/** Notify that the folder has changed. */
 public void onFolderUpdated(Folder folder) {
   if (folder == null) {
     return;
   }
   /** True if we are changing folders. */
   final boolean changingFolders = (mFolder == null || !mFolder.equals(folder));
   mFolder = folder;
   setFolderAndAccount(changingFolders);
   final ConversationListContext listContext =
       mController == null ? null : mController.getCurrentListContext();
   if (changingFolders && !ConversationListContext.isSearchResult(listContext)) {
     closeSearchField();
   }
 }