This example map shows the boundaries for counties near Denver, CO (Administrative Area Level 2), and has an event handler that styles the clicked polygon and displays an info window with the event data.
Read the documentation.
TypeScript
let map: google.maps.Map;
let featureLayer;
let infoWindow;
let lastInteractedFeatureIds = [];
let lastClickedFeatureIds = [];
function handleClick(/* MouseEvent */ e) {
lastClickedFeatureIds = e.features.map(f => f.placeId);
lastInteractedFeatureIds = [];
featureLayer.style = applyStyle;
createInfoWindow(e);
}
function handleMouseMove(/* MouseEvent */ e) {
lastInteractedFeatureIds = e.features.map(f => f.placeId);
featureLayer.style = applyStyle;
}
async function initMap() {
// Request needed libraries.
const { Map, InfoWindow } = await google.maps.importLibrary('maps') as google.maps.MapsLibrary;
map = new Map(document.getElementById('map') as HTMLElement, {
center: {lat: 39.23, lng: -105.73},
zoom: 8,
// In the cloud console, configure your Map ID with a style that enables the
// 'Administrative Area Level 2' Data Driven Styling type.
mapId: 'a3efe1c035bad51b', // Substitute your own map ID.
mapTypeControl: false,
});
// Add the feature layer.
//@ts-ignore
featureLayer = map.getFeatureLayer('ADMINISTRATIVE_AREA_LEVEL_2');
// Add the event listeners for the feature layer.
featureLayer.addListener('click', handleClick);
featureLayer.addListener('mousemove', handleMouseMove);
// Map event listener.
map.addListener('mousemove', () => {
// If the map gets a mousemove, that means there are no feature layers
// with listeners registered under the mouse, so we clear the last
// interacted feature ids.
if (lastInteractedFeatureIds?.length) {
lastInteractedFeatureIds = [];
featureLayer.style = applyStyle;
}
});
// Create the infowindow.
infoWindow = new InfoWindow({});
// Apply style on load, to enable clicking.
featureLayer.style = applyStyle;
}
// Helper function for the infowindow.
async function createInfoWindow(event) {
let feature = event.features[0];
if (!feature.placeId) return;
// Update the infowindow.
const place = await feature.fetchPlace();
let content =
'<span style="font-size:small">Display name: ' + place.displayName +
'<br/> Place ID: ' + feature.placeId +
'<br/> Feature type: ' + feature.featureType + '</span>';
updateInfoWindow(content, event.latLng);
}
// Define styles.
// Stroke and fill with minimum opacity value.
const styleDefault = {
strokeColor: '#810FCB',
strokeOpacity: 1.0,
strokeWeight: 2.0,
fillColor: 'white',
fillOpacity: 0.1, // Polygons must be visible to receive events.
};
// Style for the clicked polygon.
const styleClicked = {
...styleDefault,
fillColor: '#810FCB',
fillOpacity: 0.5,
};
// Style for polygon on mouse move.
const styleMouseMove = {
...styleDefault,
strokeWeight: 4.0,
};
// Apply styles using a feature style function.
function applyStyle(/* FeatureStyleFunctionOptions */ params) {
const placeId = params.feature.placeId;
//@ts-ignore
if (lastClickedFeatureIds.includes(placeId)) {
return styleClicked;
}
//@ts-ignore
if (lastInteractedFeatureIds.includes(placeId)) {
return styleMouseMove;
}
return styleDefault;
}
// Helper function to create an info window.
function updateInfoWindow(content, center) {
infoWindow.setContent(content);
infoWindow.setPosition(center);
infoWindow.open({
map,
shouldFocus: false,
});
}
initMap();
JavaScript
let map;
let featureLayer;
let infoWindow;
let lastInteractedFeatureIds = [];
let lastClickedFeatureIds = [];
function handleClick(/* MouseEvent */ e) {
lastClickedFeatureIds = e.features.map((f) => f.placeId);
lastInteractedFeatureIds = [];
featureLayer.style = applyStyle;
createInfoWindow(e);
}
function handleMouseMove(/* MouseEvent */ e) {
lastInteractedFeatureIds = e.features.map((f) => f.placeId);
featureLayer.style = applyStyle;
}
async function initMap() {
// Request needed libraries.
const { Map, InfoWindow } = await google.maps.importLibrary("maps");
map = new Map(document.getElementById("map"), {
center: { lat: 39.23, lng: -105.73 },
zoom: 8,
// In the cloud console, configure your Map ID with a style that enables the
// 'Administrative Area Level 2' Data Driven Styling type.
mapId: "a3efe1c035bad51b",
mapTypeControl: false,
});
// Add the feature layer.
//@ts-ignore
featureLayer = map.getFeatureLayer("ADMINISTRATIVE_AREA_LEVEL_2");
// Add the event listeners for the feature layer.
featureLayer.addListener("click", handleClick);
featureLayer.addListener("mousemove", handleMouseMove);
// Map event listener.
map.addListener("mousemove", () => {
// If the map gets a mousemove, that means there are no feature layers
// with listeners registered under the mouse, so we clear the last
// interacted feature ids.
if (lastInteractedFeatureIds?.length) {
lastInteractedFeatureIds = [];
featureLayer.style = applyStyle;
}
});
// Create the infowindow.
infoWindow = new InfoWindow({});
// Apply style on load, to enable clicking.
featureLayer.style = applyStyle;
}
// Helper function for the infowindow.
async function createInfoWindow(event) {
let feature = event.features[0];
if (!feature.placeId) return;
// Update the infowindow.
const place = await feature.fetchPlace();
let content =
'<span style="font-size:small">Display name: ' +
place.displayName +
"<br/> Place ID: " +
feature.placeId +
"<br/> Feature type: " +
feature.featureType +
"</span>";
updateInfoWindow(content, event.latLng);
}
// Define styles.
// Stroke and fill with minimum opacity value.
const styleDefault = {
strokeColor: "#810FCB",
strokeOpacity: 1.0,
strokeWeight: 2.0,
fillColor: "white",
fillOpacity: 0.1, // Polygons must be visible to receive events.
};
// Style for the clicked polygon.
const styleClicked = {
...styleDefault,
fillColor: "#810FCB",
fillOpacity: 0.5,
};
// Style for polygon on mouse move.
const styleMouseMove = {
...styleDefault,
strokeWeight: 4.0,
};
// Apply styles using a feature style function.
function applyStyle(/* FeatureStyleFunctionOptions */ params) {
const placeId = params.feature.placeId;
//@ts-ignore
if (lastClickedFeatureIds.includes(placeId)) {
return styleClicked;
}
//@ts-ignore
if (lastInteractedFeatureIds.includes(placeId)) {
return styleMouseMove;
}
return styleDefault;
}
// Helper function to create an info window.
function updateInfoWindow(content, center) {
infoWindow.setContent(content);
infoWindow.setPosition(center);
infoWindow.open({
map,
shouldFocus: false,
});
}
initMap();
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>Handle Region Boundary Click Event</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script type="module" src="./index.js"></script>
</head>
<body>
<div id="map"></div>
<!-- prettier-ignore -->
<script>(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: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "weekly"});</script>
</body>
</html>
Try Sample
Clone Sample
Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.
git clone -b sample-boundaries-click https://github.com/googlemaps/js-samples.gitcd js-samplesnpm inpm start
Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME.
git checkout sample-SAMPLE_NAMEnpm inpm start