Passing data from activity to fragment causes “ScrollView can host only one direct child” error

Question

I am making an app using this tutorial. I made some changes in my code, ie I wanted to get data from server to my main activity and pass it to my fragments. Before that , when I would open the app it worked perfectly, bu now it crashes. I have tried a bunch of answers from stackoverflow ( 1 , 2 , 3 , 4 , 5 ...) before asking a question, but none of them answered my question. When I was getting restaurants from fragment directly it worked perfectly but passing the data from the activity causes this error.

Main Activity (I pass get data from server and pass it to fragment):

TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.addTab(tabLayout.newTab().setText(getString(R.string.tab_map)));
tabLayout.addTab(tabLayout.newTab().setText(getString(R.string.tab_list)));
tabLayout.addTab(tabLayout.newTab().setText(getString(R.string.tab_my_list)));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.setTabMode(TabLayout.MODE_FIXED);

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

RestaurantsFragment restaurantsFragment = new RestaurantsFragment();
Bundle args = new Bundle();
args.putParcelableArrayList("restaurantList", (ArrayList<? extends Parcelable>) restaurantList);
restaurantsFragment.setArguments(args);

FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.sliding_tabs, restaurantsFragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();

Restaurant Fragment (I do get data from my main activity, I get the restaurants from the server when I debug):

public class RestaurantsFragment extends Fragment {

private static final String TAG = RestaurantsFragment.class.getSimpleName();

// Restaurants json url
private ProgressDialog pDialog;
private ArrayList restaurantList = new ArrayList<>();
private ListView listView;
private CustomListAdapter adapter;

@Override
public View onCreateView(LayoutInflater inflater,
                         ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_restaurants, container, false);

    Bundle bundle = this.getArguments();
    if (bundle != null) {
        restaurantList = bundle.getParcelableArrayList ("restaurantList");
    }

    listView = (ListView) view.findViewById(R.id.restaurants_list);
    adapter = new CustomListAdapter(getActivity(), restaurantList);
    listView.setAdapter(adapter);

    pDialog = new ProgressDialog(getActivity());

    pDialog.setMessage("Loading...");
    pDialog.show();


    return view;
}

fragment_restaurants

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".sliderfragments.RestaurantsFragment">

<ListView
    android:id="@+id/restaurants_list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:divider="@color/list_divider"
    android:dividerHeight="1dp"
    android:listSelector="@drawable/list_row_selector" />

</RelativeLayout>

list_row

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/list_row_selector"
android:padding="8dp">

<!-- Thumbnail Image -->
<com.android.volley.toolbox.NetworkImageView
    android:id="@+id/thumbnail"
    android:background="@drawable/default_profile"
    android:layout_width="80dp"
    android:layout_height="80dp"
    android:layout_alignParentLeft="true"
    android:layout_marginRight="8dp" />

<!-- User Name -->
<TextView
    android:id="@+id/userName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@+id/thumbnail"
    android:layout_toRightOf="@+id/thumbnail"
    android:textSize="@dimen/userName"
    android:textStyle="bold" />

<!-- Date -->
<TextView
    android:id="@+id/date"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/userName"
    android:layout_marginTop="1dip"
    android:layout_toRightOf="@+id/thumbnail"
    android:textSize="@dimen/date" />

<!-- Time -->
<TextView
    android:id="@+id/time"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/date"
    android:layout_marginTop="5dp"
    android:layout_toRightOf="@+id/thumbnail"
    android:textColor="@color/time"
    android:textSize="@dimen/time" />

</RelativeLayout>

content_main

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="@layout/app_bar_main">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

    <android.support.design.widget.TabLayout
        android:id="@+id/sliding_tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMode="scrollable" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1"
        android:background="@android:color/white" />
</android.support.design.widget.AppBarLayout>

Pager Adapter:

public class PagerAdapter extends FragmentStatePagerAdapter {
int mNumOfTabs;

public PagerAdapter(FragmentManager fm, int NumOfTabs) {
    super(fm);
    this.mNumOfTabs = NumOfTabs;
}

@Override
public Fragment getItem(int position) {

    switch (position) {
        case 0:
            MapsFragment tab1 = new MapsFragment();
            return tab1;
        case 1:
            RestaurantsFragment tab2 = new RestaurantsFragment();
            return tab2;
        case 2:
            MyRestaurantsFragment tab3 = new MyRestaurantsFragment();
            return tab3;
        default:
            return null;
    }
}

@Override
public int getCount() {
    return mNumOfTabs;
}
}

Stack trace:

10-09 12:30:12.755 32374-32374/? E/AndroidRuntime: FATAL EXCEPTION: main
  Process: com.test.kemo.restaurant, PID: 32374
  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.kemo.restaurant/com.test.kemo.restaurant.MainActivity}: java.lang.IllegalStateException: HorizontalScrollView can host only one direct child
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  at android.app.ActivityThread.access$800(ActivityThread.java:135)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:136)
  at android.app.ActivityThread.main(ActivityThread.java:5021)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:515)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643)
  at dalvik.system.NativeStart.main(Native Method)
  Caused by: java.lang.IllegalStateException: HorizontalScrollView can host only one direct child
  at android.widget.HorizontalScrollView.addView(HorizontalScrollView.java:216)
  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1083)
  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
  at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
  at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:330)
  at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:547)
  at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1174)
  at android.app.Activity.performStart(Activity.java:5347)
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2168)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 
  at android.app.ActivityThread.access$800(ActivityThread.java:135) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
  at android.os.Handler.dispatchMessage(Handler.java:102) 
  at android.os.Looper.loop(Looper.java:136) 
  at android.app.ActivityThread.main(ActivityThread.java:5021) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:515) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643) 
  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

you are adding your fragment to your sliding tab view. you wrote :

fragmentTransaction.replace(R.id.sliding_tabs, restaurantsFragment);

tab layout is a child of horizontal scrollview see documentation: https://developer.android.com/reference/android/support/design/widget/TabLayout.html

i dont know how your application works but you cant add your fragment to TabLayout here cause it makes multiple children for that that is now allowed (TabLaout is actually a horizontal scrollView inside)

in fragmentTransaction.replace() method that i mentioned you must specify the container in which you want to add the fragment. from what your code says you are using the tabLayput for title of your viewpager not for replacing your fragment in it.

make a place (container) in your main activity in which you want to add your fragment in. absolutely its not in your R.id.sliding_tabs, beside your titles of viewpager.