OnLocationChanged method not called in MyLocationOverlay when Gps is Off

Question

On the documantation it says mylocationoverlay onlocationchanged method uses both gps and network provider when ACCESS_FINE_LOCATION permission defined. When Gps is on everything is fine, onlocationchanged working but when i close gps onlocationchanged never called. Is there any problem in my class? Do i have to implement locationlistener or locationmanager?

import android.content.Context;
import android.location.Location;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;
import com.google.android.maps.Overlay;

public class FLOverlay extends MyLocationOverlay {

public FLOverlay(Context context, MapView mapView) {
    super(context, mapView);

    enableCompass();
    enableMyLocation();
}

@Override           
public synchronized void onLocationChanged(Location location) {

     /***/
}

@Override
public boolean onTap(GeoPoint p, MapView map) {

            /***/

}

}