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How to load fragment with recyclerview on start of the application?

I have built a bottom navigation tab bar in android,it has 5 fragments but the problem is on start of the application it doesn't load the recyclerview list from firestore database. and this fragment is Home Fragment. but if I randomly open another tab and then comes the to the home tab the home tab list loads itself, but it does not load automatically on start of the app
below is the code.
please assist
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private static final String TAG = "DocSnippets";
private FirebaseAuth mauth;
private FirebaseFirestore db = FirebaseFirestore.getInstance();
private CollectionReference UsersRef = db.collection("Users");
private DocumentReference noteRef = db.document("Notebook/My First Note");
private MySharedPreferences sp;
private DocumentReference currentUserRef;
private Button notificationList;
private String mUserId, tokenId, currentUserProfilePic, currentUserName, currentUserSpinnerC;
String currentUserID;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sp = MySharedPreferences.getInstance(this);
setContentView(R.layout.activity_main);
mauth = FirebaseAuth.getInstance();
// currentUserID = mauth.getCurrentUser().getUid();
UsersRef =FirebaseFirestore.getInstance().collection("Users");
mUserId = mauth.getUid();
tokenId = FirebaseInstanceId.getInstance().getToken();
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = findViewById(R.id.fab);
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();
}
});
DrawerLayout drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
navigationView.setNavigationItemSelectedListener(this);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.bottom_nav_view);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment;
fragment = null;
switch (item.getItemId()) {
case R.id.navigation_home:
fragment = new HomeFragment();
break;
case R.id.navigation_dashboard:
fragment = new DashboardFragment();
break;
case R.id.navigation_notifications:
// Intent intent = new Intent(MainActivity.this, AddPostActivity.class);
// startActivity(intent);
fragment = new NotificationsFragment();
break;
case R.id.navigation_post:
fragment = new ProfileFragment();
break;
case R.id.navigation_postlist:
fragment = new ProfileFragment();
break;
}
return loadFragment(fragment);
}
};
private boolean loadFragment(Fragment fragment) {
//switching fragment
if (fragment != null) {
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.fragment_container, fragment)
.commit();
return true;
}
return false;
}
#Override
protected void onStart()
{
super.onStart();
FirebaseUser currentUser = mauth.getCurrentUser();
if(currentUser == null)
{
SendUserToSignInActivity();
}
else
{
retrieveCurrentUserInfo();
checkUserExistence();
}
}
private void checkUserExistence() {
final String current_user_id = mauth.getCurrentUser().getUid();
}
private void SendUserToSignInActivity() {
Intent signInIntent = new Intent(MainActivity.this, SignInActivity.class);
signInIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(signInIntent);
finish();
}
#Override
public void onBackPressed() {
DrawerLayout drawer = findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#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, menu);
return true;
}
private void retrieveCurrentUserInfo(){
currentUserRef = db.collection("users").document(mUserId);
currentUserRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()){
currentUserName = (String) document.getString("username");
currentUserProfilePic =(String) document.getString("profile_pic");
currentUserSpinnerC = (String) document.getString("spinnerC");
CircleImageView UserImage = (CircleImageView) findViewById(R.id.current_user_Image);
Picasso.get()
.load(currentUserProfilePic)
.resize(50, 50)
.centerCrop()
.into(UserImage);
TextView username = (TextView) findViewById(R.id.current_user_name);
TextView spinnerC = (TextView) findViewById(R.id.current_user_spinnerC);
username.setText(currentUserName);
spinnerC.setText(currentUserSpinnerC);
}
}
}
});
}
}

The fragment is not loaded at launching your activity, so add below code in your onCreate() method
loadFragment(new HomeFragment());

You can trigger the home fragment selection manually. Paste this at the end of the onCreate function of MainActivity.
View view = navigation.findViewById(R.id.navigation_home);
view.performClick();

You are not loading/calling any fragment in your onCreate() method.
Try this way
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/**
* Your code
*/
loadFragment(LOAD_YOUR_FRAGMENT);
}

