I have searched quite a bit and I'm not totally clueless. I have implemented a temporary solution on my end but was wondering if there is a better approach out there.
I have an app that sends a person's location after every 60 seconds to a server. On my dashboard (the main screen that will go to onPause after application starts), I have registered a LocationManager with the following code:
service = (LocationManager) getSystemService(LOCATION_SERVICE);
boolean enabled = service
.isProviderEnabled(LocationManager.GPS_PROVIDER);
if (!enabled)
{
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
else
{
Criteria criteria = new Criteria();
provider = service.getBestProvider(criteria, false);
service.requestLocationUpdates(provider, 10000, 50, this);
Location location = service.getLastKnownLocation(provider);
// Initialize the location fields
if (location != null)
{
onLocationChanged(location);
}
else
{
Log.d("Location: ", "No update received");
}
}
However, as I mentioned, this activity will be minimized by the user (by pressing the home button). There is a service that gets called every 60 seconds by an AlarmManager. That service accesses static variables from the Dashboard Activity (lat, lon) and sends it to the server.
My question:
If the activity goes onPause, will the requestLocationUpdates function stop? Or will it keep working?
If it keeps working, it will keep updating the two lat and lon static String objects and the service will keep getting updated values. If they stop, the service will keep getting the same old values again and again.
Also, is there a better way to approach this problem? Using a mix of GPS Provider and Network Provider? (I need fairly accurate values).
EDIT
Here's my Alarm. This code is inside Login Activity
Intent i = new Intent(con, LocationPoller.class);
i.putExtra(LocationPoller.EXTRA_INTENT, new Intent(con,
Login.class));
i.putExtra(LocationPoller.EXTRA_PROVIDER,
LocationManager.GPS_PROVIDER);
gps = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getBroadcast(con, 0, i, 0);
gps.setRepeating(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(),
10 * 1000, pi);
Log.d("Service: ",
"GPS Service started and scheduled with AlarmManager");
Here's my receiver (also within Login activity)
private class ReceiveMessages extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
Location loc = (Location) intent.getExtras().get(
LocationPoller.EXTRA_LOCATION);
String msg;
if (loc == null)
{
msg = intent.getStringExtra(LocationPoller.EXTRA_ERROR);
}
else
{
msg = loc.toString();
}
if (msg == null)
{
msg = "Invalid broadcast received!";
}
Log.d("GPS Broadcast: ", msg);
}
}
Nothing's happening :s Not getting anything on logcat which means the broadcast isn't being received.
When activity goes on pause, all registered listeners will stop. Better way to implement this is, alarm manager sent a broadcast every 60 seconds, this broadcast receiver starts a service and this service will request a location on Wakeful thread, once location information is retrieved, update the location on server.
There is an Open source library available with an example (courtesy CommonsWare), please refer below link. Its under Apache 2.0 license
Location Polling Library
Please find my sample project using above library. I have modified few things in the above library and created my own version.
Location Polling Demo Application
Related
I have created a service which finds and then stores the user's coordinates in an SQLite database.
public class GPS_Service extends Service {
DatabaseHelper myDb;
private LocationListener locationListener;
private LocationManager locationManager;
private String latitude, longitude;
#Override
public void onCreate() {
super.onCreate();
myDb = new DatabaseHelper(this);
}
#SuppressLint("MissingPermission")
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
.setContentTitle("Service")
.setContentText("Coordinates Location Running")
.setContentIntent(pendingIntent)
.build();
startForeground(1, notification);
locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
Log.d("myTag", "Hello");
latitude = String.valueOf(location.getLatitude());
longitude = String.valueOf(location.getLongitude());
insertCoordinates(latitude, longitude);
Intent i = new Intent("location_update");
i.putExtra("latitude", latitude);
i.putExtra("longitude",longitude);
sendBroadcast(i);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(i);
}
};
locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 0, locationListener);
return START_NOT_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
if(locationManager != null)
locationManager.removeUpdates(locationListener);
}
private void insertCoordinates(String latitude, String longitude) {
boolean inserted = myDb.insertData(latitude, longitude); //Insert coordinates
//Check if insertion is completed
if(inserted)
Toast.makeText(GPS_Service.this, "Coordinates Inserted", Toast.LENGTH_SHORT).show();
else
Toast.makeText(GPS_Service.this, "Coordinates Not Inserted", Toast.LENGTH_SHORT).show();
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
I can either start or stop the service from the MainActivity like this
private void enable_buttons() {
buttonStartService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent serviceIntent = new Intent(getApplicationContext(), GPS_Service.class);
//Checks if the SDK version is higher than 26 to act accordingly
ContextCompat.startForegroundService(MainActivity.this, serviceIntent);
}
});
buttonStopService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent serviceIntent = new Intent(MainActivity.this, GPS_Service.class);
stopService(serviceIntent);
}
});
}
The problem is that when I start this service, if I either completely close the app or leave it in the background, the locationListener will work for 30 seconds and then it will stop. If I reopen the app, the service continues to work from where it stopped. Also I checked in the developer options if the service is running, and it indeed is even though the locationListener doesn't output the expected results. Any ideas?
