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Pass the data from activity to Page Adapter

I need to pass the String data to tab layout. i'm already pass the data from adapter to fragments in Tab layout. But my problem is I cannot to pass that data from activity to Adapter java class. I need to pass the data to more than one fragment. how can i do this?
Main Activity Code
package com.example.tablay;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;
import android.content.Intent;
import android.os.Bundle;
import android.provider.ContactsContract;
import com.google.android.material.tabs.TabLayout;
import java.util.List;
import java.util.Stack;
public class MainActivity extends AppCompatActivity {
private ViewPager pager;
private TabLayout tabs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pager=(ViewPager) findViewById(R.id.pager);
tabs=(TabLayout) findViewById(R.id.tabs);
pager.setAdapter(new TabFragmentPagerAdapter(getSupportFragmentManager()));
tabs.setupWithViewPager(pager);
tabs.setTabGravity(TabLayout.GRAVITY_FILL);
}
}
Page Adapter Code :
package com.example.tablay;
import android.os.Bundle;
import android.provider.ContactsContract;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import java.util.Date;
import java.util.List;
public class TabFragmentPagerAdapter extends FragmentPagerAdapter {
String[] title = new String[]{
"Tab 1", "Tab 2", "Tab 3"
};
public TabFragmentPagerAdapter(#NonNull FragmentManager fm) {
super(fm);
}
#NonNull
#Override
public Fragment getItem(int position) {
Fragment fragment=null;
switch (position){
case 0:
tab1Fragment tab1Fragment=new tab1Fragment();
Bundle bundle = new Bundle();
bundle.putString("edttext", "data From Activity");
tab1Fragment.setArguments(bundle);
return tab1Fragment;
case 1:
tab2Fragment tab2Fragment=new tab2Fragment();
bundle = new Bundle();
bundle.putString("edttext1", "data From Activity1");
tab2Fragment.setArguments(bundle);
return tab2Fragment;
case 2:
tab3Fragment tab3Fragment=new tab3Fragment();
return tab3Fragment;
default:
fragment=null;
break;
}
return fragment;
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return title[position];
}
#Override
public int getCount() {
return title.length;
}
}
Fragment Code:
package com.example.tablay;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class tab1Fragment extends Fragment {
public tab1Fragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_tab1, container, false);
TextView tes=(TextView) view.findViewById(R.id.testtab1);
String strtext = getArguments().getString("edttext");
tes.setText(strtext);
return view;
}
}
I need to pass the String data to tab layout. i'm already pass the data from adapter to fragments in Tab layout. But my problem is I cannot to pass that data from activity to Adapter java class. I need to pass the data to more than one fragment. how can i do this?

You can pass data from activity to the adapter by constructor like this :
public class MainActivity extends AppCompatActivity {
private ViewPager pager;
private TabLayout tabs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pager=(ViewPager) findViewById(R.id.pager);
tabs=(TabLayout) findViewById(R.id.tabs);
pager.setAdapter(new TabFragmentPagerAdapter(getSupportFragmentManager(),ActivityStringData));
tabs.setupWithViewPager(pager);
tabs.setTabGravity(TabLayout.GRAVITY_FILL);
}
to
public class TabFragmentPagerAdapter extends FragmentPagerAdapter {
String[] title = new String[]{
"Tab 1", "Tab 2", "Tab 3"
};
String data=null;
public TabFragmentPagerAdapter(#NonNull FragmentManager fm,String activityData) {
super(fm);
this.data=activityData
}
#NonNull
#Override
public Fragment getItem(int position) {
Fragment fragment=null;
switch (position){
case 0:
tab1Fragment tab1Fragment=new tab1Fragment();
Bundle bundle = new Bundle();
bundle.putString("edttext", "data From Activity");
tab1Fragment.setArguments(bundle);
return tab1Fragment;
case 1:
tab2Fragment tab2Fragment=new tab2Fragment();
bundle = new Bundle();
bundle.putString("edttext1", "data From Activity1");
tab2Fragment.setArguments(bundle);
return tab2Fragment;
case 2:
tab3Fragment tab3Fragment=new tab3Fragment();
return tab3Fragment;
default:
fragment=null;
break;
}
return fragment;
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return title[position];
}
#Override
public int getCount() {
return title.length;
}
}

How to setOnclickListener FAB in a fragment that will add a card in a RecyclerView

