How can I update my location with Google Maps?

Question

I know that if I use this, I can get my location, but how can I get it automatically or by clicking a button; How can I update my location?

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;

    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(this.getLocation(), 16));
    MarkerOptions a = new MarkerOptions().position(this.getLocation());
    m = mMap.addMarker(a);
}

private LatLng getLocation() {
    LatLng location = null;
    gps = new GPSTracker(MainActivity.this);
        if (gps.canGetLocation()) {
            double latitude = gps.getLatitude();
            double longitude = gps.getLongitude();
            location = new LatLng(latitude, longitude);
        return location;

    } else {
        gps.showSettingsAlert();
        location = new LatLng(-23.036602, -13.183594);
        return location;
    }
}

The only way I could do this was by restarting the activity, but I think this is not the best solution.