TL;DR:
Add android:foregroundServiceType="location" to your Service's manifest entry.
EXPLANATION
This new behavior, for Android 10, is exactly as you've described: Even though you may be using a foreground service, 30 seconds after your app leaves the screen -- location updates cease.
You might've noticed that Android 10 devices present two new choices to the user when granting location permissions (for legacy (API < 29) apps, or apps that declare the ACCESS_BACKGROUND_LOCATION permission):
"Allow all the time"
"Allow only while using this app"
"Allow only while using this app" effectively means, "Allow while the app is visible onscreen". That's because the user now has the option of selectively removing location access -- even to a foreground service -- based on that criteria. Users can change this setting at any time, even if your app is running.
The Android docs explain that the solution, android:foregroundServiceType="location", was intended for your precise use case: "Google Maps"-like apps, which have a foreground service, but are expected to continue processing location data if the user switches to another app. The technique is called "continuing a user-initiated action", and it allows you to get location updates even after your app is placed in the "background".
(The docs seem to be expanding the definition of the term "background", here. In the past, if you had a foreground service, your app was considered "in the foreground" -- at least for the purposes of task priority, Doze, and so forth. Now it appears that an app is considered "in the background", with respect to location access, if it hasn't been onscreen in the last 30 seconds.)
I am not sure what UI changes (like in the Google Play store) take place when you set a particular foregroundServiceType. Regardless, it seems to me that users are unlikely to object.
OTHER SOLUTIONS FOR ANDROID 10 DEVICES
Alternatively, you could've declared a targetSdkVersion of 28 or less, which will let your app function in a location "compatibility mode".
You also have the option of gaining the ACCESS_BACKGROUND_LOCATION permission, but the docs caution against this:
If your app doesn't require location access while running in the background, it's highly recommended that you not request ACCESS_BACKGROUND_LOCATION...
This approach isn't required, for your use case, because your Activity is used to start your Service; you can be guaranteed that your app has been onscreen at least once before the Service starts getting background location updates. (At least, I assume that that is how the OS determines the start of a "user-initiated action". Presumably, the foregroundServiceType approach won't work if you're starting the Service from a JobScheduler, or a BroadcastReceiver, or something.)
PS: Hang on to that WakeLock code. You're going to need to keep the device awake, if you want to keep getting updates at a steady 10-second pace.
I dont really see any problem in the code, but I am a bit sceptical about START_NOT_STICKY. Try START_STICKY instead.
START_STICKY
If this service's process is killed while it is started (after
returning from onStartCommand(Intent, int, int)), then leave it in the
started state but don't retain this delivered intent. Later the system
will try to re-create the service. Because it is in the started state,
it will guarantee to call onStartCommand(Intent, int, int) after
creating the new service instance; if there are not any pending start
commands to be delivered to the service, it will be called with a null
intent object, so you must take care to check for this.
START_NOT_STICKY
If this service's process is killed while it is started (after
returning from onStartCommand(Intent, int, int)), and there are no new
start intents to deliver to it, then take the service out of the
started state and don't recreate until a future explicit call to
Context.startService(Intent). The service will not receive a
onStartCommand(Intent, int, int) call with a null Intent because it
will not be re-started if there are no pending Intents to deliver.
So as you are returning START_NOT_STICKY, if the process is killed, onStartCommand() will not be called again, which is where you initialize both the listener and the locationManager.
I have an android app in which I have used FusedLocationApi to get location updates of the user.
