control-custom

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

HTML

<!doctype html>
<!--
 @license
 Copyright 2026 Google LLC. All Rights Reserved.
 SPDX-License-Identifier: Apache-2.0
-->

<html>
  <head>
    <title>Custom Controls</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>
    <gmp-map zoom="12" center="41.85, -87.65">
      <button
        id="btnCenterMap"
        slot="control-block-start-inline-center"
        title="Click to recenter the map"
        type="button">
        Center Map
      </button>
    </gmp-map>
  </body>
</html>

CSS

/**
 * @license
 * Copyright 2026 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

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

gmp-map {
  height: 100%;
}

#btnCenterMap {
  background-color: #fff;
  border: 2px solid #fff;
  border-radius: 3px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
  color: rgb(25, 25, 25);
  cursor: pointer;
  font-family: Roboto, Arial, sans-serif;
  font-size: 16px;
  line-height: 38px;
  margin: 8px 0 22px;
  padding: 0 5px;
  text-align: center;
}

JavaScript

'use strict';
/**
 * @license
 * Copyright 2026 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

const chicago = { lat: 41.85, lng: -87.65 };

// Get the gmp-map element
const mapElement = document.querySelector('gmp-map');

async function init() {
  await google.maps.importLibrary('maps');

  // Get the inner map.
  const innerMap = mapElement.innerMap;

  // Get the button element from the HTML
  const centerButton = document.getElementById('btnCenterMap');
  // Move the event listener here
  centerButton.addEventListener('click', () => {
    innerMap.setCenter(chicago);
  });
}

void init();