Handling ActionBar title with the fragment back stack?

Question

I have an Activity where I load in a ListFragment and, upon clicking, it drills down a level and a new type of ListFragment is shown,

Answer 1

Let the controlling activity do all the work as follows:

Listen for backstack events (in onCreate() of activity):

// Change the title back when the fragment is changed
    getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
        @Override
        public void onBackStackChanged() {
            Fragment fragment = getFragment();
            setTitleFromFragment(fragment);
        }
    });

Get the current fragment from the container:

/**
 * Returns the currently displayed fragment.
 * @return
 *      Fragment or null.
 */
private Fragment getFragment() {
    Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.container);
    return fragment;
}

Set the fragment inside the content view:

private void setFragment(Fragment fragment, boolean addToBackStack) {
    // Set the activity title
    setTitleFromFragment(fragment);
    .
    .
    .
}