Navigation Drawer Back Pressed Fragment Doesn't Load

I have a navigation drawer with fragments. At start, I display Home fragment as default.
There are options on navigation menu. In 2 fragments I have SwipeRefreshLayout. Until all recyclerview data are fetched then I display data and invisible SwipeRefreshLayout.
One of these fragments (included SwipeRefReshLayout) works fine but, in Home fragment something is wrong.
For example(use case)
You started app and you saw Home fragment
You clicked Profile fragment on navigation menu
You run onBackPressed(back button).
In this case data never loads and SwipeRefReshLayout is always spinning. (I also tried without refreshlayout, still same)
Any idea how to fix this? My thought is, its about displaying default fragment.
Navigation Drawer Activity
public class Page_Navigation extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
Fragment fragment;
FragmentManager fragmentManager = getSupportFragmentManager();
NavigationView navigationView;
SharedPreferences mSharedPref;
DrawerLayout drawer;
private Tracker mTracker;
FragmentTransaction fragmentTransaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_page__navigation);
//
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
TextView toolbar_head = findViewById(R.id.toolbar_head);
ImageView toolbar_image = findViewById(R.id.toolbar_image);
ImageView toolbar_profile = findViewById(R.id.toolbar_profile);
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
//
AnalyticsApplication application = (AnalyticsApplication) getApplication();
mTracker = application.getDefaultTracker();
mTracker.setScreenName("page_navigation");
mTracker.send(new HitBuilders.ScreenViewBuilder().build());
//FIRST SETTINGS
setSupportActionBar(toolbar);
Typeface customFont = Typeface.createFromAsset(getAssets(), "Montserrat-Medium.ttf");
toolbar_head.setTypeface(customFont);
//Get Sessions
mSharedPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String session_user_name = mSharedPref.getString("session_user_name", "");
String session_user_photo = mSharedPref.getString("session_user_photo", "");
//Navigation Drawer
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
navigationView.setItemIconTintList(null);
//
View headerView = navigationView.getHeaderView(0);
TextView nav_userName = (TextView) headerView.findViewById(R.id.textView_nav_userName);
CircleImageView imageView_navigation = (CircleImageView) headerView.findViewById(R.id.imageView_navigation);
Glide.with(getApplicationContext()).load(session_user_photo).into(imageView_navigation);
nav_userName.setText(session_user_name);
headerView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (drawer.isDrawerOpen(Gravity.START)) {
drawer.closeDrawer(Gravity.START);
}
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
showProfileFragment();
}
}, 300);
}
});
toolbar_image.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
drawer.openDrawer(GravityCompat.START);
}
});
toolbar_profile.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Fragment fragment;
FragmentManager manager = getSupportFragmentManager();
fragment = new Nav_Profile();
fragmentTransaction = manager.beginTransaction();
fragmentTransaction.replace(R.id.navContent, fragment).addToBackStack(null).commit();
}
});
displayDefaultFragment();
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.page__navigation, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
final int id = item.getItemId();
drawer.closeDrawer(GravityCompat.START);
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
switch (id) {
case R.id.nav_home:
fragment = new Nav_Home();
break;
case R.id.nav_contact:
fragment = new Nav_Contact();
break;
case R.id.nav_articles:
fragment = new Nav_Article();
break;
case R.id.nav_about:
fragment = new Nav_AboutUs();
break;
case R.id.nav_suggest:
fragment = new Nav_Suggest();
break;
case R.id.nav_share:
fragment = new Nav_Share();
break;
case R.id.nav_rateApp:
fragment = new Nav_RateApp();
break;
}
fragmentManager.beginTransaction()
.replace(R.id.navContent, fragment)
.addToBackStack(null)
.commit();
}
}, 350);
return true;
}
public void displayDefaultFragment() {
fragment = new Nav_Home();
fragmentManager.beginTransaction().replace(R.id.navContent, fragment).commit();
}
public void showProfileFragment() {
fragment = new Nav_Profile();
