plugins: added cloning of message elements (#6909)

Co-authored-by: Nerixyz <nerixdev@outlook.de>
Reviewed-by: pajlada <rasmus.karlsson@pajlada.com>

docs/chatterino.d.ts

@@ -206,7 +206,7 @@ declare namespace c2 {
         highlight_color: string | null;
         frozen: boolean;
         elements(): MessageElement[];
-        append_element(init: MessageElementInit): void;
+        append_element(init: MessageElementInit | MessageElement): void;
     }
 
     interface MessageConstructor {
@@ -228,7 +228,7 @@ declare namespace c2 {
         username_color?: string;
         server_received_time?: number;
         highlight_color?: string | null;
-        elements?: MessageElementInit[];
+        elements?: (MessageElementInit | MessageElement)[];
     }
 
     interface MessageElementBase {

docs/lua-meta/globals.lua

@@ -643,9 +643,10 @@ c2.Message = {}
 function c2.Message:elements() end
 
 --- Add an element to this message.
+--- If given a MessageElement, it will be cloned before being added.
 ---
----@param init MessageElementInit The element to add
-function c2.Message:append_element(init) end
+---@param elem (MessageElement|MessageElementInit) The element to add
+function c2.Message:append_element(elem) end
 
 ---A table to initialize a new message
 ---@class MessageInit
@@ -662,7 +663,7 @@ function c2.Message:append_element(init) end
 ---@field username_color? string The color of the username
 ---@field server_received_time? number The time the server received the message (in milliseconds since epoch)
 ---@field highlight_color? string|nil The color of the highlight (if any)
----@field elements? MessageElementInit[] The elements of the message
+---@field elements? (MessageElementInit|MessageElement)[] The elements of the message
 
 ---@alias MessageColor "text"|"link"|"system"|string A color for a text element - "text", "link", and "system" are special values that take the current theme into account
 

docs/wip-plugins.md

@@ -752,6 +752,7 @@ end)
 ```
 
 The full range of options can be found in the typing files ([LuaLS](./lua-meta/globals.lua), [TypeScript](./chatterino.d.ts)).
+Existing `MessageElement`s in `elements` field of the table will be cloned regardless if they can be created in Lua.
 
 ##### `Message:elements()`
 

src/controllers/plugins/api/Message.cpp

@@ -239,70 +239,6 @@ std::unique_ptr<MessageElement> elementFromTable(const sol::table &tbl)
     return el;
 }
 
-std::shared_ptr<Message> messageFromTable(const sol::table &tbl)
-{
-    auto msg = std::make_shared<Message>();
-    msg->flags = tbl.get_or("flags", MessageFlag::None);
-
-    // This takes a UTC offset (not the milliseconds since the start of the day)
-    auto parseTime = tbl.get<std::optional<qint64>>("parse_time");
-    if (parseTime)
-    {
-        msg->parseTime = datetimeFromOffset(*parseTime).time();
-    }
-
-    msg->id = tbl.get_or("id", QString{});
-    msg->searchText = tbl.get_or("search_text", QString{});
-    msg->messageText = tbl.get_or("message_text", QString{});
-    msg->loginName = tbl.get_or("login_name", QString{});
-    msg->displayName = tbl.get_or("display_name", QString{});
-    msg->localizedName = tbl.get_or("localized_name", QString{});
-    msg->userID = tbl.get_or("user_id", QString{});
-    // missing: timeoutUser
-    msg->channelName = tbl.get_or("channel_name", QString{});
-
-    auto usernameColor = tbl.get_or("username_color", QString{});
-    if (!usernameColor.isEmpty())
-    {
-        msg->usernameColor = QColor(usernameColor);
-    }
-
-    auto serverReceivedTime =
-        tbl.get<std::optional<qint64>>("server_received_time");
-    if (serverReceivedTime)
-    {
-        msg->serverReceivedTime = datetimeFromOffset(*serverReceivedTime);
-    }
-
-    // missing: badges
-    // missing: badgeInfos
-
-    // we construct a color on the fly here
-    auto highlightColor = tbl.get_or("highlight_color", QString{});
-    if (!highlightColor.isEmpty())
-    {
-        msg->highlightColor = std::make_shared<QColor>(highlightColor);
-    }
-
-    // missing: replyThread
-    // missing: replyParent
-    // missing: count
-
-    auto elements = tbl.get<std::optional<sol::table>>("elements");
-    if (elements)
-    {
-        auto size = elements->size();