Im trying to add a FAB that will add a card to the recycler view if clicked
FAB is located in the fragment where it contains the recyclerview
Here is my Adapter
package com.example.tmcpm;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.util.List;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> {
Context mContext ;
List<MediCard> mData;
public RecyclerViewAdapter(Context mContext, List<MediCard> mData) {
this.mContext = mContext;
this.mData = mData;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v ;
v = LayoutInflater.from(mContext).inflate(R.layout.fragment_medicard_recycler,parent,false);
MyViewHolder vHolder = new MyViewHolder(v);
return vHolder;
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder holder, final int position) {
int currentPosition = position;
final MediCard infoData = mData.get(position);
holder.tv_num.setText(mData.get(position).getMediCardNumber());
holder.buttonDelete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext,"Deleted Medication" , Toast.LENGTH_SHORT).show();
removeItem(infoData);
}
private void removeItem(MediCard infoData) {
int currPosition = mData.indexOf(infoData);
mData.remove(currPosition);
notifyItemRemoved(currPosition);
notifyItemRangeChanged(currPosition,mData.size());
notifyDataSetChanged();
}
});
/* holder.buttonAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext,"ADDING", Toast.LENGTH_SHORT).show();
}
});*/
}
#Override
public int getItemCount() {
return mData.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private TextView tv_num;
private Button buttonDelete;
public FloatingActionButton buttonAdd;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
tv_num = (TextView) itemView.findViewById(R.id.word);
buttonDelete = (Button) itemView.findViewById(R.id.buttonDelete);
buttonAdd = (FloatingActionButton) itemView.findViewById(R.id.floatButtonAdd);
}
}
}
THIS is my Tabbed Activity Java
package com.example.tmcpm;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import com.google.android.material.tabs.TabLayout;
import java.util.ArrayList;
import java.util.List;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager.widget.ViewPager;
public class Prescribe extends AppCompatActivity {
// private final LinkedList<String> mWordList = new LinkedList<>();
private RecyclerView myrecyclerview;
private List<MediCard> lstnum;
/**
* The {#link androidx.viewpager.widget.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* androidx.fragment.app.FragmentStatePagerAdapter.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_prescribe);
//Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
//setSupportActionBar(toolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));
/* for (int i = 1; i < 6; i++) {
mWordList.addLast("Medicine # " + i);
}*/
;
}
#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_prescribe, 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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
RecyclerView myrecyclerview;
List<MediCard> mData = new ArrayList<>();
mData.add(new MediCard("Medication 1"));
mData.add(new MediCard("Medication 2"));
mData.add(new MediCard("Medication 3"));
mData.add(new MediCard("Medication 4 "));
View rootView = null;
switch(getArguments().getInt(ARG_SECTION_NUMBER)){
case 1:
//do something
rootView = inflater.inflate(R.layout.fragment_prescribe, container, false);
break;
case 2:
//do something
rootView = inflater.inflate(R.layout.medicard_fragment,container,false);
myrecyclerview = rootView.findViewById(R.id.medicard_recyclerview);
RecyclerViewAdapter recyclerAdapter = new RecyclerViewAdapter(getContext(),mData);
myrecyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
myrecyclerview.setAdapter(recyclerAdapter);
new FragmentMedicard();
break;
case 3:
rootView = inflater.inflate(R.layout.medicard_fragment, container, false);
break;
}
//TextView textView = (TextView) rootView.findViewById(R.id.section_label);
// textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.newInstance(position + 1);
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
}
}
and the Fragment that holds the recyclerView Java
package com.example.tmcpm;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.util.List;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.RecyclerView;
public class FragmentMedicard extends Fragment implements View.OnClickListener {
View v;
private RecyclerView myrecyclerview;
private List<MediCard> mData;
FloatingActionButton fabAdd;
Context mContext;
public View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedinstanceState) {
View myView = inflater.inflate(R.layout.medicard_fragment, container, false);
fabAdd = (FloatingActionButton) myView.findViewById(R.id.floatButtonAdd);
fabAdd.setOnClickListener(this);
return myView;
}
#Override
public void onClick(View v) {
Toast.makeText(mContext,"ADDING", Toast.LENGTH_SHORT).show();
}
}
I really dont know what to do anymore
I tried putting my code for the fab in the adapter which only cause a nullpointer exception which is i think is right since its in a different fragment

Create an instance variable to hold your recyclerAdapter in your fragment. Then you can have the FAB click listener add a MediaCard to mData.
Then call
recyclerAdapter.notifyDataSetChanged();

