Custom control example

Shows how to create custom controls.

This example creates a "rotate to north" button.

custom, control
<!DOCTYPE html>
<html>
<head>
<title>Custom control example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://openlayers.org/en/v3.9.0/css/ol.css" type="text/css">
<script src="http://openlayers.org/en/v3.9.0/build/ol.js"></script>

<style>
.rotate-north {
  top: 65px;
  left: .5em;
}
.ol-touch .rotate-north {
  top: 80px;
}

</style>
</head>
<body>
<div class="container-fluid">

<div class="row-fluid">
  <div class="span12">
    <div id="map" class="map"></div>
  </div>
</div>

</div>
<script>
/**
 * Define a namespace for the application.
 */
window.app = {};
var app = window.app;


//
// Define rotate to north control.
//



/**
 * @constructor
 * @extends {ol.control.Control}
 * @param {Object=} opt_options Control options.
 */
app.RotateNorthControl = function(opt_options) {

  var options = opt_options || {};

  var button = document.createElement('button');
  button.innerHTML = 'N';

  var this_ = this;
  var handleRotateNorth = function(e) {
    this_.getMap().getView().setRotation(0);
  };

  button.addEventListener('click', handleRotateNorth, false);
  button.addEventListener('touchstart', handleRotateNorth, false);

  var element = document.createElement('div');
  element.className = 'rotate-north ol-unselectable ol-control';
  element.appendChild(button);

  ol.control.Control.call(this, {
    element: element,
    target: options.target
  });

};
ol.inherits(app.RotateNorthControl, ol.control.Control);


//
// Create map, giving it a rotate to north control.
//


var map = new ol.Map({
  controls: ol.control.defaults({
    attributionOptions: /** @type {olx.control.AttributionOptions} */ ({
      collapsible: false
    })
  }).extend([
    new app.RotateNorthControl()
  ]),
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 2,
    rotation: 1
  })
});

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