Develop Reference

Listener from DialogFragment to Fragment

I'm a beginner in Java and I'm trying to create a listener in my DialogFragment to notice my fragment that some book was removed. When the user removes a book, I want to call the removeBook method in BookFragment and update the recyclerview.
Here is my BookDialogFragment.java:
package com.compose.dietapp.ui.books;
import android.app.Dialog;
import android.content.DialogInterface;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.fragment.app.DialogFragment;
import java.util.Objects;
public class BookDialogFragment extends DialogFragment {
private final String nameToDelete;
private final int position;
private static String MESSAGE_TO_DIALOG_FRAGMENT;
public BookDialogFragment(String nameToDelete, int position) {
this.nameToDelete = nameToDelete;
this.position = position;
}
public static BookDialogFragment newInstance(String title, String nameToDelete, int position) {
BookDialogFragment frag = new BookDialogFragment(nameToDelete, position);
if (Objects.equals(nameToDelete, "none")) {
MESSAGE_TO_DIALOG_FRAGMENT = "Book removed!";
} else {
MESSAGE_TO_DIALOG_FRAGMENT = "Are you sure you want to remove the book '"
+ nameToDelete
+ "'?";
}
Bundle args = new Bundle();
args.putString("title", title);
frag.setArguments(args);
return frag;
}
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
assert getArguments() != null;
String title = getArguments().getString("title");
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getActivity());
alertDialogBuilder.setTitle(title);
alertDialogBuilder.setMessage(MESSAGE_TO_DIALOG_FRAGMENT);
if (Objects.equals(MESSAGE_TO_DIALOG_FRAGMENT, "Book removed!")) {
alertDialogBuilder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
if (dialog != null) {
dialog.dismiss();
}
}
});
} else {
alertDialogBuilder.setPositiveButton("Remove", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// here I want to callback my fragment
BookFragment deleteBook = new BookFragment();
deleteBook.removeBook(nameToDelete, position);
Bundle result = new Bundle();
result.putBoolean("value", true);
getParentFragmentManager().setFragmentResult("removed", result);
}
});
alertDialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
if (dialog != null) {
dialog.dismiss();
}
}
});
}
return alertDialogBuilder.create();
}
#Override
public void onStart() {
super.onStart();
((AlertDialog) Objects.requireNonNull(getDialog())).getButton(AlertDialog.BUTTON_NEGATIVE)
.setTextColor(Color.rgb(128, 128, 128));
}
}
And here is my BookFragment.java:
package com.compose.dietapp.ui.books;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.compose.dietapp.R;
import com.compose.dietapp.database.DatabaseAccess;
import com.compose.dietapp.databinding.FragmentBookBinding;
import java.util.ArrayList;
public class BookFragment extends Fragment{
#SuppressLint("StaticFieldLeak")
private static Activity activity;
private RecyclerView recyclerView;
private final ArrayList<Book> itensBook = new ArrayList<Book>();
private BookAdapter bookAdapter;
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
activity = this.getActivity();
View v = inflater.inflate(R.layout.fragment_book, container, false);
recyclerView = (RecyclerView) v.findViewById(R.id.book_recycler);
instanciateBooks();
return v;
}
private void instanciateBooks() {
ArrayList<ArrayList<String>> bookDatabaseValues = getDatabaseData();
if (recyclerView != null && bookDatabaseValues != null) {
createItemBook(bookDatabaseValues);
createRecyclerViewBook();
}
}
public void removeBook(String nameToDelete, int position) {
getChildFragmentManager().setFragmentResultListener("removed",
this, new FragmentResultListener() {
#Override
public void onFragmentResult(#NonNull String requestKey, #NonNull Bundle bundle) {
String result = bundle.getString("value");
Log.i("result", result);
}
});
}
private void createRecyclerViewBook() {
recyclerView.setHasFixedSize(true);
bookAdapter = new BookAdapter(activity, itensBook);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(activity,
LinearLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(bookAdapter);
}
private void createItemBook(ArrayList<ArrayList<String>> bookDatabaseValues) {
for (int i = 0; i < bookDatabaseValues.size(); i++) {
itensBook.add(new Book(
String.valueOf(bookDatabaseValues.get(i).get(0)),
String.valueOf(bookDatabaseValues.get(i).get(1)),
