My app kept crashing, complaining that “activity” could not be cast to “Callbacks” in CrimeFragment.java.
I finally found out that in CrimeListActivity.java, you need to define the class as:
public class CrimeListActivity extends SingleFragmentActivity
implements CrimeListFragment.Callbacks, CrimeFragment.Callbacks
Listing 22.13 should include code that highlights the fact that you need to specify CrimeFragment.Callbacks here.