Develop Reference

Previous fragment is not being replaced when selecting a navigation menu item

I have a navigation drawer activity that shows a list of restaurants based on some data passed from the previous activity as the home fragment. On clicking on one of the restaurant cards, another fragment is created which shows the details of the restaurant. All of these fragments have the navigation drawer activity as their parent activity. When I am selecting the home fragment menu on the navigation item, the fragment does not replace the previous fragment rather it superimposes itself on the previous fragment. I will add some images to explain the scenario.
This is my Navigation Drawer -
This is the home fragment containing the restaurant lists -
This is the fragment showing the restaurant details when clicking on one restaurant -
When I press the home item on the navigation drawer from the restaurant detail screen this happens -
Here is the relevant code-
MainActivity2.class
package com.example.wfdmockapp;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.view.Menu;
import com.example.wfdmockapp.ui.home.HomeFragment;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;
import androidx.annotation.NonNull;
import androidx.core.view.GravityCompat;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import com.example.wfdmockapp.databinding.ActivityMain2Binding;
public class MainActivity2 extends AppCompatActivity{
private static final String TAG = "MainActivity2";
private String cityId = null;
private String townId = null;
private DrawerLayout drawer;
private AppBarConfiguration mAppBarConfiguration;
private ActivityMain2Binding binding;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMain2Binding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
setSupportActionBar(binding.appBarMain.toolbar);
binding.appBarMain.fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
drawer = binding.drawerLayout;
NavigationView navigationView = binding.navView;
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
mAppBarConfiguration = new AppBarConfiguration.Builder(
R.id.nav_home)
.setOpenableLayout(drawer)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
Intent getRestaurantIntent = getIntent();
cityId = getRestaurantIntent.getStringExtra("cityId");
townId = getRestaurantIntent.getStringExtra("townId");
Bundle bundle = new Bundle();
bundle.putString("cityId",cityId);
bundle.putString("townId",townId);
System.out.println(cityId+" "+townId);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.setReorderingAllowed(true)
.replace(R.id.nav_host_fragment_content_main, HomeFragment.class, bundle)
.commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_activity2, menu);
return true;
}
#Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}
}```
HomeFragment.Java
public class HomeFragment extends Fragment {
private static final String TAG = "HomeFragment";
private RequestQueue mRequestQueue;
private String cityId = null;
private String townId = null;
private String ShopListUrl= Global.base_url+"v1/get-shop-list";
private ArrayList<Shop> shops = new ArrayList<>();
private RecyclerView recyclerView;
private ShopRecyclerViewAdapter adapter;
private GifImageView loadingAnimation;
#Override
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
Bundle bundle = this.getArguments();
if(bundle!=null){
cityId = bundle.getString("cityId");
townId = bundle.getString("townId");
System.out.println(cityId+" "+townId);
}
return inflater.inflate(R.layout.fragment_home, container, false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mRequestQueue = Volley.newRequestQueue(getContext());
loadingAnimation = view.findViewById(R.id.loading_animation);
initRecyclerView(view);
getShopList();
}
public void getShopList(){
Log.d(TAG,"Creating Shop Object");
JSONObject shopInfoObject = new JSONObject();
try {
shopInfoObject.put("city",cityId);
shopInfoObject.put("town",townId);
shopInfoObject.put("shop_type",null);
shopInfoObject.put("api_token","a4e426652ed46154d67c8af897e77022");
} catch (JSONException e) {
e.printStackTrace();
}
Log.d(TAG,"JSON Shop Object created,collecting response for Request");
JsonObjectRequest ShopListRequest = new JsonObjectRequest(Request.Method.POST, ShopListUrl, shopInfoObject, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
Log.d(TAG,"Getting response");
JSONArray shopList = response.getJSONArray("shopList");
for(int i=0;i<shopList.length();i++){
JSONObject jsonObject = shopList.getJSONObject(i);
Shop shop = new Shop();
shop.setShopId(jsonObject.getString("shopId"));
shop.setName(jsonObject.getString("title"));
shop.setTypeName(jsonObject.getString("typeName"));
shop.setLogo(Global.base_imageUrl+jsonObject.getString("logo"));
shop.setSpecialOffer(jsonObject.getString("special_offer_text"));
shop.setDeliveredBy(jsonObject.getInt("deliveredBy"));
shop.setMixMatch(jsonObject.getInt("mixAndMatch"));
shop.setDeliveryFee(jsonObject.getString("delivery_fee"));
shop.setMinimumOrder(jsonObject.getString("minOrder"));
shop.setPaymentModeText(jsonObject.getString("paymentModeText"));
shop.setShopStatus(jsonObject.getString("currentStatus"));
shops.add(shop);
}
adapter.notifyDataSetChanged();
Log.d(TAG,"Shop data fetched");
