Develop Reference

How can i make a service that follows the user location using gps?

I don't know how to follow the user's location using a service with GPS.

1. You have to create the project using Google Maps Activity:
2. You have to create the Google API key following the link in the comment and insert it here:
3. Make sure to add these permissions in your Manifest.xml :
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"/>
4. This is an example of the Maps Activity code to get the user's current position:
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
LocationManager locationManager;
private static final int REQUEST_LOCATION_PERMISSION = 1;
Marker marker;
LocationListener locationListener;
#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);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (ActivityCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]
{Manifest.permission.ACCESS_FINE_LOCATION},
REQUEST_LOCATION_PERMISSION);
}
locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
//get the location name from latitude and longitude
Geocoder geocoder = new Geocoder(getApplicationContext());
try {
List<Address> addresses =
geocoder.getFromLocation(latitude, longitude, 1);
String result = addresses.get(0).getLocality() + ":";
result += addresses.get(0).getCountryName();
LatLng latLng = new LatLng(latitude, longitude);
if (marker != null) {
marker.remove();
marker = mMap.addMarker(new MarkerOptions().position(latLng).title(result));
mMap.setMaxZoomPreference(20);
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 12.0f));
} else {
marker = mMap.addMarker(new MarkerOptions().position(latLng).title(result));
mMap.setMaxZoomPreference(20);
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 21.0f));
}
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
};
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
}
#Override
protected void onStop() {
super.onStop();
locationManager.removeUpdates(locationListener);
}}

Converting a Location to LatLng

I'm trying to set the marker on my current location, so I tried to convert a Location to a LatLng class:
LatLng mCurrentPlace= new LatLng(location.getLatitude(),location.getLongitude());
Then I recalled the addMarker method:
mMap.addMarker(new MarkerOptions()
.title(getString(R.string.default_info_title))
.position(mCurrentPlace)
.snippet(getString(R.string.default_info_snippet)))
But Launching the application by "Run", it arrested.
Where am I goning wrong?
Thanks.

public void moveMap(GoogleMap gMap, double latitude, double longitude) {
Log.v(TAG, "mapMoved: " + gMap);
LatLng latlng = new LatLng(latitude, longitude);
CameraUpdate cu = CameraUpdateFactory.newLatLngZoom(latlng, 6);
gMap.addMarker(new MarkerOptions().position(latlng));
gMap.moveCamera(cu);
}
Call this method where you want location and marker and in on mapasync callback method.
#Override
public void onMapReady(GoogleMap googleMap) {
MapsInitializer.initialize(context);
gMap = googleMap;
gMap.getUiSettings().setMapToolbarEnabled(false);
gMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
if(items.get(getLayoutPosition())!=null )
moveMap(gMap,latitude, longitude);
}
public void initializeMapView() {
if (mapView != null) {
// Initialise the MapView
mapView.onCreate(null);
// Set the map ready callback to receive the GoogleMap object
mapView.getMapAsync(this);
}
}
Override onMapReadyCallback method and do this.
Call initializeMapView method in onCreate() or In adapter onBindViewHolder

Try using the LatLng.Builder
LatLng.Builder builder = LatLng.newBuilder();
builder.setLatitude(location.getLatitude());
builder.setLongitude(location.getLongitude());
latLng = builder.build();

MAP Activity
public class MapsActivity2 extends FragmentActivity implements
OnMapReadyCallback, GoogleMap.OnMyLocationButtonClickListener {
private GoogleMap mMap;
LatLng loc;
Location location;
private double currentLatitude = 0;
private double currentLongitude = 0;
LocationManager locationManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps2);
// 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);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or atLnmove the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
// LatLng sydney = new LatLng(-34, 151);
// mMap.addMarker(new MarkerOptions().position(sydney).title("Marker
in Sydney"));
// mMap.moveCamera(CameraUpdateFactory.newLg(sydney));
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
mMap.setMyLocationEnabled(true);
mMap.setOnMyLocationButtonClickListener(MapsActivity2.this);
}
public double getLatitude(){
if(location != null){
currentLatitude = location.getLatitude();
}
// return latitude
return currentLatitude;
}
public double getLongitude(){
if(location != null){
currentLongitude = location.getLongitude();
}
// return longitude
return currentLongitude;
}
#Override
public boolean onMyLocationButtonClick() {
location=mMap.getMyLocation();
currentLatitude=getLatitude();
currentLongitude=getLongitude();
LatLng currentLocation = new LatLng(currentLatitude, currentLongitude);
mMap.moveCamera(CameraUpdateFactory.newLatLng(currentLocation));
mMap.addMarker(new MarkerOptions().position(currentLocation).title("Marker in Current Location"));
return false;
}
}
Resource XML
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.atziant.parashar.gmapsapi.MapsActivity2" />

