How to draw interactive Polyline on route google maps v2 android

Question

i have the following code which is drawing polylines for me and working fine, But the problem is that its not drawing interactive polylines, drawn lines are missing some pixels !

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.List;  import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.json.JSONArray; import org.json.JSONObject;  import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.SupportMapFragment; import com.google.android.gms.maps.model.BitmapDescriptorFactory; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.MarkerOptions; import com.google.android.gms.maps.model.Polyline; import com.google.android.gms.maps.model.PolylineOptions;  import android.app.ProgressDialog; import android.content.Context; import android.graphics.Color; import android.os.AsyncTask; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button;  public class testRoute extends FragmentActivity implements OnClickListener {      private GoogleMap myMap;     Polyline line;     Context context;      // Static LatLng     LatLng startLatLng = new LatLng(30.707104, 76.690749);     LatLng endLatLng = new LatLng(30.721419, 76.730017);      public void onCreate(Bundle bd) {         super.onCreate(bd);         setContentView(R.layout.passanger_home_call);         context = testRoute.this;          // Temp GetTrails Button         Button btntemp = (Button) findViewById(R.id.btn_pass_home_call_temp);         btntemp.setOnClickListener(this);          // GoogleMap myMap         myMap = ((SupportMapFragment) getSupportFragmentManager()                 .findFragmentById(R.id.map_pass_home_call)).getMap();         myMap.setMyLocationEnabled(true);         myMap.moveCamera(CameraUpdateFactory.newLatLng(startLatLng));         myMap.animateCamera(CameraUpdateFactory.zoomTo(12));          // Now auto clicking the button         btntemp.performClick();     }      @Override     public void onClick(View v) {          switch (v.getId()) {         case R.id.btn_pass_home_call_temp:             String urlTopass = makeURL(startLatLng.latitude,                     startLatLng.longitude, endLatLng.latitude,                     endLatLng.longitude);             new connectAsyncTask(urlTopass).execute();             break;          default:             break;         }      }      private class connectAsyncTask extends AsyncTask<Void, Void, String> {         private ProgressDialog progressDialog;         String url;          connectAsyncTask(String urlPass) {             url = urlPass;         }          @Override         protected void onPreExecute() {             // TODO Auto-generated method stub             super.onPreExecute();             progressDialog = new ProgressDialog(context);             progressDialog.setMessage("Fetching route, Please wait...");             progressDialog.setIndeterminate(true);             progressDialog.show();         }          @Override         protected String doInBackground(Void... params) {             JSONParser jParser = new JSONParser();             String json = jParser.getJSONFromUrl(url);             return json;         }          @Override         protected void onPostExecute(String result) {             super.onPostExecute(result);             progressDialog.hide();             if (result != null) {                 drawPath(result);             }         }     }      public String makeURL(double sourcelat, double sourcelog, double destlat,             double destlog) {         StringBuilder urlString = new StringBuilder();         urlString.append("http://maps.googleapis.com/maps/api/directions/json");         urlString.append("?origin=");// from         urlString.append(Double.toString(sourcelat));         urlString.append(",");         urlString.append(Double.toString(sourcelog));         urlString.append("&destination=");// to         urlString.append(Double.toString(destlat));         urlString.append(",");         urlString.append(Double.toString(destlog));         urlString.append("&sensor=false&mode=driving&alternatives=true");         return urlString.toString();     }      public class JSONParser {          InputStream is = null;         JSONObject jObj = null;         String json = "";          // constructor         public JSONParser() {         }          public String getJSONFromUrl(String url) {              // Making HTTP request             try {                 // defaultHttpClient                 DefaultHttpClient httpClient = new DefaultHttpClient();                 HttpPost httpPost = new HttpPost(url);                  HttpResponse httpResponse = httpClient.execute(httpPost);                 HttpEntity httpEntity = httpResponse.getEntity();                 is = httpEntity.getContent();              } catch (UnsupportedEncodingException e) {                 e.printStackTrace();             } catch (ClientProtocolException e) {                 e.printStackTrace();             } catch (IOException e) {                 e.printStackTrace();             }             try {                 BufferedReader reader = new BufferedReader(                         new InputStreamReader(is, "iso-8859-1"), 8);                 StringBuilder sb = new StringBuilder();                 String line = null;                 while ((line = reader.readLine()) != null) {                     sb.append(line + "\n");                 }                  json = sb.toString();                 is.close();             } catch (Exception e) {                 Log.e("Buffer Error", "Error converting result " + e.toString());             }             return json;          }     }      public void drawPath(String result) {         if (line != null) {             myMap.clear();         }         myMap.addMarker(new MarkerOptions().position(endLatLng).icon(                 BitmapDescriptorFactory.fromResource(R.drawable.redpin_marker)));         myMap.addMarker(new MarkerOptions().position(startLatLng).icon(                 BitmapDescriptorFactory.fromResource(R.drawable.redpin_marker)));         try {             // Tranform the string into a json object             final JSONObject json = new JSONObject(result);             JSONArray routeArray = json.getJSONArray("routes");             JSONObject routes = routeArray.getJSONObject(0);             JSONObject overviewPolylines = routes                     .getJSONObject("overview_polyline");             String encodedString = overviewPolylines.getString("points");             List<LatLng> list = decodePoly(encodedString);              for (int z = 0; z < list.size() - 1; z++) {                 LatLng src = list.get(z);                 LatLng dest = list.get(z + 1);                 line = myMap.addPolyline(new PolylineOptions()                         .add(new LatLng(src.latitude, src.longitude),                                 new LatLng(dest.latitude, dest.longitude))                         .width(5).color(Color.BLUE).geodesic(true));             }          } catch (Exception e) {             e.printStackTrace();         }     }      private List<LatLng> decodePoly(String encoded) {          List<LatLng> poly = new ArrayList<LatLng>();         int index = 0, len = encoded.length();         int lat = 0, lng = 0;          while (index < len) {             int b, shift = 0, result = 0;             do {                 b = encoded.charAt(index++) - 63;                 result |= (b & 0x1f) << shift;                 shift += 5;             } while (b >= 0x20);             int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));             lat += dlat;              shift = 0;             result = 0;             do {                 b = encoded.charAt(index++) - 63;                 result |= (b & 0x1f) << shift;                 shift += 5;             } while (b >= 0x20);             int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));             lng += dlng;              LatLng p = new LatLng((((double) lat / 1E5)),                     (((double) lng / 1E5)));             poly.add(p);         }          return poly;     } } 