loadingAnimation.setVisibility(View.GONE);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
if (error instanceof TimeoutError) {
Global.displayToast("Timeout! Please Try Again",getContext());
}
}
});
ShopListRequest.setRetryPolicy(new DefaultRetryPolicy(
6000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
mRequestQueue.add(ShopListRequest);
}
public void initRecyclerView(View view){
recyclerView = view.findViewById(R.id.recycler_view);
adapter = new ShopRecyclerViewAdapter(shops,getContext(),this);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
}
}```
RestaurantDetailsFragment.Java
package com.example.wfdmockapp;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.android.volley.DefaultRetryPolicy;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.TimeoutError;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import com.bumptech.glide.Glide;
import com.example.wfdmockapp.models.Restaurant;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import de.hdodenhof.circleimageview.CircleImageView;
import pl.droidsonroids.gif.GifImageView;
public class RestaurantDetailsFragment extends Fragment {
private static final String TAG = "RestaurantDetails";
private RequestQueue mRequestQueue;
private Restaurant restaurant = new Restaurant();
private String getShopDetailsUrl = Global.base_url+"v1/get-shop-details";
private String shopId;
private ArrayList<String> FoodTypeList;
//UI Components
private TextView name;
private TextView typeName;
private TextView shopMessage;
private TextView minOrder;
private TextView paymentModeText;
private RecyclerView foodTypeListRecyclerView;
private FoodTypeRecyclerViewAdapter adapter;
private TextView deliveryText;
private TextView deliveryFee;
private TextView deliveryTime;
private TextView shopStatus;
private CircleImageView shopLogo;
private LinearLayout shopDetailsView;
private GifImageView loadingAnimation;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
shopId = getArguments().getString("shopId");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_restaurant_details, container, false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
loadingAnimation = view.findViewById(R.id.shop_details_loading_animation);
shopDetailsView = view.findViewById(R.id.shop_view);
shopDetailsView.setVisibility(View.GONE);
FoodTypeList = restaurant.getFoodTypeList();
mRequestQueue = Volley.newRequestQueue(getContext());
initRecyclerView(view);
initUIComponents(view);
showRestaurantDetails(view);
}
public void showRestaurantDetails(View view){
JSONObject ShopInfoObject = new JSONObject();
try {
ShopInfoObject.put("api_token","cadbc10d3aa13257cd7c69bb3d434d00");
ShopInfoObject.put("shopId",shopId);
} catch (JSONException e) {
e.printStackTrace();
}
JsonObjectRequest getShopDetailsRequest = new JsonObjectRequest(Request.Method.POST, getShopDetailsUrl, ShopInfoObject, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONArray shopDetails = response.getJSONArray("shop");
String deliveryTextResponse = response.getString("deliveryText");
restaurant.setDeliveryText(deliveryTextResponse);
for(int i=0;i<shopDetails.length();i++){
JSONObject shopJsonObject = shopDetails.getJSONObject(i);
restaurant.setName(shopJsonObject.getString("title"));
restaurant.setTypeName(shopJsonObject.getString("typeName"));
restaurant.setShop_message(shopJsonObject.getString("shop_message"));
String ImageUrl = Global.base_imageUrl+shopJsonObject.getString("logo");
restaurant.setLogo(ImageUrl);
restaurant.setMinOrder(shopJsonObject.getString("minOrder"));
restaurant.setStatus(shopJsonObject.getString("currentStatus"));
JSONArray foodTypeListJSONArray = shopJsonObject.getJSONArray("foodTypeList");
for(int j=0;j<foodTypeListJSONArray.length();j++){
JSONObject foodTypeListJSONObject = foodTypeListJSONArray.getJSONObject(j);
Log.d(TAG,foodTypeListJSONObject.getString("foodTypeName"));
restaurant.addFoodListItems(foodTypeListJSONObject.getString("foodTypeName"));
}
adapter.notifyDataSetChanged();
restaurant.setDelivery_fee(shopJsonObject.getString("delivery_fee"));
JSONObject deliveryHours = shopJsonObject.getJSONObject("deliveryHours");
String openingHours = deliveryHours.getString("openingHour");
String closingHours = deliveryHours.getString("closingHour");
restaurant.setDeliveryTime("Delivery: "+openingHours+" - "+closingHours);
restaurant.setPaymentModeText(shopJsonObject.getString("paymentModeText"));
setUIComponentValues(restaurant,view);
loadingAnimation.setVisibility(View.GONE);
shopDetailsView.setVisibility(View.VISIBLE);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
if (error instanceof TimeoutError) {
Global.displayToast("Timeout error!Please try again",getContext());
}
}
});
getShopDetailsRequest.setRetryPolicy(new DefaultRetryPolicy(
5000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
mRequestQueue.add(getShopDetailsRequest);
}
public void initUIComponents(View view){
name = view.findViewById(R.id.shopName);
typeName = view.findViewById(R.id.shopTypename);
shopMessage = view.findViewById(R.id.shop_message);
minOrder = view.findViewById(R.id.min_order);
paymentModeText = view.findViewById(R.id.payment_Method);
deliveryFee = view.findViewById(R.id.min_delivery_fee);
deliveryText = view.findViewById(R.id.delivery_time_today);