Location is displayed in Map

Hey Guys i was just trying to make an application to display my location on google map.i tried running this code for displaying my current location in google map but it isnt displaying anything on the Map(it is displaying the map but not the location)
The application is runnng but the location marker is not there.please help
public class MapsActivity extends FragmentActivity implements
OnMapReadyCallback {
LatLng myPosition;
private GoogleMap mMap;
private FusedLocationProviderClient mFusedLocationClient;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
SupportMapFragment mapFragment = (SupportMapFragment)
getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
#Override
public void onMapReady(final GoogleMap googleMap) {
mMap = googleMap;
mFusedLocationClient =
LocationServices.getFusedLocationProviderClient(this);
if (ActivityCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION) !=
PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_COARSE_LOCATION) !=
PackageManager.PERMISSION_GRANTED) {
return;
}
Task task= mFusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
#Override
public void onSuccess(Location location) {
Toast.makeText(getBaseContext(),"code run here",
Toast.LENGTH_SHORT).show();
if (location != null) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
String a,b;
a= String.valueOf(latitude);
b= String.valueOf(longitude);
Log.d(a,b);
Toast.makeText(getBaseContext(),a+b,
Toast.LENGTH_SHORT).show();
LatLng latLng = new LatLng(latitude, longitude);
myPosition = new LatLng(latitude, longitude);
googleMap.addMarker(new
MarkerOptions().position(myPosition).title("Start"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(myPosition));
}
}
});
}
}

Have you defined the fine and coarse location in manifest?
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
also do call the requestPermisiion method if permission is not given.

Can't Remove Polyline on Google Map (Android)

I'm creating app for tracking my step. I use Google MAP API(V2). I drew my step while walking (realtime)
this is my code.
case R.id.btn_location:
if(polyline != null) {
polyline.remove();
}
if(mStatus == IDLE) {
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
getmyLocation.getmyLocation();
map.clear();
}
break;
case R.id.btn_can_location:
if (mStatus == RUNNING) {
mTimer.removeMessages(0);
mPauseTime = SystemClock.elapsedRealtime();
mStatus = IDLE;
loc_manager.removeUpdates(listener);
break;
//----------------------------------------------------------------------------------------------/
public class getMyLocation {
private void getmyLocation() {
if (loc_manager == null)
loc_manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
long time = 3000;
float minDistance = 10;
loc_manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, time, minDistance, listener);
}
}
private void getmyLocation() {
if (loc_manager == null)
loc_manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
long time = 3000;
float minDistance = 10;
loc_manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, time, minDistance, listener);
static class MyLocationManager implements LocationListener {
public void onLocationChanged(Location location) {
polyline = map.addPolyline(polylineOptions.add(new LatLng(location.getLatitude(), location.getLongitude())));
polylineOptions.width(5);
polylineOptions.color(Color.RED);
map.addPolyline(polylineOptions);
}
Drawing route for realtime is good. But Removing Polyline is not working.
Helpme

i think your problem is in this area.
case R.id.btn_location:
if(polyline != null) {
polyline.remove();
}
if(mStatus == IDLE) {
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
getmyLocation.getmyLocation();
map.clear();
}
break;
try to initilze the map like this
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
also you need to implements OnMapReadyCallback and do what ever you want inside map ready like this
#Override
public void onMapReady(GoogleMap googleMap) {
Double lat = Double.parseDouble(latt); // latt is string
Double lang = Double.parseDouble(lngg); // langg is string
LatLng location = new LatLng(lat, lang);
CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(location, 16);
googleMap.addMarker(new MarkerOptions().position(location).title(""));
googleMap.moveCamera(CameraUpdateFactory.newLatLng(location));
googleMap.animateCamera(cameraUpdate);
}
and in xml file add this line.
<fragment
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="#dimen/hundred_thirty_dp"/>
1 do not get the map object every time when you click the button. just
initialize it once in the start
2 when you call polyline.remove you also need to call map.clear();

Android Google Maps API V2 Zoom to Current Location

I'm trying to mess around with the Maps API V2 to get more familiar with it, and I'm trying to start the map centered at the user's current location. Using the map.setMyLocationEnabled(true); statement, I am able to show my current location on the map. This also adds the button to the UI that centers the map on my current location.
I want to simulate that button press in my code. I am familiar with the LocationManager and LocationListener classes and realize that using those is a viable alternative, but the functionality to center and zoom in on the user's location seems to already be built in through the button.
If the API has a method to show the user's current location, there surely must be an easier way to center on the location than to use the LocationManager/LocationListener classes, right?

