Animating Symbols

by Wolf

HTML

<div id="map"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>

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;
}

JavaScript

// This example adds an animated symbol to a polyline.

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 20.291, lng: 153.027},
    zoom: 6,
    mapTypeId: 'terrain'
  });

  // Define the symbol, using one of the predefined paths ('CIRCLE')
  // supplied by the Google Maps JavaScript API.
  var lineSymbol = {
    path: google.maps.SymbolPath.CIRCLE,
    scale: 8,
    strokeColor: '#393'
  };

  // Create the polyline and add the symbol to it via the 'icons' property.
  var line = new google.maps.Polyline({
    path: [{lat: 22.291, lng: 153.027}, {lat: 18.291, lng: 153.027}],
    icons: [{
      icon: lineSymbol,
      offset: '100%'
    }],
    map: map
  });

  animateCircle(line);
}

// Use the DOM setInterval() function to change the offset of the symbol
// at fixed intervals.
function animateCircle(line) {
    var count = 0;
    window.setInterval(function() {
      count = (count + 1) % 200;

      var icons = line.get('icons');
      icons[0].offset = (count / 2) + '%';
      line.set('icons', icons);
  }, 20);
}