deliveryTime = view.findViewById(R.id.shop_delivery_time);
shopLogo = view.findViewById(R.id.shopLogo);
shopStatus = view.findViewById(R.id.status);
}
public void setUIComponentValues(Restaurant restaurant,View view){
Glide.with(getContext()).load(restaurant.getLogo()).into(shopLogo);
name.setText(restaurant.getName());
typeName.setText(restaurant.getTypeName());
String message = restaurant.getShop_message();
System.out.println(message);
if(message.equals("")||message.equals("null")){
Log.d(TAG,"No shop message,hiding field");
LinearLayout shopMsgField = view.findViewById(R.id.shop_message_field);
shopMsgField.setVisibility(View.GONE);
}else{
shopMessage.setText(message);
}
minOrder.setText("\u20ac "+restaurant.getMinOrder()+" MIN ");
paymentModeText.setText(restaurant.getPaymentModeText());
deliveryFee.setText("Delivery \u20ac "+restaurant.getDelivery_fee());
String text = restaurant.getDeliveryText();
if(text.equals("null")||text.equals("")){
deliveryText.setVisibility(View.GONE);
}else{
deliveryText.setText(text);
}
deliveryTime.setText(restaurant.getDeliveryTime());
Global.setCurrentStatusText(restaurant.getStatus(),shopStatus);
}
public void initRecyclerView(View view){
foodTypeListRecyclerView = view.findViewById(R.id.FoodTypeRecyclerView);
adapter = new FoodTypeRecyclerViewAdapter(FoodTypeList,getContext());
foodTypeListRecyclerView.setAdapter(adapter);
foodTypeListRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
}
}```
ShopRecyclerViewAdapter.java
package com.example.wfdmockapp;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.recyclerview.widget.RecyclerView;
import com.bumptech.glide.Glide;
import com.example.wfdmockapp.models.Shop;
import java.io.FileNotFoundException;
import java.util.ArrayList;
public class ShopRecyclerViewAdapter extends RecyclerView.Adapter<ShopRecyclerViewAdapter.ViewHolder> {
private static final String TAG="ShopRecyclerViewAdapter";
private ArrayList<Shop> shops;
private Context mContext;
private Fragment fragment;
public ShopRecyclerViewAdapter(ArrayList<Shop> shops,Context mContext,Fragment fragment) {
this.shops = shops;
this.mContext = mContext;
this.fragment = fragment;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
Log.d(TAG,"Reached onCreate");
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.shoplistitem,parent,false);
ViewHolder holder = new ViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
Log.d(TAG,"Reached onBind");
try{
Glide.with(mContext).load(shops.get(position).getLogo()).into(holder.shopLogo);
}catch (Exception e){
Glide.with(mContext).load(R.drawable.shop_logo_base).into(holder.shopLogo);
}
holder.deliveryFee.setText("Delivery \u20ac "+shops.get(position).getDeliveryFee());
holder.minOrder.setText("\u20ac "+shops.get(position).getMinimumOrder()+" MIN ");
holder.paymentMethod.setText(shops.get(position).getPaymentModeText());
String status = shops.get(position).getShopStatus();
Global.setCurrentStatusText(status,holder.shopStatus);
holder.shopName.setText(shops.get(position).getName());
holder.shopTypeName.setText(shops.get(position).getTypeName());
String offerText = shops.get(position).getSpecialOffer();
if(!(offerText==null)){
holder.shopOffer.setText(offerText);
}else{
holder.offerSection.setVisibility(View.GONE);
}
int deliveredBy = shops.get(position).getDeliveredBy();
makeViewInvisible(holder.delivery_layout,deliveredBy);
int mixAndMatch = shops.get(position).getMixMatch();
makeViewInvisible(holder.mixMatchLayout,mixAndMatch);
holder.parent_layout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Bundle bundle = new Bundle();
bundle.putString("shopId",shops.get(position).getShopId());
FragmentManager fm = fragment.getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTrans = fm.beginTransaction();
fragmentTrans.replace(R.id.nav_host_fragment_content_main,RestaurantDetailsFragment.class,bundle);
fragmentTrans.setReorderingAllowed(true);
fragmentTrans.addToBackStack(null);
fragmentTrans.commit();
}
});
}
#Override
public int getItemCount() {
return shops.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
ImageView shopLogo;
TextView shopName;
TextView shopTypeName;
TextView shopOffer;
TextView minOrder;
TextView deliveryFee;
TextView paymentMethod;
TextView shopStatus;
RelativeLayout offerSection;
RelativeLayout parent_layout;
RelativeLayout delivery_layout;
RelativeLayout mixMatchLayout;
public ViewHolder(#NonNull View itemView) {
super(itemView);
shopLogo = itemView.findViewById(R.id.shop_logo);
shopName = itemView.findViewById(R.id.shop_title);
shopTypeName = itemView.findViewById(R.id.shop_typename);
shopOffer = itemView.findViewById(R.id.offer_text);
offerSection = itemView.findViewById(R.id.offer_section);
minOrder = itemView.findViewById(R.id.shop_min_order);
deliveryFee = itemView.findViewById(R.id.deliver_fee);
shopStatus = itemView.findViewById(R.id.status);
paymentMethod = itemView.findViewById(R.id.shop_payment);
parent_layout = itemView.findViewById(R.id.parent_layout);
delivery_layout = itemView.findViewById(R.id.delivered_by);
mixMatchLayout = itemView.findViewById(R.id.mix_and_match);
}
}
public void makeViewInvisible(View view,int flag){
if(flag==1){
view.setVisibility(View.GONE);
}
}
}```

