Google Maps Android V2 et la Direction de l'API

Je suis le développement d'une application où j'ai besoin de connaître le chemin d'accès entre l'utilisateur actuel posistion et d'un point d'intérêt.

Je suis sous android 2.3.3, google maps android v2 et la direction de l'api.
Mon problème est que tout le code que j'ai trouvé est pour l'ancienne version de la carte, et j'ai aussi essayé d'adapter le code, mais j'ai échoué. J'ai essayer de changer GeoPoint (non pris en charge dans cette nouvelle versione) dans LatLng.
le problème est que je ne peux pas afficher le chemin d'accès, pour le faire j'ai créer une nouvelle polyligne et je l'ajouter à la carte.

je poste mon code:

Analyseur:

public interface Parser {
    public Route parse();
}

XMLParser

public class XMLParser {
    //names of the XML tags
    protected static final String MARKERS = "markers";
    protected static final String MARKER = "marker";

    protected URL feedUrl;

    protected XMLParser(final String feedUrl) {
            try {
                    this.feedUrl = new URL(feedUrl);
            } catch (MalformedURLException e) {
                    Log.e(e.getMessage(), "XML parser - " + feedUrl);
            }
    }

    protected InputStream getInputStream() {
            try {
                    return feedUrl.openConnection().getInputStream();
            } catch (IOException e) {
                    Log.e(e.getMessage(), "XML parser - " + feedUrl);
                    return null;
            }
    }
}

JsonParser (parse le google direction json)

public class JsonParser extends XMLParser implements Parser {
/** Distance covered. **/
private int distance;
public JsonParser(String feedUrl) {
super(feedUrl);
}
/**
* Parses a url pointing to a Google JSON object to a Route object.
* @return a Route object based on the JSON object.
*/
public Route parse() {
//turn the stream into a string
final String result = convertStreamToString(this.getInputStream());
//Create an empty route
final Route route = new Route();
//Create an empty segment
final Segment segment = new Segment();
try {
//Tranform the string into a json object
final JSONObject json = new JSONObject(result);
//Get the route object
final JSONObject jsonRoute = json.getJSONArray("routes").getJSONObject(0);
//Get the leg, only one leg as we don't support waypoints
final JSONObject leg = jsonRoute.getJSONArray("legs").getJSONObject(0);
//Get the steps for this leg
final JSONArray steps = leg.getJSONArray("steps");
//Number of steps for use in for loop
final int numSteps = steps.length();
//Set the name of this route using the start & end addresses
route.setName(leg.getString("start_address") + " to " + leg.getString("end_address"));
//Get google's copyright notice (tos requirement)
route.setCopyright(jsonRoute.getString("copyrights"));
//Get the total length of the route.
route.setLength(leg.getJSONObject("distance").getInt("value"));
//Get any warnings provided (tos requirement)
if (!jsonRoute.getJSONArray("warnings").isNull(0)) {
route.setWarning(jsonRoute.getJSONArray("warnings").getString(0));
}
/* Loop through the steps, creating a segment for each one and
* decoding any polylines found as we go to add to the route object's
* map array. Using an explicit for loop because it is faster!
*/
for (int i = 0; i < numSteps; i++) {
//Get the individual step
final JSONObject step = steps.getJSONObject(i);
//Get the start position for this step and set it on the segment
final JSONObject start = step.getJSONObject("start_location");
final LatLng position = new LatLng(start.getDouble("lat"), start.getDouble("lng"));
segment.setPoint(position);
//Set the length of this segment in metres
final int length = step.getJSONObject("distance").getInt("value");
distance += length;
segment.setLength(length);
segment.setDistance(distance/1000);
//Strip html from google directions and set as turn instruction
segment.setInstruction(step.getString("html_instructions").replaceAll("<(.*?)*>", ""));
//Retrieve & decode this segment's polyline and add it to the route.
route.addPoints(decodePolyLine(step.getJSONObject("polyline").getString("points")));
//Push a copy of the segment to the route
route.addSegment(segment.copy());
}
} catch (JSONException e) {
Log.e(e.getMessage(), "Google JSON Parser - " + feedUrl);
}
return route;
}
/**
* Convert an inputstream to a string.
* @param input inputstream to convert.
* @return a String of the inputstream.
*/
private static String convertStreamToString(final InputStream input) {
final BufferedReader reader = new BufferedReader(new InputStreamReader(input));
final StringBuilder sBuf = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sBuf.append(line);
}
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
} finally {
try {
input.close();
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
}
}
return sBuf.toString();
}
/**
* Decode a polyline string into a list of LatLng.
* @param poly polyline encoded string to decode.
* @return the list of GeoPoints represented by this polystring.
*/
private List<LatLng> decodePolyLine(final String poly) {
int len = poly.length();
int index = 0;
List<LatLng> decoded = new LinkedList<LatLng>();
int lat = 0;
int lng = 0;
while (index < len) {
int b;
int shift = 0;
int result = 0;
do {
b = poly.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 = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
decoded.add(new LatLng((lat / 1E5),(lng / 1E5)));
}
return decoded;
}
}

