Source Not Found when using ListFragment & ViewPager

Question

I've been trying to create a simple Horizontal scrolling option. I have 2 ListFragments, which I would like to scroll between.

I'm getting a "Source Not Found" error when returning the View from onCreateView function.

This is my MainActivity Class:

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

    AppSectionsPagerAdapter mAppSectionsPagerAdapter;
    ViewPager mViewPager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
        final ActionBar actionBar = getActionBar();
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mAppSectionsPagerAdapter);
        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                actionBar.setSelectedNavigationItem(position);
            }
        });
        for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) {
            actionBar.addTab(
                    actionBar.newTab()
                            .setText(mAppSectionsPagerAdapter.getPageTitle(i))
                            .setTabListener(this));
        }
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {
        // When the given tab is selected, switch to the corresponding page in the ViewPager.
        mViewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {
    }

    public static class AppSectionsPagerAdapter extends FragmentPagerAdapter {

        public AppSectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }
        Fragment a;
        @Override
        public Fragment getItem(int i) {
            switch (i) {
                case 0:
                    return new FragmentA();

                default:
                    return new FragmentB();
            }
        }

        @Override
        public int getCount() {
            return 2;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return "Section " + (position + 1);
        }
    }
}

This is one of my ListFragment class (the second is the same but different name & layout file):

    public class FragmentA extends ListFragment {

        @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
                View rootView = inflater.inflate(R.layout.favorites_layout, container, false);
                updateStationsView(0);
                return rootView;
            }
}

updateStationView is a function that populates the List. removing it did not help, so I figured it's harmless.

The error is thrown right after the:

return rootView;

which returns to the onCreate functions of MainActivity.

When I'm changing the ListFragment to be a simple Fragment it works. I think I'm lacking some knowledge to figure this one out. I really want to use ListFragment...

Can someone please try an help ? Many thanks for your efforts.

Adding the XML files:

activity_main.xml:

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

favorites_layout.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent">

   <ListView 
     android:id="@+id/list"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent" />
</LinearLayout>

Answer 1

I im quite sure the issue is that your custom layout for the ListFragment does not contain a ListView. These lines of code are causing the error because you need to have a ListView inside your "favourites_layout" .xml file.

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      View rootView = inflater.inflate(R.layout.favorites_layout, container, false);
      updateStationsView(0);
      return rootView;
 }

ListFragment has a default layout that consists of a single list view. However, if you desire, you can customize the fragment layout by returning your own view hierarchy from onCreateView(LayoutInflater, ViewGroup, Bundle). To do this, your view hierarchy must contain a ListView object with the id "@android:id/list" (or list if it's in code)

So your layout could for example look like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent">

   <ListView 
     android:id="@android:id/list"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent" />
</LinearLayout>

See here for more: http://developer.android.com/reference/android/app/ListFragment.html