DirectionsJSONParser.java

/*
 * 	 This file is part of Find Your Friend.
 *
 *   Find Your Friend is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Find Your Friend is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with Find Your Friend.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.sgu.findyourfriend.utils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

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

public class DirectionsJSONParser {
	/**
	 * Receives a JSONObject and returns a list of lists containing latitude and
	 * longitude
	 */
	public List<List<HashMap<String, String>>> parse(JSONObject jObject) {

		List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String, String>>>();
		JSONArray jRoutes = null;
		JSONArray jLegs = null;
		JSONArray jSteps = null;
		JSONObject jDistance = null;
		JSONObject jDuration = null;
		JSONObject jMode = null;

		try {

			jRoutes = jObject.getJSONArray("routes");

			/** Traversing all routes */
			for (int i = 0; i < jRoutes.length(); i++) {
				jLegs = ((JSONObject) jRoutes.get(i)).getJSONArray("legs");

				List<HashMap<String, String>> path = new ArrayList<HashMap<String, String>>();

				/** Traversing all legs */
				for (int j = 0; j < jLegs.length(); j++) {

					/** Getting distance from the json data */
					jDistance = ((JSONObject) jLegs.get(j))
							.getJSONObject("distance");
					HashMap<String, String> hmDistance = new HashMap<String, String>();
					hmDistance.put("distance", jDistance.getString("text"));

					/** Getting duration from the json data */
					jDuration = ((JSONObject) jLegs.get(j))
							.getJSONObject("duration");
					HashMap<String, String> hmDuration = new HashMap<String, String>();
					hmDuration.put("duration", jDuration.getString("value"));

					// get start and end address 
					HashMap<String, String> hmAddress = new HashMap<String, String>();
					
					hmAddress.put("startAddress", ((JSONObject) jLegs.get(j))
							.getString("start_address"));
					
					hmAddress.put("endAddress", ((JSONObject) jLegs.get(j))
							.getString("end_address"));
					
					
					
					/** Adding distance object to the path */
					path.add(hmDistance);

					/** Adding duration object to the path */
					path.add(hmDuration);

					// adding start and end address 
					path.add(hmAddress);
					
					
					
					jSteps = ((JSONObject) jLegs.get(j)).getJSONArray("steps");

//					boolean isGetMode = false;
					
					/** Traversing all steps */
					for (int k = 0; k < jSteps.length(); k++) {
//						if (!isGetMode) {
//							HashMap<String, String> hmMode = new HashMap<String, String>();
//							
//							hmMode.put("travel_mode", ((JSONObject) jSteps
//									.get(k)).getString("travel_mode"));
//							
//							path.add(hmMode);
//							isGetMode = true;
//						}
						
						String polyline = "";
						polyline = (String) ((JSONObject) ((JSONObject) jSteps
								.get(k)).get("polyline")).get("points");
						List<LatLng> list = decodePoly(polyline);

						/** Traversing all points */
						for (int l = 0; l < list.size(); l++) {
							HashMap<String, String> hm = new HashMap<String, String>();
							hm.put("lat",
									Double.toString(((LatLng) list.get(l)).latitude));
							hm.put("lng",
									Double.toString(((LatLng) list.get(l)).longitude));
							path.add(hm);
						}
					}
				}
				routes.add(path);
			}

		} catch (JSONException e) {
			e.printStackTrace();
		} catch (Exception e) {
		}

		return routes;
	}

	/**
	 * Method to decode polyline points Courtesy :
	 * jeffreysambells.com/2010/05/27
	 * /decoding-polylines-from-google-maps-direction-api-with-java
	 * */
	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;
	}
}