polyline-remove

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>Removing Polylines</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 center="0, -180" zoom="3">
      <div id="floating-panel" slot="control-block-start-inline-center">
        <input id="remove-line" type="button" value="Remove line" />
        <input id="add-line" type="button" value="Restore line" />
      </div>
    </gmp-map>
  </body>
</html>

CSS

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

/* 
 * 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;
}

#floating-panel {
  position: absolute;
  top: 10px;
  left: 25%;
  z-index: 5;
  background-color: #fff;
  padding: 5px;
  border: 1px solid #999;
  text-align: center;
  font-family: 'Roboto', sans-serif;
  line-height: 30px;
  padding-left: 10px;
}

JavaScript

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

// This example adds a UI control allowing users to remove the polyline
// from the map.

let flightPath;
const mapElement = document.querySelector('gmp-map');
let innerMap;

async function init() {
  const { Polyline } = await google.maps.importLibrary('maps');
  innerMap = mapElement.innerMap;

  const flightPathCoordinates = [
    { lat: 37.772, lng: -122.214 },
    { lat: 21.291, lng: -157.821 },
    { lat: -18.142, lng: 178.431 },
    { lat: -27.467, lng: 153.027 },
  ];

  flightPath = new Polyline({
    path: flightPathCoordinates,
    strokeColor: '#FF0000',
    strokeOpacity: 1.0,
    strokeWeight: 2,
  });

  // add event listener for click event
  document.getElementById('add-line').addEventListener('click', addLine);
  document.getElementById('remove-line').addEventListener('click', removeLine);

  // initialize with line
  addLine();
}

function addLine() {
  flightPath.setMap(innerMap);
}

function removeLine() {
  flightPath.setMap(null);
}

void init();