You need to pop the fragment onBackPressed and function needs to execute from MainActivity thus.
MainActivity
public void popFragment() {
if (getSupportFragmentManager() == null)
return;
getSupportFragmentManager().popBackStack();
}
#Override
public void onBackPressed() {
if (getSupportFragmentManager().getBackStackEntryCount() > 1) {
popFragment();
}
}

Turns out, the problem was in the ShopRecyclerViewAdapter.java file.
In the line
FragmentManager fm = fragment.getActivity().getSupportFragmentManager
fragment.getActivity made the context null. Grabbing context from view instead solved the problem.
I replaced the above line with the following:
FragmentManager fm = ((FragmentActivity) view.getContext()).getSupportFragmentManager()
Here is the reference to the solution:
Replace fragment from recycler adapter

How i can download and read "PDF file" with AsyncTask

I am creating an application for School Students so that they do not miss their huge BOOKS. In this project, the student clicks “RecylerView”, immediately downloads the book “Pdf” and saves it to external storage. "like whatsapp" without database
At the moment, I have a problem in that it only sees the file, but does not save!
I am using AsyscTask "My PDF Viewer" activity which bottom
please help!!!
My Main Activity
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.RelativeLayout;
import java.util.ArrayList;
import java.util.List;
> public class MainActivity extends AppCompatActivity {
List<Product> productList;
//the recyclerview
RecyclerView recyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Animation animation = AnimationUtils.loadAnimation(this, R.anim.anim_about_card_show);
RelativeLayout relativeLayout = findViewById(R.id.rl);
relativeLayout.startAnimation(animation);
//getting the recyclerview from xml
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
//initializing the productlist
productList = new ArrayList<>();
//adding some items to our list
productList.add(
new Product(
1,
"TEst 11111 \n",
60000,
R.drawable.android,
"link1"
));
productList.add(
new Product(
1,
" More types, Methods, Conditionals \n",
60000,
R.drawable.android,
"link2"
));
productList.add(
new Product(
1,
"Loops, Arrays ",
60000,
R.drawable.android,
"lin3"
));
productList.add(
new Product(
1,
"Strings",
60000,
R.drawable.android,
"https://firebasestorage.googleapis.com/v0/b/firepdf-4c1d6.appspot.com/o/2.intro.pdf?alt=media&token=75731b04-c1e7-42c4-b988-e50a8f7e5f6b "
));
//creating recyclerview adapter
ProductAdapter adapter = new ProductAdapter(this, productList);
//setting adapter to recyclerview
recyclerView.setAdapter(adapter);
}
}
Adapter
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.widget.CardView;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.List;
> public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductViewHolder> {
//this context we will use to inflate the layout
private Context mCtx;
//we are storing all the products in a list
private List<Product> productList;
//getting the context and product list with constructor
public ProductAdapter(Context mCtx, List<Product> productList) {
this.mCtx = mCtx;
this.productList = productList;
}
#Override
public ProductViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//inflating and returning our view holder
LayoutInflater inflater = LayoutInflater.from(mCtx);
View view = inflater.inflate(R.layout.layout_products, null);
return new ProductViewHolder(view);
}
#Override
public void onBindViewHolder(ProductViewHolder holder, final int position) {
//getting the product of the specified position
final Product product = productList.get(position);
//binding the data with the viewholder views
holder.textViewTitle.setText(product.getTitle());
holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(product.getImage()));
holder.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), pdf.class);
i.putExtra("title",productList.get(position).getTitle());
i.putExtra("product",productList.get(position).getTitle());
i.putExtra("link",productList.get(position).getLink());
mCtx.startActivity(i);
}
});
}
#Override
public int getItemCount() {
return productList.size();
}
class ProductViewHolder extends RecyclerView.ViewHolder {
TextView textViewTitle;
ImageView imageView;
CardView cardView;
public ProductViewHolder(View itemView) {
super(itemView);
cardView = itemView.findViewById(R.id.cardview);// card intial
textViewTitle = itemView.findViewById(R.id.textViewTitle);
imageView = itemView.findViewById(R.id.imageView);
}
}
}
My Pdf Viewer
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.MenuItem;
import android.widget.Toast;
import com.github.barteksc.pdfviewer.PDFView;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class pdf extends AppCompatActivity {
String link="",productList="",product="";
PDFView pdfView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pdf);
product =getIntent().getStringExtra("title");
productList=getIntent().getStringExtra("productList");
link=getIntent().getStringExtra("link");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setTitle(productList);
pdfView=findViewById(R.id.pdfv);
//pdfView.fromAsset(link).load();
if (isConnected()) {
Toast.makeText(getApplicationContext(), "Internet Connected", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "No Internet Connection", Toast.LENGTH_SHORT).show();
AlertDialog.Builder builder = new AlertDialog.Builder(pdf.this);
builder.setTitle("NoInternet Connection Alert")
.setMessage("GO to Setting ?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
startActivity(new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS));
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(pdf.this,"Go Back TO HomePage!",Toast.LENGTH_SHORT).show();
}
});
//Creating dialog box
AlertDialog dialog = builder.create();
dialog.show();
}
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
link = getIntent().getStringExtra("link");
}
new pdf.RetrievePDFStream().execute(link);
}
public boolean isConnected() {
boolean connected = false;
try {
ConnectivityManager cm = (ConnectivityManager)getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo nInfo = cm.getActiveNetworkInfo();
connected = nInfo != null && nInfo.isAvailable() && nInfo.isConnected();
return connected;
} catch (Exception e) {
Log.e("Connectivity Exception", e.getMessage());
}
return connected;
}
class RetrievePDFStream extends AsyncTask<String, Void, InputStream> {
ProgressDialog progressDialog;
protected void onPreExecute()
{
progressDialog = new ProgressDialog(pdf.this);
progressDialog.setTitle("getting the book content...");
progressDialog.setMessage("Please wait...");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.show();
}
#Override
protected InputStream doInBackground(String... strings) {
InputStream inputStream = null;
try {
URL urlx = new URL(strings[0]);
HttpURLConnection urlConnection = (HttpURLConnection) urlx.openConnection();
if (urlConnection.getResponseCode() == 200) {
inputStream = new BufferedInputStream(urlConnection.getInputStream());
}
} catch (IOException e) {
return null;
}
return inputStream;
}
#Override
protected void onPostExecute(InputStream inputStream) {
pdfView.fromStream(inputStream).load();
progressDialog.dismiss();
}
}
#Override public boolean onOptionsItemSelected(MenuItem item)
{
if (item.getItemId() == android.R.id.home)//means home default hai kya yesok
{
onBackPressed();
return true;
}
return false;
}
}