fragmentManager.beginTransaction().replace(R.id.navContent, fragment).addToBackStack(null).commit();
}
}
Home Fragment
public class Nav_Home extends Fragment implements View.OnClickListener{
SharedPreferences mSharedPref;
private SwipeRefreshLayout swipeRefresh_home;
private CardView item_homeTop_coupons, item_homeTop_draws, item_homeTop_event;
private LinearLayout layout_all_article, layout_all_999;
private ScrollView shimmer_home;
private List<Model_ListItem> listNewItems;
private RecyclerView recyclerView_item_home;
private List<Model_Article> articleList;
private RecyclerView recyclerView_article_home;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
fetchItemsNew();
fetchArticlesNew();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_nav__home, container, false);
item_homeTop_coupons = view.findViewById(R.id.item_homeTop_coupons);
item_homeTop_draws = view.findViewById(R.id.item_homeTop_draws);
item_homeTop_event = view.findViewById(R.id.item_homeTop_event);
recyclerView_item_home = view.findViewById(R.id.recyclerView_item_home);
recyclerView_article_home = view.findViewById(R.id.recyclerView_article_home);
layout_all_article = view.findViewById(R.id.layout_all_article);
layout_all_999 = view.findViewById(R.id.layout_all_999);
swipeRefresh_home = view.findViewById(R.id.swipeRefresh_home);
shimmer_home = view.findViewById(R.id.shimmer_home);
item_homeTop_coupons.setOnClickListener(this);
item_homeTop_draws.setOnClickListener(this);
item_homeTop_event.setOnClickListener(this);
layout_all_999.setOnClickListener(this);
layout_all_article.setOnClickListener(this);
//first settngs
mSharedPref = PreferenceManager.getDefaultSharedPreferences(view.getContext());
String session_user_email = mSharedPref.getString("session_user_email","");
swipeRefresh_home.setRefreshing(true);
return view;
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.item_homeTop_coupons:
startActivity(new Intent(getContext(), Page_Coupon.class));
break;
case R.id.item_homeTop_draws:
startActivity(new Intent(getContext(), Page_Draw.class));
break;
case R.id.item_homeTop_event:
startActivity(new Intent(getContext(), Page_Event.class));
break;
case R.id.layout_all_999:
//999 city search activity
startActivity(new Intent(getContext(), Page_SearchCity.class));
break;
case R.id.layout_all_article:
//article fragment
Fragment fragment;
FragmentManager fragmentManager = getFragmentManager();
fragment = new Nav_Article();
fragmentManager.beginTransaction().replace(R.id.navContent, fragment).addToBackStack(null).commit();
break;
}
}
public void fetchItemsNew(){
listNewItems = new ArrayList<>();
API_Service api_service = Client.getRetrofitInstance().create(API_Service.class);
Call<List<Model_ListItem>> call = api_service.fetchItemsNew();
call.enqueue(new Callback<List<Model_ListItem>>() {
#Override
public void onResponse(Call<List<Model_ListItem>> call, Response<List<Model_ListItem>> response) {
if(response.code() == 200){
listNewItems = response.body();
Adapter_HomeItem adapter_homeItem = new Adapter_HomeItem(getContext(), listNewItems);
LinearLayoutManager layoutManager
= new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false);
recyclerView_item_home.setHasFixedSize(true);
recyclerView_item_home.setLayoutManager(layoutManager);
recyclerView_item_home.setAdapter(adapter_homeItem);
SnapHelper helper = new LinearSnapHelper();
helper.attachToRecyclerView(recyclerView_item_home);
}
}
#Override
public void onFailure(Call<List<Model_ListItem>> call, Throwable t) {
}
});
}
public void fetchArticlesNew(){
articleList = new ArrayList<>();
API_Service api_service = Client.getRetrofitInstance().create(API_Service.class);
Call<List<Model_Article>> callArticle = api_service.fetchArticlesNew();
callArticle.enqueue(new Callback<List<Model_Article>>() {
#Override
public void onResponse(Call<List<Model_Article>> call, Response<List<Model_Article>> response) {
if(response.code() == 200){
articleList = response.body();
Adapter_HomeArticles adapter_homeArticles = new Adapter_HomeArticles(getContext(), articleList);
LinearLayoutManager layoutManager
= new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
recyclerView_article_home.setLayoutManager(layoutManager);
recyclerView_article_home.setHasFixedSize(true);
recyclerView_article_home.setAdapter(adapter_homeArticles);
}
}
#Override
public void onFailure(Call<List<Model_Article>> call, Throwable t) {
}
});
}
}

