Custom Controls

  • This example demonstrates how to create a custom control on a Google Map that recenters the map to Chicago.

  • The control is a button labeled "Center Map" and is positioned at the top center of the map.

  • When clicked, the button triggers a function to set the map's center to the coordinates of Chicago.

  • This example uses TypeScript and JavaScript to create the custom control and integrate it with the Google Maps API.

This example creates a map with a "Center Map" button, which will pan the map to be centered on Chicago.

Read the documentation.

TypeScript

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')) as typeof google.maps;

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

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

void init();

JavaScript

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();

CSS

/* 
 * 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;
}

HTML

<html>
    <head>
        <title>Custom Controls</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <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))})({
      key: "GOOGLE_MAPS_API_KEY",
      v: "weekly"
    });
        </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>

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. You will also need a Google Maps API key.

The following commands clone the repository, install dependencies, and copy the environment file. 

  git clone https://github.com/googlemaps-samples/js-api-samples.git
  cd js-api-samples
  npm i
  cp .env.template .env

Once you copy the environment file, make sure to open the .env file and replace <Insert your own development API key here> with your actual API key before starting the sample. 

  cd samples/control-custom
  npm start