Try this coding:
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
Location location = locationManager.getLastKnownLocation(locationManager.getBestProvider(criteria, false));
if (location != null)
{
map.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 13));
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(location.getLatitude(), location.getLongitude())) // Sets the center of the map to location user
.zoom(17) // Sets the zoom
.bearing(90) // Sets the orientation of the camera to east
.tilt(40) // Sets the tilt of the camera to 30 degrees
.build(); // Creates a CameraPosition from the builder
map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}

After you instansiated the map object (from the fragment) add this -
private void centerMapOnMyLocation() {
map.setMyLocationEnabled(true);
location = map.getMyLocation();
if (location != null) {
myLocation = new LatLng(location.getLatitude(),
location.getLongitude());
}
map.animateCamera(CameraUpdateFactory.newLatLngZoom(myLocation,
Constants.MAP_ZOOM));
}
if you need any guidance just ask but it should be self explantory - just instansiate the myLocation object for a default one...

youmap.animateCamera(CameraUpdateFactory.newLatLngZoom(currentlocation, 16));
16 is the zoom level

mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
#Override
public void onMyLocationChange(Location location) {
CameraUpdate center=CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude()));
CameraUpdate zoom=CameraUpdateFactory.zoomTo(11);
mMap.moveCamera(center);
mMap.animateCamera(zoom);
}
});

try this code :
private GoogleMap mMap;
LocationManager locationManager;
private static final String TAG = "";
#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(map);
mapFragment.getMapAsync(this);
arrayPoints = new ArrayList<LatLng>();
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
LatLng myPosition;
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
googleMap.setMyLocationEnabled(true);
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
LatLng latLng = new LatLng(latitude, longitude);
myPosition = new LatLng(latitude, longitude);
LatLng coordinate = new LatLng(latitude, longitude);
CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(coordinate, 19);
mMap.animateCamera(yourLocation);
}
}
}
Dont forget to add permissions on AndroidManifest.xml.
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

Here's how to do it inside ViewModel and FusedLocationProviderClient, code in Kotlin
locationClient.lastLocation.addOnSuccessListener { location: Location? ->
location?.let {
val position = CameraPosition.Builder()
.target(LatLng(it.latitude, it.longitude))
.zoom(15.0f)
.build()
map.animateCamera(CameraUpdateFactory.newCameraPosition(position))
}
}

private void setUpMapIfNeeded(){
if (mMap == null){
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();//invoke of map fragment by id from main xml file
if (mMap != null) {
mMap.setMyLocationEnabled(true);//Makes the users current location visible by displaying a blue dot.
LocationManager lm=(LocationManager)getSystemService(LOCATION_SERVICE);//use of location services by firstly defining location manager.
String provider=lm.getBestProvider(new Criteria(), true);
if(provider==null){
onProviderDisabled(provider);
}
Location loc=lm.getLastKnownLocation(provider);
if (loc!=null){
onLocationChanged(loc);
}
}
}
}
// Initialize map options. For example:
// mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
#Override
public void onLocationChanged(Location location) {
LatLng latlng=new LatLng(location.getLatitude(),location.getLongitude());// This methods gets the users current longitude and latitude.
mMap.moveCamera(CameraUpdateFactory.newLatLng(latlng));//Moves the camera to users current longitude and latitude
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latlng,(float) 14.6));//Animates camera and zooms to preferred state on the user's current location.
}
// TODO Auto-generated method stub

check this out:
fun requestMyGpsLocation(context: Context, callback: (location: Location) -> Unit) {
val request = LocationRequest()
// request.interval = 10000
// request.fastestInterval = 5000
request.numUpdates = 1
request.priority = LocationRequest.PRIORITY_HIGH_ACCURACY
val client = LocationServices.getFusedLocationProviderClient(context)
val permission = ContextCompat.checkSelfPermission(context,
Manifest.permission.ACCESS_FINE_LOCATION )
if (permission == PackageManager.PERMISSION_GRANTED) {
client.requestLocationUpdates(request, object : LocationCallback() {
override fun onLocationResult(locationResult: LocationResult?) {
val location = locationResult?.lastLocation
if (location != null)
callback.invoke(location)
}
}, null)
}
}
and
fun zoomOnMe() {
requestMyGpsLocation(this) { location ->
mMap?.animateCamera(CameraUpdateFactory.newLatLngZoom(
LatLng(location.latitude,location.longitude ), 13F ))
}
}

This is working Current Location with zoom for Google Map V2
double lat= location.getLatitude();
double lng = location.getLongitude();
LatLng ll = new LatLng(lat, lng);
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(ll, 20));

In kotlin, you will get the current location then move the camera like this
map.isMyLocationEnabled = true
fusedLocationClient.lastLocation
.addOnSuccessListener { location: Location? ->
if (location != null) {
map.moveCamera(CameraUpdateFactory.newLatLngZoom(LatLng(location.latitude, location.longitude), 14f))
}
}
Also you can animate the move by using this function instead
map.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.latitude, location.longitude), 14f))