Here's the answer. I was mixing android's TabHost with the support library's FragmentTabHost. Two different things!
public class ActivityFragment extends Fragment implements TabHost.OnTabChangeListener {
private static final String FOLLOWING_SPEC = "following";
private static final String YOU_SPEC = "you";
private FragmentTabHost tabHost;
public ActivityFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_activity, container, false);
tabHost = (FragmentTabHost)view.findViewById(R.id.tabhost);
tabHost.setup(getActivity(), getChildFragmentManager(), android.R.id.tabcontent);
tabHost.addTab(tabHost.newTabSpec(FOLLOWING_SPEC).setIndicator("Following"), FollowingActivityFragment.class, null);
tabHost.addTab(tabHost.newTabSpec(YOU_SPEC).setIndicator("You"), YouActivityFragment.class, null);
tabHost.setCurrentTab(0);
return view;
}
@Override
public void onTabChanged(String s) {
}
}