Firstly you must disable SwipeRefreshLayout spinning when successfully or not fetched data:
swipeRefresh_home.setRefreshing(false);
If you do not do this spinner will be spinning all the time.
Another problem is that you have one fragment and you try to assign to it Nav_Home fragment and Nav_Profile fragment.
Fragment fragment;
public void displayDefaultFragment() {
fragment = new Nav_Home();
fragmentManager.beginTransaction().replace(R.id.navContent, fragment).commit();
}
public void showProfileFragment() {
fragment = new Nav_Profile();
fragmentManager.beginTransaction().replace(R.id.navContent, fragment).addToBackStack(null).commit();
}
Try to separate them and show like this:
Fragment homeFragment;
Fragment profileFragment;
public void displayDefaultFragment() {
homeFragment = new Nav_Home();
fragmentManager.beginTransaction().replace(R.id.navContent, homeFragment).commit();
}
public void showProfileFragment() {
profileFragment = new Nav_Profile();
fragmentManager.beginTransaction().replace(R.id.navContent, profileFragment).addToBackStack(null).commit();
}

I lost my View Pager Data When I Back From next tab

I am having four tab in my View pager I have search in google but I can,t found any solution when Swipe my view pager it work fine like 1-2-3-4 but when I try to swipe reverse 4-3-2-1 than my data get lost or you can say my adapter get lost.My View Pager is inside Activity.My Data is lost when I go to next page and back then back my data is lost.
My Main Activity is:
public class MainActivity extends AppCompatActivity {
public static int notificationCountCart = 0;
Toolbar toolbar;
ActionBar actionBar;
static ViewPager viewPager;
static TabLayout tabLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
if (toolbar != null)
setSupportActionBar(toolbar);
actionBar = getSupportActionBar();
if (actionBar != null) {
TextView textView = new TextView(this);
textView.setText("Shopping");
textView.setTextSize(20);
textView.setTypeface(null, Typeface.BOLD);
textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
textView.setGravity(Gravity.CENTER);
textView.setTextColor(getResources().getColor(R.color.white));
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setCustomView(textView);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeAsUpIndicator(new IconDrawable(this, FontAwesomeIcons.fa_angle_left).colorRes(R.color.white).actionBarSize());
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
viewPager = (ViewPager) findViewById(R.id.viewpagerrr);
tabLayout = (TabLayout) findViewById(R.id.tabs);
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
}
#Override
protected void onResume() {
super.onResume();
invalidateOptionsMenu();
}
#Override
public void onBackPressed() {
super.onBackPressed();
}
#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, menu);
return true;
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
// Get the notifications MenuItem and
// its LayerDrawable (layer-list)
MenuItem item = menu.findItem(R.id.action_cart);
NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCountCart);
// force the ActionBar to relayout its MenuItems.
// onCreateOptionsMenu(Menu) will be called again.
invalidateOptionsMenu();
return super.onPrepareOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_search) {
startActivity(new Intent(MainActivity.this, SearchResultActivity.class));
return true;
} else if (id == R.id.action_cart) {
/* NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCount);
invalidateOptionsMenu();*/
startActivity(new Intent(MainActivity.this, CartListActivity.class));
/* notificationCount=0;//clear notification count
invalidateOptionsMenu();*/
return true;
} else if (id == android.R.id.home) {
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
// startActivity(new Intent(MainActivity.this, EmptyActivity.class));
}
return super.onOptionsItemSelected(item);
}
private void setupViewPager(ViewPager viewPager) {
Adapter adapter = new Adapter(getSupportFragmentManager());
ImageListFragment fragment = new ImageListFragment();
SpeakerFragment speakerFragment = new SpeakerFragment();
adapter.addFragment(fragment, getString(R.string.item_2));
adapter.addFragment(speakerFragment, getString(R.string.item_4));
adapter.addFragment(new HeadPhone(), getString(R.string.item_3));
adapter.addFragment(new Offer(), getString(R.string.item_1));
viewPager.setAdapter(adapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
}
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);
}
}
}
My Fragment is
public class ImageListFragment extends Fragment {
String category_Name, Category_ID, Product_ID, Product_Name,
Product_Image, Product_Price, Product_Sale, Cart;
public static final String STRING_IMAGE_URI = "ImageUri";
public static final String STRING_IMAGE_POSITION = "ImagePosition";
