onLocationChanged is not called automatically

Question

I have a problem with onLocationChanged event in Android. Here's the triggering:

case R.id.start: {
    Points.add(overlay.getMyLocation()); // Points' type is ArrayList<GeoPoint>
    mgr.requestLocationUpdates(best, 0, 3, locationListener);
    }
    break;

And here's the onLocationChanged method:

public void onLocationChanged(Location location) {
    i++;
    Points.add(overlay.getMyLocation());
    MapOverlay mapOverlay = new MapOverlay(Points.get(i-1), Points.get(i));
    map.getOverlays().add(mapOverlay); //does the drawing
    mMapController.animateTo(Points.get(i));
}

So, onLocationChanged is called only once and only after I press "start". It's supposed to be called automatically every time the location has changed, right? In my case, it's not.
Please help me.

Solution

Problem seems to be solved. In onCreate, I added:

Criteria crit = new Criteria();
crit.setAccuracy(Criteria.ACCURACY_FINE);
best = mgr.getBestProvider(crit, false);
mgr.requestLocationUpdates(best, 0, 1, locationListener);

onLocationChanged now looks like that:

@Override
public void onLocationChanged(Location location) {
    i++;
    nextPoint = overlay.getMyLocation();
    latitude = nextPoint.getLatitudeE6();
    longtitude = nextPoint.getLongitudeE6();
    lastPoint = new GeoPoint((int) latitude, (int) longtitude);
    Points.add(lastPoint);
    MapOverlay mapOverlay = new MapOverlay(Points.get(i - 1), Points.get(i));
    map.getOverlays().add(mapOverlay);
    mMapController.animateTo(Points.get(i));
    nextPoint = null;
    lastPoint = null;
}

Also, very important methods:

@Override
protected void onResume() {
    super.onResume();
    mgr.requestLocationUpdates(best, 10000, 1, locationListener);
}

@Override
protected void onPause() {
    super.onPause();
    mgr.removeUpdates(locationListener);
}

And also some new permissions:

<uses-permission android:name="android.permission.ACCESS_GPS" />
        <uses-permission android:name="android.permission.ACCESS_LOCATION" />
        <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
        <uses-permission android:name="android.permission.INTERNET" />

Comments

[lomza]

ACCESS_COARSE_LOCATION is not necessary if you use ACCESS_FINE_LOCATION. Just for you to know ;)

[gumuruh]

@lomza, what is the difference?

[lomza]

@gumuruh, because ACCESS_FINE_LOCATION includes WiFi, cell and GPS location and ACCESS_COARSE_LOCATION includes just cell and WiFi. So the first permission basically includes the second one.

[gumuruh]

@lomza, that's good clarification. THanks for it. I just know it from you. :D

[Ravi Vaniya]

what is best , mgr and locationListener ?

[fklappan]

@RaviVaniya mgr is the LocationManager which you can obtain using locationManager = (LocationManager) requireContext().getSystemService(Context.LOCATION_SERVICE); - locationListener is your implementation of the Android LocationListener interface and best is a String containing the name of the provider which best meets the criteria you passed.