Trouble with saving fragments state after orientation is changed

Question

I have a trouble with saving state of current fragment after changing orientation. I've got fragments with gridview that i replace in navigation process on fragments. Actions after starting app.

1) Starting "MainActivity".

2) Adding "CenterPanelFragment" (this is a container for inner fragment).

3) Replacing in "CenterPanelFragment" fragment "FragmentCatalog"(GridView). Picture 1.

4) If i click on gridview item of "FragmentCatalog", it'll replece for fragment "FragmentCatalogStone"(Gridview). Picture 2.

5) After that i change orientation on a device,as you can see i've got the fragment "FragmentCatalog" in Landscape orientation instead of fragment "FragmentCatalogStone" in Landscape orientation. Picture 3

What things i do wrong? I attached necessary class files.

Sorry for my poor english.

Thanks a lot!

MainActivity.java

CenterPanelFragment.java

FragmentCatalog.java

FragmentCatalogStone.java

Answer 1

I found a way to resolve the problem. I simply added android:configChanges="orientation|screenSize" in manifest for my Activity, and it works!

Answer 2

if (savedInstanceState != null) 
{
    fragmentCatalog = (FragmentCatalog)getFragmentManager().getFragment(savedInstanceState, FragmentCatalog.class.getName());
}
else
{

    fragmentCatalog = new FragmentCatalog();
}

Answer 3

I might not fully have understood your code but I suspect this bit in your MainActivity's onCreate:

    frAdapter = new FragmentAdapter(getSupportFragmentManager());

    vPager = (ViewPager)findViewById(R.id.pager);
    vPager.setAdapter(frAdapter);

    vPager.setCurrentItem(1);

    vPager.setOnPageChangeListener(this);
    vPager.setOffscreenPageLimit(3);

Think you should save currentItem in onSaveInstance and retrive it:

    vPager.setCurrentItem(value_before_orientation_change);

Not 100% sure if the vPager actually overwrites your fragment as I suspect though.

Edit:

Even more likely, in your CenterPanelFragment.java in onActivityCreated you commit the catalog:

    fragmentTransaction.replace(R.id.fragment_container, fragmentCatalog);
    fragmentTransaction.addToBackStack("FragmentCatalog");
    fragmentTransaction.commit();

Maybe something as simple as setRetainInstance(true) in onCreate at CenterPanelFragment could resolve this problem.

I am pretty confident that the orientation change relaunches your CenterPanelFragment, causing a new call to onActivityCreated.

Think you could try in your FragmentCatalog:

And change this line:

fragmentTransaction.replace(R.id.fragment_container, fcAllStone);

To:

fragmentTransaction.replace(R.id.fragment_container, fcAllStone, "fragment_stone");

Now in CentralPanelFragment:

    if (savedInstanceState != null) 
    {
        Log.d(MainActivity.tag, "CenterPanelFragment not null");

        fragmentCatalog = (FragmentCatalog)getFragmentManager().getFragment(savedInstanceState, FragmentCatalog.class.getName());

        // see if stone is open
        if (savedInstanceState != null) {
            FragmentCatalogStone fragmentStone = (FragmentCatalogStone) getFragmentManager()
                    .findFragmentByTag("fragment_stone");
        if (FragmentCatalogStone != null) {
            /*
             * maybe recommit it, dont actually think anything is needed 
             * since moving the below code inside the else statement
             * prevents it from overwriting the FragmentCatalogStone
             */
        }                  
    }
    else
    {
        Log.d(MainActivity.tag, "CenterPanelFragment null");

        fragmentCatalog = new FragmentCatalog();

         android.support.v4.app.FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
         fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);

         fragmentTransaction.replace(R.id.fragment_container, fragmentCatalog);
         fragmentTransaction.addToBackStack("FragmentCatalog");
         fragmentTransaction.commit();
    }