feat: dynamically track mutability of messages (#6367)

src/common/Channel.cpp

@@ -79,6 +79,8 @@ LimitedQueueSnapshot<MessagePtr> Channel::getMessageSnapshot()
 void Channel::addMessage(MessagePtr message, MessageContext context,
                          std::optional<MessageFlags> overridingFlags)
 {
+    message->freeze();
+
     MessagePtr deleted;
 
     if (context == MessageContext::Original && this->getType() != Type::None)
@@ -157,6 +159,11 @@ void Channel::disableAllMessages()
 
 void Channel::addMessagesAtStart(const std::vector<MessagePtr> &_messages)
 {
+    for (const auto &msg : _messages)
+    {
+        msg->freeze();
+    }
+
     std::vector<MessagePtr> addedMessages =
         this->messages_.pushFront(_messages);
 
@@ -172,6 +179,10 @@ void Channel::fillInMissingMessages(const std::vector<MessagePtr> &messages)
     {
         return;
     }
+    for (const auto &msg : messages)
+    {
+        msg->freeze();
+    }
 
     auto snapshot = this->getMessageSnapshot();
     if (snapshot.size() == 0)
@@ -256,6 +267,7 @@ void Channel::fillInMissingMessages(const std::vector<MessagePtr> &messages)
 void Channel::replaceMessage(const MessagePtr &message,
                              const MessagePtr &replacement)
 {
+    replacement->freeze();
     int index = this->messages_.replaceItem(message, replacement);
 
     if (index >= 0)
@@ -266,6 +278,8 @@ void Channel::replaceMessage(const MessagePtr &message,
 
 void Channel::replaceMessage(size_t index, const MessagePtr &replacement)
 {
+    replacement->freeze();
+
     MessagePtr prev;
     if (this->messages_.replaceItem(index, replacement, &prev))
     {
@@ -276,6 +290,8 @@ void Channel::replaceMessage(size_t index, const MessagePtr &replacement)
 void Channel::replaceMessage(size_t hint, const MessagePtr &message,
                              const MessagePtr &replacement)
 {
+    replacement->freeze();
+
     auto index = this->messages_.replaceItem(hint, message, replacement);
     if (index >= 0)
     {

src/messages/Message.cpp

@@ -107,6 +107,7 @@ QJsonObject Message::toJson() const
         {"count"_L1, static_cast<qint64>(this->count)},
         {"serverReceivedTime"_L1,
          this->serverReceivedTime.toString(Qt::ISODate)},
+        {"frozen"_L1, this->frozen},
     };
 
     QJsonArray badges;

src/messages/Message.hpp

@@ -86,6 +86,16 @@ struct Message {
     };
     ReplyStatus isReplyable() const;
     uint32_t count = 1;
+
+    /// Can this message be modified?
+    ///
+    /// Our rendering and layout code expects messages to be mostly immutable.
+    /// Thus, when this flag is set, this message may not be modified.
+    /// Only flags and this member can be modified safely (from the GUI thread).
+    /// This is only used for plugins right now. This value is only ever set to
+    /// true.
+    mutable bool frozen = false;
+
     std::vector<std::unique_ptr<MessageElement>> elements;
 
     ScrollbarHighlight getScrollBarHighlight() const;
@@ -93,6 +103,11 @@ struct Message {
     std::shared_ptr<ChannelPointReward> reward = nullptr;
 
     QJsonObject toJson() const;
+
+    void freeze() const
+    {
+        this->frozen = true;
+    }
 };
 
 }  // namespace chatterino