Route (pour économiser de l'json info)

public class Route {
private String name;
private final List<LatLng> points;
private List<Segment> segments;
private String copyright;
private String warning;
private String country;
private int length;
private String polyline;
public Route() {
points = new LinkedList<LatLng>();
segments = new LinkedList<Segment>();
}
public void addPoint(final LatLng p) {
points.add(p);
}
public void addPoints(final List<LatLng> points) {
this.points.addAll(points);
}
public List<LatLng> getPoints() {
return points;
}
public void addSegment(final Segment s) {
segments.add(s);
}
public List<Segment> getSegments() {
return segments;
}
/**
* @param name the name to set
*/
public void setName(final String name) {
this.name = name;
}
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param copyright the copyright to set
*/
public void setCopyright(String copyright) {
this.copyright = copyright;
}
/**
* @return the copyright
*/
public String getCopyright() {
return copyright;
}
/**
* @param warning the warning to set
*/
public void setWarning(String warning) {
this.warning = warning;
}
/**
* @return the warning
*/
public String getWarning() {
return warning;
}
/**
* @param country the country to set
*/
public void setCountry(String country) {
this.country = country;
}
/**
* @return the country
*/
public String getCountry() {
return country;
}
/**
* @param length the length to set
*/
public void setLength(int length) {
this.length = length;
}
/**
* @return the length
*/
public int getLength() {
return length;
}
/**
* @param polyline the polyline to set
*/
public void setPolyline(String polyline) {
this.polyline = polyline;
}
/**
* @return the polyline
*/
public String getPolyline() {
return polyline;
}
}

Segment:

public class Segment {
/** Points in this segment. **/
private LatLng start;
/** Turn instruction to reach next segment. **/
private String instruction;
/** Length of segment. **/
private int length;
/** Distance covered. **/
private double distance;
/**
* Create an empty segment.
*/
public Segment() {
}
/**
* Set the turn instruction.
* @param turn Turn instruction string.
*/
public void setInstruction(final String turn) {
this.instruction = turn;
}
/**
* Get the turn instruction to reach next segment.
* @return a String of the turn instruction.
*/
public String getInstruction() {
return instruction;
}
/**
* Add a point to this segment.
* @param point LatLng to add.
*/
public void setPoint(LatLng point) {
start = point;
}
/** Get the starting point of this 
* segment.
* @return a LatLng
*/
public LatLng startPoint() {
return start;
}
/** Creates a segment which is a copy of this one.
* @return a Segment that is a copy of this one.
*/
public Segment copy() {
final Segment copy = new Segment();
copy.start = start;
copy.instruction = instruction;
copy.length = length;
copy.distance = distance;
return copy;
}
/**
* @param length the length to set
*/
public void setLength(final int length) {
this.length = length;
}
/**
* @return the length
*/
public int getLength() {
return length;
}
/**
* @param distance the distance to set
*/
public void setDistance(double distance) {
this.distance = distance;
}
/**
* @return the distance
*/
public double getDistance() {
return distance;
}
}

Mon MainActivity (il y a 326 ligne de code en raison de la localisation de l'utilisateur, vous pouvez le trouver sur google le site des développeurs, nous pouvons donc supposer deux statique point A et B et je veux aller de A à B):

public class MainActivity extends FragmentActivity{
private GoogleMap map;
private Marker currentLocation;
private PolylineOptions pathLine;
private LatLng imhere = new LatLng(41.8549038,12.4618208);
private LatLng poi = new LatLng(41.89000,12.49324);
private LocationManager mLocationManager;
private Handler mHandler;
private boolean mUseBoth;
private Context context;
//Keys for maintaining UI states after rotation.
private static final String KEY_BOTH = "use_both";
//UI handler codes.
private static final int UPDATE_LATLNG = 2;
private static final int FIVE_SECONDS = 5000;
private static final int THREE_METERS = 3;
private static final int TWO_MINUTES = 1000 * 60 * 2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
Marker colosseoMarker  = map.addMarker(new MarkerOptions()
.position(colosseo)
.title("Start")
.snippet("poi")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
Marker current pos = map.addMarker(new MarkerOptions()
.position(imhere)
.title("i'm here")
.snippet("here!")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
context =this ;
map.setOnMarkerClickListener(new OnMarkerClickListener() {
@Override
public boolean onMarkerClick(Marker marker) {
final String[] options = {"Calcola il Percorso"};
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Ottieni Informazioni aggiuntive");
builder.setPositiveButton("Calcola Percorso",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
LatLng start = new LatLng(imhere.latitude,imhere.longitude);
LatLng dest = new LatLng(poi.latitude, poi.longitude);
Route route = drawPath(start, dest);
List<LatLng> list= route.getPoints();
if(pathLine!= null) pathline =null;                         
pathLine = new PolylineOptions();
pathLine.addAll(list);
pathLine.color(Color.rgb(0,191,255));
map.addPolyline(pathLine);
}
});
AlertDialog alert = builder.create();
alert.show();
Toast.makeText(MainActivity.this, marker.getSnippet(),Toast.LENGTH_SHORT).show();
return true;
}
});
map.animateCamera(CameraUpdateFactory.newLatLngZoom(imhere, 12));
}
}
};
//Get a reference to the LocationManager object.
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
private Route drawPath(LatLng start, LatLng dest) {
Parser parser;
String jsonURL = "http://maps.google.com/maps/api/directions/json?";
final StringBuffer sBuf = new StringBuffer(jsonURL);
sBuf.append("origin=");
sBuf.append(start.latitude);
sBuf.append(',');
sBuf.append(start.longitude);
sBuf.append("&destination=");
sBuf.append(dest.latitude);
sBuf.append(',');
sBuf.append(dest.longitude);
sBuf.append("&sensor=true&mode=walking");
parser = new JsonParser(sBuf.toString());
Route r =  parser.parse();
return r;
}
}

chaque suggestion est bien accepté

OriginalL'auteur antedesk | 2012-12-17