private static MainActivity mActivity;
ArrayList<SingleItemModel> singleItemModels;
RecyclerView recyclerView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getCategoryone();
Fresco.initialize(getContext());
mActivity = (MainActivity) getActivity();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
recyclerView = (RecyclerView) inflater.inflate(R.layout.layout_recylerview_list, container, false);
return recyclerView;
}
public static class SimpleStringRecyclerViewAdapter
extends RecyclerView.Adapter<ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder> {
// private String[] mValues;
private ArrayList<SingleItemModel> mValues;
private RecyclerView mRecyclerView;
public static class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final SimpleDraweeView mImageView;
public final LinearLayout mLayoutItem;
public final ImageView mImageViewWishlist;
TextView iTemName, itemDescription, itemPrice;
public ViewHolder(View view) {
super(view);
mView = view;
mImageView = (SimpleDraweeView) view.findViewById(R.id.image1);
mLayoutItem = (LinearLayout) view.findViewById(R.id.layout_item);
mImageViewWishlist = (ImageView) view.findViewById(R.id.ic_wishlist);
iTemName = (TextView) view.findViewById(R.id.itemName);
itemDescription = (TextView) view.findViewById(R.id.itemDescription);
itemPrice = (TextView) view.findViewById(R.id.itemPrice);
}
}
public SimpleStringRecyclerViewAdapter(RecyclerView recyclerView, ArrayList<SingleItemModel> items) {
mValues = items;
mRecyclerView = recyclerView;
}
#Override
public ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder(view);
}
#Override
public void onViewRecycled(ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder holder) {
if (holder.mImageView.getController() != null) {
holder.mImageView.getController().onDetach();
}
if (holder.mImageView.getTopLevelDrawable() != null) {
holder.mImageView.getTopLevelDrawable().setCallback(null);
//
}
}
#Override
public void onBindViewHolder(final ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder holder, final int position) {
SingleItemModel singleItemModel = mValues.get(position);
holder.iTemName.setText(singleItemModel.getCategory_Name());
final Uri uri = Uri.parse(singleItemModel.getProduct_Image());
holder.mImageView.setImageURI(uri);
holder.itemPrice.setText(singleItemModel.getProduct_Price());
holder.itemDescription.setText(singleItemModel.getProduct_Sale());
}
#Override
public int getItemCount() {
return mValues.size();
}
}
public void getCategoryone() {
final RequestQueue queue = Volley.newRequestQueue(getActivity());
StringRequest stringRequest = new StringRequest(Request.Method.POST, "http://proaudiobrands.com/app/feature.php",
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i("shabina shopping response", response);
try {
singleItemModels = new ArrayList<>();
JSONObject mainObj = new JSONObject(response);
Log.d("shabina ", response);
JSONArray Feature_product = mainObj.getJSONArray("Feature_product");
for (int i = 0; i < Feature_product.length(); i++) {
JSONObject Feature_Product = Feature_product.getJSONObject(i);
String Category_Namee = Feature_Product.getString("Category_Namee");
String Category_IDs = Feature_Product.getString("Category_IDs");
JSONArray Product_List = Feature_Product.getJSONArray("Product_List");
for (int j = 0; j < Product_List.length(); j++) {
JSONObject Category_Name = Product_List.getJSONObject(j);
if (Category_Name.getString("Category_Name").equals("Microphones")) {
category_Name = Category_Name.getString("Category_Name");
Category_ID = Category_Name.getString("Category_ID");
Product_ID = Category_Name.getString("Product_ID");
Product_Name = Category_Name.getString("Product_Name");
Product_Image = Category_Name.getString("Product_Image");
Product_Price = Category_Name.getString("Product_Price");
Product_Sale = Category_Name.getString("Product_Sale");
Cart = Category_Name.getString("Cart");
Log.e("sushil Category_Name", category_Name + " " + Category_ID + " " + Product_ID + " " + Product_Name + " " + Product_Image + " " + Product_Price + " " + Product_Sale + " " + Cart);
SingleItemModel singleItemModel1 = new SingleItemModel(category_Name, Category_ID, Product_ID, Product_Name, Product_Image, Product_Price, Product_Sale, Cart);
singleItemModels.add(singleItemModel1);
}
StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(new ImageListFragment.SimpleStringRecyclerViewAdapter(recyclerView, singleItemModels));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e("error", error.toString());
}
}) {
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("method", "feature");
params.put("userId", "PRO1");
return params;
}
};
stringRequest.setRetryPolicy(new DefaultRetryPolicy(
90000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
queue.add(stringRequest);
}
}