How to send Data when cardview clicked to detail content

I try to passing data from cardview when clicked to DetailFragment, in this case I try to use interface in my adapter, but I get an error a null object reference in mOnItemClickListener.onClick(i).
I try to passing data from cardview when clicked to DetailFragment, in this case I try to use interface in my adapter.
I want to passing data to DetailMoviesFragment Class.
this is my CardviewMovieAdapter Class
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.bumptech.glide.Glide;
import com.bumptech.glide.request.RequestOptions;
import java.util.ArrayList;
public class CardviewMovieAdapter extends RecyclerView.Adapter<CardviewMovieAdapter.CardViewViewHolder> {
private ArrayList<Movie> listMovie;
Context context;
OnItemClickListener mOnItemClickListener;
public void setListMovie(ArrayList<Movie> listMovie) {
this.listMovie = listMovie;
}
public ArrayList<Movie> getListMovie() {
return listMovie;
}
public interface OnItemClickListener {
void onClick(int position);
}
public void setOnItemClickListener(final OnItemClickListener mItemClickListener) {
this.mOnItemClickListener = mItemClickListener;
}
public CardviewMovieAdapter(ArrayList<Movie> listMovie, Context context) {
this.listMovie = listMovie;
this.context = context;
}
#NonNull
#Override
public CardviewMovieAdapter.CardViewViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_movie, viewGroup,false);
return new CardViewViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final CardviewMovieAdapter.CardViewViewHolder cardViewViewHolder, final int i) {
final Movie movie = listMovie.get(i);
Glide.with(cardViewViewHolder.itemView.getContext())
.load(movie.getImageMovie())
.apply(new RequestOptions().override(350, 550))
.into(cardViewViewHolder.imgPhoto);
cardViewViewHolder.tvTitle.setText(movie.getTitleMovie());
cardViewViewHolder.tvDesc.setText(movie.getDescription());
cardViewViewHolder.btnDetail.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(cardViewViewHolder.itemView.getContext(), "Detail "+
listMovie.get(cardViewViewHolder.getAdapterPosition()).getTitleMovie(), Toast.LENGTH_SHORT).show();
}
});
cardViewViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(cardViewViewHolder.itemView.getContext(), "Kamu Memilih "+movie.getTitleMovie(), Toast.LENGTH_SHORT).show();
mOnItemClickListener.onClick(i);
}
});
// cardViewViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
// #Override
// public void onClick(View v) {
// Toast.makeText(cardViewViewHolder.itemView.getContext(), "Kamu Memilih "+movie.getTitleMovie(), Toast.LENGTH_SHORT).show();
// }
// });
}
#Override
public int getItemCount() {
return listMovie.size();
}
public class CardViewViewHolder extends RecyclerView.ViewHolder {
ImageView imgPhoto;
TextView tvTitle, tvDesc;
Button btnDetail;
public CardViewViewHolder(#NonNull View itemView) {
super(itemView);
imgPhoto = itemView.findViewById(R.id.img_item_photo);
tvTitle = itemView.findViewById(R.id.tv_title);
tvDesc = itemView.findViewById(R.id.tv_desc);
btnDetail = itemView.findViewById(R.id.btn_detail);
}
}
}
This is my MoviesFragment Class
import android.content.Intent;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.CardView;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ListView;
import java.util.ArrayList;
/**
* A simple {#link Fragment} subclass.
*/
public class MoviesFragment extends Fragment implements View.OnClickListener{
private RecyclerView rvMovie;
private String[] dataMovieTitle;
private String[] dataDescription;
private TypedArray dataPhoto;
private ArrayList<Movie> movies;
Button btnDetail;
private CardviewMovieAdapter adapter;
View view;
final static String KEY = "KEY";
public MoviesFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.fragment_movies, container, false);
//adapter = new CardviewMovieAdapter(movies,getContext());
rvMovie = view.findViewById(R.id.rv_movies);
prepare();
addItem();
showRecyclerCardView();
adapter = new CardviewMovieAdapter(movies, getContext());
adapter.setOnItemClickListener(new CardviewMovieAdapter.OnItemClickListener() {
#Override
public void onClick(int position) {
final Movie movie = movies.get(position);
DetailMoviesFragment detailMoviesFragment = new DetailMoviesFragment();
// Bundle mBundle = new Bundle();
// mBundle.putString(detailMoviesFragment.EXTRA_TITLE, movie.getTitleMovie());
// mBundle.putString(detailMoviesFragment.EXTRA_DESCRIPTION, movie.getDescription());
// mBundle.putInt(detailMoviesFragment.EXTRA_PHOTO, movie.getImageMovie());
// detailMoviesFragment.setArguments(mBundle);
MoviesFragment.newInstance(movie.getTitleMovie(), movie.getDescription(), movie.getImageMovie());
FragmentManager mFragmentManager = getFragmentManager();
if (mFragmentManager!= null) {
FragmentTransaction mFragmentTransaction = mFragmentManager.beginTransaction();
mFragmentTransaction.replace(R.id.containterFragment, detailMoviesFragment, DetailMoviesFragment.class.getSimpleName());
mFragmentTransaction.addToBackStack(null);
mFragmentTransaction.commit();
}
}
});
return view;
}
public static MoviesFragment newInstance(String title, String desc, int image) {
MoviesFragment moviesFragment = new MoviesFragment();
Bundle args = new Bundle();
args.putInt("image", image);
args.putString("title", title);
args.putString("desc", desc);
moviesFragment.setArguments(args);
return moviesFragment;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
private void showRecyclerCardView(){
rvMovie.setLayoutManager(new LinearLayoutManager(getActivity()));
CardviewMovieAdapter adapter = new CardviewMovieAdapter(movies,getActivity());
rvMovie.setAdapter(adapter);
}
private void prepare() {
dataMovieTitle = getResources().getStringArray(R.array.data_movie_name);
dataDescription = getResources().getStringArray(R.array.data_desc_movie);
dataPhoto = getResources().obtainTypedArray(R.array.data_photo_movie);
}
private void addItem(){
movies = new ArrayList<>();
for (int i=0; i < dataMovieTitle.length; i++){
Movie movie = new Movie();
movie.setImageMovie(dataPhoto.getResourceId(i, -1));
movie.setTitleMovie(dataMovieTitle[i]);
movie.setDescription(dataDescription[i]);
movies.add(movie);
}
}
#Override
public void onClick(View v) {
if(v.getId() == R.id.card_view){
}
}
}
and this is DetailMoviesActivity Class
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
public class DetailMovieActivity extends AppCompatActivity {
Movie movie;
TextView tvTitle, tvDesc;
ImageView ivMovie;
Button btnDetail;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail_movie);
initView();
}
private void initView() {
movie = (Movie) getIntent().getSerializableExtra("informasi");
String judul = movie.getTitleMovie();
String desc = movie.getDescription();
int img = movie.getImageMovie();
tvTitle.setText(judul);
tvDesc.setText(desc);
Picasso.get().load(img).into(ivMovie);
}
}

