Develop Reference

LocationListener how to stop when onLocationChanged() is called?

I want locationlistener to stop using gps when the location is changed, is this possible ?

public class MyActivity extends AppCompatActivity implements LocationListener {
private LocationManager locationManager;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
}
#Override
public void onLocationChanged(Location location) {
locationManager.removeUpdates(this);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
}
here this is the reference to LocationListener Interface.
If you want only single location update then you can call
locationManager.requestSingleUpdate(LocationManager.GPS_PROVIDER, this, Looper.getMainLooper());

Android LocationListener on Service with Thread

I´d like to implement a LocationListener in this way.
1 - Activity_first - Call LocationListener, but I have some spinner and this don´t respond when the LocationListener are onStart(). I´d like to implement with a Thread.
2 - When the onLocationChanged() in LocationListener gets called, I call Geocoder, and when the address is different than null, I save it on the shared preferences, and stop it.
Point 2, must be done in the background because the user might be in an Activity when I get the Geocoder's address (about 10 seconds, it depend on connection)
I was testing with IntentService, but of course, I doesn't work.
My Code
public class Carga_1 extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.carga_1);
// Todo Create Spinner, etc
startService(new Intent(Carga_1.this, LocationService2.class));
}
}
public class LocationService2 extends Service {
public static final String BROADCAST_ACTION = "Hello World";
//public LocationManager locationManager; testted
//public MyLocationListener listener; tested
public Location previousBestLocation = null;
Thread my_thread;
#Override
public IBinder onBind(Intent intent) {
Log.d("[GPS_coord]", "????");
return null;
}
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onStart(Intent intent, int startId) {
Runnable r = new Runnable() {
public void run() {
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
MyLocationListener listener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, listener);
}
};
my_thread = new Thread(r);
my_thread.start();
}
#Override
public void onDestroy() {
super.onDestroy();
my_thread.stop();
}
private void get_address(double lat, double longi) {
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
List<Address> addresses;
try {
addresses = geocoder.getFromLocation(lat, longi, 1);
//SAVE ON SharedPrefereces
this.stopSelf();
}
catch (IOException e) {
Log.d("[GPS_geocoder]", "Decodificacion Erronea");
}
}
public class MyLocationListener implements LocationListener {
public void onLocationChanged(final Location loc) {
Log.i("GPS_Service", "Location changed");
Log.d("GPS_Service", String.valueOf(loc.getLatitude() + " : " + String.valueOf(loc.getLongitude())));
get_address(loc.getLatitude(), loc.getLongitude());
}
public void onProviderDisabled(String provider) {
Log.i("GPS_Service", "DES_habilitado");
}
public void onProviderEnabled(String provider) {
Log.i("GPS_Service", "Habilitado");
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}

Android: requestLocationUpdates

I have managed to get a fix on an android device's location (both with network provider and gps provider) using:
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
but i would like calculate the phones location at the same moment once using the NETWORK_PROVIDER and then the GPS_PROVIDER so that i can compare each accuracy together.
Does anyone know how to pinpoint the device once with NETWORK_PROVIDER and then with GPS_PROVIDER?

Use 2 Location Listeners
public class MainActivity extends Activity {
private Location networkLocation = null;
private Location gpsLocation = null;
private class NetworkLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
// if you only want one location
// if (networkLocation == null)
networkLocation = location;
if (gpsLocation != null) {
// do something
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onProviderDisabled(String provider) {}
}
private class GpsLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
// if you only want one location
// if (gpsLocation == null)
gpsLocation = location;
if (networkLocation != null) {
// do something
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onProviderDisabled(String provider) {}
}
}

Android Location listener in Service does not work until I reactivate WiFi/mobile network

My location listener works normally, collects data without any problem. But sometimes it doesn't collect any data. I have to turn off and restart my location provider at this time. Restarting fixes the problem,however, it's probably not the best thing the user is expected to do.
When I use GPS as provider, there is no problem.
Location listener works in Service. I can't understand the problem. Is it about Android or my code?
Thanks in advance.

You could use new location provider (FusedLocationProvider), which combines info from different location providers, so if your device has any possibility to obtain location, You'll get know it. Of course, You should enable in preferences for your device to use location info by apps.
Check developers.android.com for extended info about this provider.
This is solution working fine for me:
public class FusedLocationListener implements GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener {
public interface LocationListener {
public void onReceiveLocation(Location location);
}
private LocationListener mListener;
public static final String TAG = "Fused";
private LocationClient locationClient;
private LocationRequest locationRequest;
protected int minDistanceToUpdate = 1000;
protected int minTimeToUpdate = 10*1000;
protected Context mContext;
#Override
public void onConnected(Bundle bundle) {
Log.d(TAG, "Connected");
locationRequest = new LocationRequest();
locationRequest.setSmallestDisplacement(1);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setInterval(30000);
locationRequest.setNumUpdates(1);
locationClient.requestLocationUpdates(locationRequest, this);
}
#Override
public void onDisconnected() {
Log.d(TAG, "Disconnected");
}
#Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.d(TAG, "Failed");
}
private static FusedLocationListener instance;
public static synchronized FusedLocationListener getInstance(Context context, LocationListener listener){
if (null==instance) {
instance = new FusedLocationListener(context, listener);
}
return instance;
}
private FusedLocationListener(Context context, LocationListener listener){
mContext = context;
mListener = listener;
}
public void start(){
Log.d(TAG, "Listener started");
locationClient = new LocationClient(mContext,this,this);
locationClient.connect();
}
#Override
public void onLocationChanged(Location location) {
Log.d(TAG, "Location received: " + location.getLatitude() + ";" + location.getLongitude());
//notify listener with new location
mListener.onReceiveLocation(location);
}
public void stop() {
locationClient.removeLocationUpdates(this);
}
}
Usage:
public class MyActivity extends Activity implements FusedLocationListener.LocationListener {
#Override
public void onCreate(Bundle savedInstanceState) {
FusedLocationListener locationListener FusedLocationListener.getInstance(getApplicationContext(), this);
locationListener.start();
}
#Override
public void onReceiveLocation(Location location) {
//handle location here
}
}

Why dont you use both *GPS_PROVIDER* and *NETWORK_PROVIDER* ? I tried this and it was working fine.
Does this error occur while testing on other devices also or only your device ?

You can create detect both of these for me I've used both GPS_PROVIDER and NETWORK_PROVIDER if It can't detect any GPS after 20seconds it will try to use NETWORK provider
///First create MYlocation class
public class MyLocation {
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 20000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
#Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public void cancelTimer()
{ timer1.cancel();
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}
/Into your main class you can use it like this which I implies to a webview
public class Main extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mWebView=(WebView)findViewById(R.id.webview);
final String string_loc = getIntent().getExtras().getString("nearest");
LocationResult locationResult = new LocationResult(){
#Override
public void gotLocation(Location location) {
passLat=Double.toString(location.getLatitude());
passLong=Double.toString(location.getLongitude());
maps="http://maps.google.com/maps?q="+string_loc+"+loc:"+passLat+","+passLong+"&hq=hospital&t=m&z=12";
mWebView.loadUrl(maps);
}
};
myLocation.getLocation(this, locationResult);
}
}
}
//Hoping this would help you

Using the network provider requires internet connection to work. It collects some information from the cell and wifi hotspots. It then queries a backend server which looks up its database and gives an approximate location. The device can prefetch some location info so you don't need constant internet connection but when the device moves out of the prefetch location, it will need internet connection again.
This might be your problem that you loose internet connection sometime (wifi going to sleep) and restarting the provider gets it to reconnect to the internet again. Again this is at best a guess on my part :)

Access LocationManager/ LocationListener from class

I'm kinda lost here: In my main activity, I register a LocationManager and connect it to a LocationListener to use myLocation.getLatitude() and such.
Now I need to use the Location- methods from another class.
I can't use those object from another class because I cant intantiate the main activity.
I can't use getters to pass the L.Manager or L.Listener around, because those are non- static again.
So, in general, how do i access objects that I created in the main activity?
Any hints on how to organize this better? Is the LocationListener class within the main activity class a stupid thing to do in general?
public class URNavActivity extends Activity
{
public LocationManager mlocManager;
public LocationListener mlocListener;
...
}
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mResourceProxy = new DefaultResourceProxyImpl(getApplicationContext());
actVar=this;
initGraph();
setMap();
gpsEnable();
initMyLocation();
getItems();
initOverlay();
}
public void gpsEnable ()
{
mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
}
public class MyLocationListener implements LocationListener
{
#Override
public void onLocationChanged(Location loc)
{
loc.getLatitude();
loc.getLongitude();
myMap.getController().setCenter(new GeoPoint(lati, longi));
}

First and foremost your LocationListener should not be part of an activity. Activities have a clearly defined lifecycle and can come into being, and be destroyed, by the Android framework on an as-needed basis. Therefore the instance variables of your Activity will need to be re-initialised in your activity's onResume() method, making them completely unsuitable for long-term storage.
So. Start by creating a sticky service to manage the starting and stopping of location updates. Being sticky means that the service instance hangs around between invocations and therefore you can reliably use instance variables and know that they will retain their values until the service is terminated. This service should also implement the LocationListener interface, and now it can store the Location notified to it when onLocationChanged is invoked:
public class LocationService extends Service implements LocationListener {
private LocationManager locationManager;
private Location location;
#Override
public int onStartCommand(final Intent intent, final int flags, final int startId) {
Logging.i(CLAZZ, "onHandleIntent", "invoked");
if (intent.getAction().equals("startListening")) {
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
}
else {
if (intent.getAction().equals("stopListening")) {
locationManager.removeUpdates(this);
locationManager = null;
}
}
return START_STICKY;
}
#Override
public IBinder onBind(final Intent intent) {
return null;
}
public void onLocationChanged(final Location location) {
this.location = location;
// TODO this is where you'd do something like context.sendBroadcast()
}
public void onProviderDisabled(final String provider) {
}
public void onProviderEnabled(final String provider) {
}
public void onStatusChanged(final String arg0, final int arg1, final Bundle arg2) {
}
}
Now you have a service you can start and stop the location updates as you need them. This also allows you to continue to receive and process location changes even when your application is not in the foreground, if that is what you want.
You now have two choices on how to make that Location information available: Use context.sendBroadcast() to propagate the new Location to (for example) an activity, or use the bound service approach to allow other classes to invoke the exposed API and obtain the Location. See http://developer.android.com/guide/topics/fundamentals/bound-services.html for more details on creating a bound service.
Note that there are many other aspects to listening for location updates that I have not included here, for the sake of clarity.

