How to observe Gps Provider continually? - android

I want to know when the GPS on the device is tuned on, and the location is changed.
Here is what I've done:
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
public class MyLocationListener implements LocationListener
{
#Override
public void onLocationChanged(Location loc)
{
Toast.makeText( getApplicationContext(),"onlocation changed",Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider)
{
Toast.makeText( getApplicationContext(),"providerdisabled",Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderEnabled(String provider)
{
Toast.makeText( getApplicationContext(),"provideenabled",Toast.LENGTH_SHORT).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
}
It is working fine when my app runs in the foreground, but when I close it, I won't get any more updates. I'd like to know how to get this information continuosly until my application is uninstalled.

You need to put this in a service and start the service sticky.
Also you should think about using the FusedLocationManager by using GooglePlayServices.
For more info about GooglePlayServices and locations read here

Related

Crush when turn off the gps

I receive crush, when user turn off the gps.
I have code like this to detect location`s user
if(locationManager == null) {
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000L,
15f, mLocationListener);
} else if(locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)){
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000L,
15f, mLocationListener);
} else {
Toast.makeText(this, "Please turn on gps on ypur phone", Toast.LENGTH_SHORT).show();
}
When user open app with gps, then turn off it, I receive crush like this
java.lang.AbstractMethodError: abstract method "void android.location.LocationListener.onProviderDisabled(java.lang.String)"
I tried to detect when user turn off gps, but I get crush earlier, then receiver detect
Find the declaration of mLocationListerner. Surely it overrite onLocationChanged(). But you may have forgotten override onProviderDisabled(). Do it even if it's empty. Override also onStatusChanged() and onProviderEnabled().
Luck.
LocationListener mLocationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
....
}
#Override
public void onProviderDisabled(String provider) { }
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
#Override
public void onProviderEnabled(String provider) { }
};

How to get initial location with LocationManager?

I've been getting current location with GoogleApiClient up until now but I've just noticed that it's much simpler to do it with LocationManager using LocationListener since it can even detect when GPS service was turned on or off by the user.
But I have a problem when getting user's first location after the LocationManager was initialized.
LocationManager has 4 listeners but none of them give you your first location. It does have a onLocationChanged listener but it only activates when you move.
This is how I'm using it:
// Init LocationManager (needed to track if GPS is turned on or not
locationManager = (LocationManager) getApplicationContext().getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
end of oncreate......
/*
LocationListener (Listening if GPS service is turned on/off)
*/
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderDisabled(String provider) {
}

Android locationManager requestLocationUpdates not called

I'm making an android application which keeps track of your location to eventually draw your route on a google map. Everything seems to be working except for one thing which, strangely enough, did work before. I think I did not change anything that matters to the function call and most examples I found did it the same way I did.
In my onCreate method I do the following:
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 2000, 0, locationListener);
later i call upon the LocationListener:
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
but somehow this does not get called. Tried logging everywhere, everything returned a value except for the ones in the onLocationChanged. Doesn't work with GPS_PROVIDER either
All the relevant code:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tracking);
setUpMapIfNeeded();
// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
// Tell the program to get location updates every 2 seconds(2000ms)
// I sadly don't get called..
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 2000, 0, locationListener);
}
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
System.out.Println("I'm just here for debugging purposes");
System.out.Println("Sadly I don't appear in Logcat");
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
public void onProviderEnabled(String provider) {
}
public void onProviderDisabled(String provider) {
}
};
Did you add permission in manifest file?

Android GPS onLocationChanged never called

I have an android application and I would like to obtain the location.
For this I follow the android documentation, but it doesn't work. The onLocationChanged method is never called.
public class GPSTestActivity extends Activity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
{
Toast.makeText(this, "GPS available", 3000).show();
}
else
{
Toast.makeText(this, "GPS not available", 3000).show();
}
LocationListener locationListener = new LocationListener()
{
public void onLocationChanged(Location location)
{
System.out.println("RECEIVED LOCATION");
}
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
public void onProviderEnabled(String provider)
{
}
public void onProviderDisabled(String provider)
{
}
};
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
}
In the AndroidManifest.mf I've include the permision:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
I'm trying to test the application with the emulator in DDMS console. I set a longitude and a latitude, then presss the send button, but the onLocationChanged method is not called.
What I'm doing wrong?
Thank in advance
put parms to the call:
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 10f, locationListener);
I've found the problem.
I was testing with Android 2.3.3. and there is a bug. Testing with Google API (Level 10) works perfect.

How to determine whether GPS position has been acquired on android?

Let's say I have a button which calls another activity only if the system knows the EXACT user's location. I made a dialog to ask the user to turn on GPS if it's disabled, but when the user enables GPS and pushes the button again, I will probably not have the exact location yet. Can anyone help me with this ?
You need to create a LocationListener, and wait for the callback. It is pretty well described in the api docs:
// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
// When you get here you have a location...
useTheNewLocationToEnableTheButton(location);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
You can listen for GpsStatus events, to make sure that user actually enabled GPS (GPS_EVENT_STARTED), and to be notified when GPS gets position fix (GPS_EVENT_FIRST_FIX).
If you don't know coordinates, the best way is to display a ProgressDialog while retrieving a location and, when you got it, dismiss ProgressDialog and launch your activity.
final LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
//here you can get coordinates via location.getLongitude() and
//location.getLatitude() methods, dismiss the progress dialog and
//start your activity
locationManager.removeUpdates(this);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

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