You can try with delete the setOnItemClickListener and call intent from cardViewViewHolder.itemView.setOnClickListener

How to refresh RecyclerView in one fragment when data changed in another fragment

How do I refresh the data from a local database to RecyclerView when data was successfully submitted? I use the tabs on the application. 2nd-Tab functions to submit the data, and if successful, the data will be stored in localDB.
Data on localDB I will present at the 3rd-Tab.
But what happens, I have to swipe 1st-Tab, then swipe to the 2nd-Tab and then swipe to the new 3rd-Tab data on my localDB successfully displayed.
If the 2nd-Tab me to submit the data, then I swipe to 3rd-Tab, the data will not appear on the list of data.
How do I get the data directly displayed without the need to swipe to the first 1st-Tab and then to the 2nd-Tab and 3rd-Tab ???
MainActivity :
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import com.bertho.gmyl.fragments.EngagedFragment;
import com.bertho.gmyl.fragments.RequestFragment;
import com.bertho.gmyl.fragments.SigninFragment;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.engine_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFrag(new SigninFragment(), "SIGN-IN");
adapter.addFrag(new EngagedFragment(), "ENGAGED ID");
adapter.addFrag(new RequestFragment(), "LOCATION");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFrag(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
EngagedFragment (2nd-Tab) Form to save data
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.bertho.gmyl.R;
import com.bertho.gmyl.model.Engaged;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.bertho.gmyl.realm.RealmHelper;
public class EngagedFragment extends Fragment implements View.OnClickListener {
private static final String TAG = EngagedFragment.class.getSimpleName();
private EditText nama, email, nohp;
private Button btnSaveConnection;
private DatabaseReference mFirebaseDatabase;
private FirebaseDatabase mFirebaseInstance;
private RelativeLayout mRoot;
private View rootView;
private String userId;
private TextView lblNama, lblEmail, lblNohp;
private RelativeLayout relativeLayout;
private RealmHelper realmHelper;
public EngagedFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_engaged, container, false);
realmHelper = new RealmHelper(getActivity());
String appName = getResources().getString(R.string.app_name);
loadLocalDB();
nama = (EditText) rootView.findViewById(R.id.txtName);
email = (EditText) rootView.findViewById(R.id.txtEmail);
nohp = (EditText) rootView.findViewById(R.id.txtNoHp);
lblNama = (TextView) rootView.findViewById(R.id.lblNameval);
lblEmail = (TextView) rootView.findViewById(R.id.lblEmailval);
lblNohp = (TextView) rootView.findViewById(R.id.lblNohpval);
relativeLayout = (RelativeLayout) rootView.findViewById(R.id.panelLabelDetail);
btnSaveConnection = (Button) rootView.findViewById(R.id.btnEngaged);
mFirebaseInstance = FirebaseDatabase.getInstance();
mFirebaseDatabase = mFirebaseInstance.getReference("tbl_engaged");
mFirebaseInstance.getReference("titleapp").setValue(appName);
mFirebaseInstance.getReference("titleapp").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Log.e(TAG, "TITLE UPDATED FROM FIREBASE");
String appTitle = dataSnapshot.getValue(String.class);
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle(appTitle);
}
#Override
public void onCancelled(DatabaseError error) {
Log.e(TAG, "FAILED TO READ TITLE FROM FIREBASE.", error.toException());
}
});
btnSaveConnection.setOnClickListener(this);
return rootView;
}
private void showSnack(String notify) {
mRoot = (RelativeLayout) rootView.findViewById(R.id.frag_engaged);
Snackbar snackbar = Snackbar.make(mRoot, notify, Snackbar.LENGTH_LONG);
snackbar.show();
}
public void onClick(View v) {
if(v.getId() == R.id.btnEngaged) {
String txtName = nama.getText().toString();
String txtEmail = email.getText().toString();
String txtNo = nohp.getText().toString();
if(txtName.equals("") || txtName.isEmpty()) {
showSnack("Name must filled");
nama.requestFocus();
} else if (txtEmail.equals("") || txtEmail.isEmpty()) {
showSnack("Email must filled");
email.requestFocus();
} else if (txtNo.equals("") || txtNo.isEmpty()) {
showSnack("No.HP must filled");
nohp.requestFocus();
} else {
createUser(txtName, txtEmail, txtNo);
saveToLocalDB(txtName, txtEmail, txtNo);
}
}
}
private void saveToLocalDB(String txtName, String txtEmail, String txtNo) {
realmHelper.addEngaged(txtName, txtEmail, txtNo);
}
private void loadLocalDB() {
realmHelper.getAllData();
}
private void createUser(String name, String email, String nohp) {
userId = mFirebaseDatabase.push().getKey();
Engaged user = new Engaged(name, email, nohp);
mFirebaseDatabase.child(userId).setValue(user);
addUserChangeListener();
}
private void addUserChangeListener() {
mFirebaseDatabase.child(userId).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Engaged user = dataSnapshot.getValue(Engaged.class);
if (user == null) {
Log.e(TAG, "ENGAGED DATA IS NULL");
return;
}
Log.e(TAG, "ENGAGED DATA IS CHANGED!" + user.name + ", " + user.email);
lblNama.setText(user.name);
lblEmail.setText(user.email);
lblNohp.setText(user.nohp);
//relativeLayout.setVisibility(View.VISIBLE);
nama.setText("");
email.setText("");
nohp.setText("");
}
#Override
public void onCancelled(DatabaseError error) {
// Failed to read value
Log.e(TAG, "FAILED TO READ USER", error.toException());
}
});
}
}
RequestFragment (3rd-Tab) To display localDB
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.bertho.gmyl.R;
import com.bertho.gmyl.adapter.AdapterEngaged;
import com.bertho.gmyl.model.ModelEngaged;
import com.bertho.gmyl.realm.RealmHelper;
import java.util.ArrayList;
public class RequestFragment extends Fragment {
private static final String TAG = "RequestFragment";
private RecyclerView recyclerView;
private View rootView;
private ArrayList<ModelEngaged> data;
private RealmHelper helper;
public RequestFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_request, container, false);
data = new ArrayList<>();
helper = new RealmHelper(getActivity());
recyclerView = (RecyclerView) rootView.findViewById(R.id.rvArticle);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
setRecyclerView();
return rootView;
}
public void setRecyclerView() {
try {
data = helper.findAllArticle();
} catch (Exception e) {
e.printStackTrace();
}
AdapterEngaged adapter = new AdapterEngaged(data, new AdapterEngaged.OnItemClickListener() {
#Override
public void onClick(ModelEngaged item) {
Toast.makeText(getContext(), "LIST CLICKED", Toast.LENGTH_LONG).show();
}
});
recyclerView.setAdapter(adapter);
}
#Override
public void onResume() {
super.onResume();
try {
data = helper.findAllArticle();
} catch (Exception e) {
e.printStackTrace();
}
setRecyclerView();
}
}
Everything went smoothly, it's just that I hope the data can be displayed when the form is submitted and can be directly viewed on the 3rd-Tab

