Wijmo 5 [Allowing Checkbox for selecting row ]

This fiddle implement selecting row in group using checkbox

HTML

<link rel="stylesheet" href="http://cdn.wijmo.com/5.latest/styles/wijmo.min.css">
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="http://code.jquery.com/jquery-2.2.4.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.grid.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/interop/angular/wijmo.angular.min.js"></script>
<div ng-app="app">
        <div ng-controller="appCtrl">
            <wj-flex-grid style="height:500px;" items-source="gdata" item-formatter="itemFormatter" selection-mode="ListBox" control="flex" >
              
            </wj-flex-grid>
            <input type="button" ng-click="GetSelectedRows()" value="Get selected rows" />
            {{selection}}
        </div>
    </div>

CSS

.select{
            background:blue !important;
        }
        .deselect{
            background:red !important;
        }

JavaScript

var getData = function (value) {
            var countries = 'India,Japan,UK,US,China'.split(','),
           data = [];
            for (var i = 0; i < value; i++) {
                data.push({
                    id: i + 1,
                    country: countries[i % countries.length],
                    sales: Math.random() * 10000,
                    downloads: Math.random() * 200,
                    active: i % 3 == 0
                });
            }
            return data;
        };


        var app = angular.module('app', ['wj']);
        app.controller('appCtrl', function ($scope) {
           
            $scope.gdata = new wijmo.collections.CollectionView(getData(1000));
            var groupDesc = new wijmo.collections.PropertyGroupDescription('country');
            $scope.gdata.groupDescriptions.push(groupDesc);
            $scope.$watch('flex', function() {
                var flex = $scope.flex;
                if (flex) {
                    // add a checkbox in group header
                    flex.formatItem.addHandler(function (s, e) {
                        if (e.panel == flex.cells && flex.columns[e.col].binding == 'active') {
                            var row = flex.rows[e.row];
                          
                            if (row.dataItem.active) {
                                row.cssClass = 'select';
                            }
                            else {
                                row.cssClass = 'deselect';
                            }
                           
                             
                        }
                        if (e.panel.rows[e.row] instanceof wijmo.grid.GroupRow && e.panel.cellType != wijmo.grid.CellType.RowHeader) {
                            var chk = document.createElement('input');
                            chk.type = 'checkbox';
                            chk.style.marginLeft = '6px';
                            chk.className = 'custom-check-box';
            ...