Replace your MainActivity with below
public class MainActivity extends AppCompatActivity {
public static int notificationCountCart = 0;
Toolbar toolbar;
ActionBar actionBar;
static ViewPager viewPager;
static TabLayout tabLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
if (toolbar != null)
setSupportActionBar(toolbar);
actionBar = getSupportActionBar();
if (actionBar != null) {
TextView textView = new TextView(this);
textView.setText("Shopping");
textView.setTextSize(20);
textView.setTypeface(null, Typeface.BOLD);
textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
textView.setGravity(Gravity.CENTER);
textView.setTextColor(getResources().getColor(R.color.white));
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setCustomView(textView);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeAsUpIndicator(new IconDrawable(this, FontAwesomeIcons.fa_angle_left).colorRes(R.color.white).actionBarSize());
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
viewPager = (ViewPager) findViewById(R.id.viewpagerrr);
viewPager.setOffscreenPageLimit(4);
tabLayout = (TabLayout) findViewById(R.id.tabs);
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
}
#Override
protected void onResume() {
super.onResume();
invalidateOptionsMenu();
}
#Override
public void onBackPressed() {
super.onBackPressed();
}
#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, menu);
return true;
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
// Get the notifications MenuItem and
// its LayerDrawable (layer-list)
MenuItem item = menu.findItem(R.id.action_cart);
NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCountCart);
// force the ActionBar to relayout its MenuItems.
// onCreateOptionsMenu(Menu) will be called again.
invalidateOptionsMenu();
return super.onPrepareOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_search) {
startActivity(new Intent(MainActivity.this, SearchResultActivity.class));
return true;
} else if (id == R.id.action_cart) {
/* NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCount);
invalidateOptionsMenu();*/
startActivity(new Intent(MainActivity.this, CartListActivity.class));
/* notificationCount=0;//clear notification count
invalidateOptionsMenu();*/
return true;
} else if (id == android.R.id.home) {
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
// startActivity(new Intent(MainActivity.this, EmptyActivity.class));
}
return super.onOptionsItemSelected(item);
}
private void setupViewPager(ViewPager viewPager) {
Adapter adapter = new Adapter(getSupportFragmentManager());
ImageListFragment fragment = new ImageListFragment();
SpeakerFragment speakerFragment = new SpeakerFragment();
adapter.addFragment(fragment, getString(R.string.item_2));
adapter.addFragment(speakerFragment, getString(R.string.item_4));
adapter.addFragment(new HeadPhone(), getString(R.string.item_3));
adapter.addFragment(new Offer(), getString(R.string.item_1));
viewPager.setAdapter(adapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
}
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);
}
}
}

How to implement void OnFragmentInteractionListener?