Try this,
Create an Interface in EngagedFragment
say,
public interface SubmitListener {
void onSubmit();
}
private SubmitListener onSubmitListener;
public void setSubmitListener(SubmitListener onSubmitListener){
this.onSubmitListener = onSubmitListener;
}
public SubmitListener getOnSubmitListener(){
return onSubmitListener;
}
In saveToLocalDB(...) method
call
onSubmitListener.onSubmit();
In MainActivity:
1) Update the below statement:
public class MainActivity extends AppCompatActivity implements EngagedFragment.SubmitListener
2) Make your ViewPagerAdapter adapter; variable as Global variable;
while adding fragment:
EngagedFragment engagedFrag = new EngagedFragment();
adapter.addFrag(engagedFrag, "ENGAGED ID");
...
viewPager.setAdapter(adapter);
3) add this after setting adapter
engagedFrag.setSubmitListener(this);
4) Override onSubmit() method and try the below code in that method
if(viewPager != null){
if(adapter != null){
Fragment fragment = adapter.getItem(2);
if(fragment != null){
RequestFragment requestFragment = (RequestFragment) fragment;
requestFragment.setRecyclerView();
}
}
}

try this
mViewPager.setOffscreenPageLimit(0);
if that doesnt help, please check below SO question:
fragment refresh On Swip
and about : mViewPager.setOffscreenPageLimit(0); this might not work as i found in one of #commonware 's answer's, the following :-
"Does ViewPager require a minimum of 1 offscreen pages
Yes. If I am reading the source code correctly, you should be getting a warning about this in LogCat, something like:
Requested offscreen page limit 0 too small; defaulting to 1"