String.valueOf(bookDatabaseValues.get(i).get(2)),
String.valueOf(bookDatabaseValues.get(i).get(3)),
String.valueOf(bookDatabaseValues.get(i).get(4))
));
}
}
public static ArrayList<ArrayList<String>> getDatabaseData() {
if (activity != null) {
return getArrayListsFromDatabase();
}
return null;
}
private static ArrayList<ArrayList<String>> getArrayListsFromDatabase() {
DatabaseAccess databaseAccess = openDatabase();
ArrayList<ArrayList<String>> books = databaseAccess.getBook();
closeDatabase(databaseAccess);
return books;
}
private static void closeDatabase(DatabaseAccess databaseAccess) {
databaseAccess.close();
}
#NonNull
private static DatabaseAccess openDatabase() {
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(activity);
databaseAccess.open();
return databaseAccess;
}
}
Here is my BookAdapter.java:
package com.compose.dietapp.ui.books;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentManager;
import androidx.recyclerview.widget.RecyclerView;
import com.compose.dietapp.R;
import java.io.InputStream;
import java.util.ArrayList;
public class BookAdapter extends RecyclerView.Adapter<BookViewHolder> {
public static FragmentManager supportFragment;
private final Context context;
private final ArrayList<Book> itens;
public BookAdapter(Context context, ArrayList<Book> itens) {
this.context = context;
this.itens = itens;
}
#NonNull
#Override
public BookViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.item_recycler_book, parent, false);
BookViewHolder viewHolder = new BookViewHolder(view);
supportFragment = ((AppCompatActivity)context).getSupportFragmentManager();
return viewHolder;
}
#Override
public void onBindViewHolder(#NonNull BookViewHolder bookViewHolder, int position) {
Book book = itens.get(position);
bookViewHolder.nome.setText(book.getName());
bookViewHolder.bookType.setText(book.getBookType());
imageInstanciate(bookViewHolder);
}
private void imageInstanciate(#NonNull BookViewHolder bookViewHolder) {
new DownloadImageFromInternet((ImageView) bookViewHolder.bookImage)
.execute("https://pbs.twimg.com/profile_images/630285593268752384/iD1MkFQ0.png");
}
private class DownloadImageFromInternet extends AsyncTask<String, Void, Bitmap> {
ImageView imageView;
public DownloadImageFromInternet(ImageView imageView) {
this.imageView = imageView;
}
protected Bitmap doInBackground(String... urls) {
String imageURL = urls[0];
Bitmap bimage = null;
try {
InputStream in = new java.net.URL(imageURL).openStream();
bimage = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error Message", e.getMessage());
e.printStackTrace();
}
return bimage;
}
protected void onPostExecute(Bitmap result) {
imageView.setImageBitmap(result);
}
}
#Override
public int getItemCount() {
return itens.size();
}
}
Here is my BookViewHolder.java:
package com.compose.dietapp.ui.books;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.fragment.app.FragmentManager;
import androidx.recyclerview.widget.RecyclerView;
import com.compose.dietapp.R;
public class BookViewHolder extends RecyclerView.ViewHolder {
TextView nome;
TextView bookType;
ImageView bookImage;
public BookViewHolder(#NonNull View itemView) {
super(itemView);
nome = itemView.findViewById(R.id.nome);
bookType = itemView.findViewById(R.id.email);
bookImage = itemView.findViewById(R.id.book_image);
itemView.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
int position = getLayoutPosition();
return true;
}
});
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String nomeDelete = nome.getText().toString();
int position = getLayoutPosition();
FragmentManager fm = BookAdapter.supportFragment;
BookDialogFragment bookDialogFragment =
BookDialogFragment.newInstance("Atenção:", nomeDelete, position);
bookDialogFragment.show(fm, "fragment_alert");
}
});
}
}
I've seen other similar solutions, but I didn't get to implement them in my code. Can anyone help me?

Going through your code, it doesn't seem like you're using Navigation Component. So let's do it this way.
Your BookDialogFragment is a child fragment to BookFragment. So basically, you should set a result in your dialog when remove button is clicked. Then set up a result listener code in you parent fragment (BookFragment), so as to get immediate result to act upon.
First part, set a result when remove is clicked
NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
...
if (Objects.equals(MESSAGE_TO_DIALOG_FRAGMENT, "Book removed!")) {
...
