Google Maps Android API v2 creating a new LocationSource

Question

A LocationSource is defined in Google Maps Android API v2.

It is used for googlemap as the location provider. By default, the location source is provided by the gps module on the phone.

But now I want to use a another Location source, the location data will be sent to android device periodically.

I have no idea how to implement this interface. Are there any example out there? Can anyone help me with it? The document did not say anything about it.

Answer 1

Here is a simple implementation of LocationSource interface. In my case I'm registering both GPS and Network location providers. As mentioned by @CommonsWare, implementation may very depending on your needs. I would suggest reading official documentation about Location service in order to better understand how to utilize your needs and save some battery power

public class CurrentLocationProvider implements LocationSource, LocationListener
{
    private OnLocationChangedListener listener;
    private LocationManager locationManager;

    public CurrentLocationProvider(Context context)
    {
        locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    }

    @Override
    public void activate(OnLocationChangedListener listener)
    {
        this.listener = listener;
        LocationProvider gpsProvider = locationManager.getProvider(LocationManager.GPS_PROVIDER);
        if(gpsProvider != null)
        {
            locationManager.requestLocationUpdates(gpsProvider.getName(), 0, 10, this);
        }

        LocationProvider networkProvider = locationManager.getProvider(LocationManager.NETWORK_PROVIDER);;
        if(networkProvider != null) {
            locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000 * 60 * 5, 0, this);
        }
    }

    @Override
    public void deactivate()
    {
        locationManager.removeUpdates(this);
    }

    @Override
    public void onLocationChanged(Location location)
    {
        if(listener != null)
        {
            listener.onLocationChanged(location);
        }
    }

    @Override
    public void onProviderDisabled(String provider)
    {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider)
    {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras)
    {
        // TODO Auto-generated method stub

    }
}

And here is how I would use this class:

protected void setUpMap() {
    //init routine
    .......

    this.map.setLocationSource(new CurrentLocationProvider(this));
    .......       
}

EDIT Please not that this solution is obsolete! You need to use FusedLocationProviderApi in conjunction with GoogleApiClient for tracking current location

Answer 2

Are there any example out there?

There is not much to the interface, and its implementation is very dependent upon your app.

This sample project implements the LocationSource interface on the main activity:

  @Override
  public void activate(OnLocationChangedListener listener) {
    this.mapLocationListener=listener;
  }

  @Override
  public void deactivate() {
    this.mapLocationListener=null;
  }

All I do is hold onto the OnLocationChangedListener that we are handed in activate(). Then, when you have a location fix that you wish to feed to the map, call onLocationChanged() on that listener, supplying a Location object (the same Location object you might get back from LocationManager).

Answer 3

Here is the solution using the FusedLocationProviderApi:

Android: Google Maps location with low battery usage