Polygon With Hole

  • This example demonstrates creating polygons with inner holes on a map using the Google Maps JavaScript API.

  • It involves defining separate paths for the outer and inner boundaries of the polygon, with the inner path wound in the opposite direction.

  • The google.maps.Polygon class is used to construct the polygon, accepting an array of paths and styling options.

  • An alternative approach using the Data layer for simpler hole creation is also mentioned.

  • Code samples in TypeScript and JavaScript, along with HTML and CSS, are provided for implementation.

This example creates a polygon with an inner hole, by defining an inner path wound in the opposite direction to the outer path. Note that you can also use the Data layer, which offers a simpler way of creating holes because it handles the order of the inner and outer paths for you.

Read the documentation.

TypeScript

// This example creates a triangular polygon with a hole in it.

function initMap(): void {
  const map = new google.maps.Map(
    document.getElementById("map") as HTMLElement,
    {
      zoom: 5,
      center: { lat: 24.886, lng: -70.268 },
    }
  );

  // Define the LatLng coordinates for the polygon's  outer path.
  const outerCoords = [
    { lat: 25.774, lng: -80.19 },
    { lat: 18.466, lng: -66.118 },
    { lat: 32.321, lng: -64.757 },
  ];

  // Define the LatLng coordinates for the polygon's inner path.
  // Note that the points forming the inner path are wound in the
  // opposite direction to those in the outer path, to form the hole.
  const innerCoords = [
    { lat: 28.745, lng: -70.579 },
    { lat: 29.57, lng: -67.514 },
    { lat: 27.339, lng: -66.668 },
  ];

  // Construct the polygon, including both paths.
  const bermudaTriangle = new google.maps.Polygon({
    paths: [outerCoords, innerCoords],
    strokeColor: "#FFC107",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FFC107",
    fillOpacity: 0.35,
  });

  bermudaTriangle.setMap(map);
}

declare global {
  interface Window {
    initMap: () => void;
  }
}
window.initMap = initMap;
index.ts

JavaScript

// This example creates a triangular polygon with a hole in it.
function initMap() {
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 5,
    center: { lat: 24.886, lng: -70.268 },
  });
  // Define the LatLng coordinates for the polygon's  outer path.
  const outerCoords = [
    { lat: 25.774, lng: -80.19 },
    { lat: 18.466, lng: -66.118 },
    { lat: 32.321, lng: -64.757 },
  ];
  // Define the LatLng coordinates for the polygon's inner path.
  // Note that the points forming the inner path are wound in the
  // opposite direction to those in the outer path, to form the hole.
  const innerCoords = [
    { lat: 28.745, lng: -70.579 },
    { lat: 29.57, lng: -67.514 },
    { lat: 27.339, lng: -66.668 },
  ];
  // Construct the polygon, including both paths.
  const bermudaTriangle = new google.maps.Polygon({
    paths: [outerCoords, innerCoords],
    strokeColor: "#FFC107",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FFC107",
    fillOpacity: 0.35,
  });

  bermudaTriangle.setMap(map);
}

window.initMap = initMap;
index.js

CSS

/* 
 * Always set the map height explicitly to define the size of the div element
 * that contains the map. 
 */
#map {
  height: 100%;
}

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

style.css

HTML

<html>
  <head>
    <title>Polygon With Hole</title>

    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script type="module" src="./index.js"></script>
  </head>
  <body>
    <div id="map"></div>

    <!-- 
      The `defer` attribute causes the script to execute after the full HTML
      document has been parsed. For non-blocking uses, avoiding race conditions,
      and consistent behavior across browsers, consider loading using Promises. See
      https://developers.google.com/maps/documentation/javascript/load-maps-js-api
      for more information.
      -->
    <script
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly"
      defer
    ></script>
  </body>
</html>
index.html

Try Sample

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application. 

  git clone -b sample-polygon-hole https://github.com/googlemaps/js-samples.git
  cd js-samples
  npm i
  npm start

Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME. 

  git checkout sample-SAMPLE_NAME
  npm i
  npm start