Develop Reference

Proximity Alert not triggering

I'm having some trouble getting my proximity alert to work on my Android app that's running on an Emulator. Basically the proximity alert should start an activity that will (for now) print to the log, however when a desired location is set for the alert, and the emulator's location is set at that particular location, nothing happens. Here is the code for the proximity alert:
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Intent intent = new Intent(MY_PROXIMITY_ALERT);
PendingIntent proxIntent = PendingIntent.getActivity(MapActivity.this, 0, intent, 0);
lm.addProximityAlert(latlng.latitude, latlng.longitude, 100, -1, proxIntent);
Now MY_PROXIMITY_ALERT is declared in the manifest as stated below:
<receiver android:name=".myLocationReceiver">
<intent-filter>
<action android:name="PROXIMITY_ALERT"/>
</intent-filter>
</receiver>
And here is my code for myLocationReceiver
public class myLocationReceiver extends BroadcastReceiver{
private static final String TAG = "myLocationReceiver";
#Override
public void onReceive(Context context, Intent intent) {
final String key = LocationManager.KEY_PROXIMITY_ENTERING;
final Boolean entering = intent.getBooleanExtra(key, false);
if(entering) {
Log.d(TAG, "onReceive: Entering proximity of location");
}
}
}
I believe my problem has something to do with the Intent or PendingIntent object but I'm not entirely sure. Also I have heard that usually the GPS will take about a minute to actually register the proximity, but I still do not get a log message even after some time.
Thanks!

You've created an Intent with action MY_PROXIMITY_ALERT and then used PendingIntent.getActivity() to get a PendingIntent to pass to the LocationManager. When the proximity conditions are satisfied, LocationManager will try to start an Activity that is listening for action MY_PROXIMITY_ALERT.
Intent intent = new Intent(MY_PROXIMITY_ALERT);
PendingIntent proxIntent = PendingIntent.getActivity(MapActivity.this, 0, intent, 0);
In your manifest, you've declared a BroadcastReceiver that is listening for action MY_PROXIMITY_ALERT. This won't work.
Since you want the proximity alert to trigger a BroadcastReceiver, you need to get the PendingIntent like this:
Intent intent = new Intent(MY_PROXIMITY_ALERT);
PendingIntent proxIntent = PendingIntent.getBroadcast(MapActivity.this, 0, intent, 0);
Personally, I think it would be better to use an "explicit" Intent instead of an "implicit" Intent. In that case you would do it like this:
Intent intent = new Intent(MapActivity.this, myLocationReceiver.class);
PendingIntent proxIntent = PendingIntent.getBroadcast(MapActivity.this, 0, intent, 0);
You don't need to use the ACTION in the Intent.
Using an "explicit" Intent tells Android exactly what component (class) to launch. If you use an "implicit" Intent, Android has to search for components that advertise that they can handle certain ACTIONs.

Google location API: request location updates with pending intent?

I have started to implement the Google Location API using this tutorial.
I've managed to get it to work in my application quite fine, it updates my location at the right intervals etc. Now I am working on how to update my location when the device is in sleep mode. According to the documentation, this method is the way to go:
public void requestLocationUpdates (LocationRequest request, PendingIntent callbackIntent);
My question is, how do I set up this PendingIntent, and how do I handle it? I've seen tutorials of how to handle other types of intent, but I am not sure how to apply them to this.

You can either register Broardcast Reciever or Activity through pending intent.Sample Example for registering boardcast reciever:
String proximitys = "ACTION";
IntentFilter filter = new IntentFilter(proximitys);
registerReceiver(mybroadcast, filter);
Intent intent = new Intent(proximitys);
PendingIntent proximityIntent = PendingIntent.getBroadcast(this, 0,
intent, PendingIntent.FLAG_CANCEL_CURRENT);
locationManager.requestLocationUpdates(provider, mintime, mindistance,
proximityIntent);
Your Broardcast Reciever:
public class ProximityIntentReceiver extends BroadcastReceiver {
#SuppressWarnings("deprecation")
#Override
public void onReceive(Context arg0, Intent intent) {
//action to be performed
}

requestLocationUpdates with PendingIntent and Broadcast - what broadcasts do I get