Code is Working fine And Drawing Route from one place to another but not drawing the interactive Routes

Screent Shot :-

I think problem is with my drawPath() method :

public void drawPath(String result) {         if (line != null) {             myMap.clear();         }         myMap.addMarker(new MarkerOptions().position(endLatLng).icon(                 BitmapDescriptorFactory.fromResource(R.drawable.redpin_marker)));         myMap.addMarker(new MarkerOptions().position(startLatLng).icon(                 BitmapDescriptorFactory.fromResource(R.drawable.redpin_marker)));         try {             // Tranform the string into a json object             final JSONObject json = new JSONObject(result);             JSONArray routeArray = json.getJSONArray("routes");             JSONObject routes = routeArray.getJSONObject(0);             JSONObject overviewPolylines = routes                     .getJSONObject("overview_polyline");             String encodedString = overviewPolylines.getString("points");             List<LatLng> list = decodePoly(encodedString);              for (int z = 0; z < list.size() - 1; z++) {                 LatLng src = list.get(z);                 LatLng dest = list.get(z + 1);                 line = myMap.addPolyline(new PolylineOptions()                         .add(new LatLng(src.latitude, src.longitude),                                 new LatLng(dest.latitude, dest.longitude))                         .width(5).color(Color.BLUE).geodesic(true));             }          } catch (Exception e) {             e.printStackTrace();         }     } 

Ignore The markers just suggest me about adding interactive polyline?

Answer 1

Instead of creating too many short Polylines just create one like here:

PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true); for (int z = 0; z < list.size(); z++) {     LatLng point = list.get(z);     options.add(point); } line = myMap.addPolyline(options); 

I'm also not sure you should use geodesic when your points are so close to each other.

Answer 2

I've created a couple of map tutorials that will cover what you need

Animating the map describes howto create polylines based on a set of LatLngs. Using Google APIs on your map : Directions and Places describes howto use the Directions API and animate a marker along the path.

Take a look at these 2 tutorials and the Github project containing the sample app.

It contains some tips to make your code cleaner and more efficient:

• Using Google HTTP Library for more efficient API access and easy JSON handling.
• Using google-map-utils library for maps-related functions (like decoding the polylines)
• Animating markers