Zooming to a Set of Markers

Alter the viewport to ensure a group of objects are visible

by dvojka

HTML

<script src="https://heremaps.github.io/maps-api-for-javascript-examples/test-credentials.js"></script>
<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=yes">
    <meta http-equiv="Content-type" content="text/html;charset=UTF-8">
    <title>Zooming to a Set of Markers using padding</title>
    <link rel="stylesheet" type="text/css" href="https://js.api.here.com/v3/3.1/mapsjs-ui.css" />
    <link rel="stylesheet" type="text/css" href="demo.css" />
    <link rel="stylesheet" type="text/css" href="styles.css" />
    <link rel="stylesheet" type="text/css" href="../template.css" />
    <script type="text/javascript" src='../test-credentials.js'></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-core.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-service.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-ui.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-mapevents.js"></script>
  </head>
  <body id="markers-on-the-map">
    <div class="page-header">
        <h3>Zooming to a Set of Markers using padding</h3>
        <p>Alter the viewport to ensure a group of objects are visible</p>
    </div>
    <div id="map"></div>
    <script type="text/javascript" src='demo.js'></script>
  </body>
</html>

CSS

#map {
    width: 95%;
    height: 400px;
    background: grey;
}

#panel {
    width: 100%;
    height: 400px;
}

JavaScript

/**
 * Adds three markers and alters the view bounds of the map to ensure that all
 * markers are visible
 *
 * @param  {H.Map} map      A HERE Map instance within the application
 */
function addMarkersAndSetViewBounds() {
  // create map objects
  var toronto = new H.map.Marker({lat:43.7,  lng:-79.4}),
      boston = new H.map.Marker({lat:42.35805, lng:-71.0636}),
      washington = new H.map.Marker({lat:38.8951, lng:-77.0366}),
      group = new H.map.Group();

  // add markers to the group
  group.addObjects([toronto, boston, washington]);
  map.addObject(group);

  // get geo bounding box for the group and set it to the map
  map.getViewModel().setLookAtData({
    bounds: group.getBoundingBox()
  });
}

/**
 * Boilerplate map initialization code starts below:
 */

//Step 1: initialize communication with the platform
// In your own code, replace variable window.apikey with your own apikey
var platform = new H.service.Platform({
  apikey: window.apikey
});
var defaultLayers = platform.createDefaultLayers();

//Step 2: initialize a map - this map is centered over Europe
// note that all the markers are in North America...
var map = new H.Map(document.getElementById('map'),
  defaultLayers.vector.normal.map,{
  center: {lat:52, lng:5},
  zoom: 5,
  pixelRatio: window.devicePixelRatio || 1,
  padding: {top: 50, left: 50, bottom: 50, right: 50}
});
// add a resize listener to make sure that the map occupies the whole container
window.addEventListener('resize', () => map.getViewPort().resize());

//Step 3: make the map interactive
// MapEvents enables the event system
// Behavior implements default interactions for pan/zoom (also on mobile touch environments)
var behavior = new H.mapevents.Behavior(new H.mapevents.MapEvents(map));

// Now use the map as required...
addMarkersAndSetViewBounds(map);