} else {
alertDialogBuilder.setPositiveButton("Remove", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// here I want to callback my fragment
BookFragment deleteBook = new BookFragment();
deleteBook.removeBook(nameToDelete, position);
Bundle result = new Bundle();
result.putBoolean("value", true);
getParentFragmentManager().setFragmentResult("removed", result);
}
});
alertDialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
...
}
}
}
Then, listen for and act on the result in you BookFragment, wherever you want to, with these lines.
getChildFragmentManager().setFragmentResultListener("removed", this, new FragmentResultListener() {
#Override
public void onFragmentResult(#NonNull String requestKey, #NonNull Bundle bundle) {
// We use a Boolean here, but any type that can be put in a Bundle is supported
Boolean result = bundle.getString("value");
// Do something with the result
}
});
PS: You can use constant variables where you have "removed" and "value" for accuracy.
Hope this helps :)

IndexOutOfBoundsException when making one Arraylist equal to another

I am trying to filter my RecyclerView using SearchView by following this guide: https://www.geeksforgeeks.org/searchview-in-android-with-recyclerview/
However, I am getting an IndexOutOfBoundsException when making one Arraylist equal to another, which I believe is happening at this portion of the code here:
public void filterList(ArrayList filteredlist) {
// below line is to add our filtered
// list in our course array list.
book_title = filteredlist;
// below line is to notify our adapter
// as change in recycler view data.
notifyDataSetChanged();
}
Here is the full code for my adapter class:
package com.benjamin.kwok.recipertracker;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.LinearLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.MyViewHolder> {
private Context context;
private Activity activity;
private ArrayList book_id, book_title, book_author, book_pages;
CustomAdapter(Activity activity, Context context, ArrayList book_id, ArrayList book_title, ArrayList book_author,
ArrayList book_pages){
this.activity = activity;
this.context = context;
this.book_id = book_id;
this.book_title = book_title;
this.book_author = book_author;
this.book_pages = book_pages;
}
public void filterList(ArrayList filteredlist) {
// below line is to add our filtered
// list in our course array list.
book_title = filteredlist;
// below line is to notify our adapter
// as change in recycler view data.
notifyDataSetChanged();
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.my_row, parent, false);
return new MyViewHolder(view);
}
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
public void onBindViewHolder(#NonNull final MyViewHolder holder, final int position) {
holder.book_title_txt.setText(String.valueOf(book_title.get(position)));
holder.book_author_txt.setText(String.valueOf(book_author.get(position)));
holder.book_pages_txt.setText(String.valueOf(book_pages.get(position)));
//Recyclerview onClickListener
holder.mainLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(context, UpdateActivity.class);
intent.putExtra("id", String.valueOf(book_id.get(position)));
intent.putExtra("title", String.valueOf(book_title.get(position)));
intent.putExtra("author", String.valueOf(book_author.get(position)));
intent.putExtra("pages", String.valueOf(book_pages.get(position)));
activity.startActivityForResult(intent, 1);
}
});
}
#Override
public int getItemCount() {
return book_id.size();
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView book_id_txt, book_title_txt, book_author_txt, book_pages_txt;
LinearLayout mainLayout;
MyViewHolder(#NonNull View itemView) {
super(itemView);
book_title_txt = itemView.findViewById(R.id.recipe_title_txt);
book_author_txt = itemView.findViewById(R.id.book_description_txt);
book_pages_txt = itemView.findViewById(R.id.recipe_pages_txt);
mainLayout = itemView.findViewById(R.id.mainLayout);
//Animate Recyclerview
Animation translate_anim = AnimationUtils.loadAnimation(context, R.anim.translate_anim);
mainLayout.setAnimation(translate_anim);
}
}
}
And the full code for my MainActivity:
package com.benjamin.kwok.recipertracker;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.SearchView;
import androidx.core.app.ActivityCompat;
import androidx.core.content.FileProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.Manifest;
import android.app.Activity;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.preference.PreferenceManager;
import android.provider.MediaStore;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView;