-        for (size_t i = 1; i <= size; i++)
-        {
-            msg->elements.emplace_back(
-                elementFromTable(elements->get<sol::table>(i)));
-        }
-    }
-
-    // missing: reward
-    return msg;
-}
-
 void checkWritable(Message *msg)
 {
     if (msg->frozen)
@@ -333,6 +269,8 @@ decltype(auto) memberAccessor()
         });
 }
 
+std::shared_ptr<Message> messageFromTable(const sol::table &tbl);
+
 }  // namespace
 
 namespace chatterino::lua::api::message {
@@ -852,16 +790,104 @@ void createUserType(sol::table &c2)
             return MessageElements(msg);
         },
         "append_element",
-        [](Message *msg, const sol::table &tbl) {
-            checkWritable(msg);
-            auto el = elementFromTable(tbl);
-            if (el)
-            {
-                msg->elements.emplace_back(std::move(el));
-            }
-        });
+        sol::overload(
+            // Message:append_element(MessageElementInit)
+            // Create a new element
+            [](Message *msg, const sol::table &tbl) {
+                checkWritable(msg);
+                auto el = elementFromTable(tbl);
+                if (el)
+                {
+                    msg->elements.emplace_back(std::move(el));
+                }
+            },
+            // Message:append_element(MessageElement)
+            // Create a clone of the given element and add it to the message
+            [](Message *msg, ElementRef &element) {
+                checkWritable(msg);
+                msg->elements.emplace_back(element.constElement()->clone());
+            }));
 }
 
 }  // namespace chatterino::lua::api::message
 
+namespace {
+
+using namespace chatterino;
+
+std::shared_ptr<Message> messageFromTable(const sol::table &tbl)
+{
+    auto msg = std::make_shared<Message>();
+    msg->flags = tbl.get_or("flags", MessageFlag::None);
+
+    // This takes a UTC offset (not the milliseconds since the start of the day)
+    auto parseTime = tbl.get<std::optional<qint64>>("parse_time");
+    if (parseTime)
+    {
+        msg->parseTime = datetimeFromOffset(*parseTime).time();
+    }
+
+    msg->id = tbl.get_or("id", QString{});
+    msg->searchText = tbl.get_or("search_text", QString{});
+    msg->messageText = tbl.get_or("message_text", QString{});
+    msg->loginName = tbl.get_or("login_name", QString{});
+    msg->displayName = tbl.get_or("display_name", QString{});
+    msg->localizedName = tbl.get_or("localized_name", QString{});
+    msg->userID = tbl.get_or("user_id", QString{});
+    // missing: timeoutUser
+    msg->channelName = tbl.get_or("channel_name", QString{});
+
+    auto usernameColor = tbl.get_or("username_color", QString{});
+    if (!usernameColor.isEmpty())
+    {
+        msg->usernameColor = QColor(usernameColor);
+    }
+
+    auto serverReceivedTime =
+        tbl.get<std::optional<qint64>>("server_received_time");
+    if (serverReceivedTime)
+    {
+        msg->serverReceivedTime = datetimeFromOffset(*serverReceivedTime);
+    }
+
+    // missing: badges
+    // missing: badgeInfos
+
+    // we construct a color on the fly here
+    auto highlightColor = tbl.get_or("highlight_color", QString{});
+    if (!highlightColor.isEmpty())
+    {
+        msg->highlightColor = std::make_shared<QColor>(highlightColor);
+    }
+
+    // missing: replyThread
+    // missing: replyParent
+    // missing: count
+
+    auto elements = tbl.get<std::optional<sol::table>>("elements");
+    if (elements)
+    {
+        auto size = elements->size();
+        for (size_t i = 1; i <= size; i++)
+        {
+            auto ref =
+                elements->get<std::optional<lua::api::message::ElementRef>>(i);
+            if (ref.has_value())
+            {
+                msg->elements.emplace_back(ref->constElement()->clone());
+            }
+            else
+            {
+                msg->elements.emplace_back(
+                    elementFromTable(elements->get<sol::table>(i)));
+            }
+        }
+    }
+
+    // missing: reward
+    return msg;
+}
+
+}  // namespace
+
 #endif

src/controllers/plugins/api/Message.hpp

@@ -192,9 +192,10 @@ c2.Message = {}
 function c2.Message:elements() end
 
 --- Add an element to this message.
+--- If given a MessageElement, it will be cloned before being added.
 ---
----@param init MessageElementInit The element to add
-function c2.Message:append_element(init) end
+---@param elem (MessageElement|MessageElementInit) The element to add
+function c2.Message:append_element(elem) end
 
 ---A table to initialize a new message
 ---@class MessageInit
@@ -211,7 +212,7 @@ function c2.Message:append_element(init) end
 ---@field username_color? string The color of the username
 ---@field server_received_time? number The time the server received the message (in milliseconds since epoch)
 ---@field highlight_color? string|nil The color of the highlight (if any)
----@field elements? MessageElementInit[] The elements of the message
+---@field elements? (MessageElementInit|MessageElement)[] The elements of the message
 
 ---@alias MessageColor "text"|"link"|"system"|string A color for a text element - "text", "link", and "system" are special values that take the current theme into account
 

src/messages/MessageElement.cpp

@@ -25,6 +25,9 @@
 #include <QJsonObject>
 #include <QJsonValue>
 
+#include <memory>
+#include <utility>
+
 #ifdef CHATTERINO_WITH_PRIVATE_QT_API
 #    include <QtGui/private/qtextengine_p.h>
 #endif
@@ -106,6 +109,14 @@ void MessageElement::addFlags(MessageElementFlags flags)
     this->flags_.set(flags);
 }
 
+void MessageElement::cloneFrom(const MessageElement &source)
+{
+    this->link_ = source.link_;
+    this->tooltip_ = source.tooltip_;
+    this->flags_ = source.flags_;
+    this->trailingSpace = source.trailingSpace;
+}
+
 QJsonObject MessageElement::toJson() const
 {
     return {
@@ -158,6 +169,13 @@ std::string_view ImageElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> ImageElement::clone() const
+{
+    auto im = std::make_unique<ImageElement>(this->image_, this->getFlags());
+    im->cloneFrom(*this);
+    return im;
+}
+
 CircularImageElement::CircularImageElement(ImagePtr image, int padding,
                                            QColor background,
                                            MessageElementFlags flags)
@@ -197,6 +215,14 @@ std::string_view CircularImageElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> CircularImageElement::clone() const
+{
+    auto im = std::make_unique<CircularImageElement>(
+        this->image_, this->padding(), this->background(), this->getFlags());
+    im->cloneFrom(*this);
+    return im;
+}
+
 // EMOTE
 EmoteElement::EmoteElement(const EmotePtr &emote, MessageElementFlags flags,
                            const MessageColor &textElementColor)
@@ -290,6 +316,14 @@ std::string_view EmoteElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> EmoteElement::clone() const
+{
+    auto elem = std::make_unique<EmoteElement>(this->emote_, this->getFlags(),
+                                               this->textColor_);
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 LayeredEmoteElement::LayeredEmoteElement(
     std::vector<LayeredEmoteElement::Emote> &&emotes, MessageElementFlags flags,
     const MessageColor &textElementColor)
@@ -490,6 +524,15 @@ std::string_view LayeredEmoteElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> LayeredEmoteElement::clone() const
+{
+    std::vector<Emote> emotesCopy = this->emotes_;
+    auto elem = std::make_unique<LayeredEmoteElement>(
+        std::move(emotesCopy), this->getFlags(), this->textElementColor_);
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 // BADGE
 BadgeElement::BadgeElement(const EmotePtr &emote, MessageElementFlags flags)
     : MessageElement(flags)
@@ -541,6 +584,12 @@ std::string_view BadgeElement::type() const
 {
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
+std::unique_ptr<MessageElement> BadgeElement::clone() const
+{
+    auto elem = std::make_unique<BadgeElement>(this->emote_, this->getFlags());
+    elem->cloneFrom(*this);
+    return elem;
+}
 
 // MOD BADGE
 ModBadgeElement::ModBadgeElement(const EmotePtr &data,
@@ -573,6 +622,14 @@ std::string_view ModBadgeElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> ModBadgeElement::clone() const
+{
+    auto elem =
+        std::make_unique<ModBadgeElement>(this->getEmote(), this->getFlags());
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 // VIP BADGE
 VipBadgeElement::VipBadgeElement(const EmotePtr &data,
                                  MessageElementFlags flags_)
@@ -600,6 +657,13 @@ std::string_view VipBadgeElement::type() const
 {
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
+std::unique_ptr<MessageElement> VipBadgeElement::clone() const
