Comparing layers
This example allows comparison of two layers with resizable map panes using the Split.js library.
TypeScript
function initMap(): void { const mapOptions = { center: { lat: 44.5250489, lng: -110.83819 }, zoom: 18, scaleControl: false, streetViewControl: false, }; // instantiate the map on the left with control positioning mapLeft = new google.maps.Map( document.getElementById("map-left") as HTMLElement, { ...mapOptions, mapTypeId: "satellite", tilt: 0, // at high zoom levels we need to maintain the same projection fullscreenControlOptions: { position: google.maps.ControlPosition.LEFT_BOTTOM, }, mapTypeControlOptions: { position: google.maps.ControlPosition.LEFT_TOP, }, zoomControlOptions: { position: google.maps.ControlPosition.LEFT_BOTTOM, }, } ); // instantiate the map on the right with control positioning mapRight = new google.maps.Map( document.getElementById("map-right") as HTMLElement, { ...mapOptions, fullscreenControlOptions: { position: google.maps.ControlPosition.RIGHT_BOTTOM, }, mapTypeControlOptions: { position: google.maps.ControlPosition.RIGHT_TOP, }, zoomControlOptions: { position: google.maps.ControlPosition.RIGHT_BOTTOM, }, } ); // helper function to keep maps in sync function sync(...maps: google.maps.Map[]) { let center: google.maps.LatLng, zoom: number; function update(changedMap) { maps.forEach((m) => { if (m === changedMap) { return; } m.setCenter(center); m.setZoom(zoom); }); } maps.forEach((m) => { m.addListener("bounds_changed", () => { const changedCenter = m.getCenter()!; const changedZoom = m.getZoom()!; if (changedCenter !== center || changedZoom !== zoom) { center = changedCenter; zoom = changedZoom; update(m); } }); }); } sync(mapLeft, mapRight); function handleContainerResize() { const width = (document.getElementById("container") as HTMLElement) .offsetWidth; ( document.getElementById("map-left") as HTMLElement ).style.width = `${width}px`; ( document.getElementById("map-right") as HTMLElement ).style.width = `${width}px`; } // trigger to set map container size since using absolute handleContainerResize(); // add event listener window.addEventListener("resize", handleContainerResize); //@ts-ignore Split(["#left", "#right"], { sizes: [50, 50], }); } declare global { interface Window { initMap: () => void; } } window.initMap = initMap;
JavaScript
function initMap() { const mapOptions = { center: { lat: 44.5250489, lng: -110.83819 }, zoom: 18, scaleControl: false, streetViewControl: false, }; // instantiate the map on the left with control positioning mapLeft = new google.maps.Map(document.getElementById("map-left"), { ...mapOptions, mapTypeId: "satellite", tilt: 0, // at high zoom levels we need to maintain the same projection fullscreenControlOptions: { position: google.maps.ControlPosition.LEFT_BOTTOM, }, mapTypeControlOptions: { position: google.maps.ControlPosition.LEFT_TOP, }, zoomControlOptions: { position: google.maps.ControlPosition.LEFT_BOTTOM, }, }); // instantiate the map on the right with control positioning mapRight = new google.maps.Map(document.getElementById("map-right"), { ...mapOptions, fullscreenControlOptions: { position: google.maps.ControlPosition.RIGHT_BOTTOM, }, mapTypeControlOptions: { position: google.maps.ControlPosition.RIGHT_TOP, }, zoomControlOptions: { position: google.maps.ControlPosition.RIGHT_BOTTOM, }, }); // helper function to keep maps in sync function sync(...maps) { let center, zoom; function update(changedMap) { maps.forEach((m) => { if (m === changedMap) { return; } m.setCenter(center); m.setZoom(zoom); }); } maps.forEach((m) => { m.addListener("bounds_changed", () => { const changedCenter = m.getCenter(); const changedZoom = m.getZoom(); if (changedCenter !== center || changedZoom !== zoom) { center = changedCenter; zoom = changedZoom; update(m); } }); }); } sync(mapLeft, mapRight); function handleContainerResize() { const width = document.getElementById("container").offsetWidth; document.getElementById("map-left").style.width = `${width}px`; document.getElementById("map-right").style.width = `${width}px`; } // trigger to set map container size since using absolute handleContainerResize(); // add event listener window.addEventListener("resize", handleContainerResize); //@ts-ignore Split(["#left", "#right"], { sizes: [50, 50], }); } 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; } #container, #left, #right, .map, .gutter { height: 100%; } #left, #right, .gutter { float: left; position: relative; overflow: hidden; } #map-left { position: absolute; left: 0; top: 0; } #map-right { position: absolute; right: 0; top: 0; } .gutter { background-color: #eee; background-repeat: no-repeat; background-position: 50%; } .gutter.gutter-horizontal { cursor: col-resize; background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAeCAYAAADkftS9AAAAIklEQVQoU2M4c+bMfxAGAgYYmwGrIIiDjrELjpo5aiZeMwF+yNnOs5KSvgAAAABJRU5ErkJggg=="); }
HTML
<html> <head> <title>Split Map Panes</title> <script src="https://cdnjs.cloudflare.com/ajax/libs/split.js/1.5.11/split.min.js"></script> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="container"> <div id="left"> <div id="map-left" class="map"></div> </div> <div id="right"> <div id="map-right" class="map"></div> </div> </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-split-map-panes https://github.com/googlemaps/js-samples.git
cd js-samples
npm i
npm start
Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME
.
git checkout sample-SAMPLE_NAME
npm i
npm start