altered version of the olMap.Demo.js

olMap.Demo.js

var map;
var highlightStyleCache = {};
$('#btnAddDemo').click(function (evt) {
  evt.preventDefault();
  olMapControls.Layers.ReadGpx("gpx/track.gpx", "Bycycle Tour Wuppertal 100km", "id_gpx100km");

  addHoverSupport();
  
  $(this).parent().remove();
}); 


$("#" + olMapControls.map.div).on('ReadGpx', function(){    
  var index = olMapControls.Layers.Tiles.length-1;
  var value = olMapControls.Layers.Tiles[index];
  console.log("index: " + index);
  console.log("value: " + value);
  AddButtonToOverlay("tracks",index, value);

});



var addHoverSupport = function(){
  map = olMapControls.map.olmap;

  var featureOverlay = new ol.FeatureOverlay({
    map: map,
    style: function(feature, resolution) {
      var text = resolution < 5000 ? feature.get('name') : '';
      if (!highlightStyleCache[text]) {
        highlightStyleCache[text] = [new ol.style.Style({
          stroke: new ol.style.Stroke({
            color: '#f00',
            width: 1
          }),
          fill: new ol.style.Fill({
            color: 'rgba(255,0,0,0.1)'
          }),
          text: new ol.style.Text({
            font: '12px Calibri,sans-serif',
            text: text,
            fill: new ol.style.Fill({
              color: '#000'
            }),
            stroke: new ol.style.Stroke({
              color: '#f00',
              width: 3
            })
          })
        })];
      }
      return highlightStyleCache[text];
    }
  });
  map.on('pointermove', function(evt) {
    if (evt.dragging) {
      return;
    }
    var pixel = map.getEventPixel(evt.originalEvent);
    displayFeatureInfo(pixel);
  });

  map.on('click', function(evt) {
    displayFeatureInfo(evt.pixel);
  });

};

var highlight;
var displayFeatureInfo = function(pixel) {

  var feature = map.forEachFeatureAtPixel(pixel, function(feature, layer) {
    return feature;
  });

  if (feature !== highlight) {
    if (highlight) {
      featureOverlay.removeFeature(highlight);
    }
    if (feature) {
      featureOverlay.addFeature(feature);
    }
    highlight = feature;
  }

};