android - Fragment view in ViewPager is not restored when resuming

Question

I have ActionBar Tabs setup. It consists of 4 tabs. Everything is fine until I navigate away from TabbedFragment and returning back.

I create tabs like this:

  @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final ActionBar actionBar = getActionBar();

        tabs = Lists.newArrayList();
        tabs.add(new TabDefinition<>("Tab 1"));
        tabs.add(new TabDefinition<>("Tab 2"));
        tabs.add(new TabDefinition<>("Tab 3"));
        tabs.add(new TabDefinition<>("Tab 4"));


        for (TabDefinition tab : tabs) {
            actionBar.addTab(actionBar.newTab()
                .setText(tab.text)
                .setTag(tab.tag)
                .setTabListener(this));
        }
    }

And initialize adapter like this:

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

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    viewPager = (ViewPager) view.findViewById(R.id.pager);

    viewPager.setAdapter(new FragmentStatePagerAdapter(getFragmentManager()) {

        @Override
        public Fragment getItem(int position) {
            return tabs.get(position).fragment;
        }

        @Override
        public int getCount() {
            return tabs.size();
        }
    });

    viewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            getActionBar().setSelectedNavigationItem(position);
        }
    });

    viewPager.setCurrentItem(getActionBar().getSelectedNavigationIndex(), true);
}

When returning back to TabbedFragment selected tab and 1 next to it would not have any content. Just empty view. But if I select current + 2 fragment content is loaded. And then returning to that first fragment content is reloaded.
For example I have A, B, C, D tabs. Before leaving TabbedFragment I had selected tab A. When returning to TabbedFragment I still am at tab A, but it's empty. So is tab B.
But when selecting tab C it is created and loaded. Returning to tab A it is recreated.

What could be the problem here?

Answer 1

After a while ran into the same problem again, so updating this question. If you're using FragmentStatePagerAdapter you should provide FragmentManager via getChildFragmentManager() instead of getFragmentManager(). See Issue 55068: ViewPager doesn't refresh child fragments when back navigation via backstack