When I launch my app I get following exception:
java.lang.RuntimeException: com.demo.mtin.mtin.MainActivity must implement OnFragmentInteractionListener
Can someone help me with this?
What code I need to add in MainActivity and where?
I have two blank fragments: PopularFragment and RatedFragment
MainActivity bellow:
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private MoviesAdapter mAdapter;
#Override
protected void onResume() {
SharedPreferences sharedPref = getBaseContext().getSharedPreferences(getString(R.string.preference_file_key), Context.MODE_PRIVATE);
String order = sharedPref.getString("order", "popular");
if (order.equals("popular")) {
getPopularMovies();
} else {
getTopRatedMovies();
}
super.onResume();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// uci i postaviti order -> popular
Log.d("NESTO", "NESTO-onCreate");
PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
}
}
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PageAdapter adapter = new PageAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}

This is actually a pretty straight-forward error message, go for this:
public class MainActivity extends AppCompatActivity implements PopularFragment.OnFragmentInteractionListener, RatedFragment.OnFragmentInteractionListener { ...
#Override
public void onFragmentInteraction(Uri uri) {
}}
You must indicate that your activity implement the fragment's interface, then implement it (can be void though).
And have the following in your fragments :
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}

Going back from a fragment to the previous which have viewpager

I am developing an app which have a single activity and several fragments.
The first fragment contains a viewpager which have 3-4 fragments extra. I can switch from one fragment to another easily and the viewpager works fine, but when i am going back from one fragment to the first(not in viewpager), the viewpager is not loading all fragments. Below is the code:
mainactivity.java
public class MainActivity extends ActionBarActivity implements View.OnClickListener {
private String[] mOptionMenu;
private DrawerLayout mDrawerLayout;
private DrawerLayout loginlayout;
private RelativeLayout mDrawerRelativeLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mTitleSection;
private CharSequence mTitleApp;
private Fragment mFragment = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn1= (Button) findViewById(R.id.button1);
Button btn2= (Button) findViewById(R.id.button2);
Button login= (Button) findViewById(R.id.login);
Button about= (Button) findViewById(R.id.about);
about.setOnClickListener(this);
login.setOnClickListener(this);
btn2.setOnClickListener(this);
btn1.setOnClickListener(this);
FontChangeCrawler fontChanger = new FontChangeCrawler(getAssets(), "fonts/font.ttf");
fontChanger.replaceFonts((ViewGroup)this.findViewById(android.R.id.content));
if (findViewById(R.id.content_frame) != null) {
if (savedInstanceState != null) {
return;
}
FirstFragment firstFragment = new FirstFragment();
firstFragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction().addToBackStack(null)
.add(R.id.content_frame, firstFragment).commit();
}
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerRelativeLayout = (RelativeLayout) findViewById(R.id.left_drawer);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.drawable.ic_drawer, R.string.drawer_open,
R.string.drawer_close) {
public void onDrawerClosed(View view) {
getSupportActionBar().setTitle(mTitleSection);
ActivityCompat.invalidateOptionsMenu(MainActivity.this);
}
public void onDrawerOpened(View drawerView) {
getSupportActionBar().setTitle(mTitleSection);
ActivityCompat.invalidateOptionsMenu(MainActivity.this);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
getSupportActionBar().setCustomView(R.layout.actionbar_image);
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_HOME
| ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#662e91")));
mDrawerLayout.setDrawerListener(new DrawerLayout.DrawerListener() {
#Override
public void onDrawerSlide(View drawerView, float slideOffset) {
}
#Override
public void onDrawerOpened(View drawerView) {
}
#Override
public void onDrawerClosed(View drawerView) {
}
#Override
public void onDrawerStateChanged(int newState) {