Recyclerview with cards in a fragment shows nothing

I am trying to make an activity which has a fragment inside with a recyclerView and cards on it. Right now, it only shows the activity, the fragment is empty, and I don't know what is going on here.
This is the code of the activity, the fragment, and the adapter
Activity:
package com.laorden.goodreasons.habits;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.VisibleForTesting;
import android.support.design.widget.NavigationView;
import android.support.test.espresso.IdlingResource;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.view.Window;
import android.view.WindowManager;
import com.laorden.goodreasons.Injection;
import com.laorden.goodreasons.R;
import com.laorden.goodreasons.statistics.StatisticsActivity;
import com.laorden.goodreasons.util.ActivityUtils;
import com.laorden.goodreasons.util.EspressoIdlingResource;
public class HabitsActivity extends AppCompatActivity {
private DrawerLayout mDrawerLayout;
private HabitsPresenter mHabitsPresenter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.habits_act);
Window w = getWindow();
w.setFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
// Set up the toolbar.
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ActionBar ab = getSupportActionBar();
ab.setHomeAsUpIndicator(R.drawable.ic_menu);
ab.setDisplayHomeAsUpEnabled(true);
// Set up the navigation drawer.
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerLayout.setStatusBarBackground(R.color.colorPrimaryDark);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
if (navigationView != null) {
setupDrawerContent(navigationView);
}
HabitsFragment habitsFragment =
(HabitsFragment) getSupportFragmentManager().findFragmentById(R.id.contentFrame);
if (habitsFragment == null) {
// Create the fragment
habitsFragment = HabitsFragment.newInstance();
ActivityUtils.addFragmentToActivity(
getSupportFragmentManager(), habitsFragment, R.id.contentFrame);
}
// Create the presenter
mHabitsPresenter = new HabitsPresenter(habitsFragment,
Injection.provideUseCaseHandler());
}
/* // Load previously saved state, if available.
if (savedInstanceState != null) {
TasksFilterType currentFiltering =
(TasksFilterType) savedInstanceState.getSerializable(CURRENT_FILTERING_KEY);
mTasksPresenter.setFiltering(currentFiltering);
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
outState.putSerializable(CURRENT_FILTERING_KEY, mTasksPresenter.getFiltering());
super.onSaveInstanceState(outState);
}*/
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// Open the navigation drawer when the home icon is selected from the toolbar.
mDrawerLayout.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
private void setupDrawerContent(NavigationView navigationView) {
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.list_navigation_menu_item:
// Do nothing, we're already on that screen
break;
case R.id.statistics_navigation_menu_item:
Intent intent =
new Intent(HabitsActivity.this, StatisticsActivity.class);
startActivity(intent);
break;
default:
break;
}
// Close the navigation drawer when an item is selected.
menuItem.setChecked(true);
mDrawerLayout.closeDrawers();
return true;
}
});
}
#VisibleForTesting
public IdlingResource getCountingIdlingResource() {
return EspressoIdlingResource.getIdlingResource();
}
}
Fragment:
package com.laorden.goodreasons.habits;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import com.laorden.goodreasons.R;
import com.laorden.goodreasons.habits.domain.model.Habit;
import java.util.ArrayList;
import java.util.List;
public class HabitsFragment extends android.support.v4.app.Fragment implements HabitsContract.View {
private HabitsContract.Presenter mPresenter;
private HabitsAdapter mListAdapter;
private RecyclerView recyclerView;
public HabitsFragment() {
// Requires empty public constructor
}
public static HabitsFragment newInstance() {
return new HabitsFragment();
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
List<Habit> habitsList = new ArrayList<>();
habitsList.add(new Habit(R.drawable.smoke,"Quit smoking",300));
habitsList.add(new Habit(R.drawable.books,"Read more",600));
habitsList.add(new Habit(R.drawable.sleep,"Get more sleep",600));
mListAdapter = new HabitsAdapter(getContext(),habitsList);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.habits_frag, container, false);
recyclerView = root.findViewById(R.id.rv_list);
recyclerView.setAdapter(mListAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
return root;
}
#Override
public void onResume() {
super.onResume();
mPresenter.start();
}
#Override
public void setLoadingIndicator(boolean active) {
}
#Override
public void showHabits(List<Habit> habits) {
}
#Override
public void showHabitDetailsUi(String habitId) {
}
#Override
public boolean isActive() {
return false;
}
#Override
public void setPresenter(HabitsContract.Presenter presenter) {
mPresenter = presenter;
}
}
Adapter:
package com.laorden.goodreasons.habits;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.laorden.goodreasons.R;
import com.laorden.goodreasons.habits.domain.model.Habit;
import java.util.List;
public class HabitsAdapter extends RecyclerView.Adapter<HabitsAdapter.myViewHolder> {
Context mContext;
List<Habit> mData;
public HabitsAdapter(Context mContext, List<Habit> mData) {
this.mContext = mContext;
this.mData = mData;
}
#Override
public myViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View v = inflater.inflate(R.layout.card_item,parent,false);
return new myViewHolder(v);
}
#Override
public void onBindViewHolder(myViewHolder holder, int position) {
holder.background_image.setImageResource(mData.get(position).getBackground());
holder.tv_title.setText(mData.get(position).getHabitName());
holder.tv_nbSubscribers.setText(mData.get(position).getNumSubscribers() + " Joined");
}
#Override
public int getItemCount() {
return 0;
}
public class myViewHolder extends RecyclerView.ViewHolder {
ImageView background_image;
TextView tv_title,tv_nbSubscribers;
public myViewHolder(View itemView) {
super(itemView);
background_image = itemView.findViewById(R.id.card_background);
tv_title = itemView.findViewById(R.id.card_title);
tv_nbSubscribers = itemView.findViewById(R.id.card_numberUsers);
}
}
}
If you need any other code snippets, please tell me (maybe the xml
layouts)
Thanks

