     channel        = revive channel
     listController = @getListController channel.typeConstant
     listController.addItem channel
+    @updateTopicFollowButtons channel
 
 
   removeFromChannel: (channel) ->

    listController = @getListController channel.typeConstant
    item           = listController.itemForId channel.getId()
    listController.removeItem item


  notificationHasArrived: (update) ->

      else {}

    return section.listController


  updateTopicFollowButtons: (channel) ->

    for name in ['hot', 'followedTopics']
      item = @sections[name].listController.itemForId channel.getId()
      continue  unless item
      state = if channel.isParticipant then 'Following' else 'Follow'
      item.followButton.setState state


  # fixme:
