Draw a path through a list of Latlng in Google Map v2

Question

Sorry about my English grammar ! If u can't understand something, free to ask me again !

I use Volley to draw a path between two point in Google Map

 private void getPath(LatLng origin, LatLng dest) {
    // Origin of route
    String str_origin = "origin=" + origin.latitude + "," + origin.longitude;

    // Destination of route
    String str_dest = "destination=" + dest.latitude + "," + dest.longitude;

    // Sensor enabled
    String sensor = "sensor=false";

    // Building the parameters to the web service
    String parameters = str_origin + "&" + str_dest + "&" + sensor;

    // Output format
    String output = "json";

    // Building the url to the web service
    String url = "https://maps.googleapis.com/maps/api/directions/" + output + "?" + parameters;

    showDialog();
    JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.GET,
            url, null, new Response.Listener<JSONObject>() {

        @Override
        public void onResponse(JSONObject response) {
            DirectionsJSONParser parser = new DirectionsJSONParser();
            routes = parser.parse(response);

            List<LatLng> points = null;
            PolylineOptions lineOptions = null;
            MarkerOptions markerOptions = new MarkerOptions();

            // Traversing through all the routes
            for (int i = 0; i < routes.size(); i++) {
                points = new ArrayList<LatLng>();
                lineOptions = new PolylineOptions();

                // Fetching i-th route
                List<HashMap<String, String>> path = routes.get(i);

                // Fetching all the points in i-th route
                for (int j = 0; j < path.size(); j++) {
                    HashMap<String, String> point = path.get(j);

                    double lat = Double.parseDouble(point.get("lat"));
                    double lng = Double.parseDouble(point.get("lng"));
                    LatLng position = new LatLng(lat, lng);

                    points.add(position);
                }

                // Adding all the points in the route to LineOptions
                lineOptions.addAll(points);
                lineOptions.width(2);
                lineOptions.color(Color.RED);
            }
            if (mGoogleMap != null) {
                // Drawing polyline in the Google Map for the i-th route
                mGoogleMap.addPolyline(lineOptions);
            }

            hideDialog();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d("APP", "Error: " + error.getMessage());
            Toast.makeText(getApplicationContext(),
                    error.getMessage(), Toast.LENGTH_SHORT).show();
            // hide the progress dialog
            hideDialog();
        }
    });
    // Adding request to request queue
    App.getInstance().addToRequestQueue(jsonObjReq);
}

This code works correctly. But now, I have a list of point (Numbers of point > 2).

How can I draw a path through all points.

I try to write an Asyntask and in doInBackground() function I loop "getPath(x1, x2)" but it's not work.

In my understanding : volley run in background, put it inside an Asyntask (also run in background ) ????!!!!!!

Answer 1

First of all bind click listener on your map

googleMap.setOnMapClickListener(this);

Then, add all point in a list and then draw polyline b/w them.As I am doing below

@Override  
 public void onMapClick(LatLng latlan) {  
  
   latLang.add(latlan);  
   GeoPoint point = new GeoPoint(latlan.latitude, latlan.longitude);  
   listPoints.add((IGeoPoint) point);  
   MarkerOptions marker = new MarkerOptions().position(latlan);  
   googleMap.addMarker(marker);  
   if (latLang.size() > 1) {  
    PolylineOptions polyLine = new PolylineOptions().color(  
      Color.BLUE).width((float) 7.0);  
    polyLine.add(latlan);  
    LatLng previousPoint = latLang.get(latLang.size() - 2);  
    polyLine.add(previousPoint);  
    googleMap.addPolyline(polyLine);  
     }  
 }