Android fragments must be static

I've got this error, but I don't know how to resolve this error.
Error: Fragments should be static such that they can be re-instantiated by the system, and anonymous classes are not static [ValidFragment]
Please help me if you know how to solve
This is the MainActivity.java
import android.annotation.TargetApi;
import android.app.ProgressDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.res.ColorStateList;
import android.content.res.Configuration;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private DrawerLayout mDrawerLayout;
private String keyPref = "test";
private SharedPreferences pref;
private static SharedPreferences.Editor editor;
private static ViewPager view;
private FoodListFragment makanan = new FoodListFragment() {
#Override
public void doRefresh() {
updateData();
}
};
private FoodListFragment minuman = new FoodListFragment() {
#Override
public void doRefresh() {
updateData();
}
};
private FoodListFragment snack = new FoodListFragment() {
#Override
public void doRefresh() {
updateData();
}
};
private Adapter adapter = new Adapter(getSupportFragmentManager());
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 4343;
private BroadcastReceiver mRegistrationBroadcastReceiver;
private static ProgressDialog loading;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pref = getApplicationContext().getSharedPreferences(keyPref, MODE_PRIVATE);
editor = pref.edit();
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final ActionBar ab = getSupportActionBar();
ab.setHomeAsUpIndicator(R.drawable.ic_menu);
ab.setDisplayHomeAsUpEnabled(true);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
if (navigationView != null) {
setupDrawerContent(navigationView);
}
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
if (viewPager != null) {
setupViewPager(viewPager);
}
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setBackgroundTintList(ColorStateList.valueOf(Color.rgb(183,28,28)));
fab.setOnClickListener(new View.OnClickListener() {
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
#Override
public void onClick(View view) {
Intent intent = new Intent(getApplicationContext(), CartActivity.class);
MainActivity.this.startActivity(intent);
}
});
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
DBHelper db = new DBHelper(this);
mRegistrationBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//mRegistrationProgressBar.setVisibility(ProgressBar.GONE);
SharedPreferences sharedPreferences =
PreferenceManager.getDefaultSharedPreferences(context);
boolean sentToken = sharedPreferences
.getBoolean(QuickstartPreferences.SENT_TOKEN_TO_SERVER, false);
}
};
loading = new ProgressDialog(this);
loading.setMessage("Loading");
loading.setTitle("Menu");
updateData();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
return true;
}
#Override
protected void onPause() {
super.onPause();
LocalBroadcastManager.getInstance(this).unregisterReceiver(mRegistrationBroadcastReceiver);
}
#Override
protected void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,
new IntentFilter(QuickstartPreferences.REGISTRATION_COMPLETE));
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
mDrawerLayout.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
public void updateData() {
ServerHelper server = new ServerHelper() {
#Override
public void onStart() {
loading.show();
}
#Override
public void onFinish() {
loading.dismiss();
}
#Override
public void onSuccess(int statusCode, String response) {
try {
editor.putString("response", response);
editor.commit();
makanan.clearFood();
minuman.clearFood();
snack.clearFood();
JSONArray foods = new JSONArray(response);
for (int i = 0; i <= foods.length()-1; i++) {
JSONObject object = foods.getJSONObject(i);
JSONObject subs = object.getJSONObject("SubCategory");
FoodCategory addFood = new FoodCategory(subs.getString("name"), subs.getString("photo"));
if (subs.getString("categories_id").contains("1")) {
makanan.addFood(addFood);
} else if (subs.getString("categories_id").contains("2")) {
minuman.addFood(addFood);
} else if (subs.getString("categories_id").contains("3")) {
snack.addFood(addFood);
}
}
makanan.doneRefresh();
minuman.doneRefresh();
snack.doneRefresh();
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(view.getContext(),"Terjadi masalah koneksi, silahkan coba kembali", Toast.LENGTH_LONG).show();
}
loading.dismiss();
}
#Override
public void onFailure(int statusCode, String response) {
if (view != null) {
Snackbar.make(view, "Terjadi Masalah Koneksi", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
} else {
Toast.makeText(MainActivity.this,"Terjadi Masalah Koneksi", Toast.LENGTH_LONG).show();
}
makanan.doneRefresh();
minuman.doneRefresh();
snack.doneRefresh();
loading.dismiss();
}
};
server.getAllSubs();
}
private void setupViewPager(ViewPager viewPager) {
makanan.setRetainInstance(true);
minuman.setRetainInstance(true);
snack.setRetainInstance(true);
adapter.addFragment(makanan, "Makanan");
adapter.addFragment(minuman, "Minuman");
adapter.addFragment(snack, "Snack");
viewPager.setAdapter(adapter);
updateData();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
}
private void setupDrawerContent(final NavigationView navigationView) {
View header = navigationView.getHeaderView(0);
TextView username = (TextView) header.findViewById(R.id.main_username);
DBHelper db = new DBHelper(this);
username.setText(db.getUsers().getName());
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.nav_home: {
menuItem.setChecked(true);
break;
}
case R.id.nav_order: {
navigationView.getMenu().getItem(0).setChecked(true);
Intent order = new Intent(MainActivity.this, OrderActivity.class);
startActivity(order);
break;
}
case R.id.nav_cart: {
navigationView.getMenu().getItem(0).setChecked(true);
Intent cart = new Intent(MainActivity.this, CartActivity.class);
startActivity(cart);
break;
}
case R.id.nav_logout: {
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setMessage("Anda yakin ingin logout akun anda ?");
dialog.setNegativeButton("Batal",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface arg0, int arg1) {
}
});
dialog.setPositiveButton("Keluar",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface arg0, int arg1) {
DBHelper logout = new DBHelper(MainActivity.this);
logout.clearSPConfig();
LocalBroadcastManager.getInstance(MainActivity.this).unregisterReceiver(mRegistrationBroadcastReceiver);
Intent goLogin = new Intent(MainActivity.this, LoginMainActivity.class);
startActivity(goLogin);
}
});
AlertDialog alertDialog = dialog.create();
alertDialog.show();
}
}
mDrawerLayout.closeDrawers();
return true;
}
});
}
public static class Adapter extends FragmentPagerAdapter {
private final List<Fragment> mFragments = new ArrayList<>();
private final List<String> mFragmentTitles = new ArrayList<>();
public Adapter(FragmentManager fm) {
super(fm);
}
public void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mFragmentTitles.add(title);
}
#Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
#Override
public int getCount() {
return mFragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitles.get(position);
}
}
}
and this is the fragment class FoodListFragment.java
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.annotation.UiThread;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.InflateException;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public abstract class FoodListFragment extends Fragment {
private ArrayList<FoodCategory> foodList = new ArrayList<FoodCategory>();
private RecyclerView rv;
private RecyclerViewAdapter adapter;
private SwipeRefreshLayout swipeLayout;
private View view;
FoodListFragment() {
}
public void addFoods(ArrayList<FoodCategory> food) {
foodList = food;
if (adapter != null) {
adapter.notifyDataSetChanged();
}
}
public void addFood(FoodCategory food) {
foodList.add(food);
if (adapter != null) {
adapter.notifyDataSetChanged();
}
}
public void clearFood() {
foodList.clear();
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// final RecyclerView rv = (RecyclerView) inflater.inflate(R.layout.fragment_food_list, container, false);
view = inflater.inflate(R.layout.fragment_food_list, null);
swipeLayout = (SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
doRefresh();
}
});
swipeLayout.setColorSchemeColors(Color.RED, Color.GRAY);
RecyclerView rv = (RecyclerView) view.findViewById(R.id.recyclerview);
setupRecyclerView(rv);
return view;
}
private void setupRecyclerView(final RecyclerView recyclerView) {
//recyclerView.setLayoutManager(new LinearLayoutManager(recyclerView.getContext()));
recyclerView.setLayoutManager(new GridLayoutManager(recyclerView.getContext(), 2));
recyclerView.setHasFixedSize(true);
setRetainInstance(true);
adapter = new RecyclerViewAdapter(getActivity(),foodList);
recyclerView.setAdapter(adapter);
}
public void doneRefresh(){
if (swipeLayout != null) {
swipeLayout.setRefreshing(false);
}
}
public abstract void doRefresh();
}

You are declaring your Fragment as abstract class. Abstract class can't be instantiated. It can be used only as a base class. The way you are trying to use it (anonymous class) is not possible in Android framework. A Fragment class must be a subclass of Fragment (or an existing subclass of it) and concrete.
Remove abstract keyword
public class FoodListFragment extends Fragment {
Things your are trying to achieve with
public abstract void doRefresh();
should be done using an interface.