ChatItem *chatItem = dynamic_cast<ChatItem *>(itemAt(event->pos()));
BufferId bufferId = chatItem->data(MessageModel::BufferIdRole).value<BufferId>();
if(!bufferId.isValid())
ChatItem *chatItem = dynamic_cast<ChatItem *>(itemAt(event->pos()));
BufferId bufferId = chatItem->data(MessageModel::BufferIdRole).value<BufferId>();
if(!bufferId.isValid())