It's the 15th anniversary of Google Maps Platform - Check out the latest news and announcements

Listening to Events

This example adds a user-editable rectangle to the map. When the user changes the bounds of the rectangle, an info window pops up displaying the new bounds.

Read the documentation.

TypeScript

// This example adds a user-editable rectangle to the map.
// When the user changes the bounds of the rectangle,
// an info window pops up displaying the new bounds.

let rectangle: google.maps.Rectangle;
let map: google.maps.Map;

let infoWindow: google.maps.InfoWindow;

function initMap(): void {
  map = new google.maps.Map(document.getElementById("map") as HTMLElement, {
    center: { lat: 44.5452, lng: -78.5389 },
    zoom: 9,
  });

  const bounds = {
    north: 44.599,
    south: 44.49,
    east: -78.443,
    west: -78.649,
  };

  // Define the rectangle and set its editable property to true.
  rectangle = new google.maps.Rectangle({
    bounds: bounds,
    editable: true,
    draggable: true,
  });

  rectangle.setMap(map);

  // Add an event listener on the rectangle.
  rectangle.addListener("bounds_changed", showNewRect);

  // Define an info window on the map.
  infoWindow = new google.maps.InfoWindow();
}

/** Show the new coordinates for the rectangle in an info window. */
function showNewRect() {
  const ne = rectangle.getBounds().getNorthEast();
  const sw = rectangle.getBounds().getSouthWest();

  const contentString =
    "<b>Rectangle moved.</b><br>" +
    "New north-east corner: " +
    ne.lat() +
    ", " +
    ne.lng() +
    "<br>" +
    "New south-west corner: " +
    sw.lat() +
    ", " +
    sw.lng();

  // Set the info window's content and position.
  infoWindow.setContent(contentString);
  infoWindow.setPosition(ne);

  infoWindow.open(map);
}

JavaScript

// This example adds a user-editable rectangle to the map.
// When the user changes the bounds of the rectangle,
// an info window pops up displaying the new bounds.
let rectangle;
let map;
let infoWindow;

function initMap() {
  map = new google.maps.Map(document.getElementById("map"), {
    center: { lat: 44.5452, lng: -78.5389 },
    zoom: 9,
  });
  const bounds = {
    north: 44.599,
    south: 44.49,
    east: -78.443,
    west: -78.649,
  };
  // Define the rectangle and set its editable property to true.
  rectangle = new google.maps.Rectangle({
    bounds: bounds,
    editable: true,
    draggable: true,
  });
  rectangle.setMap(map);
  // Add an event listener on the rectangle.
  rectangle.addListener("bounds_changed", showNewRect);
  // Define an info window on the map.
  infoWindow = new google.maps.InfoWindow();
}

/** Show the new coordinates for the rectangle in an info window. */
function showNewRect() {
  const ne = rectangle.getBounds().getNorthEast();
  const sw = rectangle.getBounds().getSouthWest();
  const contentString =
    "<b>Rectangle moved.</b><br>" +
    "New north-east corner: " +
    ne.lat() +
    ", " +
    ne.lng() +
    "<br>" +
    "New south-west corner: " +
    sw.lat() +
    ", " +
    sw.lng();
  // Set the info window's content and position.
  infoWindow.setContent(contentString);
  infoWindow.setPosition(ne);
  infoWindow.open(map);
}

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;
}

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Listening to Events</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script src="./app.js"></script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>

All

<!DOCTYPE html>
<html>
  <head>
    <title>Listening to Events</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <style type="text/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>
    <script>
      "use strict";

      // This example adds a user-editable rectangle to the map.
      // When the user changes the bounds of the rectangle,
      // an info window pops up displaying the new bounds.
      let rectangle;
      let map;
      let infoWindow;

      function initMap() {
        map = new google.maps.Map(document.getElementById("map"), {
          center: {
            lat: 44.5452,
            lng: -78.5389,
          },
          zoom: 9,
        });
        const bounds = {
          north: 44.599,
          south: 44.49,
          east: -78.443,
          west: -78.649,
        }; // Define the rectangle and set its editable property to true.

        rectangle = new google.maps.Rectangle({
          bounds: bounds,
          editable: true,
          draggable: true,
        });
        rectangle.setMap(map); // Add an event listener on the rectangle.

        rectangle.addListener("bounds_changed", showNewRect); // Define an info window on the map.

        infoWindow = new google.maps.InfoWindow();
      }
      /** Show the new coordinates for the rectangle in an info window. */

      function showNewRect() {
        const ne = rectangle.getBounds().getNorthEast();
        const sw = rectangle.getBounds().getSouthWest();
        const contentString =
          "<b>Rectangle moved.</b><br>" +
          "New north-east corner: " +
          ne.lat() +
          ", " +
          ne.lng() +
          "<br>" +
          "New south-west corner: " +
          sw.lat() +
          ", " +
          sw.lng(); // Set the info window's content and position.

        infoWindow.setContent(contentString);
        infoWindow.setPosition(ne);
        infoWindow.open(map);
      }
    </script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>
"use strict"; // This example adds a user-editable rectangle to the map. // When the user changes the bounds of the rectangle, // an info window pops up displaying the new bounds. let rectangle; let map; let infoWindow; function initMap() { map = new google.maps.Map(document.getElementById("map"), { center: { lat: 44.5452, lng: -78.5389, }, zoom: 9, }); const bounds = { north: 44.599, south: 44.49, east: -78.443, west: -78.649, }; // Define the rectangle and set its editable property to true. rectangle = new google.maps.Rectangle({ bounds: bounds, editable: true, draggable: true, }); rectangle.setMap(map); // Add an event listener on the rectangle. rectangle.addListener("bounds_changed", showNewRect); // Define an info window on the map. infoWindow = new google.maps.InfoWindow(); } /** Show the new coordinates for the rectangle in an info window. */ function showNewRect() { const ne = rectangle.getBounds().getNorthEast(); const sw = rectangle.getBounds().getSouthWest(); const contentString = "<b>Rectangle moved.</b><br>" + "New north-east corner: " + ne.lat() + ", " + ne.lng() + "<br>" + "New south-west corner: " + sw.lat() + ", " + sw.lng(); // Set the info window's content and position. infoWindow.setContent(contentString); infoWindow.setPosition(ne); infoWindow.open(map); }
/* 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; }
<!DOCTYPE html> <html> <head> <title>Listening to Events</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBIwzALxUPNbatRBj3Xi1Uhp0fFzwWNBkE&callback=initMap&libraries=&v=weekly" defer ></script> <!-- jsFiddle will insert css and js --> </head> <body> <div id="map"></div> </body> </html>

Create a starter application from sample

A skeleton starter application using TypeScript, Webpack, and Babel can be generated from this sample using one of the methods below.

Run Locally

Node.js is required to run this sample locally. Follow these instructions to install Node.js and NPM.

npm i -g '@googlemaps/js-samples'
googlemaps-js-samples init rectangle-event DESTINATION_FOLDER

Run in Google Cloud Shell

Google Cloud Shell is an interactive shell environment for Google Cloud Platform that makes it easy for you to learn and experiment with GCP and manage your projects and resources from your web browser.

Run in Cloud Shell