Openlayers - Drag Features

by astanislaus

HTML

<link rel="stylesheet" href="https://openlayers.org/en/v3.20.1/css/ol.css">
<script src="https://openlayers.org/en/v3.20.1/build/ol.js"></script>
<div id="map" class="map"></div>
<div id="msg">Drag the markers</div>

CSS

html, body, #map { width:100%; height:100%; margin:0; }
#map {
    position: absolute;
    z-index: 5;
}
#msg {
    position: absolute;
    z-index: 10;
    left: 50%;
    transform: translate(-50%, 5px);
    background-color: rgba(40,40,40,.8);
    padding: 10px;
    color: #eee;
    width: 350px;
    text-align: center;
}

JavaScript

var coord1 = [-5707673.76, -3499420.81];
var coord2 = [-6707673.76, -3499420.81];

var lineStyle = new ol.style.Style({
  stroke: new ol.style.Stroke({ color: '#ffcc33', width: 3 })
});
var styleMarker = new ol.style.Style({
  image: new ol.style.Icon({
    scale: .7, anchor: [0.5, 1],
    src: '//raw.githubusercontent.com/jonataswalker/map-utils/master/images/marker.png'
  })
});

var marker1 = new ol.geom.Point(coord1);
var featureMarker1 = new ol.Feature(marker1);
var marker2 = new ol.geom.Point(coord2);
var featureMarker2 = new ol.Feature(marker2);

var line = new ol.geom.LineString([coord1, coord2]);
var lineFeature = new ol.Feature(line);

var vector = new ol.layer.Vector({
  source: new ol.source.Vector({
  	features: [lineFeature, featureMarker1, featureMarker2]
  }),
  style: [lineStyle, styleMarker]
});

var map = new ol.Map({
	target: 'map',
  layers: [new ol.layer.Tile({ source: new ol.source.OSM() }), vector],
  view: new ol.View({ center: coord1, zoom: 5 })
});

var translate1 = new ol.interaction.Translate({
	features: new ol.Collection([featureMarker1])
});
var translate2 = new ol.interaction.Translate({
	features: new ol.Collection([featureMarker2])
});
map.addInteraction(translate1);
map.addInteraction(translate2);

var coordMarker1, coordMarker2;
translate1.on('translatestart', function (evt) {
  coordMarker2 = marker2.getCoordinates();
});
translate1.on('translating', function (evt) {
  line.setCoordinates([coordMarker2, evt.coordinate]);
});
translate2.on('translatestart', function (evt) {
  coordMarker1 = marker1.getCoordinates();
});
translate2.on('translating', function (evt) {
  line.setCoordinates([coordMarker1, evt.coordinate]);
});

map.on('pointermove', function(e) {
  if (e.dragging) return;
  var hit = map.hasFeatureAtPixel(map.getEventPixel(e.originalEvent));
  map.getTargetElement().style.cursor = hit ? 'pointer' : '';
});