I have setup an alarm which is received by a BroadcastReceiver which launches a WakefulIntentService (class LocationMonitor). In the LocationMonitor I have :
private static final int MIN_TIME_BETWEEN_SCANS = 1 * 30 * 1000;
private static final int MIN_DISTANCE = 0;
#Override
protected void doWakefulWork(Intent intent) {
final CharSequence action = intent.getAction();
if (action == null) { // monitor command from the alarm manager
// the call below enables the LocationReceiver
BaseReceiver.enable(this, ENABLE, LocationReceiver.class);
if (lm == null) lm = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
Intent i = new Intent(this, LocationReceiver.class);
PendingIntent pi = PendingIntent.getBroadcast(this, NOT_USED, i,
PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_CANCEL_CURRENT);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BETWEEN_SCANS, MIN_DISTANCE, pi);
} else if (ac_location_data.equals(action)) {
final Bundle extras = intent.getExtras();
if (extras != null) {
final Location loc = (Location) extras
.get(LocationManager.KEY_LOCATION_CHANGED);
if (loc == null) {
w("NULL LOCATION - EXTRAS : " + extras); //Log.w
// while gps is disabled I keep getting this :
// NULL LOCATION - EXTRAS : Bundle[{providerEnabled=false}]
} else {
final double lon = loc.getLongitude();
final double lat = loc.getLatitude();
w("latitude :" + lat + " -- longitude : " + lon);
}
}
}
}
I have several issues with the code above.
If GPS is initially disabled and then I enable it I get a bunch of W/GpsLocationProvider(...): Unneeded remove listener for uid 1000. The warning comes from here. I can't find in the code where is this removing of listeners triggered, nor can I see where they are assigned the uid 1000 (apparently the system server).
When I enable the gps I get the location as expected and then a "RemoteException"
LocationManagerService(...): RemoteException calling onLocationChanged on Receiver{4083ee68 Intent PendingIntent{4084e6b8: PendingIntentRecord{4083ef78 gr.uoa.di.monitoring.android broadcastIntent}}}mUpdateRecords: {gps=UpdateRecord{40838180 mProvider: gps mUid: 10064}}
which is not really a RemoteException, just a PendingIntent.CancelledException - the message is quite misleading. Or so I think : it comes from here which calls this. My question is : why is it reusing the Intent - shouldn't the FLAG_ONE_SHOT dispose of it ?
But the most important question is : when I register a PendingIntent like this what intents do I expect to receive ? And what flags should I use ?
Keep in mind I am using this pattern cause I want to have the phone update its position even when asleep and this achieves it (I do get the location updates). I try to simulate requestSingleUpdate (unavailable in 2.3) using FLAG_ONE_SHOT.
Receiver :
public final class LocationReceiver extends BaseReceiver {
private static final Class<? extends Monitor> MONITOR_CLASS =
LocationMonitor.class;
#Override
public void onReceive(Context context, Intent intent) {
d(intent.toString());
final String action = intent.getAction();
d(action + "");
final Intent i = new Intent(context, MONITOR_CLASS);
i.fillIn(intent, 0); // TODO do I need flags ?
i.setAction(ac_location_data.toString());
WakefulIntentService.sendWakefulWork(context, i);
}
}

To this question:
when I register a PendingIntent like this what intents do I expect to
receive ? And what flags should I use ?
When you register for location updates and pass a PendingIntent, this PendingIntent will be triggered when the LocationManager decides to inform you about a location update. You can provide pretty much whatever you want, depending on what you want to happen when the PendingIntent is triggered. The LocationManager will add an extra to the Intent that is sent. This extra has the bundle key LocationManager.KEY_LOCATION_CHANGED and the object associated with that key is a Location object.
LocationManager will use this PendingIntent again and again to inform your app of location updates, so I think using PendingIntent.FLAG_ONE_SHOT is probably not such a good idea. If you only want a single update, why don't you just unregister after you get one update?
EDIT: Add code to cancel any previously requested updates before registering for updates
Before you call registerLocationUpdates(), do this to cancel any previously registered updates:
Intent i = new Intent(this, LocationReceiver.class);
// Get any existing matching PendingIntent
PendingIntent pi = PendingIntent.getBroadcast(this, NOT_USED, i,
PendingIntent.FLAG_NO_CREATE);
if (pi != null) {
// Cancel any updates for this PendingIntent, because we are about to
// invalidate it
lm.removeUpdates(pi);
}
// Create a new PendingIntent and cancel any previous one
pi = PendingIntent.getBroadcast(this, NOT_USED, i,
PendingIntent.FLAG_CANCEL_CURRENT);
// Now register for location updates...
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BETWEEN_SCANS, MIN_DISTANCE, pi);
NOTE: Actually, I don't know why you need to cancel any previous PendingIntent and create a new one in this case. You can just get a PendingIntent and if you have already registered for location updates with that PendingIntent, I don't think that registering again will cause the PendingIntent to be used multiple times. If you want to try that, all you need to do is to remove PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_CANCEL_CURRENT from your existing code. I think that is a better/cleaner/clearer solution.