FloatingActionButton add_button;
FloatingActionButton camera_button;
ImageView empty_imageview;
ImageView imageView;
TextView no_data;
MyDatabaseHelper myDB;
ArrayList<String> recipe_id, recipe_title, recipe_description, recipe_minutes;
CustomAdapter customAdapter;
final static private int NEW_PICTURE = 1;
private String mCameraFileName;
private static final String TAG = "CapturePicture";
static final int REQUEST_PICTURE_CAPTURE = 1;
private String pictureFilePath;
private String deviceIdentifier;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},1);
// SharedPreferences mSharedPreference= PreferenceManager.getDefaultSharedPreferences(this);
// SharedPreferences.Editor editor = mSharedPreference.edit();
// String text= mSharedPreference.getString(getString(R.string.name), "");
//// name_output.setText(text);
recyclerView = findViewById(R.id.recyclerView);
add_button = findViewById(R.id.add_button);
camera_button = findViewById(R.id.camera_button);
empty_imageview = findViewById(R.id.empty_imageview);
imageView = findViewById(R.id.imageView);
no_data = findViewById(R.id.no_data);
add_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, AddActivity.class);
startActivity(intent);
}
});
camera_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 100);
}
});
myDB = new MyDatabaseHelper(MainActivity.this);
recipe_id = new ArrayList<>();
recipe_title = new ArrayList<>(10);
recipe_description = new ArrayList<>();
recipe_minutes = new ArrayList<>();
storeDataInArrays();
customAdapter = new CustomAdapter(MainActivity.this,this, recipe_id, recipe_title, recipe_description,
recipe_minutes);
recyclerView.setAdapter(customAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));
loadData();
}
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 100) {
Bundle bundle = data.getExtras();
Bitmap captureImage = (Bitmap) bundle.get("data");
imageView.setImageBitmap(captureImage);
saveToGallery();
}
if(resultCode == RESULT_OK){
Toast.makeText(this, "Image added to Gallery", Toast.LENGTH_LONG);
}
}
private void saveToGallery(){
BitmapDrawable draw = (BitmapDrawable) imageView.getDrawable();
Bitmap bitmap = draw.getBitmap();
FileOutputStream outStream = null;
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File(sdCard.getAbsolutePath() + "/RecipeImages");
dir.mkdirs();
String fileName = String.format("%d.jpg", System.currentTimeMillis());
File outFile = new File(dir, fileName);
MediaScannerConnection.scanFile(this, new String[] { outFile.getPath() }, new String[] { "image/jpeg" }, null);
try {
outStream = new FileOutputStream(outFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outStream);
try {
outStream.flush();
} catch (IOException e) {
e.printStackTrace();
}
try {
outStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
void storeDataInArrays(){
Cursor cursor = myDB.readAllData();
if(cursor.getCount() == 0){
empty_imageview.setVisibility(View.VISIBLE);
no_data.setVisibility(View.VISIBLE);
}else{
while (cursor.moveToNext()){
recipe_id.add(cursor.getString(0));
recipe_title.add(cursor.getString(1));
recipe_description.add(cursor.getString(2));
recipe_minutes.add(cursor.getString(3));
}
empty_imageview.setVisibility(View.GONE);
no_data.setVisibility(View.GONE);
}
}
public void loadData() {
SharedPreferences mPreferences = PreferenceManager.getDefaultSharedPreferences(this);
String name = mPreferences.getString("name","");
setTitle(name+"'s" + " Recipe Tracker");
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.my_menu, menu);
// return super.onCreateOptionsMenu(menu);
MenuItem searchItem = menu.findItem(R.id.actionSearch);
// getting search view of our item.
SearchView searchView = (SearchView) searchItem.getActionView();
// below line is to call set on query text listener method.
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
// inside on query text change method we are
// calling a method to filter our recycler view.
filter(newText);
return false;
}
});
return true;
}
private void filter(String text) {
// creating a new array list to filter our data.
ArrayList filteredlist = new ArrayList<>();
// running a for loop to compare elements.
for (String item : recipe_title) {
// checking if the entered string matched with any item of our recycler view.
if (item.toLowerCase().contains(text.toLowerCase())) {
// if the item is matched we are
// adding it to our filtered list.
filteredlist.add(item);
}
}
if (filteredlist.isEmpty()) {
// if no item is added in filtered list we are
// displaying a toast message as no data found.
