code: function _setSelectedItem(index) {
          if (index !== this._selectedItemIndex) {
              var oldIndex = this._selectedItemIndex;
              this._selectedItemIndex = index;
              this.layout.setLayoutOptions({
                  selectedItemIndex: index
              });
              if ((oldIndex >= 0) && this._renderables.items[oldIndex].removeClass){
                  this._renderables.items[oldIndex].removeClass('selected');
              }
              if (this._renderables.items[index].addClass) {
                  this._renderables.items[index].addClass('selected');
              }
              if (oldIndex >= 0) {
                  this._eventOutput.emit('tabchange', {
                      target: this,
                      index: index,
                      oldIndex: oldIndex,
                      item: this._renderables.items[index],
                      oldItem: ((oldIndex >= 0) && (oldIndex < this._renderables.items.length)) ? this._renderables.items[oldIndex] : undefined
                  });
              }
          }
      }
docs: Helper function that is called whenever a new item is selected