private static final String FRAGMENT_TAG = "browseFragment";

	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		navigateToBrowse(0);
	}

	private void navigateToBrowse(int browseId)
	{
		BrowseFragment fragment = getBrowseFragment();
		if (fragment == null || fragment.getBrowseId() != browseId)
		{
			fragment = new BrowseFragment();
			fragment.setBrowseId(browseId);
			FragmentTransaction transaction = getFragmentManager().beginTransaction();
			transaction.setCustomAnimations(
					R.animator.slide_in_from_right, R.animator.slide_out_to_left,
					R.animator.slide_in_from_left, R.animator.slide_out_to_right);
			transaction.replace(R.id.container, fragment, FRAGMENT_TAG);
			// If this is not the top level root, we add it to the fragment back stack,
			// so that actionbar toggle and Back will work appropriately:
			if (browseId > 0)
			{
				transaction.addToBackStack(null);
			}
			transaction.commit();
		}
	}

	public int getCurrentBrowseId()
	{
		BrowseFragment fragment = getBrowseFragment();
		if (fragment == null)
		{
			return 1;
		}
		return fragment.getBrowseId();
	}

	private BrowseFragment getBrowseFragment()
	{
		return (BrowseFragment) getFragmentManager().findFragmentByTag(FRAGMENT_TAG);
	}

	@Override
	public void onNext()
	{
		navigateToBrowse(getCurrentBrowseId()+1);
	}

	public static class BrowseFragment extends Fragment
	{
		private static final String ARG_BROWSE_ID = "browseId";
		private OnListener mListener;

		@Override
		public void onAttach(Context context)
		{
			super.onAttach(context);
			if (context instanceof BrowseFragment.OnListener)
			{
				mListener = (BrowseFragment.OnListener) context;
			}
			else
			{
				throw new RuntimeException(context.toString()
						                           + " must implement OnListener");
			}
		}

		@Override
		public void onDetach()
		{
			super.onDetach();
			mListener = null;
		}

		public int getBrowseId()
		{
			Bundle args = getArguments();
			if (args != null)
			{
				return args.getInt(ARG_BROWSE_ID);
			}
			return 0;
		}

		public void setBrowseId(int browseId)
		{
			Bundle args = new Bundle(1);
			args.putInt(ARG_BROWSE_ID, browseId);
			setArguments(args);
		}

		public interface OnListener
		{
			void onNext();
		}
	}
}