Location reset in Android Maps API

Question

My code creates a route between two points on the map at the coordinates I am trying to pass from the coordinate of my current location to fromPosition, using the low code. But he’s giving 0.0 on Log. i;

double lat;
double lng;

LatLng fromPosition = new LatLng(lat, lng);
LatLng toPosition = new LatLng(-5.082434, -42.807364);

But I need the co-penned fromPosition to be my current position.

Thanks for any help.

public class MapsActivity2 extends FragmentActivity  {

private GoogleMap map;

double lat;
double lng;

LatLng fromPosition = new LatLng(lat, lng);
LatLng toPosition = new LatLng(-5.082434, -42.807364);

ArrayList<LatLng> directionPoint;
Marker mPositionMarker;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps2);
    initializeMap();

    Log.i("david", "LATLNG= " + fromPosition);

    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    long tempo = 1000; //5 minutos
    float distancia = 1; // 30 metros

    map.setMyLocationEnabled(true);



    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER , tempo , distancia,  new LocationListener() {


        @Override
        public void onStatusChanged(String arg0, int arg1, Bundle arg2) {

        }

        @Override
        public void onProviderEnabled(String arg0) {
            Toast.makeText(getApplicationContext(), "GPS Habilitado", Toast.LENGTH_LONG).show();

        }

        @Override
        public void onProviderDisabled(String arg0) {
            Toast.makeText(getApplicationContext(), "GPS Desabilitado", Toast.LENGTH_LONG).show();
        }

        @Override
        public void onLocationChanged(Location location) {
            if (location == null)
                return;

             map.setMyLocationEnabled(true);

             lat = location.getLatitude();
             lng = location.getLongitude();


            map.moveCamera(CameraUpdateFactory.newLatLngZoom(new
                    LatLng(lat, lng), 16));

            if (mPositionMarker == null) {

                mPositionMarker = map.addMarker(new MarkerOptions()
                        .flat(true)
                        .icon(BitmapDescriptorFactory
                                .fromResource(R.drawable.car))
                        .anchor(0.5f, 0.5f)
                        .position(
                                new LatLng(location.getLatitude(), location
                                        .getLongitude())));
            }


            animateMarker(mPositionMarker, location); // Helper method for smooth
            // animation

            map.animateCamera(CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude())));

        }


        public void animateMarker(final Marker marker, final Location location) {
            final Handler handler = new Handler();
            final long start = SystemClock.uptimeMillis();
            final LatLng startLatLng = marker.getPosition();
            final double startRotation = marker.getRotation();
            final long duration = 500;

            final Interpolator interpolator = new LinearInterpolator();

            handler.post(new Runnable() {
                @Override
                public void run() {
                    long elapsed = SystemClock.uptimeMillis() - start;
                    float t = interpolator.getInterpolation((float) elapsed
                            / duration);

                    double lng = t * location.getLongitude() + (1 - t)
                            * startLatLng.longitude;
                    double lat = t * location.getLatitude() + (1 - t)
                            * startLatLng.latitude;

                    float rotation = (float) (t * location.getBearing() + (1 - t)
                            * startRotation);

                    marker.setPosition(new LatLng(lat, lng));
                    marker.setRotation(rotation);

                    if (t < 1.0) {
                        // Post again 16ms later.
                        handler.postDelayed(this, 16);
                    }
                }
            });
        }
    }, null);
}

private void initializeMap() {
    if (map == null) {
        map = ((SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map)).getMap();



        new WebserviceTask(this).execute();





    }
}


public void setDirectionPoints(ArrayList<LatLng> result) {
    directionPoint = new ArrayList<LatLng>();
    directionPoint = result;
}

protected void onResume() {
    super.onResume();
    initializeMap();
}

public class WebserviceTask extends
        AsyncTask<Void, Void, ArrayList<LatLng>> {
    MapsActivity2 mContext;
    PolylineOptions rectline;

    public WebserviceTask(MapsActivity2 context) {
        this.mContext = context;
    }

    @Override
    protected void onPostExecute(ArrayList<LatLng> result) {
        super.onPostExecute(result);
        if (result != null) {
            rectline = new PolylineOptions().width(10).color(Color.BLUE);

            for (int i = 0; i < result.size(); i++)
                rectline.add(result.get(i));
            map.addPolyline(rectline);
        }
    }

    @Override
    protected ArrayList<LatLng> doInBackground(Void... params) {
        GMapV2Direction md = new GMapV2Direction();
        Document doc = md.getDocument(fromPosition, toPosition,
                GMapV2Direction.MODE_DRIVING);
        if (doc != null) {
            ArrayList<LatLng> directionPoint = md.getDirection(doc);

            rectline = new PolylineOptions().width(10).color(Color.RED);

            for (int i = 0; i < directionPoint.size(); i++)
                rectline.add(directionPoint.get(i));

            return directionPoint;
        } else
            return null;
    }

}

}

Answer 1

In this section of your method

public void onLocationChanged(Location location) {
    if (location == null)
        return;

     map.setMyLocationEnabled(true);

     lat = location.getLatitude();
     lng = location.getLongitude();
}

you arrow the new lat and lng, but never a new fromLocation, ie it will always stay with 0,0;