in Android google maps api v2 for 4.0, show the routes from current location to given lat long

Question

For android in google maps api v2 its showing whole earth by following all the steps from here http://mobisys.in/blog/2012/12/google-rolls-out-android-maps-api-v2/ , can i zoom

Answer 1

Android maps api V2 have Polyline class to draw the route on a map.

Polyline line1 = map.addPolyline(new PolylineOptions()
 .add(new LatLng(50.5, 34.1), new LatLng(40.7, -74.0))
 .width(5)
 .color(0xFFFF0000));

Answer 2

Finally i solved this problem by using this code.. : try this class :

import java.io.InputStream;
import java.util.ArrayList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.google.android.gms.maps.model.LatLng;

import android.content.Context;
import android.util.Log;

public class GMapV2Direction {
    public final static String MODE_DRIVING = "driving";
    public final static String MODE_WALKING = "walking";

    public GMapV2Direction() { }

    public Document getDocument(LatLng start, LatLng end, String mode) {
        String url = "http://maps.googleapis.com/maps/api/directions/xml?" 
                + "origin=" + start.latitude + "," + start.longitude  
                + "&destination=" + end.latitude + "," + end.longitude 
                + "&sensor=false&units=metric&mode=driving";

        try {
            HttpClient httpClient = new DefaultHttpClient();
            HttpContext localContext = new BasicHttpContext();
            HttpPost httpPost = new HttpPost(url);
            HttpResponse response = httpClient.execute(httpPost, localContext);
            InputStream in = response.getEntity().getContent();
            DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document doc = builder.parse(in);
            return doc;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String getDurationText (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("duration");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "text"));
        Log.i("DurationText", node2.getTextContent());
        return node2.getTextContent();
    }

    public int getDurationValue (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("duration");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "value"));
        Log.i("DurationValue", node2.getTextContent());
        return Integer.parseInt(node2.getTextContent());
    }

    public String getDistanceText (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("distance");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "text"));
        Log.i("DistanceText", node2.getTextContent());
        return node2.getTextContent();
    }

    public int getDistanceValue (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("distance");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "value"));
        Log.i("DistanceValue", node2.getTextContent());
        return Integer.parseInt(node2.getTextContent());
    }

    public String getStartAddress (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("start_address");
        Node node1 = nl1.item(0);
        Log.i("StartAddress", node1.getTextContent());
        return node1.getTextContent();
    }

    public String getEndAddress (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("end_address");
        Node node1 = nl1.item(0);
        Log.i("StartAddress", node1.getTextContent());
        return node1.getTextContent();
    }

    public String getCopyRights (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("copyrights");
        Node node1 = nl1.item(0);
        Log.i("CopyRights", node1.getTextContent());
        return node1.getTextContent();
    }

    public ArrayList<LatLng> getDirection (Document doc) {
        NodeList nl1, nl2, nl3;
        ArrayList<LatLng> listGeopoints = new ArrayList<LatLng>();
        nl1 = doc.getElementsByTagName("step");
        if (nl1.getLength() > 0) {
            for (int i = 0; i < nl1.getLength(); i++) {
                Node node1 = nl1.item(i);
                nl2 = node1.getChildNodes();

                Node locationNode = nl2.item(getNodeIndex(nl2, "start_location"));
                nl3 = locationNode.getChildNodes();
                Node latNode = nl3.item(getNodeIndex(nl3, "lat"));
                double lat = Double.parseDouble(latNode.getTextContent());
                Node lngNode = nl3.item(getNodeIndex(nl3, "lng"));
                double lng = Double.parseDouble(lngNode.getTextContent());
                listGeopoints.add(new LatLng(lat, lng));

                locationNode = nl2.item(getNodeIndex(nl2, "polyline"));
                nl3 = locationNode.getChildNodes();
                latNode = nl3.item(getNodeIndex(nl3, "points"));
                ArrayList<LatLng> arr = decodePoly(latNode.getTextContent());
                for(int j = 0 ; j < arr.size() ; j++) {
                    listGeopoints.add(new LatLng(arr.get(j).latitude, arr.get(j).longitude));
                }

                locationNode = nl2.item(getNodeIndex(nl2, "end_location"));
                nl3 = locationNode.getChildNodes();
                latNode = nl3.item(getNodeIndex(nl3, "lat"));
                lat = Double.parseDouble(latNode.getTextContent());
                lngNode = nl3.item(getNodeIndex(nl3, "lng"));
                lng = Double.parseDouble(lngNode.getTextContent());
                listGeopoints.add(new LatLng(lat, lng));
            }
        }

        return listGeopoints;
    }

    private int getNodeIndex(NodeList nl, String nodename) {
        for(int i = 0 ; i < nl.getLength() ; i++) {
            if(nl.item(i).getNodeName().equals(nodename))
                return i;
        }
        return -1;
    }

    private ArrayList<LatLng> decodePoly(String encoded) {
        ArrayList<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 position = new LatLng((double) lat / 1E5, (double) lng / 1E5);
            poly.add(position);
        }
        return poly;
    }
}

you can get sample code here

LatLng fromPosition = new LatLng(13.687140112679154, 100.53525868803263);
LatLng toPosition = new LatLng(13.683660045847258, 100.53900808095932);

GoogleMap mMap = ((SupportMapFragment)getSupportFragmentManager()
        .findFragmentById(R.id.map)).getMap();
GMapV2Direction md = new GMapV2Direction();

Document doc = md.getDocument(fromPosition, toPosition, GMapV2Direction.MODE_DRIVING);
ArrayList<LatLng> directionPoint = md.getDirection(doc);
PolylineOptions rectLine = new PolylineOptions().width(3).color(Color.RED);

for(int i = 0 ; i < directionPoint.size() ; i++) {          
rectLine.add(directionPoint.get(i));
}

mMap.addPolyline(rectLine);

:- https://docs.google.com/uc?export=download&id=0B0MdROeR0jbvWVVNUV9jbk1OeEE