Toast.makeText(this, "No Data Found..", Toast.LENGTH_SHORT).show();
} else {
// at last we are passing that filtered
// list to our adapter class.
customAdapter.filterList(filteredlist);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if(item.getItemId() == R.id.delete_all){
confirmDialog();
}
return super.onOptionsItemSelected(item);
}
void confirmDialog(){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Delete All?");
builder.setMessage("Are you sure you want to delete all Data?");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
MyDatabaseHelper myDB = new MyDatabaseHelper(MainActivity.this);
myDB.deleteAllData();
//Refresh Activity
Intent intent = new Intent(MainActivity.this, MainActivity.class);
startActivity(intent);
finish();
}
});
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
builder.create().show();
}
}
As soon as I start typing in a new search query, this error seems to get thrown.

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

favorite Recycler view updates only on relaunching app

I developed a word app that contains English vocabularies and users can add their favorite word by clicking on a floating button. Every time my favorite list has at list one item it is updated but when it's empty it doesn't show anything but when I run app again list updates.
if you need any code let me know to send it .
UPDATE:
Inner page :
selectDb();
if(selectFavoriteState()){
favorite.setImageResource(R.drawable.ic_favorite_like);
}else {
favorite.setImageResource(R.drawable.ic_favorite_maylike);
}
favorite.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (selectFavoriteState()){
favorite.setImageResource(R.drawable.ic_favorite_maylike);
updateUnfavorited();
}else {
favorite.setImageResource(R.drawable.ic_favorite_like);
updateFavorited();
}
}
});
private void selectDb(){
destpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/ielts/";
database = SQLiteDatabase.openOrCreateDatabase(destpath + "/md_book.db", null);
}
private boolean selectFavoriteState(){
#SuppressLint("Recycle") Cursor cursor = database.rawQuery("SELECT * FROM main WHERE id = " + id, null);
while (cursor.moveToNext()){
favoriteState = cursor.getString(cursor.getColumnIndex("fav"));
}
return favoriteState.equals("1");
}
private void updateFavorited(){
database.execSQL( "UPDATE main SET fav = 1 WHERE id = " + id);
}
private void updateUnfavorited(){
database.execSQL( "UPDATE main SET fav = 0 WHERE id = " + id);
}
Update 2:
package farmani.com.essentialwordsforielts.mainPage;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.annotation.Nullable;
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 farmani.com.essentialwordsforielts.R;
public class PageFragment extends Fragment {
private int mPage;
public static final String ARG_PAGE = "ARG_PAGE";
RecyclerView recyclerView;
AdapterFav adapterFav;
public static PageFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate( Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
if (mPage == 1) {
recyclerView = (RecyclerView) view.findViewById(R.id.my_recycler_view);
AdapterList adapter = new AdapterList(MainActivity.context);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.context));
}
if (mPage == 2) {
recyclerView = (RecyclerView) view.findViewById(R.id.my_recycler_view);
adapterFav = new AdapterFav(MainActivity.context);
recyclerView.setAdapter(adapterFav);
recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.context));
}
return view;
}
#Override
public void onResume() {
super.onResume();
if (adapterFav != null){
adapterFav.notifyDataSetChanged();
}
}
}
Update 3 :AdapterFav
package farmani.com.essentialwordsforielts.mainPage;
import android.content.Context;
import android.content.Intent;
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.LinearLayout;
import android.widget.TextView;
import farmani.com.essentialwordsforielts.R;
import farmani.com.essentialwordsforielts.innerpage.ActivityInnerPage;
public class AdapterFav extends RecyclerView.Adapter<ViewHolder> {
Context context;
LayoutInflater inflater;
TextView title;
ImageView avatar;
LinearLayout cardAdapter;
public AdapterFav(Context context){
this.context = context;
inflater = LayoutInflater.from(context);
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.adapter_card_view, parent, false);
title = (TextView) view.findViewById(R.id.title1);
avatar = (ImageView) view.findViewById(R.id.avatar);
