Fragments onResume from back stack

Solution 1:

For a lack of a better solution, I got this working for me: Assume I have 1 activity (MyActivity) and few fragments that replaces each other (only one is visible at a time).

In MyActivity, add this listener:

getSupportFragmentManager().addOnBackStackChangedListener(getListener());

(As you can see I'm using the compatibility package).

getListener implementation:

private OnBackStackChangedListener getListener()
    {
        OnBackStackChangedListener result = new OnBackStackChangedListener()
        {
            public void onBackStackChanged() 
            {                   
                FragmentManager manager = getSupportFragmentManager();

                if (manager != null)
                {
                    MyFragment currFrag = (MyFragment) manager.findFragmentById(R.id.fragmentItem);

                    currFrag.onFragmentResume();
                }                   
            }
        };

        return result;
    }

MyFragment.onFragmentResume() will be called after a "Back" is pressed. few caveats though:

1. It assumes you added all transactions to the backstack (using FragmentTransaction.addToBackStack())
2. It will be activated upon each stack change (you can store other stuff in the back stack such as animation) so you might get multiple calls for the same instance of fragment.

Solution 2:

I've changed the suggested solution a little bit. Works better for me like that:

private OnBackStackChangedListener getListener() {
    OnBackStackChangedListener result = new OnBackStackChangedListener() {
        public void onBackStackChanged() {
            FragmentManager manager = getSupportFragmentManager();
            if (manager != null) {
                int backStackEntryCount = manager.getBackStackEntryCount();
                if (backStackEntryCount == 0) {
                    finish();
                }
                Fragment fragment = manager.getFragments()
                                           .get(backStackEntryCount - 1);
                fragment.onResume();
            }
        }
    };
    return result;
}

Solution 3:

After a popStackBack() you can use the following callback : onHiddenChanged(boolean hidden) within your fragment