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//MainActivity

public class MainActivity extends AppCompatActivity {

    static ArrayList<String> places = new ArrayList<String>();
    static ArrayList<LatLng> locations = new ArrayList<LatLng>();
    static ArrayAdapter arrayAdapter;

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

        SharedPreferences sharedPreferences = this.getSharedPreferences("com.example", Context.MODE_PRIVATE);

        ArrayList<String> latitudes = new ArrayList<>();
        ArrayList<String> longitudes = new ArrayList<>();

        places.clear();
        latitudes.clear();
        longitudes.clear();
        locations.clear();

        try {

            places = (ArrayList<String>) ObjectSerializer.deserialize(sharedPreferences.getString("places",ObjectSerializer.serialize(new ArrayList<String>())));
            latitudes = (ArrayList<String>) ObjectSerializer.deserialize(sharedPreferences.getString("lats",ObjectSerializer.serialize(new ArrayList<String>())));
            longitudes = (ArrayList<String>) ObjectSerializer.deserialize(sharedPreferences.getString("lons",ObjectSerializer.serialize(new ArrayList<String>())));


        } catch (Exception e) {
            e.printStackTrace();
        }

        if (places.size() > 0 && latitudes.size() > 0 && longitudes.size() > 0) {
            if (places.size() == latitudes.size() && places.size() == longitudes.size()) {
                for (int i=0; i < latitudes.size(); i++) {
                    locations.add(new LatLng(Double.parseDouble(latitudes.get(i)), Double.parseDouble(longitudes.get(i))));
                }
            }
        } else {
            places.add("Add a new place...");
            locations.add(new LatLng(0,0));
        }


        ListView listView = findViewById(R.id.listView);


        arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, places);

        listView.setAdapter(arrayAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Intent intent = new Intent(getApplicationContext(), MapsActivity.class);
                intent.putExtra("placeNumber",i);

                startActivity(intent);
            }
        });

    }
}

//MapsActivity

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleMap.OnMapLongClickListener {

    LocationManager locationManager;
    LocationListener locationListener;
    private GoogleMap mMap;

    public void centerMapOnLocation(Location location, String title) {
        if (location != null) {
            LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
            mMap.clear();
            mMap.addMarker(new MarkerOptions().position(userLocation).title(title));
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 12));
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener);
                Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                centerMapOnLocation(lastKnownLocation, "Your Location");
            }
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        mMap.setOnMapLongClickListener(this);

        Intent intent = getIntent();
        if (intent.getIntExtra("placeNumber",0) == 0) {
            // Zoom in on user location
            locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
            locationListener = new LocationListener() {
                @Override
                public void onLocationChanged(Location location) {
                    centerMapOnLocation(location, "Your Location");
                }

                @Override
                public void onStatusChanged(String s, int i, Bundle bundle) {

                }

                @Override
                public void onProviderEnabled(String s) {

                }

                @Override
                public void onProviderDisabled(String s) {

                }
            };

            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener);
                Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                centerMapOnLocation(lastKnownLocation, "Your Location");
            } else {
                ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
            }
        } else {
            Location placeLocation = new Location(LocationManager.GPS_PROVIDER);
            placeLocation.setLatitude(MainActivity.locations.get(intent.getIntExtra("placeNumber",0)).latitude);
            placeLocation.setLongitude(MainActivity.locations.get(intent.getIntExtra("placeNumber",0)).longitude);

            centerMapOnLocation(placeLocation, MainActivity.places.get(intent.getIntExtra("placeNumber",0)));
        }
    }

    @Override
    public void onMapLongClick(LatLng latLng) {

        Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());

        String address = "";

        try {

            List<Address> listAdddresses = geocoder.getFromLocation(latLng.latitude,latLng.longitude,1);

            if (listAdddresses != null && listAdddresses.size() > 0) {
                if (listAdddresses.get(0).getThoroughfare() != null) {
                    if (listAdddresses.get(0).getSubThoroughfare() != null) {
                        address += listAdddresses.get(0).getSubThoroughfare() + " ";
                    }
                    address += listAdddresses.get(0).getThoroughfare();
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        if (address.equals("")) {
            SimpleDateFormat sdf = new SimpleDateFormat("HH:mm yyyy-MM-dd");
            address += sdf.format(new Date());
        }

        mMap.addMarker(new MarkerOptions().position(latLng).title(address));

        MainActivity.places.add(address);
        MainActivity.locations.add(latLng);

        MainActivity.arrayAdapter.notifyDataSetChanged();

        SharedPreferences sharedPreferences = this.getSharedPreferences("com.example.zappycode.memorableplaces", Context.MODE_PRIVATE);

        try {

            ArrayList<String> latitudes = new ArrayList<>();
            ArrayList<String> longitudes = new ArrayList<>();

            for (LatLng coord : MainActivity.locations) {
                latitudes.add(Double.toString(coord.latitude));
                longitudes.add(Double.toString(coord.longitude));
            }

            sharedPreferences.edit().putString("places", ObjectSerializer.serialize(MainActivity.places)).apply();
            sharedPreferences.edit().putString("lats", ObjectSerializer.serialize(latitudes)).apply();
            sharedPreferences.edit().putString("lons", ObjectSerializer.serialize(longitudes)).apply();


        } catch (Exception e) {
            e.printStackTrace();
        }

        Toast.makeText(this,"Location Saved!",Toast.LENGTH_SHORT).show();
    }
}