cardAdapter = (LinearLayout) view.findViewById(R.id.card_adapter);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.title.setText(MainActivity.favorite.get(position).getWord());
String img = MainActivity.favorite.get(position).getImg();
int id = MainActivity.context.getResources().getIdentifier(img, "drawable", MainActivity.context.getPackageName());
holder.avatar.setImageResource(id);
holder.cardAdapter.setOnClickListener(clickListener);
holder.cardAdapter.setId(position);
}
View.OnClickListener clickListener = new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = view.getId();
Intent intent = new Intent (MainActivity.context, ActivityInnerPage.class);
intent.putExtra("name", "favorite");
intent.putExtra("id", position + "");
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
MainActivity.context.startActivity(intent);
}
};
#Override
public int getItemCount() {
return MainActivity.favorite.size();
}
}
Update 4: MainActivity
package farmani.com.essentialwordsforielts.mainPage;
import android.Manifest;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Build;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.design.widget.NavigationView;
import android.support.design.widget.TabLayout;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import com.nabinbhandari.android.permissions.PermissionHandler;
import com.nabinbhandari.android.permissions.Permissions;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import farmani.com.essentialwordsforielts.R;
import farmani.com.essentialwordsforielts.search.ActivitySearch;
import farmani.com.essentialwordsforielts.setting.ActivitySetting;
public class MainActivity extends AppCompatActivity {
public static Context context;
public static ArrayList<Structure> list = new ArrayList<>();
public static ArrayList<Structure> favorite = new ArrayList<>();
DrawerLayout drawerLayout;
NavigationView navigationView;
ImageView hamburger;
SQLiteDatabase database;
String destPath;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.navigation_activity_main);
Permissions.check(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE},
" storage permissions are required to copy database", new Permissions.Options()
.setSettingsDialogTitle("Warning!").setRationaleDialogTitle("Info"),
new PermissionHandler() {
#Override
public void onGranted() {
setupDB();
selectList();
selectFavorite();
}
});
context = getApplicationContext();
setTabOption();
drawerLayout = findViewById(R.id.navigation_drawer);
navigationView = findViewById(R.id.navigation_view);
hamburger = findViewById(R.id.hamburger);
hamburger.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
drawerLayout.openDrawer(Gravity.START);
}
});
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
int id = item.getItemId();
if (id == R.id.exit) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
MainActivity.this);
alertDialog.setTitle(R.string.exit);
alertDialog.setMessage(R.string.exit_ask);
alertDialog.setCancelable(false);
alertDialog.setPositiveButton(R.string.yes,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int
which) {
finish();
}
});
alertDialog.setNegativeButton(R.string.no,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int
which) {
dialog.cancel();
}
});
alertDialog.show();
}else if (id == R.id.search) {
Intent intent = new Intent(MainActivity.this, ActivitySearch.class);
MainActivity.this.startActivity(intent);
} else if (id == R.id.setting) {
Intent intent = new Intent(MainActivity.this, ActivitySetting.class);
MainActivity.this.startActivity(intent);
}
return true;
}
});
}
#Override
public void onBackPressed() {
if (drawerLayout.isDrawerOpen(Gravity.START)) {
drawerLayout.closeDrawer(Gravity.START);
} else {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
MainActivity.this);
alertDialog.setTitle(R.string.exit);
alertDialog.setMessage(R.string.exit_ask);
alertDialog.setCancelable(false);
alertDialog.setPositiveButton(R.string.yes,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
alertDialog.setNegativeButton(R.string.no,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
}
private void setTabOption() {
ViewPager viewPager = findViewById(R.id.viewpager);
viewPager.setAdapter(new AdapterFragment(getSupportFragmentManager(),
context));
TabLayout tabStrip = findViewById(R.id.tabs);
tabStrip.setupWithViewPager(viewPager);
}
#Override
protected void onResume() {
super.onResume();
if (!list.isEmpty()){
list.clear();
selectList();
} if (!favorite.isEmpty()){
favorite.clear();
selectFavorite();
}
}
