Map View draw directions using google Directions API - decoding polylines

user_846601 0
Viewed 15560

I'm trying to use the Google directions API to show directions on my mapview but I am having difficulties getting the data from the JSON response. I can get the "levels" and "points" strings but can't work out how to decode them to points on the map.

Any help would be much appreciated.

polyline android-mapview google-maps android json
4 Answers

below code decode any encoded polyline

private List<LatLng> decodePoly(String encoded) {
    List<LatLng> poly = new ArrayList<>();
    int index = 0, len = encoded.length();
    int lat = 0, lng = 0;

    while (index < len) {
        int b=0, shift = 0, result = 0;
        do {
            if(index<len) {
                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 {
            if(index<len) {
                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;
}
user_32415820
Related