Odtnhj

I am trying to develop one activity, which contains TabLayout, which is build using one Fragment, but used a few times (same layout, different data). But when I have such a configuration, my app doesn't even go inside of getItem() method and doesn't show up my layout. Any ideas where is the problem?

My code:
Activity:

public class IndoorArenaActivity extends AppCompatActivity 
@Override
protected void onCreate(Bundle savedInstanceState) 
 super.onCreate(savedInstanceState);
 setContentView(R.layout.my_arena);

 TabLayout tabLayout = findViewById(R.id.tabs);
 final ViewPager viewPager = findViewById(R.id.viewPager);
 final PageAdapterArena adapter = new PageAdapterArena
 (getSupportFragmentManager(), tabLayout.getTabCount());
 viewPager.setAdapter(adapter);
 viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

 tabLayout.addTab(tabLayout.newTab().setText("today"));
 tabLayout.addTab(tabLayout.newTab().setText("tomorrow"));
 tabLayout.addTab(tabLayout.newTab().setText("13/11"));
 tabLayout.addTab(tabLayout.newTab().setText("14/11"));
 tabLayout.addTab(tabLayout.newTab().setText("15/11"));
 tabLayout.addTab(tabLayout.newTab().setText("16/11"));
 tabLayout.addTab(tabLayout.newTab().setText("17/11"));
 tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);


 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) 
 getMenuInflater().inflate(R.menu.menu_main, menu);
 return true;


@Override
public boolean onOptionsItemSelected(MenuItem item) 
 int id = item.getItemId();
 // if (id == R.id.action_settings) 
 // return true;
 // 

 return super.onOptionsItemSelected(item);

Adapter:

public class PageAdapterArena extends FragmentStatePagerAdapter 
int mNumOfTabs;

public PageAdapterArena(FragmentManager fm, int NumOfTabs) 
 super(fm);
 this.mNumOfTabs = NumOfTabs;


@Override
public Fragment getItem(int position) 

 Fragment fragment = null;
 switch(position)
 case 0:
 fragment = IndoorArenaFragment.newInstance();
 break;
 
 return fragment;


@Override
public int getCount() 
 return mNumOfTabs;

Fragment:

public class IndoorArenaFragment extends Fragment 

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
 return inflater.inflate(R.layout.indoor_arena_fragment, container, false);


public static Fragment newInstance() 
 IndoorArenaFragment fragment = new IndoorArenaFragment();
 return fragment;

Layout for activity:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".IndoorArena.IndoorArenaActivity">

<android.support.design.widget.TabLayout
 android:id="@+id/tabs"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:background="?attr/colorPrimary"
 android:elevation="6dp"
 android:minHeight="?attr/actionBarSize"
 app:tabMode="scrollable"/>

<android.support.v4.view.ViewPager
 android:id="@+id/viewPager"
 android:layout_width="match_parent"
 android:layout_height="fill_parent"
 android:layout_below="@id/tab_layout" />

Layout for fragment:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

 <LinearLayout
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:orientation="horizontal">

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:padding="20dp"
 android:text="7:00"
 android:textAppearance="?android:attr/textAppearanceLarge" />

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_marginLeft="50dp"
 android:text="Olga (Gatsby)"
 android:textAppearance="?android:attr/textAppearanceLarge" />

 </LinearLayout>


 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:padding="20dp"
 android:text="8:00"
 android:textAppearance="?android:attr/textAppearanceLarge" />

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:padding="20dp"
 android:text="9:00"
 android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

App doesn't show up any errors, only the fragment looks like this:

And I would like to show up like this (each fragment):

You're actually passing in NumOfTabs of 0 when you create the adapter, that's why you're getting an empty view in the ViewPager, and getItem not being called. To fix this, you just need to move your adapter creation line after adding the tabs:

TabLayout tabLayout = findViewById(R.id.tabs);
ViewPager viewPager = findViewById(R.id.viewPager);
tabLayout.addTab(tabLayout.newTab().setText("today"));
tabLayout.addTab(tabLayout.newTab().setText("tomorrow"));
tabLayout.addTab(tabLayout.newTab().setText("13/11"));
tabLayout.addTab(tabLayout.newTab().setText("14/11"));
tabLayout.addTab(tabLayout.newTab().setText("15/11"));
tabLayout.addTab(tabLayout.newTab().setText("16/11"));
tabLayout.addTab(tabLayout.newTab().setText("17/11"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

// Create adapter after adding the tabs
PageAdapterArena adapter = new PageAdapterArena(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));