That is because you are returning 0 in the getItemCount method
Change this :
#Override
public int getItemCount() {
return 0;
}
To this:
#Override
public int getItemCount() {
return (mData != null ? mData.size():0);
}

you should set layout manager first
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.habits_frag, container, false);
recyclerView = root.findViewById(R.id.rv_list);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setAdapter(mListAdapter);
return root;
}
also you need to change the getItemCount into
#Override
public int getItemCount() {
if(mData!=null){return mData.size();}else return 0;
}

The reason you are getting empty list because your method getItemCount returns 0.
Here is the modified method.
#Override
public int getItemCount() {
return mData!=null ? mData.size():0;
}

Retrofit RecyclerView not working in tab layout

I've been trying to implement a recycler view inside a fragment which displays parsed data using the retrofit library. Whenever I run the project the lists don't show and the monitor says "E/RecyclerView: No adapter attached; skipping layout". Here is my code:
MainActivity:
package com.example.ahmed.newsapp
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.design.widget.TabLayout;
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private static final int ACTIVITY_NUM = 0;
// TODO - insert your themoviedb.org API KEY here
private final static String API_KEY = "<API KEY CENSORED>";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Find the view pager that will allow the user to swipe between fragments
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
// Create an adapter that knows which fragment should be shown
FragmentAdapter adapter = new FragmentAdapter(getSupportFragmentManager
());
// Set the adapter onto the view pager
viewPager.setAdapter(adapter);
TabLayout ob=(TabLayout) findViewById(R.id.sliding_tabs);
ob.setupWithViewPager(viewPager);
}
}
FragmentAdapter:
package com.example.ahmed.newsapp;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
/**
* Created by ahmed on 3/22/2017.
*/
public class FragmentAdapter extends FragmentPagerAdapter {
private String tabs[]=new String[]{"Home","Family Members","Colors"};
public FragmentAdapter(FragmentManager fm){
super(fm);
}
#Override
public Fragment getItem(int position) {
switch(position){
case 0:
return new HomeActivity();
case 1:
return new HomeActivity();
/* case 2:
return new ColorFragment();*/
}
return null;
}
#Override
public CharSequence getPageTitle(int position) {
return tabs[position];
}
#Override
public int getCount() {
return 2;
}
}
NewsAdapter:
package com.example.ahmed.newsapp;
/**
* Created by ahmed on 27-08-17.
*/
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.List;
public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.NewsViewHolder> {
private List<News> news;
private int rowLayout;
private Context context;
public static class NewsViewHolder extends RecyclerView.ViewHolder {
LinearLayout moviesLayout;
TextView movieTitle;
TextView data;
TextView movieDescription;
TextView rating;
public NewsViewHolder(View v) {
super(v);
moviesLayout = (LinearLayout) v.findViewById(R.id.movies_layout);
movieTitle = (TextView) v.findViewById(R.id.title);
data = (TextView) v.findViewById(R.id.subtitle);
movieDescription = (TextView) v.findViewById(R.id.description);
rating = (TextView) v.findViewById(R.id.rating);
}
}
public NewsAdapter(List<News> news, Context context) {
this.news = news;
// this.rowLayout = rowLayout;
this.context = context;
}
#Override
public NewsViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item_news, parent, false);
return new NewsViewHolder(view);
}
#Override
public void onBindViewHolder(NewsViewHolder holder, final int position) {
holder.movieTitle.setText(news.get(position).getTitle());
holder.data.setText(news.get(position).getReleaseDate());
holder.movieDescription.setText(news.get(position).getOverview());
holder.rating.setText(news.get(position).getVoteAverage().toString());
}
#Override
public int getItemCount() {
return news.size();
}
}
HomeActivity:
package com.example.ahmed.newsapp;
import android.os.Bundle;
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.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import static android.content.ContentValues.TAG;
public class HomeActivity extends Fragment {
RecyclerView recyclerView;
private final static String API_KEY = "<API KEY CENSORED>";
NewsAdapter adapter;
List<News> news,dummy;
View rootview;
public HomeActivity() {
// Required empty public constructor
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootview = inflater.inflate(R.layout.activity_home, container, false);
if (API_KEY.isEmpty()) {
Toast.makeText(getContext(), "Please obtain your API KEY first from themoviedb.org", Toast.LENGTH_LONG).show();
return rootview;
}
ApiInterface apiService =
ApiClient.getClient().create(ApiInterface.class);
recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view);
adapter= new NewsAdapter(dummy,getContext());
Call<NewsResponse> call = apiService.getTopRatedMovies(API_KEY);
call.enqueue(new Callback<NewsResponse>() {
#Override
public void onResponse(Call<NewsResponse> call, Response<NewsResponse> response) {
news = response.body().getResults();
adapter.notifyDataSetChanged();
adapter=new NewsAdapter(news,getContext());
recyclerView.setAdapter(adapter);
// adapter.setData(news);
Log.d(TAG, "Number of movies received: " + news.size());
}
#Override
public void onFailure(Call<NewsResponse> call, Throwable t) {
// Log error here since request failed
Log.e(TAG, t.toString());
}
});
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
return rootview;
}
}

