Question

I am able to draw path between two sets of geo-coordinates from reference of
j2memaprouteprovider.
I am able to get current location latitude and longitude.
How do i implement these coordinates in the following class to get path drawn from current position to target position.

MapRouteActivity.java

public class MapRouteActivity extends MapActivity {

LinearLayout linearLayout;
MapView mapView;
private Road mRoad;
static Context context = null;
String GPSPROVIDER = LocationManager.GPS_PROVIDER;
private static final long MIN_GEOGRAPHIC_POOLING_TIME_PERIOD = 10000;
private static final float MIN_GEOGRAPHIC_POOLING_DISTANCE = (float) 5.0;
public LocationManager gpsLocationManager;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    mapView = (MapView) findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true);

    context = this;

    /* Get a listener for GPS */
    LocationListener gpsLocationListener = null;

    gpsLocationListener = new GpsLocationListener(this);

    /* Start Location Service for GPS */
    gpsLocationManager = (LocationManager) this
            .getSystemService(Context.LOCATION_SERVICE);

    /* Register GPS listener with Location Manager */
    gpsLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
            MIN_GEOGRAPHIC_POOLING_TIME_PERIOD,
            MIN_GEOGRAPHIC_POOLING_DISTANCE, gpsLocationListener);
    if (gpsLocationManager == null) {
        gpsLocationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER,
                MIN_GEOGRAPHIC_POOLING_TIME_PERIOD,
                MIN_GEOGRAPHIC_POOLING_DISTANCE, gpsLocationListener);
    }

    boolean isAvailableGps = gpsLocationManager
            .isProviderEnabled(GPSPROVIDER);

    if (isAvailableGps) {

        Location loc = gpsLocationManager.getLastKnownLocation("gps");

        if (loc != null) {

            double lattitude = loc.getLatitude();
            double longitude = loc.getLongitude();

            Toast.makeText(
                    MapRouteActivity.this,
                    "Longitude iss  " + lattitude + "   Latitude iss   "
                            + longitude, Toast.LENGTH_LONG).show();

        }
    }
    new Thread() {
        @Override
        public void run() {
            double fromLat = 49.85, fromLon = 24.016667, toLat = 50.45, toLon = 30.523333;
            String url = RoadProvider
                    .getUrl(fromLat, fromLon, toLat, toLon);
            InputStream is = getConnection(url);
            mRoad = RoadProvider.getRoute(is);
            mHandler.sendEmptyMessage(0);
        }
    }.start();

}

Handler mHandler = new Handler() {
    public void handleMessage(android.os.Message msg) {
        TextView textView = (TextView) findViewById(R.id.description);
        textView.setText(mRoad.mName + " " + mRoad.mDescription);
        MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
        List<Overlay> listOfOverlays = mapView.getOverlays();
        listOfOverlays.clear();
        listOfOverlays.add(mapOverlay);
        mapView.invalidate();
    };
};

private InputStream getConnection(String url) {
    InputStream is = null;
    try {
        URLConnection conn = new URL(url).openConnection();
        is = conn.getInputStream();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return is;
}

@Override
protected boolean isRouteDisplayed() {
    return false;
}

public static class GpsLocationListener implements LocationListener {
    private ImageView mCurrentPointer;

    public GpsLocationListener(Context context) {

    }

    public void onLocationChanged(Location loc) {

        if (loc != null) {

            double latitude = loc.getLatitude();
            double longitude = loc.getLongitude();
            GeoPoint point = new GeoPoint((int) (latitude * 1E6),
                    (int) (longitude * 1E6));
            Toast.makeText(
                    context,
                    "Longitude is  " + longitude + "   Latitude is   "
                            + latitude, Toast.LENGTH_LONG).show();
        }

    }

    @Override
    public void onProviderDisabled(String provider) {

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

}
}

class MapOverlay extends com.google.android.maps.Overlay {
Road mRoad;
ArrayList<GeoPoint> mPoints;

public MapOverlay(Road road, MapView mv) {
    mRoad = road;
    if (road.mRoute.length > 0) {
        mPoints = new ArrayList<GeoPoint>();
        for (int i = 0; i < road.mRoute.length; i++) {
            mPoints.add(new GeoPoint((int) (road.mRoute[i][1] * 1000000),
                    (int) (road.mRoute[i][0] * 1000000)));
        }
        int moveToLat = (mPoints.get(0).getLatitudeE6() + (mPoints.get(
                mPoints.size() - 1).getLatitudeE6() - mPoints.get(0)
                .getLatitudeE6()) / 2);
        int moveToLong = (mPoints.get(0).getLongitudeE6() + (mPoints.get(
                mPoints.size() - 1).getLongitudeE6() - mPoints.get(0)
                .getLongitudeE6()) / 2);
        GeoPoint moveTo = new GeoPoint(moveToLat, moveToLong);

        MapController mapController = mv.getController();
        mapController.animateTo(moveTo);
        mapController.setZoom(7);
    }
    }

