolder.image_url.setOnClickListener(clickListenerImage);
personViewHolder.businessName.setTag(personViewHolder);
personViewHolder.difference.setTag(personViewHolder);
personViewHolder.business_id.setTag(personViewHolder);
personViewHolder.image_url.setTag(personViewHolder);
personViewHolder.locality.setTag(personViewHolder);
personViewHolder.businessName.setText(Html.fromHtml(person.getBusinessname()));
String firstLetter = String.valueOf(person.getBusinessname().charAt(0));
ColorGenerators generator = ColorGenerators.MATERIAL; // or use DEFAULT
int color = generator.getColor(person.getBusinessname());
TextDrawable drawable = TextDraw
