CODEWITHSUNDEEP
androidandroid-fragmentsscreen-orientation
learner
learner

Reputation: 11780

How to recover fragments after screen orientation replacement

I have an activity with two fragments: DogFragment, LegoFragment. In portrait mode I show DogFragment and in landscape mode I show LegoFragment. My problem is that the fragments aren’t remembering their states after rotation. Is there a way to save the fragment’s states? Understand that the activity is recreated during orientation changes and that based on the orientation I create and attach either DogFragment or LegoFragment to the activity.

Here is the activity’s onCreate method where I add the fragments.

@Override

protected void onCreate(Bundle savedInstanceState) {
   
  super.onCreate(savedInstanceState);
    
  setContentView(R.layout.activity_main);

  if (getResources().getConfiguration().orientation == 
     Configuration.ORIENTATION_PORTRAIT) {

   addDogFragment();

  } else {
  
    addLegoFragment();

  }

}

private void addDogFragment() {
  DogFragment fragment = DogFragment.newInstance(null, null);
   
  getSupportFragmentManager().beginTransaction().
  replace(R.id.fragment_container, fragment).commit();

}



private void addLegoFragment() {

  LegoFragment fragment = LegoFragment.newInstance(null, null);
    
  getSupportFragmentManager().beginTransaction().
  replace(R.id.fragment_container, fragment).commit();

}

I know that the FragmentManager has a copy of my fragments. But I am not sure the best way to solve this problem. If I call replace with a tag, do I just findByTag and then call replace again? Or is there a standard way to do these things?

Upvotes: 1

Views: 231

Answers (2)

F.Will
F.Will

Reputation: 46

if (getResources().getConfiguration().orientation == 
 Configuration.ORIENTATION_PORTRAIT)
    attachFragment(R.id.fragment_container, "dogFragment",     DogFragment.class.getName());
else 
    attachFragment(R.id.fragment_container, "legoFragment", LegoFragment.class.getName());


private FragmentTransaction mCurTransaction;
private FragmentManager mFragmentManager;
public void attachFragment(int containerViewId, String tag, String fragmentClassName){
    if (mFragmentManager == null)
        mFragmentManager = getSupportFragmentManager(); // or getFragmentManager();

    if (mCurTransaction == null)
        mCurTransaction = mFragmentManager.beginTransaction();

    // Do we already have this fragment?
    Fragment fragment = mFragmentManager.findFragmentByTag(tag);
    if (fragment != null){
        mCurTransaction.attach(fragment);
    }else {
        fragment = Fragment.instantiate(this, fragmentClassName);
        mCurTransaction.add(containerViewId, fragment, tag);
    }
}

Upvotes: 0

Derek Fung
Derek Fung

Reputation: 8211

Try this, create a similar function for LegoFragment

private void setDogFragment() {
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    Fragment removeFragment = mFragmentManager.findFragmentByTag("lego");
    if (removeFragment!=null) {
        transaction.detach(removeFragment);
    }
    Fragment fragment = mFragmentManager.findFragmentByTag("dog");
    if (fragment != null) {
        transaction.attach(fragment);
    } else {
        fragment = new DogFragment();
        transaction.add(R.id.fragment_container, fragment,
                "dog");
    }
    transaction.commit();
}

Upvotes: 1

Related Questions