i think the problem is in your FragmentAdapter class
just remove return null; statement from your FragmentAdapter like below code
#Override
public Fragment getItem(int position) {
Fragment fragment=null;
switch(position){
case 0:
fragment= new HomeActivity();
case 1:
fragment= new HomeActivity();
/* case 2:
return new ColorFragment();*/
}
return fragment;
}
change this
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view);
adapter= new NewsAdapter(dummy,getContext());

You don't need to recreate your adapter when you receive response.
It may looks like:
recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new NewsAdapter(null, getActivity());
recyclerView.setAdapter(adapter);
Call<NewsResponse> call = apiService.getTopRatedMovies(API_KEY);
call.enqueue(new Callback<NewsResponse>() {
#Override
public void onResponse(Call<NewsResponse> call, Response<NewsResponse> response) {
news = response.body().getResults();
adapter.setData(news);
Log.d(TAG, "Number of movies received: " + news.size());
}
...
And in NewsAdapter:
...
public void setData(Collection<News> newData) {
news.clear();
news.addAll(newData);
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return news == null ? 0 : news.size();
}
...

When I call next fragment form current the tab selection will not change on Button click

I am trying to develop an android app in which I am going to include tab with fragment. Please find below code for Activity :
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
public class EnterActivity extends AppCompatActivity {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_enter);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
tabLayout.getTabAt(3).select();
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new EnterCodeFragment(), "ENTER CODE");
adapter.addFragment(new HistoryFragment(), "HISTORY");
adapter.addFragment(new HelpFragment(), "HELP");
adapter.addFragment(new LogoutFragment(), "LOGOUT");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
Below logic I used to call other fragment on button click.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_main, container, false);
Button loginButton = (Button)v.findViewById(R.id.button);
loginButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View view) {
Fragment fragment = new EnterCodeFragment();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.activity_main,fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
// ViewPagerAdapter.get
}
});
return v;
}
When I click on button it will move to the next fragment but tab selection will not change. I think it is creating a new fragment. Any help would be appreciated.

I think you not initialize fragment properly update like above code
Button loginButton = (Button)v.findViewById(R.id.button);
loginButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View view) {
EnterCodeFragment fragment = new EnterCodeFragment(); // check this
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.activity_main,fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
// ViewPagerAdapter.get
}
});