text: var DemoApp = angular.module('DemoApp', ['dx']);
  
  DemoApp.controller('DemoController', function DemoController($scope, $element) {
      $scope.dataSource = filterData("");
      $scope.isFirstLevel = true;
  
      $scope.chartOptions = {
          bindingOptions: {
              dataSource: "dataSource",
          },
          title: "The Most Populated Countries by Continents",
          series: {
              type: "bar"
          },
          legend: {
              visible: false
          },
          valueAxis: {
              showZero: false
          },
          onPointClick: function (e) {
              if ($scope.isFirstLevel) {
                  $scope.isFirstLevel = false;
                  removePointerCursor($element);
                  $scope.dataSource = filterData(e.target.originalArgument);
              }
          },
          customizePoint: function () {
              var pointSettings = {
                  color: colors[Number($scope.isFirstLevel)]
              };
  
              if (!$scope.isFirstLevel) {
                  pointSettings.hoverStyle = {
                      hatching: "none"
                  };
              }
  
              return pointSettings;
          }
      };
      $scope.buttonOptions = {
          text: "Back",
          icon: "chevronleft",
          bindingOptions: {
              visible: "!isFirstLevel"
          },
          onClick: function () {
              if (!$scope.isFirstLevel) {
                  $scope.isFirstLevel = true;
                  addPointerCursor($element);
                  $scope.dataSource = filterData("");
              }
          }
      };
  
      addPointerCursor($element);
  });
  
  function filterData(name) {
      return data.filter(function (item) {
          return item.parentID === name;
      });
  }
  
  function addPointerCursor(element) {
      element.find("#chart").addClass("pointer-on-bars");
  }
  
  function removePointerCursor(element) {
      element.find("#chart").removeClass("pointer-on-bars");
  }