+{
+    auto elem =
+        std::make_unique<VipBadgeElement>(this->getEmote(), this->getFlags());
+    elem->cloneFrom(*this);
+    return elem;
+}
 
 // FFZ Badge
 FfzBadgeElement::FfzBadgeElement(const EmotePtr &data,
@@ -632,6 +696,14 @@ std::string_view FfzBadgeElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> FfzBadgeElement::clone() const
+{
+    auto elem = std::make_unique<FfzBadgeElement>(
+        this->getEmote(), this->getFlags(), this->color);
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 // TEXT
 TextElement::TextElement(const QString &text, MessageElementFlags flags,
                          const MessageColor &color, FontStyle style)
@@ -642,6 +714,15 @@ TextElement::TextElement(const QString &text, MessageElementFlags flags,
     this->words_ = text.split(' ');
     // fourtf: add logic to store multiple spaces after message
 }
+TextElement::TextElement(TextElement::CloneConstructorTag /*hack*/,
+                         QStringList words, MessageElementFlags flags,
+                         const MessageColor &color, FontStyle style)
+    : MessageElement(flags)
+    , words_(std::move(words))
+    , color_(color)
+    , style_(style)
+{
+}
 
 void TextElement::addToContainer(MessageLayoutContainer &container,
                                  const MessageLayoutContext &ctx)
@@ -872,6 +953,15 @@ std::string_view TextElement::type() const
 {
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
+std::unique_ptr<MessageElement> TextElement::clone() const
+{
+    auto elem = std::make_unique<TextElement>(
+        TextElement::CloneConstructorTag{}, this->words_, this->getFlags(),
+        this->color_, this->style_);
+
+    elem->cloneFrom(*this);
+    return elem;
+}
 
 SingleLineTextElement::SingleLineTextElement(const QString &text,
                                              MessageElementFlags flags,
@@ -883,6 +973,15 @@ SingleLineTextElement::SingleLineTextElement(const QString &text,
     , words_(text.split(' '))
 {
 }
+SingleLineTextElement::SingleLineTextElement(
+    SingleLineTextElement::CloneConstructorTag /*hack*/, QStringList words,
+    MessageElementFlags flags, const MessageColor &color, FontStyle style)
+    : MessageElement(flags)
+    , color_(color)
+    , style_(style)
+    , words_(std::move(words))
+{
+}
 
 void SingleLineTextElement::addToContainer(MessageLayoutContainer &container,
                                            const MessageLayoutContext &ctx)
@@ -1014,6 +1113,16 @@ std::string_view SingleLineTextElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> SingleLineTextElement::clone() const
+{
+    auto elem = std::make_unique<SingleLineTextElement>(
+        SingleLineTextElement::CloneConstructorTag{}, this->words_,
+        this->getFlags(), this->color_, this->style_);
+
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 LinkElement::LinkElement(const Parsed &parsed, const QString &fullUrl,
                          MessageElementFlags flags, const MessageColor &color,
                          FontStyle style)
@@ -1025,6 +1134,21 @@ LinkElement::LinkElement(const Parsed &parsed, const QString &fullUrl,
     this->setTooltip(parsed.original);
 }
 
+LinkElement::LinkElement(TextElement::CloneConstructorTag /*hack*/,
+                         QStringList lowercase, QStringList original,
+                         const QString &fullUrl, MessageElementFlags flags,
+                         const MessageColor &color, FontStyle style)
+    : TextElement({}, flags, color, style)
+    , linkInfo_(fullUrl)
+    , lowercase_(std::move(lowercase))
+    , original_(std::move(original))
+{
+    if (!this->original_.isEmpty())
+    {
+        this->setTooltip(this->original_.at(0));
+    }
+}
+
 void LinkElement::addToContainer(MessageLayoutContainer &container,
                                  const MessageLayoutContext &ctx)
 {
@@ -1054,9 +1178,20 @@ std::string_view LinkElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> LinkElement::clone() const
+{
+    auto elem = std::make_unique<LinkElement>(
+        LinkElement::CloneConstructorTag{}, this->lowercase_, this->original_,
+        this->linkInfo_.originalUrl(), this->getFlags(), this->color_,
+        this->style_);
+
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 MentionElement::MentionElement(const QString &displayName, QString loginName_,
-                               MessageColor fallbackColor_,
-                               MessageColor userColor_)
+                               const MessageColor &fallbackColor_,
