私のアプリケーションは、JSON を使用してパス/方向を指定できます。JSONで指定されたパスで異なる色に変更するにはどうすればよいですか?
たとえば、フォーム ポイント A からポイント B は赤、B から C は黄色、C から D は緑などです。
コードは次のとおりです。
JSON でポイントを取得します。
private void parsing(GeoPoint start, GeoPoint end) throws ClientProtocolException, IOException, JSONException, URISyntaxException{
HttpClient httpclient = new DefaultHttpClient();
StringBuilder urlstring = new StringBuilder();
urlstring.append("https://maps.googleapis.com/maps/api/directions/json?origin=")
.append(Double.toString((double)start.getLatitudeE6()/1E6)).append(",").append(Double.toString((double)start.getLongitudeE6()/1E6)).append("&destination=")
.append(Double.toString((double)end.getLatitudeE6()/1E6)).append(",").append(Double.toString((double)end.getLongitudeE6()/1E6))
.append("&sensor=false");
//urlstring.append("http://maps.googleapis.com/maps/api/directions/json?origin=Toronto&destination=Montreal&sensor=true");
url = new URI(urlstring.toString());
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
InputStream is = null;
is = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
reader.close();
String result = sb.toString();
JSONObject jsonObject = new JSONObject(result);
JSONArray routeArray = jsonObject.getJSONArray("routes");
JSONObject routes = routeArray.getJSONObject(0);
JSONObject overviewPolylines = routes.getJSONObject("overview_polyline");
String encodedString = overviewPolylines.getString("points");
List<GeoPoint> pointToDraw = decodePoly(encodedString);
//Added line:
mv_mapview.getOverlays().add(new RoutePathOverlay(pointToDraw));
}
JSON で指定されたジオポイントのリスト。
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));
//n = new Node(p,);
poly.add(p);
}
return poly;
}
およびオーバーレイクラス
public class RoutePathOverlay extends Overlay {
private int _pathColor;
private final List<GeoPoint> _points;
private boolean _drawStartEnd;
public RoutePathOverlay(List<GeoPoint> points) {
this(points, Color.GREEN, true);
}
public RoutePathOverlay(List<GeoPoint> points, int pathColor, boolean drawStartEnd) {
_points = points;
_pathColor = pathColor;
_drawStartEnd = drawStartEnd;
}
private void drawOval(Canvas canvas, Paint paint, Point point) {
Paint ovalPaint = new Paint(paint);
ovalPaint.setStyle(Paint.Style.FILL_AND_STROKE);
ovalPaint.setStrokeWidth(2);
int _radius = 6;
RectF oval = new RectF(point.x - _radius, point.y - _radius, point.x + _radius, point.y + _radius);
canvas.drawOval(oval, ovalPaint);
}
public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
Projection projection = mapView.getProjection();
if (shadow == false && _points != null) {
Point startPoint = null, endPoint = null;
Path path = new Path();
//We are creating the path
for (int i = 0; i < _points.size(); i++) {
GeoPoint gPointA = _points.get(i);
Point pointA = new Point();
projection.toPixels(gPointA, pointA);
//if()
if (i == 0) { //This is the start point
startPoint = pointA;
path.moveTo(pointA.x, pointA.y);
} else {
if (i == _points.size() - 1)//This is the end point
endPoint = pointA;
path.lineTo(pointA.x, pointA.y);
}
}
Paint paint = new Paint();
paint.setAntiAlias(true);
// if(){
paint.setColor(_pathColor);
//}
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(5);
paint.setAlpha(90);
if (getDrawStartEnd()) {
if (startPoint != null) {
drawOval(canvas, paint, startPoint);
}
if (endPoint != null) {
drawOval(canvas, paint, endPoint);
}
}
if (!path.isEmpty())
canvas.drawPath(path, paint);
}
return super.draw(canvas, mapView, shadow, when);
}
public boolean getDrawStartEnd() {
return _drawStartEnd;
}
public void setDrawStartEnd(boolean markStartEnd) {
_drawStartEnd = markStartEnd;
}
}