IssueTracker

Android Version: 4.2.2

UI Setup:

1 Activity:
   Main Activity - hosts fragments. Fragments 1 & 2 (defined below) are swapped via FragmentTransaction.
2 Fragments
   1.) ListFragment - Contains a typical listview. Referenced as "Fragment 1"
   2.) PagerFragment - Extends upport.v4.app.Fragment.  Referenced as "Fragment 2". Hosts a support.v4.view.ViewPager and a support.v4.app.FragmentStatePagerAdapter.
   3.) ListFragment - Contains a typical listview. Referenced as "Fragment 3.n" THIS is the view that is controlled by the ViewPager.

Heirarchy:
- Activity
   -> ListFragment
   -> PagerFragment (instance of Fragment)
        - > ListFragment ( n instances of ListFragment )


Brief synopsis of issue:
When traversing backstack from Fragment 1 to Fragment 2, the contents of Fragment 3.n do not repopulate.

Replication:

1.) Create activity to load Fragment ***2*** upon startup. Note correct loading of paged fragment (Fragment 3.m)'s list fragment.
2.) Via action, instruct Activity to replace Fragment 1 with Fragment 2. Note correct loading of Fragment 2's listview elements (addToBackStack() is subsequently called).
3.) Press back button. Note that the ViewPager is loaded with the correct state (e.g. the PageTitle depicts the last viewed fragment). PROBLEM OCCURS HERE.....Note *the absence of* the Fragment 3.n screen. If you swipe to the right *once*, the ViewPager fragment for that *also does not* show on screen. Swipe right once more and the view pager *does* show the fragment on screen. Swipe left....still nothing. Swipe left again (back to original fragment) and the Fragment 3.n contents are *now being shown*.

Observations:
1.) The lifecycle methods on the ViewPager's parent fragment (Fragment 2) *are* being called (onViewStateRestored() and onResume() ).
2.) FragmentStatePagerAdapter's getItem() not being called for Fragment 3.0 and 3.1 upon back navigation. Once Fragment 3.2 is navigated to (via first swipe right in above procedure), getItem() is called to retrieve Fragment 3.2.
3.) Swipe right once more and getItem() called for Fragment 3.3 (present on screen fragment is 3.2)
4.) Swipe left from Fragment 3.2 and a call to getItem() is made for Fragment 3.0. Swipe left to Fragment 3.0 and fragment contents are now onscreen.
5.) Regardless of setting viewpager's setSaveEnabled(true/false), onSaveInstanceState() is not called.
6.) Error occurs whether or not the listadapter driving Fragment 3.n's list views utilized view recycling or not.
7.) ViewPager's host fragment calls onCreateView() and executes the exact same body of code during app startup as well as during back navigation.
8.) Explicit calls to viewpager's host fragment's view (obtained via getView() on host fragment)'s refreshDrawableState() and requestLayout() yield no change.

Potential issue:
getItem() not being called when view pager's host fragment recreates the fragment upon fragment resume.