+                               const MessageColor &userColor_)
     : TextElement(displayName,
                   {MessageElementFlag::Text, MessageElementFlag::Mention})
     , fallbackColor_(fallbackColor_)
@@ -1065,9 +1200,22 @@ MentionElement::MentionElement(const QString &displayName, QString loginName_,
 {
 }
 
+MentionElement::MentionElement(TextElement::CloneConstructorTag /* hack */,
+                               QStringList words, QString loginName_,
+                               const MessageColor &fallbackColor_,
+                               const MessageColor &userColor_)
+    : TextElement(MentionElement::CloneConstructorTag{}, std::move(words),
+                  {MessageElementFlag::Text, MessageElementFlag::Mention})
+    , fallbackColor_(fallbackColor_)
+    , userColor_(userColor_)
+    , userLoginName_(std::move(loginName_))
+{
+}
+
 template <typename>
 MentionElement::MentionElement(const QString &displayName, QString loginName_,
-                               MessageColor fallbackColor_, QColor userColor_)
+                               const MessageColor &fallbackColor_,
+                               QColor userColor_)
     : TextElement(displayName,
                   {MessageElementFlag::Text, MessageElementFlag::Mention})
     , fallbackColor_(fallbackColor_)
@@ -1078,7 +1226,7 @@ MentionElement::MentionElement(const QString &displayName, QString loginName_,
 
 template MentionElement::MentionElement(const QString &displayName,
                                         QString loginName_,
-                                        MessageColor fallbackColor_,
+                                        const MessageColor &fallbackColor_,
                                         QColor userColor_);
 
 void MentionElement::addToContainer(MessageLayoutContainer &container,
@@ -1141,6 +1289,17 @@ std::string_view MentionElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> MentionElement::clone() const
+{
+    auto elem = std::make_unique<MentionElement>(
+        TextElement::CloneConstructorTag{}, this->words_, this->userLoginName_,
+        this->fallbackColor_, this->userColor_);
+
+    elem->setTooltip(this->getTooltip());
+    elem->setTrailingSpace(this->hasTrailingSpace());
+    return elem;
+}
+
 // TIMESTAMP
 TimestampElement::TimestampElement()
     : TimestampElement(getApp()->isTest() ? QTime::fromMSecsSinceStartOfDay(0)
@@ -1209,6 +1368,13 @@ std::string_view TimestampElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> TimestampElement::clone() const
+{
+    auto elem = std::make_unique<TimestampElement>(this->time_);
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 // TWITCH MODERATION
 TwitchModerationElement::TwitchModerationElement()
     : MessageElement(MessageElementFlag::ModeratorTools)
@@ -1258,6 +1424,13 @@ std::string_view TwitchModerationElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> TwitchModerationElement::clone() const
+{
+    auto elem = std::make_unique<TwitchModerationElement>();
+    elem->cloneFrom(*this);
+    return elem;
+}
+
 LinebreakElement::LinebreakElement(MessageElementFlags flags)
     : MessageElement(flags)
 {
@@ -1285,6 +1458,13 @@ std::string_view LinebreakElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> LinebreakElement::clone() const
+{
+    auto elem = std::make_unique<LinebreakElement>(this->getFlags());
+    elem->setTrailingSpace(this->hasTrailingSpace());
+    return elem;
+}
+
 ScalingImageElement::ScalingImageElement(ImageSet images,
                                          MessageElementFlags flags)
     : MessageElement(flags)
@@ -1327,6 +1507,13 @@ std::string_view ScalingImageElement::type() const
 {
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
+std::unique_ptr<MessageElement> ScalingImageElement::clone() const
+{
+    auto elem =
+        std::make_unique<ScalingImageElement>(this->images_, this->getFlags());
+    elem->setTrailingSpace(this->hasTrailingSpace());
+    return elem;
+}
 
 ReplyCurveElement::ReplyCurveElement()
     : MessageElement(MessageElementFlag::RepliedMessage)
@@ -1363,4 +1550,11 @@ std::string_view ReplyCurveElement::type() const
     return std::remove_pointer_t<decltype(this)>::TYPE;
 }
 
+std::unique_ptr<MessageElement> ReplyCurveElement::clone() const
+{
+    auto elem = std::make_unique<ReplyCurveElement>();
+    elem->setTrailingSpace(this->hasTrailingSpace());
+    return elem;
+}
+
 }  // namespace chatterino

src/messages/MessageElement.hpp

@@ -196,10 +196,16 @@ public:
     /// member.