@Override
public boolean draw(Canvas canvas, MapView mv, boolean shadow, long when) {
    super.draw(canvas, mv, shadow);
    drawPath(mv, canvas);
    return true;
}

public void drawPath(MapView mv, Canvas canvas) {
    int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
    Paint paint = new Paint();
    paint.setColor(Color.GREEN);
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(3);
    for (int i = 0; i < mPoints.size(); i++) {
        Point point = new Point();
        mv.getProjection().toPixels(mPoints.get(i), point);
        x2 = point.x;
        y2 = point.y;
        if (i > 0) {
            canvas.drawLine(x1, y1, x2, y2, paint);
        }
        x1 = x2;
        y1 = y2;
    }
}
}

I want to assign current position lattiude and longitude value to fromLat and fronLon variable in above code here:

new Thread() {
        @Override
        public void run() {
            double fromLat = 49.85, fromLon = 24.016667, toLat = 50.45, toLon = 30.523333;
            String url = RoadProvider
                    .getUrl(fromLat, fromLon, toLat, toLon);
            InputStream is = getConnection(url);
            mRoad = RoadProvider.getRoute(is);
            mHandler.sendEmptyMessage(0);
        }
    }.start();

Help !!

Answer 1

Its very Simple—

Make your Activity like this:–

 public class GoogleMapLocationActivity extends MapActivity {

 private LocationManager myLocationManager;
 private LocationListener myLocationListener;
 private TextView myLongitude, myLatitude;
 private MapView myMapView;
 private MapController myMapController;
 LinearLayout zoomLayout;
 GeoPoint myLastPosition;
 AddItemizedOverlay mapOvlay;

 private void CenterLocatio(GeoPoint centerGeoPoint)
 {
  myMapController.animateTo(centerGeoPoint);

  List<Overlay> mapOverlays = myMapView.getOverlays();
  Drawable drawable = this.getResources().getDrawable(R.drawable.map_point);

  if(myLastPosition != null){
  mapOvlay = new AddItemizedOverlay(myLastPosition ,centerGeoPoint,drawable );
  OverlayItem overlayitem = new OverlayItem(centerGeoPoint,"","" );
  mapOvlay.addOverlay(overlayitem);
  mapOverlays.add(mapOvlay);
  }
      myLastPosition = centerGeoPoint;

};

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  myMapView = (MapView)findViewById(R.id.mapview);
         myLastPosition = null;
     myMapController = myMapView.getController();
     myMapController.setZoom(18); //Fixed Zoom Level

  myLocationManager = (LocationManager)getSystemService(
    Context.LOCATION_SERVICE);

  myLocationListener = new MyLocationListener();

  myLocationManager.requestLocationUpdates(
    LocationManager.GPS_PROVIDER,
    0,
    0,
    myLocationListener);

 private class MyLocationListener implements LocationListener{

      public void onLocationChanged(Location argLocation) {
        GeoPoint myGeoPoint = new GeoPoint(
        (int)(argLocation.getLatitude()*1000000),
         (int)(argLocation.getLongitude()*1000000));

     GeoPoint newGeoPoint = new  GeoPoint(myGeoPoint.getLatitudeE6() ,myGeoPoint.getLongitudeE6());
   CenterLocatio(newGeoPoint);
  }

  public void onProviderDisabled(String provider) {
      Toast.makeText(getBaseContext(),"GPS Disabled" ,Toast.LENGTH_SHORT).show();
  }

  public void onProviderEnabled(String provider) {
      Toast.makeText(getBaseContext(),"GPS Enabled" ,Toast.LENGTH_SHORT).show();
  }

  public void onStatusChanged(String provider,
    int status, Bundle extras) {
      Toast.makeText(getBaseContext(),"GPS Unavailable" ,Toast.LENGTH_SHORT).show();
  }
 }

 @Override
 protected boolean isRouteDisplayed() {
  return false;
 };

}

AddItemizedOverlay.class—–

public class AddItemizedOverlay extends ItemizedOverlay<OverlayItem> {

       private ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>();

       private Context context;
       private GeoPoint mGpt1;
       private GeoPoint mGpt2;

       public AddItemizedOverlay(GeoPoint gp1,GeoPoint gp2, Drawable defaultMarker) {

            super(boundCenterBottom(defaultMarker));
             mGpt1 = gp1;
             mGpt2 = gp2;
        }


       public AddItemizedOverlay(Drawable defaultMarker) {
            super(boundCenterBottom(defaultMarker));
       }

       public AddItemizedOverlay(Drawable defaultMarker, Context context) {
            this(defaultMarker);
            this.context = context;
       }

       @Override
       protected OverlayItem createItem(int i) {
          return mapOverlays.get(i);
       }

       @Override
       public int size() {
          return mapOverlays.size();
       }

       @Override
       protected boolean onTap(int index) {
          Log.e("Tap", "Tap Performed");
          return true;
       }

       public void addOverlay(OverlayItem overlay) {
          mapOverlays.add(overlay);
           this.populate();
       }

       public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                long when) {
             super.draw(canvas, mapView, shadow);
             Paint paint;
             paint = new Paint();
             paint.setColor(Color.RED);
             paint.setAntiAlias(true);
             paint.setStyle(Style.STROKE);
             paint.setStrokeWidth(2);
             Point pt1 = new Point();
             Point pt2 = new Point();
             Projection projection = mapView.getProjection();
             projection.toPixels(mGpt1, pt1);
             projection.toPixels(mGpt2, pt2);
             canvas.drawLine(pt1.x, pt1.y, pt2.x, pt2.y, paint);
             return true;
          }
    }

Hope it will help you…