External map

main.js

import 'ol/ol.css';
import Map from 'ol/Map';
import OSM from 'ol/source/OSM';
import TileLayer from 'ol/layer/Tile';
import View from 'ol/View';
import {
  Control,
  FullScreen,
  defaults as defaultControls,
} from 'ol/control';
import {fromLonLat} from 'ol/proj';

class UnusableMask extends Control {
  constructor() {
    super({
      element: document.createElement('div'),
    });
    this.element.setAttribute('hidden', 'hidden');
    this.element.className = 'ol-mask';
    this.element.innerHTML = '<div>Map not usable</div>';
  }
}

const localMapTarget = document.getElementById('map');

const map = new Map({
  target: localMapTarget,
  controls: defaultControls().extend([new FullScreen(), new UnusableMask()]),
  layers: [
    new TileLayer({
      source: new OSM(),
    }),
  ],
  view: new View({
    center: fromLonLat([37.41, 8.82]),
    zoom: 4,
  }),
});

let mapWindow;
function closeMapWindow() {
  if (mapWindow) {
    mapWindow.close();
    mapWindow = undefined;
  }
}
// Close external window in case the main page is closed or reloaded
window.addEventListener('pagehide', closeMapWindow);

const button = document.getElementById('external-map-button');

function resetMapTarget() {
  localMapTarget.style.height = '';
  map.setTarget(localMapTarget);
  button.disabled = false;
}

function updateOverlay() {
  if (!mapWindow) {
    return;
  }
  const externalMapTarget = mapWindow.document.getElementById('map');
  if (!externalMapTarget) {
    return;
  }
  if (document.visibilityState === 'visible') {
    // Show controls and enable keyboard input
    externalMapTarget.classList.remove('unusable');
    externalMapTarget.setAttribute('tabindex', '0');
    externalMapTarget.focus();
  } else {
    // Hide all controls and disable keyboard input
    externalMapTarget.removeAttribute('tabindex');
    externalMapTarget.classList.add('unusable');
  }
}
window.addEventListener('visibilitychange', updateOverlay);

button.addEventListener('click', function () {
  const blockerNotice = document.getElementById('blocker-notice');
  blockerNotice.setAttribute('hidden', 'hidden');
  button.disabled = true;

  // Reset button and map target in case window did not load or open
  let timeoutKey = setTimeout(function () {
    closeMapWindow();
    resetMapTarget();
    blockerNotice.removeAttribute('hidden');
    timeoutKey = undefined;
  }, 3000);

  mapWindow = window.open(
    'resources/external-map-map.html',
    'MapWindow',
    'toolbar=0,location=0,menubar=0,width=800,height=600'
  );
  mapWindow.addEventListener('DOMContentLoaded', function () {
    const externalMapTarget = mapWindow.document.getElementById('map');
    localMapTarget.style.height = '0px';
    map.setTarget(externalMapTarget);

    if (timeoutKey) {
      timeoutKey = clearTimeout(timeoutKey);
    }
    mapWindow.addEventListener('pagehide', function () {
      resetMapTarget();
      // Close window in case user does a page reload
      closeMapWindow();
    });

    updateOverlay();
  });
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>External map</title>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/elm-pep"></script>
    <!-- The lines below are only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v3/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,TextDecoder"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/3.18.3/minified.js"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <input id="external-map-button" type="button" value="Open external map"></input>
    <span id="blocker-notice" hidden>Could not open map in external window. If you are using a popup or ad blocker you may need to disable it for this example.</span>
    <script src="main.js"></script>
  </body>
</html>

resources/external-map-map.html

<html lang="en">
  <head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="../css/ol.css" type="text/css">
    <style>
      body {
        margin: 0;
      }
      .map {
        height: 100%;
      }
      .map.unusable .ol-mask {
        height: 100%;
        display: flex;
        align-items: center;
        justify-content: center;
        user-select: none;
        background-color: rgba(0, 0, 0, .7);
        color: white;
        font: bold 3rem 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      }
      .map.unusable .ol-control {
        display: none;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
  </body>
</html>

External map

main.js

index.html

resources/external-map-map.html

package.json