android get and parse Google Directions

Question

google Directions API

I read this guide now I can build a correct request to receive the xml file containg the directions from address A to address B. What I need is

Answer 1

you might want to have a quick view of the route that will be created by the waypoint_polyline and the coordinate list directly. For this google have release decoding api "Interactive Polyline Encoder Utility"

You can paste the waypoint_polyline value to Encoded Polyline text field at address Interactive Polyline Encoder Utility

Answer 2

I've tweaked urobo's answer above (very slightly) to give you LatLngs which you'll want for Google Maps for Android V2:

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;
}

Answer 3

I was also trying to use the Direction Api of Google in Android. So I made an open source project to help doing that. You can find it here:https://github.com/MathiasSeguy-Android2EE/GDirectionsApiUtils

How it works, definitly simply:

public class MainActivity extends ActionBarActivity implements DCACallBack{
/**
 * Get the Google Direction between mDevice location and the touched location using the     Walk
 * @param point
 */
private void getDirections(LatLng point) {
     GDirectionsApiUtils.getDirection(this, startPoint, endPoint, GDirectionsApiUtils.MODE_WALKING);
}

/*
 * The callback
 * When the directions is built from the google server and parsed, this method is called and give you the expected direction
 */
@Override
public void onDirectionLoaded(List<GDirection> directions) {        
    // Display the direction or use the DirectionsApiUtils
    for(GDirection direction:directions) {
        Log.e("MainActivity", "onDirectionLoaded : Draw GDirections Called with path " + directions);
        GDirectionsApiUtils.drawGDirection(direction, mMap);
    }
}

Answer 4

I found this example on the web I'll try to use it. polyline decoding example

private List<GeoPoint> decodePoly(String encoded) {

  List<GeoPoint> poly = new ArrayList<GeoPoint>();
  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;

      GeoPoint p = new GeoPoint((int) (((double) lat / 1E5) * 1E6),
           (int) (((double) lng / 1E5) * 1E6));
      poly.add(p);
  }

  return poly;
}