title: AmCharts, capturing click event for period selector
body: <p>I'm using AmCharts 3 and I was wondering is there a way to capture an event for clicking the buttons of the period selector?</p>
  
  <p><a href="http://docs.amcharts.com/3/javascriptstockchart/PeriodSelector" rel="nofollow">The Docs</a> state I can add a listener to the period selector of the type 'changed' but then the event runs almost anytime</p>
  
  <p>There is a listener for 'zoomed', but it runs every time I zoom my chart regardless if I clicked the period selector</p>
  
  <p>Here's my attempt:</p>
  
  <pre><code>chart = AmCharts.makeChart(scope.vm.chartId, chartSettings);
      AmCharts.addInitHandler(function () {
      // add events to item
      _.each(chart.panels, function (item) {
      //item.addListener("zoomed", onZoomed);
      item.addListener("changed", function(e) {
      console.debug("changed " + e.periodString);
     });
   });
  });
  </code></pre>