Draw hollow Polygon on Map, using addHole() method

Anonymous

07:12

Example to draw hollow Polygon on Map, on user clicked location.

Refer to Google document to create hollow Polygon. It demonstrate with addHole(LatLng... points), actually I can only found addHole(Iterable<latlng> points) in com.google.android.gms.maps.model.PolygonOptions class! This example demonstrate how to apply Iterable<latlng> on PolygonOptions.

(related: What is Iterable?)

Modify java code from the last exercise of "Draw tranparent circle".

package com.example.androidmapsv2;

import java.util.ArrayList;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.Circle;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.PolygonOptions;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.FragmentManager;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity 
 implements OnMapClickListener{
 
 final int RQS_GooglePlayServices = 1;
 private GoogleMap myMap;
 
 TextView tvLocInfo;
 
 Circle myCircle;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  tvLocInfo = (TextView)findViewById(R.id.locinfo);
  
  FragmentManager myFragmentManager = getFragmentManager();
  MapFragment myMapFragment 
   = (MapFragment)myFragmentManager.findFragmentById(R.id.map);
  myMap = myMapFragment.getMap();

  myMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
  
  myMap.setOnMapClickListener(this);

 }
 
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  // Inflate the menu; this adds items to the action bar if it is present.
  getMenuInflater().inflate(R.menu.activity_main, menu);
  return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  switch (item.getItemId()) {
     case R.id.menu_legalnotices:
      String LicenseInfo = GooglePlayServicesUtil.getOpenSourceSoftwareLicenseInfo(
        getApplicationContext());
      AlertDialog.Builder LicenseDialog = new AlertDialog.Builder(MainActivity.this);
      LicenseDialog.setTitle("Legal Notices");
      LicenseDialog.setMessage(LicenseInfo);
      LicenseDialog.show();
         return true;
     }
  return super.onOptionsItemSelected(item);
 }

 @Override
 protected void onResume() {

  super.onResume();

  int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());
  
  if (resultCode == ConnectionResult.SUCCESS){
   Toast.makeText(getApplicationContext(), 
     "isGooglePlayServicesAvailable SUCCESS", 
     Toast.LENGTH_LONG).show();
  }else{
   GooglePlayServicesUtil.getErrorDialog(resultCode, this, RQS_GooglePlayServices);
  }
  
 }


 @Override
 public void onMapClick(LatLng point) {
  
  //generate points on outter path
  ArrayList<LatLng> outter = new ArrayList<LatLng>();  
  outter.add(new LatLng(point.latitude-5, point.longitude-5)); 
  outter.add(new LatLng(point.latitude-5, point.longitude+5)); 
  outter.add(new LatLng(point.latitude+5, point.longitude+5)); 
  outter.add(new LatLng(point.latitude+5, point.longitude-5));
  
  //generate points on inner path
  ArrayList<LatLng> inner = new ArrayList<LatLng>();  
  inner.add(new LatLng(point.latitude-4, point.longitude-4)); 
  inner.add(new LatLng(point.latitude-4, point.longitude+4)); 
  inner.add(new LatLng(point.latitude+4, point.longitude+4)); 
  inner.add(new LatLng(point.latitude+4, point.longitude-4));
   
  PolygonOptions polygonOptions = 
    new PolygonOptions()
     .addAll(outter)
     .addHole(inner)
     .fillColor(Color.BLUE)
     .strokeWidth(1);

  myMap.addPolygon(polygonOptions);
 }

}