}
});
}
#Override
public void onClick(View v) {
switch(v.getId())
{
case R.id.button1:
FirstFragment firstFragment = new FirstFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new FirstFragment()).commit();
mDrawerLayout.closeDrawer(Gravity.LEFT);
break;
case R.id.login:
callLoginDialog();
break;
case R.id.about:
about abt = new about();
abt.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction()
.add(R.id.content_frame, abt).commit();
mDrawerLayout.closeDrawer(Gravity.LEFT);
break;
}
}
public class FontChangeCrawler
{
private Typeface typeface;
public FontChangeCrawler(Typeface typeface)
{
this.typeface = typeface;
}
public FontChangeCrawler(AssetManager assets, String assetsFontFileName)
{
typeface = Typeface.createFromAsset(assets, "fonts/font.ttf");
}
public void replaceFonts(ViewGroup viewTree)
{
View child;
for(int i = 0; i < viewTree.getChildCount(); ++i)
{
child = viewTree.getChildAt(i);
if(child instanceof ViewGroup)
{
// recursive call
replaceFonts((ViewGroup)child);
}
else if(child instanceof TextView)
{
// base case
((TextView) child).setTypeface(typeface);
}
}
}
}
public void callLoginDialog()
{
Dialog myDialog = new Dialog(this);
myDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
myDialog.setContentView(R.layout.loginwindow);
myDialog.setCancelable(false);
TextView reg= (TextView) myDialog.findViewById(R.id.register);
Button login = (Button) myDialog.findViewById(R.id.login);
EditText emailaddr = (EditText) myDialog.findViewById(R.id.editText2);
EditText password = (EditText) myDialog.findViewById(R.id.editText3);
myDialog.show();
reg.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Register",
Toast.LENGTH_LONG).show();
}
});
login.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
//your login calculation goes here
}
});
myDialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
#Override
public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
dialog.cancel();
return true;
}
return false;
}
});
}
#Override
public void onBackPressed() {
if(mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
mDrawerLayout.closeDrawer(Gravity.LEFT);
}
else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
switch (item.getItemId()) {
case R.id.user:
mDrawerLayout.closeDrawer(Gravity.LEFT);
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
}
firstfragment.java
public class FirstFragment extends Fragment {
public ViewPager viewPager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_first,
container, false);
viewPager = (ViewPager) rootView.findViewById(pager);
viewPager.setAdapter(new ViewPagerAdapter(getFragmentManager()));
viewPager.setCurrentItem(0);
PagerTitleStrip pagerTitleStrip= (PagerTitleStrip) rootView.findViewById(R.id.titlestrip);
pagerTitleStrip.setNonPrimaryAlpha(Float.parseFloat("0.3"));
viewPager.setPageTransformer(true, new ViewPager.PageTransformer() {
#Override
public void transformPage(View view, float position) {
final float normalizedposition = Math.abs(Math.abs(position) - 1);
view.setAlpha(normalizedposition);
}
});
Typeface font = Typeface.createFromAsset(getActivity().getAssets(), "fonts/font.ttf");
for (int counter = 0 ; counter<pagerTitleStrip.getChildCount(); counter++) {
if (pagerTitleStrip.getChildAt(counter) instanceof TextView) {
((TextView)pagerTitleStrip.getChildAt(counter)).setTypeface(font);
}
}
return rootView;
}
}
viewpageadapter.java
public class ViewPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 4;
// Tab Titles
private String tabtitles[] = new String[] { "Home", "Men", "Women", "Children" };
Context context;
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
switch (position) {
// Open FragmentTab1.java
case 0:
SecondFragment fragmenttab1 = new SecondFragment();
return fragmenttab1;
// Open FragmentTab2.java
case 1:
ThirdFragment fragmenttab2 = new ThirdFragment();
return fragmenttab2;
case 2:
Fourthfragment fragmenttab3 = new Fourthfragment();
return fragmenttab3;
case 3:
FifthFragment fragmenttab4 = new FifthFragment();
return fragmenttab4;
}
return null;
}
#Override
public CharSequence getPageTitle(int position) {
return tabtitles[position];
}
}

Try changing viewPager.setAdapter(new ViewPagerAdapter(getFragmentManager())); with viewPager.setAdapter(new ViewPagerAdapter(getChildFragmentManager()));