Added events for when the active thread (ie the message thread that a user is responding to) changes

web/react/stores/post_store.jsx

@@ -18,6 +18,7 @@ var SEARCH_TERM_CHANGE_EVENT = 'search_term_change';
 var SELECTED_POST_CHANGE_EVENT = 'selected_post_change';
 var MENTION_DATA_CHANGE_EVENT = 'mention_data_change';
 var ADD_MENTION_EVENT = 'add_mention';
+var ACTIVE_THREAD_CHANGED_EVENT = 'active_thread_changed';
 
 var PostStore = assign({}, EventEmitter.prototype, {
 
@@ -93,6 +94,18 @@ var PostStore = assign({}, EventEmitter.prototype, {
     this.removeListener(ADD_MENTION_EVENT, callback);
   },
 
+  emitActiveThreadChanged: function(rootId, parentId) {
+    this.emit(ACTIVE_THREAD_CHANGED_EVENT, rootId, parentId);
+  },
+
+  addActiveThreadChangedListener: function(callback) {
+    this.on(ACTIVE_THREAD_CHANGED_EVENT, callback);
+  },
+
+  removeActiveThreadChangedListener: function(callback) {
+    this.removeListener(ACTIVE_THREAD_CHANGED_EVENT, callback);
+  },
+
   getCurrentPosts: function() {
     var currentId = ChannelStore.getCurrentId();
 
@@ -186,6 +199,9 @@ PostStore.dispatchToken = AppDispatcher.register(function(payload) {
     case ActionTypes.RECIEVED_ADD_MENTION:
       PostStore.emitAddMention(action.id, action.username);
       break;
+    case ActionTypes.RECEIVED_ACTIVE_THREAD_CHANGED:
+      PostStore.emitActiveThreadChanged(action.root_id, action.parent_id);
+      break;
 
     default:
   }

web/react/utils/constants.jsx

@@ -18,6 +18,7 @@ module.exports = {
     RECIEVED_POST_SELECTED: null,
     RECIEVED_MENTION_DATA: null,
     RECIEVED_ADD_MENTION: null,
+    RECEIVED_ACTIVE_THREAD_CHANGED: null,
 
     RECIEVED_PROFILES: null,
     RECIEVED_ME: null,