Following is the scenario:
1. I have a singleton Watcher class in which I define the pending intent to get the locations even when app is in background. Following is the code:
private PendingIntent pendingIntent;
private Watcher() {
Intent locationIntent = new Intent(context, Receiver.class);
pendingIntent = PendingIntent.getBroadcast(
context, 007 /*requestcode*/, locationIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
}
Then, when I have successfully connected location services, I request for location updates:
LocationServices.FusedLocationApi.
requestLocationUpdates(googleApiClient, locationRequest, pendingIntent);
Now, whenever Receiver class which extends WakefulBroadcastReceiver gets the location update, it starts the Service.class. The service class extends IntentService.
Following is the code:
#Override
synchronized protected void onHandleIntent(final Intent intent) {
if(LocationResult.hasResult(intent)) {
LocationResult locationResult= LocationResult.extractResult(intent);
Location location = locationResult.getLastLocation();
printLocation(location);
}
So my question is, given the above steps, why does the onHandleIntent gets woken up by the LocationReceiver multiple times within a period of 5 milliseconds. The lat, lng and accuracy are all the same. I have defined the
setFastestInterval(5 seconds); and
setInterval(1 minute);
Also the location accuracy is BALANCED_POWER_ACCURACY;
In my app, the
LocationServices.FusedLocationApi.
requestLocationUpdates(googleApiClient, locationRequest, pendingIntent);
do gets called multiple times. But according to the documentation: "Any previously registered requests that have the same PendingIntent (as defined by equals(Object)) will be replaced by this request." And I am using the same pendingIntent object to call requestLocationUpdates.
Thanks in advance.
Hi Kanika you can set the minimum displacement before passing your location request object this will help you to get updates only when you have certain minimum displacement. you can use below method for doing same.
setSmallestDisplacement(float smallestDisplacementMeters)
Also FYI api reference link , https://developers.google.com/android/reference/com/google/android/gms/location/LocationRequest
I can't seem to figure this one out. I have a broadcastReceiver that is registered in the manifest. I ping for gps once a minute, the broadcastReceiver's onReceive fires and starts a service. This service grabs a wakelock just in case, sends the GPS Coords to our server using an ASyncTask and releases the wakelock, and calls stopSelf(). This fires consistantly on my Nexus 6p and an HTC.
However on a Samsung GS5, this only works for so long. The time it stops seems random but usually within 30 mins, sometimes as short as 5 mins. The broadcastReceiver never gets called again, meaning the onReceive just stops firing.
All power saving settings on the samsung are turned off that I can notice. Unless there is a super tricky hidden one, I can't figure out how the Samsung phone can stop this broadcastReceiver, or stop GPS, whichever is happening.
This happens even if the app is not swiped closed. The phone goes idle, screen turns off, and about 5-30 mins later, the phone stops getting coords.
This happens whether I use GPS_PROVIDER or NETWORK_PROVIDER although with network provider it seems to happen even faster.
Here is where I start the GPS.
public void startBackgroundGPS () {
Activity activity = this.cordova.getActivity();
Context context = activity.getApplicationContext();
ComponentName component = new ComponentName(context, LocationReceiver.class);
int status = context.getPackageManager().getComponentEnabledSetting(component);
Log.d(TAG, Integer.toString(status));
if(status == PackageManager.COMPONENT_ENABLED_STATE_ENABLED || status == PackageManager.COMPONENT_ENABLED_STATE_DEFAULT) {
Log.d(TAG, "receiver is enabled");
//getPackageManager().setComponentEnabledSetting(component, PackageManager.COMPONENT_ENABLED_STATE_DISABLED , PackageManager.DONT_KILL_APP);
} else if(status == PackageManager.COMPONENT_ENABLED_STATE_DISABLED) {
Log.d(TAG, "receiver is disabled");
context.getPackageManager().setComponentEnabledSetting(component, PackageManager.COMPONENT_ENABLED_STATE_ENABLED , PackageManager.DONT_KILL_APP);
}
Intent intent = new Intent(context, LocationReceiver.class);
intent.setAction("myBroadcast");
intent.putExtra("session_id", session_id);
intent.putExtra("device_id", device_id);
//intent.addFlags(Intent.FLAG_FROM_BACKGROUND);
PendingIntent pendingIntent = PendingIntent.getBroadcast(activity.getApplicationContext(), 58534, intent, PendingIntent.FLAG_UPDATE_CURRENT);
//Register for broadcast intents
locationManager = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 60000, 0, pendingIntent);
}
Here is my broadcastReceiver
public class LocationReceiver extends BroadcastReceiver {
//private static boolean semaphore = true;
#Override
public void onReceive(Context context, Intent intent) {
Log.d("DistanceFilterLocationService", intent.getAction());
Location location = (Location) intent.getExtras().get(android.location.LocationManager.KEY_LOCATION_CHANGED);
Intent locationServiceIntent = new Intent(context, DistanceFilterLocationService.class);
locationServiceIntent.putExtra("device_id", intent.getStringExtra("device_id"));
locationServiceIntent.putExtra("session_id", intent.getStringExtra("session_id"));
Double longi = location.getLongitude();
Double lati = location.getLatitude();
locationServiceIntent.putExtra("longitude", longi);
locationServiceIntent.putExtra("latitude", lati);
locationServiceIntent.putExtra("accuracy", location.getAccuracy());
locationServiceIntent.putExtra("time", location.getTime());
context.startService(locationServiceIntent);
}
}
Here is my broadcastreceiver in the manifest.
<receiver android:name="com.mypackage.LocationReceiver">
<intent-filter>
<action android:name="myBroadcast" />
</intent-filter>
</receiver>
Anyone run into something like this? Found a couple similar questions but no answers were given. This one is killing me as it completely destroys the purpose of the app on Samsung phones.
Thanks for any help.
Maybe it is not a good answer, but perhaps the android version could be the problem. Or, maybe some addons from Samsung... did you test on other Samsung phone (maybe another android version)?
I have registered my LocationManager for location updates, every 10 seconds
mgr.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 10 * 1000, 50, this);
But the onLocationChanged callback returns a location every 10 secs, which(the location) is more than 2 hours old. And that time-stamp is never changing.
The problem is:
2 hours back I was in a complete different location(home) where I used the device on a wifi. Now currently I am in some other location(office) on a different wifi where my application shows my current location as home. Same thing happened at home yesterday, when it was showing office as my current location. It got to work(started showing correct location) when I closed my app, opened FourSquare app and re-opened my app.
Complete Code:
public class LocationService extends Service implements LocationListener {
public static double curLat = 0.0;
public static double curLng = 0.0;
private LocationManager mgr;
private String best;
private Location location;
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
mgr = (LocationManager) getSystemService(LOCATION_SERVICE);
best = LocationManager.NETWORK_PROVIDER;
location = mgr.getLastKnownLocation(best);
if (location != null) {
dumpLocation(location);
mgr.requestLocationUpdates(LocationManager.GPS_PROVIDER,
10 * 1000, 50, this);
}
return START_NOT_STICKY;
}
}
private void dumpLocation(Location l) {
SimpleDateFormat s = new SimpleDateFormat("dd/MM/yyyy:hh:mm:ss",
Locale.ENGLISH);
String format = s.format(l.getTime());
//The above time is always 28/03/2013:09:26:41 which is more than 2 hrs old
curLat = l.getLatitude();
curLng = l.getLongitude();
}
#Override
public void onLocationChanged(Location location) {
dumpLocation(location);
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
Being started in an Activity this way:
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
Intent i = new Intent(this, LocationService.class);
pi = PendingIntent.getService(this, 0, i,
PendingIntent.FLAG_UPDATE_CURRENT);
am.cancel(pi);
am.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
SystemClock.elapsedRealtime(), 10000, pi);
Permissions in manifest:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
I can get the correct location now, by opening some other location based app like Maps, Navigator, Foursquare etc.., But why my app isn't able to get a new/fresh fix from the provider.
Thank You
You are getting old location because of this line
location = mgr.getLastKnownLocation(best);
because if GPS is not enabled then it will show you the old location . So remove this code It will work like a champ
You can also refer to this library
https://github.com/nagendraksrivastava/Android-Location-Tracking-Library
On the basis of your comments I have edited the answer Okay Let me explain line by line
location = mgr.getLastKnownLocation(best); it will give you object of last know location then it will go inside if condition and it will call dumplocation and will get last location data and after that you called
mgr.requestLocationUpdates(LocationManager.GPS_PROVIDER,
10 * 1000, 50, this);
but suppose GPS provider is disabled then it will not fetch new location so you will get old location only . So either you can change it like
if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
{
locationManager.requestSingleUpdate(LocationManager.GPS_PROVIDER,new NagendraSingleLocationListener(),null);
}
else
{
locationManager.requestSingleUpdate(LocationManager.NETWORK_PROVIDER,new NagendraSingleLocationListener(),null);
}
I think because you cancel your pending intent right away, thus the requestLocationUpdate would not start update before you cancel. Why don't you sleep may be for 2 second before cancel.
