3d-polygon-click-event

Sample code supporting Google Maps Platform JavaScript API documentation. author(s): Geo Developer IX Documentation Team

HTML

<!doctype html>
<!--
 @license
 Copyright 2025 Google LLC. All Rights Reserved.
 SPDX-License-Identifier: Apache-2.0
-->

<html>
  <head>
    <title>Map</title>

    <script>
      // prettier-ignore
      (g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})({
            });
    </script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>

CSS

/*
* @license
* Copyright 2025 Google LLC. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0
*/

/* 
 * Always set the map height explicitly to define the size of the div element
 * that contains the map. 
 */
html,
map {
  height: 100%;
}
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

'use strict';
/*
 * @license
 * Copyright 2025 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

async function init() {
  const { Map3DElement, Polygon3DInteractiveElement } =
    await google.maps.importLibrary('maps3d');

  const map = new Map3DElement({
    center: { lat: 40.6842, lng: -74.0019, altitude: 1000 },
    heading: 340,
    tilt: 70,
    mode: 'HYBRID',
  });

  document.body.append(map);

  const polygonOptions = {
    strokeColor: '#0000ff80',
    strokeWidth: 8,
    fillColor: '#ff000080',
    drawsOccludedSegments: false,
  };

  const examplePolygon = new Polygon3DInteractiveElement(polygonOptions);

  examplePolygon.path = [
    { lat: 40.7144, lng: -74.0208 },
    { lat: 40.6993, lng: -74.019 },
    { lat: 40.7035, lng: -74.0004 },
    { lat: 40.7144, lng: -74.0208 },
  ];

  examplePolygon.addEventListener('gmp-click', function (event) {
    // change the color of the polygon stroke and fill colors to a random alternatives!
    this.fillColor = randomizeHexColor(this.fillColor);
    this.strokeColor = randomizeHexColor(this.strokeColor);
    console.log(event);
  });

  map.append(examplePolygon);
}

function randomizeHexColor(originalHexColor) {
  console.log(originalHexColor);
  const alpha = originalHexColor.substring(7);

  // Generate random values for Red, Green, Blue (0-255)
  const r = Math.floor(Math.random() * 256);
  const g = Math.floor(Math.random() * 256);
  const b = Math.floor(Math.random() * 256);

  console.log(r + ' ' + g + ' ' + b);

  // Convert decimal to 2-digit hex, padding with '0' if needed
  const rHex = ('0' + r.toString(16)).slice(-2);
  const gHex = ('0' + g.toString(16)).slice(-2);
  const bHex = ('0' + b.toString(16)).slice(-2);

  // Combine parts: '#' + random RGB + original Alpha (if any)
  return `#${rHex}${gHex}${bHex}${alpha}`;
}

void init();