     virtual std::string_view type() const = 0;
 
+    /// Creates a new identical message element.
+    virtual std::unique_ptr<MessageElement> clone() const = 0;
+
 protected:
     MessageElement(MessageElementFlags flags);
     bool trailingSpace = true;
 
+    /// Copy MessageElement private data from `source` to this MessageElement
+    void cloneFrom(const MessageElement &source);
+
 private:
     Link link_;
     QString tooltip_;
@@ -222,6 +228,8 @@ public:
     QJsonObject toJson() const override;
     std::string_view type() const override;
 
+    std::unique_ptr<MessageElement> clone() const override;
+
 private:
     ImagePtr image_;
 };
@@ -240,6 +248,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
     ImagePtr image() const
     {
@@ -264,12 +273,23 @@ private:
 // contains a text, it will split it into words
 class TextElement : public MessageElement
 {
+protected:
+    struct CloneConstructorTag {
+    };
+
 public:
     static constexpr std::string_view TYPE = "text";
 
     TextElement(const QString &text, MessageElementFlags flags,
                 const MessageColor &color = MessageColor::Text,
                 FontStyle style = FontStyle::ChatMedium);
+
+    /// This is intended only for cloning the element.
+    TextElement(TextElement::CloneConstructorTag, QStringList words,
+                MessageElementFlags flags,
+                const MessageColor &color = MessageColor::Text,
+                FontStyle style = FontStyle::ChatMedium);
+
     ~TextElement() override = default;
 
     void addToContainer(MessageLayoutContainer &container,
@@ -277,6 +297,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
     const MessageColor &color() const noexcept;
     FontStyle fontStyle() const noexcept;
@@ -299,12 +320,22 @@ protected:
 // contains a text that will be truncated to one line
 class SingleLineTextElement : public MessageElement
 {
+    struct CloneConstructorTag {
+    };
+
 public:
     static constexpr std::string_view TYPE = "single-line-text";
 
     SingleLineTextElement(const QString &text, MessageElementFlags flags,
                           const MessageColor &color = MessageColor::Text,
                           FontStyle style = FontStyle::ChatMedium);
+
+    /// This is intended only for cloning the element.
+    SingleLineTextElement(SingleLineTextElement::CloneConstructorTag,
+                          QStringList words, MessageElementFlags flags,
+                          const MessageColor &color = MessageColor::Text,
+                          FontStyle style = FontStyle::ChatMedium);
+
     ~SingleLineTextElement() override = default;
 
     void addToContainer(MessageLayoutContainer &container,
@@ -312,6 +343,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
     const MessageColor &color() const
     {
@@ -349,6 +381,14 @@ public:
                 MessageElementFlags flags,
                 const MessageColor &color = MessageColor::Text,
                 FontStyle style = FontStyle::ChatMedium);
+
+    /// This is intended only for cloning the element.