I would offer two elegant ways to access your object from anywhere:
use a Singleton design pattern
use ProjectApp class. This class can be accessed from any activity simply by calling getApplication().
ProjectApp app = (ProjectApp)getApplication();
I used a combination of the two:
public class MyApp extends Application {
private MyLocation mMyLocation;
#Override
public void onCreate() {
super.onCreate();
mMyLocation = new MyLocation();
mMyLocation.getLocation(this, GlobalData.getInstance(), true);
}
}
You can see that GlobalData is a singleton class that implements LocationResult interface, meaning that it will send the updated location to this object.
When I need to get the updated location, I take it from GlobalData.
Here is MyLocation class implementation (I used some code from here and made some changes:
package com.pinhassi.android.utilslib;
import java.util.Timer;
import java.util.TimerTask;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
public class MyLocation {
private Timer timer1;
private LocationManager lm;
private LocationResult locationResult;
private boolean gps_enabled=false;
private boolean network_enabled=false;
private boolean mContinuesUpdates;
private int decimalAccuracy;
/**
* Class constructor
*/
public MyLocation(){
decimalAccuracy = 0;
}
public boolean getLocation(Context context, LocationResult result, boolean continuesUpdates)
{
mContinuesUpdates = continuesUpdates;
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 20000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(getDecimalAccurated(location));
if (!mContinuesUpdates)
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(getDecimalAccurated(location));
if (!mContinuesUpdates)
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
#Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(getDecimalAccurated(gps_loc));
else
locationResult.gotLocation(getDecimalAccurated(net_loc));
return;
}
if(gps_loc!=null){
locationResult.gotLocation(getDecimalAccurated(gps_loc));
return;
}
if(net_loc!=null){
locationResult.gotLocation(getDecimalAccurated(net_loc));
return;
}
locationResult.gotLocation(null);
}
}
/**
* called when the GPS returns a location.
* can be called multiple times as the location is updated
*/
public interface LocationResult {
public void gotLocation(Location location);
}
/**
* sets location result accuracy
* #param n number of places after the point. negative value or 0 means not set.
*/
public void setDecimalAccuracy(int n)
{
this.decimalAccuracy = n;
}
private Location getDecimalAccurated(Location location) {
if (decimalAccuracy > 0){
double accuracy = Math.pow(10, this.decimalAccuracy);
int ix;
ix = (int)(location.getLatitude() * accuracy);
location.setLatitude(((double)ix)/accuracy);
ix = (int)(location.getLongitude() * accuracy);
location.setLongitude(((double)ix)/accuracy);
}
return location;
}
}

I'll talk in general since I had the same issue:
How to manage the LocationListener and lit this listener access the activity ..
This was my try :
The Listener :
public class MyLocationListener implements LocationListener{
ProgressDialog dialog;
LocationManager locManager;
Context context;
public MyLocationListener (Context context,ProgressDialog dialog){
this.context = context;
this.dialog = dialog;
}
public void startSearch() {
locManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
// If the network provider works run it , else try GPS provider
// TODO : what happens if GPS and Network providers are not suuported ??
if(!locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER) )
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,
0, this);
else
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0,
0, this);
dialog = new ProgressDialog(context);
dialog.setTitle("");
dialog.setMessage(context.getString(R.string.pleaseWait));
dialog.setButton(context.getString(R.string.cancel), new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
locManager.removeUpdates(MyLocationListener .this);
dialog.dismiss();
return;
}
});
dialog.show();
}
// Location Listener implementation
// read Android doc for more info
// this methods is triggered when new location ( latitiude and longitude ) is found by the system
private void updateWithNewLocation(Location location) {
if (location != null) {
double lat = location.getLatitude();
double lng = location.getLongitude();
//THIS IS MY ACTIVITY
MainActivity mainActivity = (MainActivity) context;
mainActivity.init();
} else {
//this.setSummary( "No location found" );
}
// remove the listener , we don't need it anymore
locManager.removeUpdates(this);
dialog.hide();
}
public void onLocationChanged(Location location) {
updateWithNewLocation(location);
}
public void onProviderDisabled(String provider) {
updateWithNewLocation(null);
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
init the listener in the MainActivity like this :
ProgressDialog dialog;
.
.
.
new MyLocationListener (this, dialog).startSearch();
I don't know if that help ? but that was my solution ...