private void setupDB() {
try {
destPath =
Environment.getExternalStorageDirectory().getAbsolutePath() + "/ielts/";
File file = new File(destPath);
if (!file.exists()) {
file.mkdirs();
file.createNewFile();
CopyDB(getBaseContext().getAssets().open("md_book.db"),
new FileOutputStream(destPath + "/md_book.db"));
}
} catch (IOException e1) {
e1.printStackTrace();
}
}
private void CopyDB(InputStream inputStream, OutputStream outputStream)
throws IOException {
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) > 0) {
outputStream.write(buffer, 0, length);
}
inputStream.close();
outputStream.close();
}
private void selectFavorite() {
database = SQLiteDatabase.openOrCreateDatabase(destPath + "/md_book.db",
null);
#SuppressLint("Recycle") Cursor cursor = database.rawQuery("SELECT * FROM main WHERE fav = 1",
null);
while (cursor.moveToNext()) {
String word = cursor.getString(cursor.getColumnIndex("word"));
String definition =
cursor.getString(cursor.getColumnIndex("definition"));
String trans = cursor.getString(cursor.getColumnIndex("trans"));
String img = cursor.getString(cursor.getColumnIndex("img"));
int id = cursor.getInt(cursor.getColumnIndex("id"));
Structure struct = new Structure(word, definition, trans, img, id);
struct.setWord(word);
struct.setDefinition(definition);
struct.setTrans(trans);
struct.setImg(img);
struct.setId(id);
favorite.add(struct);
}
}
private void selectList() {
database = SQLiteDatabase.openOrCreateDatabase(destPath + "/md_book.db",
null);
#SuppressLint("Recycle") Cursor cursor = database.rawQuery("SELECT * FROM main", null);
while (cursor.moveToNext()) {
String word = cursor.getString(cursor.getColumnIndex("word"));
String definition =
cursor.getString(cursor.getColumnIndex("definition"));
String trans = cursor.getString(cursor.getColumnIndex("trans"));
String img = cursor.getString(cursor.getColumnIndex("img"));
int id = cursor.getInt(cursor.getColumnIndex("id"));
Structure struct = new Structure(word, definition, trans, img, id);
struct.setWord(word);
struct.setDefinition(definition);
struct.setTrans(trans);
struct.setImg(img);
struct.setId(id);
list.add(struct);
}
}
}
Update 5 innerpage activity
package farmani.com.essentialwordsforielts.innerpage;
import android.annotation.SuppressLint;
import android.content.ClipData;
import android.content.ClipboardManager;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toolbar;
import java.lang.reflect.Field;
import farmani.com.essentialwordsforielts.R;
import farmani.com.essentialwordsforielts.mainPage.AdapterFav;
public class ActivityInnerPage extends AppCompatActivity {
private TextView contentDescriptione;
private TextView moreDescriptione;
private ImageView avatar;
private ImageView imgCopy;
private ImageView imgShare;
private ImageView imgSms;
private ImageView imgGmail;
private FloatingActionButton favorite;
private CollapsingToolbarLayout collapsingToolbarLayout;
public String word;
public String definition;
public String trans;
public String img;
public int id;
private String destpath;
private SQLiteDatabase database;
private String favoriteState;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_inner_page);
final android.support.v7.widget.Toolbar toolbar = findViewById(R.id.toolbar);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
});
Bundle extras = getIntent().getExtras();
if (extras != null) {
int layoutId = Integer.parseInt(extras.getString("id"));
String pageName = extras.getString("name");
assert pageName != null;
if (pageName.equals("list")) {
id = MainActivity.list.get(layoutId).getId();
word = MainActivity.list.get(layoutId).getWord();
definition = MainActivity.list.get(layoutId).getDefinition();
trans = MainActivity.list.get(layoutId).getTrans();
img = MainActivity.list.get(layoutId).getImg();
} else if (pageName.equals("favorite")) {
id = MainActivity.favorite.get(layoutId).getId();
word = MainActivity.favorite.get(layoutId).getWord();
definition = MainActivity.favorite.get(layoutId).getDefinition();
trans = MainActivity.favorite.get(layoutId).getTrans();
img = MainActivity.favorite.get(layoutId).getImg();
}
}
contentDescriptione = findViewById(R.id.content_description);
moreDescriptione = findViewById(R.id.more_description);
imgCopy = findViewById(R.id.img_copy);
imgShare = findViewById(R.id.img_share);
imgSms = findViewById(R.id.img_sms);
imgGmail = findViewById(R.id.img_gmail);
avatar = findViewById(R.id.avatar);
favorite = findViewById(R.id.favorite);