PendingIntents keep caching same object

i ve been facing some problems trying to pass data through intents and pending intents to a BroadcastReceiver, concerning proximity alerts. More specifically, am trying to pass an object, that among others holds the user's constantly changing position. I ve tried various tactics being proposed here (and not only) but none worked, resulting to either null values or same-as-first-time created intents, when the intent is retrieved on the BroadcastReceiver's side. Tactics used:
Flagging the intent that carries the object with:FLAG_ACTIVITY_NEW_TASK+FLAG_ACTIVITY_CLEAR_TOP+FLAG_ACTIVITY_SINGLE_TOP
Result:Null values on the BroadacastReceiver's side
Flagging the pending intent created using the initial intent, with:FLAG_UPDATE_CURRENT or FLAG_CANCEL_CURRENT
Result:Null values on the BroadacastReceiver's side
Acquiring a random ID for intent or the pending intent using System.currentTimeMillis();
Result:Intents are not fired or received at all
Nothing described above. Result:Retrieving the same initial value every time.
Code for the calling method (stripped from any experimentations/producing null values):
private void setProximityAlert(MyCar myCar) {
String locService = Context.LOCATION_SERVICE;
LocationManager locationManager;
locationManager = (LocationManager)getSystemService(locService);
float radius = myCar.getMyCarRadius();
long expiration = myCar.getMyCarExpiration();
myService.setMyDriverLat(userLat);//setting user's position
myService.setMyDriverLng(userLng);//setting user's position
Intent intent = new Intent(myCar.getMyCarName());
intent.putExtra("myCar",myCar);
PendingIntent proximityIntent = PendingIntent.getBroadcast(this, -1, intent, 0);
locationManager.addProximityAlert(myCar.getMyCarLat(), myCar.getMyCarLng(), radius, expiration, proximityIntent);
}
Code for the calling method that sets the intent filter and registers the BroadcastReceiver:
public void addNewCarPoint (MyCar myCar){
IntentFilter filter = new IntentFilter(myCar.getMyCarName());
registerReceiver(new ProximityAlertReceiver(), filter);
setProximityAlert(myCar);
}
Code for the BroadcastReceiver's side:
public class ProximityAlertReceiver extends BroadcastReceiver {
#Override
public void onReceive (Context context, Intent intent) {
MyCar myCar=(MyCar)intent.getParcelableExtra("myCar");
driverLoc=(String)Double.toString(myCar.getMyDriverLat());
Toast.makeText(context, userLoc, Toast.LENGTH_SHORT).show();
Intent i = new Intent(context, MyCarDiscoveryPrompt.class);
context.startActivity(i);//firing intent
}
public void intentDataLoader(){
}
}
Any ideas would be more than welcome.
Thank you in advance.

