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Rectangle Zoom

  • This example demonstrates dynamically creating and updating a rectangle overlay on a Google Map based on the current viewport bounds.

  • The rectangle's dimensions are adjusted whenever the map's zoom level changes, ensuring it covers the visible area.

  • The sample code is provided in both TypeScript and JavaScript, allowing for flexibility in implementation.

  • It leverages the Google Maps JavaScript API'szoom_changed event andRectangle class for seamless integration.

  • The rectangle's appearance is customizable with options for stroke color, fill color, and opacity.

This example creates a rectangle based on the viewport on anyzoom-changed event.

Read thedocumentation.

TypeScript

// This example creates a rectangle based on the viewport// on any 'zoom-changed' event.functioninitMap():void{constmap=newgoogle.maps.Map(document.getElementById("map")asHTMLElement,{zoom:11,center:{lat:40.74852,lng:-73.981687},mapTypeId:"terrain",});constrectangle=newgoogle.maps.Rectangle();map.addListener("zoom_changed",()=>{// Get the current bounds, which reflect the bounds before the zoom.rectangle.setOptions({strokeColor:"#FF0000",strokeOpacity:0.8,strokeWeight:2,fillColor:"#FF0000",fillOpacity:0.35,map,bounds:map.getBounds()asgoogle.maps.LatLngBounds,});});}declareglobal{interfaceWindow{initMap:()=>void;}}window.initMap=initMap;
Note: Read theguide on using TypeScript and Google Maps.

JavaScript

// This example creates a rectangle based on the viewport// on any 'zoom-changed' event.functioninitMap(){constmap=newgoogle.maps.Map(document.getElementById("map"),{zoom:11,center:{lat:40.74852,lng:-73.981687},mapTypeId:"terrain",});constrectangle=newgoogle.maps.Rectangle();map.addListener("zoom_changed",()=>{// Get the current bounds, which reflect the bounds before the zoom.rectangle.setOptions({strokeColor:"#FF0000",strokeOpacity:0.8,strokeWeight:2,fillColor:"#FF0000",fillOpacity:0.35,map,bounds:map.getBounds(),});});}window.initMap=initMap;
Note: The JavaScript is compiled from the TypeScript snippet.

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

<html>  <head>    <title>Rectangle Zoom</title>    <link rel="stylesheet" type="text/css" href="./style.css" />    <script type="module" src="./index.js"></script>  </head>  <body>    <div></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>

Try Sample

Clone Sample

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

gitclone-bsample-rectangle-zoomhttps://github.com/googlemaps/js-samples.gitcdjs-samplesnpminpmstart

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

gitcheckoutsample-SAMPLE_NAMEnpminpmstart

Except as otherwise noted, the content of this page is licensed under theCreative Commons Attribution 4.0 License, and code samples are licensed under theApache 2.0 License. For details, see theGoogle Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.

Last updated 2025-12-11 UTC.