collapsingToolbarLayout = findViewById(R.id.collapsing_toolbar);
collapsingToolbarLayout.getExpandedTitleMarginStart();
collapsingToolbarLayout.setTitle(word);
collapsingToolbarLayout.setExpandedTitleColor(getResources().getColor(android.R.color.holo_red_light));
contentDescriptione.setText(definition);
moreDescriptione.setText(trans);
int imgageId = MainActivity.context.getResources().getIdentifier(img, "drawable", MainActivity.context.getPackageName());
avatar.setImageResource(imgageId);
SharedPreferences prefes = getSharedPreferences("font_size", MODE_PRIVATE);
int value = prefes.getInt("fontsize", 16);
contentDescriptione.setTextSize(value);
moreDescriptione.setTextSize(value);
selectDb();
if(selectFavoriteState()){
favorite.setImageResource(R.drawable.ic_favorite_like);
}else {
favorite.setImageResource(R.drawable.ic_favorite_maylike);
}
favorite.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (selectFavoriteState()){
favorite.setImageResource(R.drawable.ic_favorite_maylike);
updateUnfavorited();
}else {
favorite.setImageResource(R.drawable.ic_favorite_like);
updateFavorited();
}
}
});
imgCopy.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final ClipboardManager clipboardManager =
(ClipboardManager)ActivityInnerPage.this.getSystemService(Context.CLIPBOARD_SERVICE);
final ClipData clip = ClipData.newPlainText(word, trans+definition);
assert clipboardManager != null;
clipboardManager.setPrimaryClip(clip);
Snackbar.make(view,"متن کپی شد ",Snackbar.LENGTH_SHORT).show();
}
});
imgShare.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent shareIntent = new Intent(Intent.ACTION_SEND);
shareIntent.setType("text/plain");
shareIntent.putExtra(Intent.EXTRA_TEXT, definition+trans);
shareIntent.putExtra(Intent.EXTRA_SUBJECT, word);
startActivity(Intent.createChooser(shareIntent, "Share"));
}
});
imgGmail.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
try {
Intent emailIntent = new Intent(Intent.ACTION_SENDTO
, Uri.fromParts("mailto", "", null));
emailIntent.putExtra(Intent.EXTRA_SUBJECT, word);
emailIntent.putExtra(Intent.EXTRA_TEXT, definition);
startActivity(Intent.createChooser(emailIntent, "Send email..."));
}catch (Exception e){
Snackbar.make(view,"برنامه ای برای ارسال ایمیل یافت نشد",Snackbar.LENGTH_SHORT).show();
}
}
});
imgSms.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
try {
Intent sendSms = new Intent(Intent.ACTION_VIEW);
sendSms.putExtra("sms_body", definition + trans);
sendSms.setType("vnd.android-dir/mms-sms");
startActivity(sendSms);
}catch (Exception e){
Snackbar.make(view,"برنامه ای برای ارسال پیام یافت نشد",Snackbar.LENGTH_SHORT).show();
}
}
});
}
private void selectDb(){
destpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/ielts/";
database = SQLiteDatabase.openOrCreateDatabase(destpath + "/md_book.db", null);
}
private boolean selectFavoriteState(){
#SuppressLint("Recycle") Cursor cursor = database.rawQuery("SELECT * FROM main WHERE id = " + id, null);
while (cursor.moveToNext()){
favoriteState = cursor.getString(cursor.getColumnIndex("fav"));
}
return favoriteState.equals("1");
}
private void updateFavorited(){
database.execSQL( "UPDATE main SET fav = 1 WHERE id = " + id);
}
private void updateUnfavorited(){
database.execSQL( "UPDATE main SET fav = 0 WHERE id = " + id);
}
}

In your FloatingActionButton onClick method after you save the new item in your database, insert your new item into your recyclerview datasource list and call notifyDatasetChanged() on the adapter.

Choice 1: in onResume() stub of MainActivity, call selectList() and selectFavorite() and then load the PageFragment again so that the new list is loaded properly.
This is the shortest wayout but this approach is very much unoptimized and is not recommended.
Choice 2: You will have to insert the new item in database as well as add it to the List and then call notifyDatasetChanged
In MainActivity within methods selectList() and selectFavorite() after you perform list.add(struct) and favourite.add(struct) respectively, you will have to call notifyDatasetChanged() for the Adapter.
But the problem is your RecyclerView is in the PageFragment whereas you're populating the list in MainActivity.
So move your selectList() and selectFavorite() to PageFragment where you first initialize the RecylerView then, set the Adapter and then populate the list and finally call notifyDatasetChanged() on your adapters.

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.