Showing a content Div on hover of a marker in HERE Maps

Question

I am new to here maps and need to show a div on marker hover. I have been able to put markers with icons but now need to show a div with some extra information. Does HERE maps API provide this functionality? Any doc URL or piece of code will be appreciated. NOTE: I am using HERE maps JS API for web.

Answer 1

You can create a tooltip effect by adding various event listeners to the map to check if the mouse pointer is over an object.

(function (ctx) {
  // ensure CSS is injected
  var tooltipStyleNode = ctx.createElement('style'),
    css = '#nm_tooltip{' +
      ' color:white;' +
      ' background:black;' +
      ' border: 1px solid grey;' +
      ' padding-left: 1em; ' +
      ' padding-right: 1em; ' +
      ' display: none;  ' +
      ' min-width: 120px;  ' +
      '}';

  tooltipStyleNode.type = 'text/css';
  if (tooltipStyleNode.styleSheet) { // IE
    tooltipStyleNode.styleSheet.cssText = css;
  } else {
    tooltipStyleNode.appendChild(ctx.createTextNode(css));
  }
  if (ctx.body) {
    ctx.body.appendChild(tooltipStyleNode);
  } else if (ctx.addEventListener) {
    ctx.addEventListener('DOMContentLoaded',  function () {
      ctx.body.appendChild(tooltipStyleNode);
    }, false);
  } else {
    ctx.attachEvent('DOMContentLoaded',  function () {
      ctx.body.appendChild(tooltipStyleNode);
    });
  }
})(document);


Object.defineProperty(Tooltip.prototype, 'visible', {
  get: function() {
    return this._visible;
  },
  set: function(visible) {
    this._visible = visible;
    this.tooltip.style.display = visible ? 'block' : 'none';
  }
});


function Tooltip(map) {
  var that = this;
  that.map = map;
  that.tooltip  = document.createElement('div');
  that.tooltip.id = 'nm_tooltip';
  that.tooltip.style.position = 'absolute';
  obj = null,
  showTooltip = function () {
    var point = that.map.geoToScreen(obj.getPosition()),
      left = point.x - (that.tooltip.offsetWidth / 2),
      top = point.y + 1; // Slight offset to avoid flicker.
    that.tooltip.style.left = left + 'px';
    that.tooltip.style.top = top + 'px';
    that.visible = true;
    that.tooltip.innerHTML =  obj.title;
  };


  map.getElement().appendChild(that.tooltip);
  map.addEventListener('pointermove', function (evt) {
    obj = that.map.getObjectAt(evt.currentPointer.viewportX,
        evt.currentPointer.viewportY);
    if(obj && obj.title){
      showTooltip();
    } else {
      that.visible = false;
    }
  });

  map.addEventListener('tap', function (evt){
    that.tooltip.visible  = false;
  });
  map.addEventListener('drag', function (evt){
    if (that.visible) {
      showTooltip();
    }
  });
};

This is initialised by passing the map object as shown:

function addTooltipControlToMap(map) {
  tooltip = new Tooltip(map);
}

The code as written is looking for a .title attribute to be added to the map objects - this could be updated to use .getData() if preferred. Tooltips can be initialised as shown below, taking either text or html:

function addMarkersWithTooltips(map) {

    // Simple Marker with tooltip
  var brandenburgerTorMarker = new H.map.Marker(
    {lat:52.516237, lng: 13.35}),
    fernsehturmMarker = new H.map.Marker(
      {lat:52.520816, lng:13.409417});

  brandenburgerTorMarker.title = 'Brandenburger Tor';

  // Marker with HTML Tooltip
  fernsehturmMarker.title ='<div>' +
    '<h2>Tooltip with HTML content<\/h2>' +
    '<img width=\'120\' height=90 src=' +
    '\'http://upload.wikimedia.org/wikipedia/commons/' +
    '8/84/Berlin-fernsehturm.JPG\' ' +
    'alt=\'\'/><br/><b>Fernsehturm, Berlin<\/b>' +
    '<\/div>';

  // Add the markers onto the map
  map.addObjects([brandenburgerTorMarker, fernsehturmMarker]);
}