Hmm i think i ve found something:
I placed the BroadcastReceiver (ProximityAlerReceiver), used to detect proximity alerts in the same class (MyCarTracking.class), where the LocationListener.class is located. This,
provides immediate access to fresh location updates, creating a new intent wrapped in a new pendingIntent to be fired to the BroadcastReceiver (only when the proximity criteria are met).
flags:FLAG_ACTIVITY_NEW_TASK+FLAG_ACTIVITY_SINGLE_TOP and FLAG_CANCEL_CURRENT on intent and pendingIntent, were kept respectively. More specifically:
Code for LocationListener:
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateWithNewLocation(location);//update application based on new location
}
public void onProviderDisabled(String provider){
updateWithNewLocation(null);//update application if provider disabled
}
public void onProviderEnabled(String provider){
// Update application if provider enabled
}
public void onStatusChanged(String provider, int status, Bundle extras){
//update application if provider hardware status changed
}
};
Code for setProximityAlert() method:
private void setProximityAlert() {
String locService = Context.LOCATION_SERVICE;
Context context =getApplicationContext();
LocationManager locationManager;
locationManager = (LocationManager)getSystemService(locService);
float radius = myCar.getMyCarRadius();
long expiration = myCar.getMyCarExpiration();
Intent intent = new Intent(CAR_DISCOVERED);
intent.putExtra("myCar",myCar);
locationManager.getLastKnownLocation(provider);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);//flagging intent
PendingIntent proximityIntent = PendingIntent.getBroadcast(context, -1, intent, PendingIntent.FLAG_CANCEL_CURRENT);//flagging pendingIntent
locationManager.addProximityAlert(myCar.getMyCarLat(), myCar.getMyCarLng(), radius, expiration, proximityIntent);//setting proximity alert
}
This solution works producing fresh intents with fresh location updates.
Thank you all for your help and your interest :)

Try adding
intent.setData(uri);
where uri is some unique value for each pending intent

I've been struggling with this problem as well. It took me a whole night to find that a weird bug I had was related to this issue.
Here's a good discussion on google code on the subject: http://groups.google.com/group/android-developers/browse_thread/thread/b2060b27c8934921
I've solved all my problems by (ab)using both the uri in SetData and the (reserved) request code in PendingEvent.GetWhatever.
I'm also using FLAG_CANCEL_CURRENT on my intents and making sure only pendingintents that share the same purpose get the same data, action and uri.
Hope it helps a little bit.

Android: How to get location information from intent bundle extras when using LocationManager.requestLocationUpdates()

I am trying to use Android's LocationManager requestLocationUpdates. Everything is working until I try to extract the actual location object that in my broadcast receiver. Do I need to specifically define the "extras" to my custom intent so that the Android LocationManager before I pass it to requestLocationUpdates so it knows how to add it into the intent, or will it create the extras-bundle regardless when it passes the fired intent to the broadcast receiver?
My code looks like this:
Intent intent = new Intent("com.myapp.swarm.LOCATION_READY");
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(),
0, intent, 0);
//Register for broadcast intents
int minTime = 5000;
int minDistance = 0;
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, minTime,
minDistance, pendingIntent);
I have a broadcast receiver that is defined in the manifesto as:
<receiver android:name=".LocationReceiver">
<intent-filter>
<action android:name="com.myapp.swarm.LOCATION_READY" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</receiver>
And the broadcast receiver class as:
public class LocationReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
//Do this when the system sends the intent
Bundle b = intent.getExtras();
Location loc = (Location)b.get("KEY_LOCATION_CHANGED");
Toast.makeText(context, loc.toString(), Toast.LENGTH_SHORT).show();
}
}
My "loc" object is coming up null.

OK, I managed to fix it by changing the KEY_LOCATION_CHANGED in the broadcast receiver code to:
public class LocationReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
//Do this when the system sends the intent
Bundle b = intent.getExtras();
Location loc = (Location)b.get(android.location.LocationManager.KEY_LOCATION_CHANGED);
Toast.makeText(context, loc.toString(), Toast.LENGTH_SHORT).show();
}
}

i ve tried to code and test the solution you proposed, since i am facing similar problems concerning proximity alerts and intents carrying location objects. According the information you provided, you managed to overcome the null object retrieval, on the BroadcastReceiver's side. What you might did not observe is that now you should be receiving the same location as the one your intent was first created (also seen it as: intent caching problem).
In order to overcome this problem, i used FLAG_CANCEL_CURRENT, as being proposed by many people here and it works pretty fine, fetching fresh (and juicy :P) location values. So the line defining your pending intent should look like this:
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(),
0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
However, you can ignore this if:
your purpose was just to receive a location value once
you managed to overcome it in some other way not visible in your post