maptalks - Marker animation along a line

Marker animation along a line

index.html

<!DOCTYPE html>
<html>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Animation - Marker animation along a line</title>
  <style type="text/css">
    html,body{margin:0px;height:100%;width:100%}
    .container{float:left;width:100%;height:100%}
    .pane{background:#34495e;line-height:28px;color:#fff;z-index:10;position:absolute;top:20px;right:20px}
    .pane a{display:block;color:#fff;text-align:left;padding:0 10px;min-width:28px;min-height:28px;float:left}
  </style>
  <link rel="stylesheet" href="https://unpkg.com/maptalks/dist/maptalks.css">
  <script type="text/javascript" src="https://unpkg.com/maptalks/dist/maptalks.min.js"></script>
  <body>

    <div id="map" class="container"></div>
    <div class="pane"><a href="javascript:replay();">Replay</a></div>

    <script>
      var map = new maptalks.Map('map', {
        center: [-0.113049,51.498568],
        zoom: 14,
        baseLayer: new maptalks.TileLayer('base', {
          urlTemplate: 'https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png',
          subdomains: ["a","b","c","d"],
          attribution: '&copy; <a href="http://osm.org">OpenStreetMap</a> contributors, &copy; <a href="https://carto.com/">CARTO</a>'
        })
      });

      var layer = new maptalks.VectorLayer('vector', { forceRenderOnMoving : true }).addTo(map);
      var marker = new maptalks.Marker(map.getCenter()).addTo(layer);

      var start = map.getCenter(),
        // offset from line start to line end.
        offset = getOffset(),
        end = start.add(offset);

      var arrow = new maptalks.LineString(
        [start, end],
        {
          'id' : 'arrow',
          'arrowStyle' : 'classic',
          'arrowPlacement' : 'vertex-last'
        }
      )
      .addTo(layer);

      replay();

      function replay() {
        marker.setCoordinates(start);
        marker.bringToFront().animate({
          //animation translate distance
          translate: [offset['x'], offset['y']]
        }, {
          duration: 2000,
          //let map focus on the marker
          focus : true
        });
      }

      function getOffset() {
        var center = map.getCenter();
        var extent = map.getExtent();
        marker.setCoordinates(center);
        return extent.getMax().sub(map.getCenter()).multi(1 / 2);
      }

    </script>
  </body>
</html>

var map = new maptalks.Map('map', {
  center: [-0.113049, 51.498568],
  zoom: 14,
  baseLayer: new maptalks.TileLayer('base', {
    urlTemplate: 'https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png',
    subdomains: ["a", "b", "c", "d"],
    attribution: '© <a href="http://osm.org">OpenStreetMap</a>  contributors, © <a href="https://carto.com/">CARTO</a> '
  })
});

var layer = new maptalks.VectorLayer('vector', {
  forceRenderOnMoving: true
}).addTo(map);
var marker = new maptalks.Marker(map.getCenter()).addTo(layer);

var start = map.getCenter(),
  // offset from line start to line end.
  offset = getOffset(),
  end = start.add(offset);

var arrow = new maptalks.LineString(
  [start, end], {
    'id': 'arrow',
    'arrowStyle': 'classic',
    'arrowPlacement': 'vertex-last'
  }
)
  .addTo(layer);

replay();

function replay() {
  marker.setCoordinates(start);
  marker.bringToFront().animate({
    //animation translate distance
    translate: [offset['x'], offset['y']]
  }, {
    duration: 2000,
    //let map focus on the marker
    focus: true
  });
}

function getOffset() {
  var center = map.getCenter();
  var extent = map.getExtent();
  marker.setCoordinates(center);
  return extent.getMax().sub(map.getCenter()).multi(1 / 2);
}