This example demonstrates adding controls that store state. It shows a map with two buttons, "Set Center" and "Center Map". The "Set Center" button can be used to store the center of the map. Pressing the "Center Map" button will pan the map to the previously stored center.
Read the documentation.
TypeScript
let map: google.maps.Map;
const chicago: google.maps.LatLngLiteral = { lat: 41.85, lng: -87.65 };
/**
* The CenterControl adds a control to the map that recenters the map on
* Chicago.
*/
class CenterControl {
private map_: google.maps.Map;
private center_: google.maps.LatLng;
constructor(
controlDiv: HTMLElement,
map: google.maps.Map,
center: google.maps.LatLngLiteral
) {
this.map_ = map;
// Set the center property upon construction
this.center_ = new google.maps.LatLng(center);
controlDiv.style.clear = "both";
// Set CSS for the control border
const goCenterUI = document.createElement("button");
goCenterUI.id = "goCenterUI";
goCenterUI.title = "Click to recenter the map";
controlDiv.appendChild(goCenterUI);
// Set CSS for the control interior
const goCenterText = document.createElement("div");
goCenterText.id = "goCenterText";
goCenterText.innerHTML = "Center Map";
goCenterUI.appendChild(goCenterText);
// Set CSS for the setCenter control border
const setCenterUI = document.createElement("button");
setCenterUI.id = "setCenterUI";
setCenterUI.title = "Click to change the center of the map";
controlDiv.appendChild(setCenterUI);
// Set CSS for the control interior
const setCenterText = document.createElement("div");
setCenterText.id = "setCenterText";
setCenterText.innerHTML = "Set Center";
setCenterUI.appendChild(setCenterText);
// Set up the click event listener for 'Center Map': Set the center of
// the map
// to the current center of the control.
goCenterUI.addEventListener("click", () => {
const currentCenter = this.center_;
this.map_.setCenter(currentCenter);
});
// Set up the click event listener for 'Set Center': Set the center of
// the control to the current center of the map.
setCenterUI.addEventListener("click", () => {
const newCenter = this.map_.getCenter()!;
if (newCenter) {
this.center_ = newCenter;
}
});
}
}
function initMap(): void {
map = new google.maps.Map(document.getElementById("map") as HTMLElement, {
zoom: 12,
center: chicago,
});
// Create the DIV to hold the control and call the CenterControl()
// constructor passing in this DIV.
const centerControlDiv = document.createElement("div");
const control = new CenterControl(centerControlDiv, map, chicago);
// @ts-ignore
centerControlDiv.index = 1;
centerControlDiv.style.paddingTop = "10px";
map.controls[google.maps.ControlPosition.TOP_CENTER].push(centerControlDiv);
}
declare global {
interface Window {
initMap: () => void;
}
}
window.initMap = initMap;
JavaScript
let map;
const chicago = { lat: 41.85, lng: -87.65 };
/**
* The CenterControl adds a control to the map that recenters the map on
* Chicago.
*/
class CenterControl {
map_;
center_;
constructor(controlDiv, map, center) {
this.map_ = map;
// Set the center property upon construction
this.center_ = new google.maps.LatLng(center);
controlDiv.style.clear = "both";
// Set CSS for the control border
const goCenterUI = document.createElement("button");
goCenterUI.id = "goCenterUI";
goCenterUI.title = "Click to recenter the map";
controlDiv.appendChild(goCenterUI);
// Set CSS for the control interior
const goCenterText = document.createElement("div");
goCenterText.id = "goCenterText";
goCenterText.innerHTML = "Center Map";
goCenterUI.appendChild(goCenterText);
// Set CSS for the setCenter control border
const setCenterUI = document.createElement("button");
setCenterUI.id = "setCenterUI";
setCenterUI.title = "Click to change the center of the map";
controlDiv.appendChild(setCenterUI);
// Set CSS for the control interior
const setCenterText = document.createElement("div");
setCenterText.id = "setCenterText";
setCenterText.innerHTML = "Set Center";
setCenterUI.appendChild(setCenterText);
// Set up the click event listener for 'Center Map': Set the center of
// the map
// to the current center of the control.
goCenterUI.addEventListener("click", () => {
const currentCenter = this.center_;
this.map_.setCenter(currentCenter);
});
// Set up the click event listener for 'Set Center': Set the center of
// the control to the current center of the map.
setCenterUI.addEventListener("click", () => {
const newCenter = this.map_.getCenter();
if (newCenter) {
this.center_ = newCenter;
}
});
}
}
function initMap() {
map = new google.maps.Map(document.getElementById("map"), {
zoom: 12,
center: chicago,
});
// Create the DIV to hold the control and call the CenterControl()
// constructor passing in this DIV.
const centerControlDiv = document.createElement("div");
const control = new CenterControl(centerControlDiv, map, chicago);
// @ts-ignore
centerControlDiv.index = 1;
centerControlDiv.style.paddingTop = "10px";
map.controls[google.maps.ControlPosition.TOP_CENTER].push(centerControlDiv);
}
window.initMap = 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;
}
#goCenterUI,
#setCenterUI {
background-color: #fff;
border: 2px solid #fff;
border-radius: 3px;
box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
cursor: pointer;
float: left;
margin-bottom: 22px;
text-align: center;
}
#goCenterText,
#setCenterText {
color: rgb(25, 25, 25);
font-family: Roboto, Arial, sans-serif;
font-size: 15px;
line-height: 25px;
padding-left: 5px;
padding-right: 5px;
}
#setCenterUI {
margin-left: 12px;
}
HTML
<html>
<head>
<title>Adding State to Controls</title>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script type="module" src="./index.js"></script>
</head>
<body>
<div id="map"></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 these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.
git clone -b sample-control-custom-state 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