Android Draw Multiple polygon on Map overlay

Android Draw Multiple polygon on  Map overlay



Below I wrote the code for how to draw a multiple polygon on Google map overlay.
I hope it will help full for you.


Screen Shot

Activity Source code

package com.example.androidtest;

import java.util.ArrayList;

import java.util.List;

import android.os.Bundle;

import com.google.android.maps.GeoPoint;

import com.google.android.maps.MapView;

import com.google.android.maps.Overlay;

import com.google.android.maps.Projection;

import com.google.android.maps.MapActivity;

import com.google.android.maps.MapController;

/**

 * @author vijayakumar

 */

public class AndroidprojectMApActivity extends MapActivity {

       MapView myMapView = null;

       MapController myMC = null;

       GeoPoint geoPoint = null;

        GeoPoint gP1;

       private List<Overlay> mapOverlays;

     PathOverlay pathOverlay = null;

       private Projection projection;

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

       /** Called when the activity is first created. */

       @Override

       public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        myMapView = (MapView) findViewById(R.id.mapview);

        myMapView.setBuiltInZoomControls(true);

          mapOverlays = myMapView.getOverlays();       

          projection = myMapView.getProjection();

          MapController mapController = myMapView.getController();

          mapController.setZoom(14);

          mapOverlays.add(new PathOverlay());

       

       }

       @Override

       protected boolean isRouteDisplayed() {

        // TODO Auto-generated method stub

        return false;

       }

      }

Overlay Source Code

package com.example.androidtest; 

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.Point;

import android.util.Log;

import com.google.android.maps.GeoPoint;

import com.google.android.maps.MapView;

import com.google.android.maps.Overlay;

import com.google.android.maps.Projection;

class PathOverlay extends Overlay{

       Point startPoint = null, endPoint = null;

       Path path  = null;

       GeoPoint gPointA;

       GeoPoint gPointA1;

       Point pointA ;

       Point pointA1 ;

      //private final List<GeoPoint> _points;

  

    public void draw(Canvas canvas, MapView mapv, boolean shadow){

        super.draw(canvas, mapv, shadow);

        Projection projection = mapv.getProjection();

        Paint   mPaint = new Paint();

        mPaint.setDither(true);

        mPaint.setColor(Color.parseColor("#FF0000"));

        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);

        mPaint.setStrokeJoin(Paint.Join.BEVEL);

        mPaint.setStrokeCap(Paint.Cap.BUTT);

        mPaint.setStrokeWidth(2);

          InputStream is = mapv.getResources().openRawResource(R.raw.json);

          byte[] buffer;

            try {

                  buffer = new byte[is.available()];

                    while (is.read(buffer) != -1);

                      String jsontext = new String(buffer);

                      JSONObject  fromobj3 = null;

                      JSONObject  fromobj4 = null;

                      JSONObject  fromobj5 = null;

                      JSONObject jObject2 =  new JSONObject(jsontext);

                      JSONObject  fromobj = jObject2.getJSONObject("kml");

                      JSONObject  fromobj1 = fromobj.getJSONObject("document");

                      JSONObject  fromobj2 = fromobj1.getJSONObject("folder");

                      JSONArray entries = fromobj2.getJSONArray("placemark");

                      int i;

                      for (i=0;i<entries.length();i++)

                      {

                            JSONObject post = entries.getJSONObject(i);

                            fromobj3 = post.getJSONObject("polygon");

                            fromobj4 = fromobj3.getJSONObject("outerboundaryis");

                            fromobj5 = fromobj4.getJSONObject("linearring");

                            String  coordinates =   fromobj5.getString("coordinates").toString();

                           

                                String[] coor = coordinates.split("0.00 ");

                                path = new Path();

                                             for(int j = 0; j<coor.length;j++) {

                                                       String latlong[] = coor[j].substring(0, coor[j].length()-1).split(",");

                                                         Double lon = Double.valueOf(latlong[0].toString());

                                                         Double lat = Double.valueOf(latlong[1].toString());

                                                         gPointA = new GeoPoint((int) (lat * 1E6), (int)((lon) * 1E6));

                                                            pointA = new Point();

                                                            projection.toPixels(gPointA, pointA);

                                                            Log.d("greenzone", "Geo Points   ::    " +gPointA.getLatitudeE6()  +" :: " + gPointA.getLongitudeE6());

                                                            if (j == 0) { //This is the start point

                                                             path.moveTo(pointA.x,pointA.y);

                                                            }

                                                            else {

                                                            if (j == coor.length - 1)// This is the link last point to first point

                                                               {

                                                             path.lineTo(pointA.x, pointA.y);

                                                                }

                                                            else// this is the first and last middle points

                                                               {

                                                             path.lineTo(pointA.x, pointA.y);

                                                                }

                                                               }

                                                    }

                                             canvas.drawPath(path, mPaint);

                                                  }

                   

            } catch (IOException e) {

                  // TODO Auto-generated catch block

                  e.printStackTrace();

            } catch (JSONException e) {

                  // TODO Auto-generated catch block

                  e.printStackTrace();

            }

     

    }

   

}

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