Java tutorial
/*** Copyright (c) 2012 CommonsWare, LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Covered in detail in the book _The Busy Coder's Guide to Android Development_ https://commonsware.com/Android */ package com.commonsware.android.mapsv2.location; import android.Manifest; import android.annotation.SuppressLint; import android.content.pm.PackageManager; import android.location.Criteria; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.view.Menu; import android.view.MenuItem; import android.widget.Toast; import com.google.android.gms.maps.CameraUpdate; import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.GoogleMap.OnInfoWindowClickListener; import com.google.android.gms.maps.LocationSource; import com.google.android.gms.maps.OnMapReadyCallback; import com.google.android.gms.maps.SupportMapFragment; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.Marker; import com.google.android.gms.maps.model.MarkerOptions; public class MainActivity extends AbstractMapActivity implements OnMapReadyCallback, OnInfoWindowClickListener, LocationSource, LocationListener { private static final String STATE_IN_PERMISSION = "inPermission"; private static final String STATE_AUTO_FOLLOW = "autoFollow"; private static final int REQUEST_PERMS = 1337; private boolean isInPermission = false; private OnLocationChangedListener mapLocationListener = null; private LocationManager locMgr = null; private Criteria crit = new Criteria(); private boolean needsInit = false; private GoogleMap map = null; private boolean autoFollow = true; @Override protected void onCreate(Bundle state) { super.onCreate(state); if (state == null) { needsInit = true; } else { isInPermission = state.getBoolean(STATE_IN_PERMISSION, false); autoFollow = state.getBoolean(STATE_AUTO_FOLLOW, true); } onCreateForRealz(canGetLocation()); } @SuppressLint("MissingPermission") @Override public void onMapReady(final GoogleMap map) { this.map = map; if (needsInit) { CameraUpdate center = CameraUpdateFactory.newLatLng(new LatLng(40.76793169992044, -73.98180484771729)); CameraUpdate zoom = CameraUpdateFactory.zoomTo(15); map.moveCamera(center); map.animateCamera(zoom); } addMarker(map, 40.748963847316034, -73.96807193756104, R.string.un, R.string.united_nations); addMarker(map, 40.76866299974387, -73.98268461227417, R.string.lincoln_center, R.string.lincoln_center_snippet); addMarker(map, 40.765136435316755, -73.97989511489868, R.string.carnegie_hall, R.string.practice_x3); addMarker(map, 40.70686417491799, -74.01572942733765, R.string.downtown_club, R.string.heisman_trophy); map.setInfoWindowAdapter(new PopupAdapter(getLayoutInflater())); map.setOnInfoWindowClickListener(this); map.setMyLocationEnabled(true); locMgr = (LocationManager) getSystemService(LOCATION_SERVICE); crit.setAccuracy(Criteria.ACCURACY_FINE); follow(); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putBoolean(STATE_IN_PERMISSION, isInPermission); outState.putBoolean(STATE_AUTO_FOLLOW, autoFollow); } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { isInPermission = false; if (requestCode == REQUEST_PERMS) { if (canGetLocation()) { onCreateForRealz(true); } else { finish(); // denied permission, so we're done } } } @Override public void onStart() { super.onStart(); follow(); } @Override public void onStop() { map.setLocationSource(null); locMgr.removeUpdates(this); super.onStop(); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.actions, menu); menu.findItem(R.id.follow).setChecked(autoFollow); return super.onCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { if (item.getItemId() == R.id.follow) { item.setChecked(!item.isChecked()); autoFollow = item.isChecked(); follow(); return true; } return super.onOptionsItemSelected(item); } @Override public void onInfoWindowClick(Marker marker) { Toast.makeText(this, marker.getTitle(), Toast.LENGTH_LONG).show(); } @Override public void activate(OnLocationChangedListener listener) { this.mapLocationListener = listener; } @Override public void deactivate() { this.mapLocationListener = null; } @Override public void onLocationChanged(Location location) { if (mapLocationListener != null) { mapLocationListener.onLocationChanged(location); LatLng latlng = new LatLng(location.getLatitude(), location.getLongitude()); CameraUpdate cu = CameraUpdateFactory.newLatLng(latlng); map.animateCamera(cu); } } @Override public void onProviderDisabled(String provider) { // unused } @Override public void onProviderEnabled(String provider) { // unused } @Override public void onStatusChanged(String provider, int status, Bundle extras) { // unused } private void addMarker(GoogleMap map, double lat, double lon, int title, int snippet) { map.addMarker(new MarkerOptions().position(new LatLng(lat, lon)).title(getString(title)) .snippet(getString(snippet))); } private void onCreateForRealz(boolean canGetLocation) { if (canGetLocation) { if (readyToGo()) { setContentView(R.layout.activity_main); SupportMapFragment mapFrag = (SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.map); mapFrag.getMapAsync(this); } } else if (!isInPermission) { isInPermission = true; ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.ACCESS_FINE_LOCATION }, REQUEST_PERMS); } } private boolean canGetLocation() { return (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED); } @SuppressLint("MissingPermission") private void follow() { if (map != null && locMgr != null) { if (autoFollow) { locMgr.requestLocationUpdates(0L, 0.0f, crit, this, null); map.setLocationSource(this); map.getUiSettings().setMyLocationButtonEnabled(false); } else { map.getUiSettings().setMyLocationButtonEnabled(true); map.setLocationSource(null); locMgr.removeUpdates(this); } } } }