RegionFragment.java

package com.example.rover;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.gms.location.Geofence;

import java.util.ArrayList;
import java.util.List;

import io.rover.Rover;
import io.rover.RoverObserver;

/**
 * A fragment representing a list of Items.
 * <p>
 * Activities containing this fragment MUST implement the {@link com.example.rover.RegionFragment.OnRegionFragmentInteractionListener}
 * interface.
 */
public class RegionFragment extends Fragment {

    // TODO: Customize parameter argument names
    private static final String ARG_COLUMN_COUNT = "column-count";
    // TODO: Customize parameters
    private int mColumnCount = 1;
    private OnRegionFragmentInteractionListener mListener;
    private RoverObserver mRoverObserver;
    private RegionRecyclerViewAdapter mAdapter;

    /**
     * Mandatory empty constructor for the fragment manager to instantiate the
     * fragment (e.g. upon screen orientation changes).
     */
    public RegionFragment() {
    }

    // TODO: Customize parameter initialization
    @SuppressWarnings("unused")
    public static RegionFragment newInstance(int columnCount) {
        RegionFragment fragment = new RegionFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_COLUMN_COUNT, columnCount);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (getArguments() != null) {
            mColumnCount = getArguments().getInt(ARG_COLUMN_COUNT);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_region_list, container, false);

        // Set the adapter
        if (view instanceof RecyclerView) {
            Context context = view.getContext();
            RecyclerView recyclerView = (RecyclerView) view;
            if (mColumnCount <= 1) {
                recyclerView.setLayoutManager(new LinearLayoutManager(context));
            } else {
                recyclerView.setLayoutManager(new GridLayoutManager(context, mColumnCount));
            }
            mAdapter = new RegionRecyclerViewAdapter(new ArrayList<Geofence>(), mListener);
            recyclerView.setAdapter(mAdapter);
        }
        return view;
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        mAdapter = null;
    }

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

        mRoverObserver = new MyRoverObserver();
        Rover.addObserver(mRoverObserver);
    }

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

        Rover.deleteObserver(mRoverObserver);
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnRegionFragmentInteractionListener {
        void onRegionFragmentEnterClick(String id);
        void onRegionFragmentExitClick(String id);
    }

    private class MyRoverObserver implements RoverObserver.GeofenceRegistrationObserver {
        @Override
        public void onRegisteredGeofences(List<Geofence> geofences) {
            if (mAdapter != null) {
                mAdapter.clear();
                mAdapter.addAll(geofences);
            }
        }
    }
}