+    LinkElement(TextElement::CloneConstructorTag, QStringList lowercase,
+                QStringList original, const QString &fullUrl,
+                MessageElementFlags flags,
+                const MessageColor &color = MessageColor::Text,
+                FontStyle style = FontStyle::ChatMedium);
+
     ~LinkElement() override = default;
     LinkElement(const LinkElement &) = delete;
     LinkElement(LinkElement &&) = delete;
@@ -376,6 +416,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 private:
     LinkInfo linkInfo_;
@@ -400,14 +441,21 @@ public:
     static constexpr std::string_view TYPE = "mention";
 
     explicit MentionElement(const QString &displayName, QString loginName_,
-                            MessageColor fallbackColor_,
-                            MessageColor userColor_);
+                            const MessageColor &fallbackColor_,
+                            const MessageColor &userColor_);
+
+    /// This is intended only for cloning the element.
+    explicit MentionElement(TextElement::CloneConstructorTag, QStringList words,
+                            QString loginName_,
+                            const MessageColor &fallbackColor_,
+                            const MessageColor &userColor_);
     /// Deprioritized ctor allowing us to pass through a potentially invalid userColor_
     ///
     /// If the userColor_ is invalid, we fall back to the fallbackColor_
     template <typename = void>
     explicit MentionElement(const QString &displayName, QString loginName_,
-                            MessageColor fallbackColor_, QColor userColor_);
+                            const MessageColor &fallbackColor_,
+                            QColor userColor_);
     ~MentionElement() override = default;
     MentionElement(const MentionElement &) = delete;
     MentionElement(MentionElement &&) = delete;
@@ -435,6 +483,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 private:
     /**
@@ -467,6 +516,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 protected:
     virtual MessageLayoutElement *makeImageLayoutElement(const ImagePtr &image,
@@ -512,6 +562,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 private:
     MessageLayoutElement *makeImageLayoutElement(
@@ -543,6 +594,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 protected:
     virtual MessageLayoutElement *makeImageLayoutElement(const ImagePtr &image,
@@ -561,6 +613,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 protected:
     MessageLayoutElement *makeImageLayoutElement(const ImagePtr &image,
@@ -576,6 +629,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 protected:
     MessageLayoutElement *makeImageLayoutElement(const ImagePtr &image,
@@ -592,6 +646,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 protected:
     MessageLayoutElement *makeImageLayoutElement(const ImagePtr &image,
@@ -622,6 +677,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 private:
     QTime time_;
@@ -643,6 +699,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 };
 
 // Forces a linebreak
@@ -658,6 +715,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 };
 
 // Image element which will pick the quality of the image based on ui scale
@@ -675,6 +733,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 
 private:
     ImageSet images_;
@@ -692,6 +751,7 @@ public:
 
     QJsonObject toJson() const override;
     std::string_view type() const override;
+    std::unique_ptr<MessageElement> clone() const override;
 };
 
 }  // namespace chatterino

tests/src/IrcMessageHandler.cpp

@@ -651,3 +651,38 @@ TEST(TestIrcMessageHandlerP, Integrity)
 {
     ASSERT_FALSE(UPDATE_SNAPSHOTS);  // make sure fixtures are actually tested
 }
+
+TEST_P(TestIrcMessageHandlerP, CloneElements)
+{
+    auto channel = makeMockTwitchChannel(u"pajlada"_s, *this->snapshot);
+
+    VectorMessageSink sink;
+
+    for (auto prevInput : this->snapshot->param("prevMessages").toArray())
+    {
+        auto *ircMessage = Communi::IrcMessage::fromData(
+            prevInput.toString().toUtf8(), nullptr);
+        ASSERT_NE(ircMessage, nullptr);
+        IrcMessageHandler::parseMessageInto(ircMessage, sink, channel.get());
+        delete ircMessage;
+    }
+
+    auto *ircMessage =
+        Communi::IrcMessage::fromData(this->snapshot->inputUtf8(), nullptr);
+    ASSERT_NE(ircMessage, nullptr);
+    IrcMessageHandler::parseMessageInto(ircMessage, sink, channel.get());
+    delete ircMessage;
+
+    for (const auto &message : sink.messages())
+    {
+        for (const auto &original : message->elements)
+        {
+            auto originalObj = original->toJson();
+            auto clonedObj = original->clone()->toJson();
+            ASSERT_EQ(originalObj, clonedObj)
+                << "\noriginal:\n"
+                << QJsonDocument(originalObj).toJson() << "\ncloned:\n"
+                << QJsonDocument(clonedObj).toJson();
+        }
+    }
+}