ctive;
      }
      if (!this.active) {
        this.unselectAllItems();
      }
    },
    
    toggle: function() {
      this.opened = !this.opened;
    },

    activate: function() {
      if (this.hasItems() && this.active) {
        this.toggle();
        this.unselectAllItems();
      }
    }
    
  });

</script>
</polymer-element>
