HighCharts: Labels visible over tooltip

Question

Labels on my chart are showing over tooltip, which doesn't look very nice. I tried to play with zIndex, but to no result. How can I make tooltips not transparent? Here's my jsFiddle: http://www.jsfiddle.net/4scfH/3/

$(function() {
  var chart;
  $(document).ready(function() {
    chart = new Highcharts.Chart({
      chart: {
        renderTo: 'graf1',
        plotBackgroundColor: null,
        plotBorderWidth: null,
        plotShadow: false
      },

      title: {
        margin: 40,
        text: 'Podíl všech potřeb'
      },
      tooltip: {
        //pointFormat: '<b>{point.y} Kč [{point.percentage}%]</b>',
        percentageDecimals: 2,
        backgroundColor: "rgba(255,255,255,1)",
        formatter: function() {
          return this.point.name + '<br />' + '<b>' + Highcharts.numberFormat(this.y).replace(",", " ") + ' Kč [' + Highcharts.numberFormat(this.percentage, 2) + '%]</b>';
        }
      },
      plotOptions: {
        pie: {
          allowPointSelect: true,
          cursor: 'pointer',
          dataLabels: {
            enabled: true,
            color: '#000000',
            connectorWidth: 2,
            useHTML: true,
            formatter: function() {
              return '<span style="color:' + this.point.color + '"><b>' + this.point.name + '</b></span>';
            }
          }
        }
      },
      series: [{
        type: 'pie',
        name: 'Potřeba',
        data: [
          ['Firefox', 45.0],
          ['IE', 26.8], {
            name: 'Chrome',
            y: 12.8,
            sliced: true,
            selected: true
          },
          ['Safari', 8.5],
          ['Opera', 6.2],
          ['Others', 0.7]
        ]
      }]
    });
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://code.highcharts.com/highcharts.js"></script>
<div id="graf1" style="width: 400px; height: 250px; float:left"></div>

Answer 1

You can set useHTML and define your own tooltip via css:

http://jsfiddle.net/4scfH/4/

tooltip: {
    borderWidth: 0,
    backgroundColor: "rgba(255,255,255,0)",
    borderRadius: 0,
    shadow: false,
    useHTML: true,
    percentageDecimals: 2,
    formatter: function () {
        return '<div class="tooltip">' + this.point.name + '<br />' + '<b>' + Highcharts.numberFormat(this.y).replace(",", " ") + ' Kč [' + Highcharts.numberFormat(this.percentage, 2) + '%]</b></div>';
    }
},

CSS

.label {
    z-index: 1 !important;
}

.highcharts-tooltip span {
    background-color: white;
    border:1 px solid green;
    opacity: 1;
    z-index: 9999 !important;
}

.tooltip {
    padding: 5px;
}

Explanation: when you set useHTML to true, it displays the tooltip text as HTML on the HTML layer, but still draws an SVG shape in the highcharts display SVG for the box and arrow. You would end up with data labels looking like they were drawn on top of the tooltip, but the tooltip text itself on top of the data labels. The config options above effectively hide the SVG tooltip shape and build and style the tooltip purely with HTML/CSS. The only down-side is that you lose the little "arrow" pointer.