From my experience android will give you a location when you request the updates even if gps has not enough sattelites to work. So even if gps is on - if you are inside or in a location that is bad (like under a bridge) android will deliver an old fix to you. Can be a very old one indeed.
The only thing I found to be working 100% is to generelly not use the first position but only remember the time. When new positions arrive you can check that the time is newer than the last. If you want to only use very precise positions you may also need to check that location.getAccuracy() is low (the lower the better).
I use gps to get my timestamps for a soap interface as the android clock can be very off sometimes and this was the only way for me to get a valid time from gps.
I'm new to Android and I'm having the following problem. I'm writing a sample application where I have an intent service that first checks all location providers to get the last known location. If none of the last known locations provides an accurate (or timely) enough location then the location manager's requestLocationUpdates method is called with a BroadcastReceiver intent. Each time the broadcast receiver's onReceive method is called it should check the location to see if it is accurate and/or timely enough. I also have a TimerTask in the intent service that eventually goes off and should check to see if an accurate and/or timely enough location update has been obtained. The problem I'm having is that I don't know how to get the location data obtained in the broadcast receiver back to the intent service. Seems like this should be an easy thing to do but I've been agonizing over this for days. The only way I can think to do it is to write the data to an SQLite db in the broadcast receiver and then read those records back in the intent service, but this seems unnecessarily complicated. Does anyone know what the right way is to get the data back to the intent service? Should I even be using a broadcast receiver for requestLocationUpdates? Is there an easier way to do this? Here is the code
public class GetLocationService extends IntentService {
public GetLocationService() {
super("something");
}
LocationManager locationManager;
long maxFixLateness;
float maxFixPosUncertainty;
boolean usableLocObtained;
Location bestLoc = null;
float bestLocScore = 0;
Intent locChangeI;
PendingIntent pLocChangeI;
#Override
final protected void onHandleIntent(Intent intent) {
maxFixLateness = 30000;
maxFixPosUncertainty = 30;
long curTime = System.currentTimeMillis();
LocationManager locationManager = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
// Check for a usable location fix
List<string> matchingProviders = locationManager.getAllProviders();
for (String provider : matchingProviders) {
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
// ...some code to check if the location is accurate or timely
// enough
}
}
if (bestLoc == null) {
locChangeI = new Intent(this, HandleLocationUpdateReceiver.class);
pLocChangeI = PendingIntent.getBroadcast(this, 0, locChangeI,
PendingIntent.FLAG_UPDATE_CURRENT);
usableLocObtained = false;
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 0, 0, pLocChangeI);
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 0, 0, pLocChangeI);
// Call the timer that will periodically check to see if a usable
// location has been obtained.
new LocFixCheckTimer(60000, 30, 1000);
}
}
private class LocFixCheckTimer {
Timer timer;
long numChecks;
public LocFixCheckTimer(long initSearchTime, long maxRechecks,
long recheckFreq) {
numChecks = maxRechecks;
timer = new Timer();
// Wait 2 seconds before checking for a fix again
timer.schedule(new CheckLocTask(), initSearchTime, recheckFreq);
}
class CheckLocTask extends TimerTask {
public void run() {
if (numChecks > 0) {
if (usableLocObtained == true) {
// I want to use the location data obtained from the
// HandleLocationUpdateReceiver's onReceive method
// but I don't how to get that data here.
}
} else {
// Cancel the timer. We've timed-out on searching
// for a usable location fix
timer.cancel();
}
--numChecks;
}
}
}
}
Here is the broadcast receiver:
public class HandleLocationUpdateReceiver extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
Location loc = (Location) intent.getExtras().get(LocationManager.KEY_LOCATION_CHANGED);
if (loc != null)
{
double lat = loc.getLatitude();
double lon = loc.getLongitude();
// Do some checking to see how accurate and timely the location is
// here and somehow get it back to the intent service.
}
}
}
Thanks for the help!
Use a listener for sending back data to your activity or service. It is provided in this link