Which method is being called after popBackStack?

Question

I have an activity where I am calling three fragments - each depending on each other:

A(ctivity) -> f1 (Fragment one, title {is|should}: list) -> f2 (Fragment two,

Answer 1

use addOnBackStackChangedListener method in your BaseActivity, which will be called any time backstack changes

getSupportFragmentManager().addOnBackStackChangedListener(
            new FragmentManager.OnBackStackChangedListener() {
                public void onBackStackChanged() {
                    FragmentManager fm = getSupportFragmentManager();

                    if (fm != null) {
                        int backStackCount = fm.getBackStackEntryCount();
                        if (backStackCount == 0) {
                            if (getSupportActionBar() != null) {
                                getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_menu);
                            }
                            setToolbarTittle(R.string.app_name);
                        } else {
                            if (getSupportActionBar() != null) {
                                getSupportActionBar().setHomeAsUpIndicator(R.drawable.back);
                            }
                        }
                    }
                }
            });