Manage MessageContentModels properly so we don't leak memory.

- Manage MessageContentModels properly so we don't leak memory creating new ones every time the role is refreshed.
- Parent and reply MessageContentModels to their message to make sure they get cleaned up when the parent is deleted.
- Make sure ReactionModels are cleaned up on room change to stop that list just growing.

src/models/messagecontentmodel.cpp

@@ -31,8 +31,8 @@
 
 using namespace Quotient;
 
-MessageContentModel::MessageContentModel(NeoChatRoom *room, const Quotient::RoomEvent *event, bool isReply, bool isPending)
-    : QAbstractListModel(nullptr)
+MessageContentModel::MessageContentModel(NeoChatRoom *room, const Quotient::RoomEvent *event, bool isReply, bool isPending, MessageContentModel *parent)
+    : QAbstractListModel(parent)
     , m_room(room)
     , m_eventId(event != nullptr ? event->id() : QString())
     , m_eventSenderId(event != nullptr ? event->senderId() : QString())
@@ -43,8 +43,8 @@ MessageContentModel::MessageContentModel(NeoChatRoom *room, const Quotient::Room
     initializeModel();
 }
 
-MessageContentModel::MessageContentModel(NeoChatRoom *room, const QString &eventId, bool isReply, bool isPending)
-    : QAbstractListModel(nullptr)
+MessageContentModel::MessageContentModel(NeoChatRoom *room, const QString &eventId, bool isReply, bool isPending, MessageContentModel *parent)
+    : QAbstractListModel(parent)
     , m_room(room)
     , m_eventId(eventId)
     , m_isPending(isPending)
@@ -58,15 +58,16 @@ void MessageContentModel::initializeModel()
     Q_ASSERT(m_room != nullptr);
     // Allow making a model for an event that is being downloaded but will appear later
     // e.g. a reply, but we need an ID to know when it has arrived.
-    Q_ASSERT(!m_eventId.isEmpty());
+    // Also note that a pending event may not have an event ID yet but as long as we have an event
+    // pointer we can pass out the transaction ID until it is set.
+    Q_ASSERT(!m_eventId.isEmpty() || m_event != nullptr);
 
     Quotient::connectUntil(m_room.get(), &NeoChatRoom::extraEventLoaded, this, [this](const QString &eventId) {
         if (m_room != nullptr) {
             if (eventId == m_eventId) {
-                m_event = loadEvent<RoomEvent>(m_room->getEvent(eventId)->fullJson());
-                Q_EMIT eventUpdated();
+                intiializeEvent(m_room->getEvent(eventId));
                 updateReplyModel();
-                resetContent();
+                resetModel();
                 return true;
             }
         }
@@ -164,7 +165,12 @@ void MessageContentModel::intiializeEvent(const QString &eventId)
 void MessageContentModel::intiializeEvent(const Quotient::RoomEvent *event)
 {
     m_event = loadEvent<RoomEvent>(event->fullJson());
-    auto senderId = event->senderId();
+    // a pending event may not previously have had an event ID so update.
+    if (m_eventId.isEmpty()) {
+        m_eventId = m_event->id();
+    }
+
+    auto senderId = m_event->senderId();
     // A pending event might not have a sender ID set yet but in that case it must
     // be the local member.
     if (senderId.isEmpty()) {
@@ -422,9 +428,9 @@ void MessageContentModel::updateReplyModel()
 
     const auto replyEvent = m_room->findInTimeline(eventHandler.getReplyId());
     if (replyEvent == m_room->historyEdge()) {
-        m_replyModel = new MessageContentModel(m_room, eventHandler.getReplyId(), true);
+        m_replyModel = new MessageContentModel(m_room, eventHandler.getReplyId(), true, false, this);
     } else {
-        m_replyModel = new MessageContentModel(m_room, replyEvent->get(), true);
+        m_replyModel = new MessageContentModel(m_room, replyEvent->get(), true, false, this);
     }
 
     connect(m_replyModel, &MessageContentModel::eventUpdated, this, [this]() {

src/models/messagecontentmodel.h

@@ -75,8 +75,12 @@ public:
     };
     Q_ENUM(Roles)
 
-    explicit MessageContentModel(NeoChatRoom *room, const Quotient::RoomEvent *event, bool isReply = false, bool isPending = false);
-    MessageContentModel(NeoChatRoom *room, const QString &eventId, bool isReply = false, bool isPending = false);
+    explicit MessageContentModel(NeoChatRoom *room,
+                                 const Quotient::RoomEvent *event,
+                                 bool isReply = false,
+                                 bool isPending = false,
+                                 MessageContentModel *parent = nullptr);
+    MessageContentModel(NeoChatRoom *room, const QString &eventId, bool isReply = false, bool isPending = false, MessageContentModel *parent = nullptr);
 
     bool showAuthor() const;
     void setShowAuthor(bool showAuthor);

src/models/messageeventmodel.cpp

@@ -88,7 +88,6 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
         // HACK: Reset the model to a null room first to make sure QML dismantles
         // last room's objects before the room is actually changed
         beginResetModel();
-        m_readMarkerModels.clear();
         m_currentRoom->disconnect(this);
         m_currentRoom = nullptr;
         endResetModel();
@@ -96,6 +95,9 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
         // Don't clear the member objects until the model has been fully reset and all
         // refs cleared.
         m_memberObjects.clear();
+        m_contentModels.clear();
+        m_reactionModels.clear();
+        m_readMarkerModels.clear();
     }
 
     beginResetModel();
@@ -442,13 +444,8 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
     }
 
     if (role == ContentModelRole) {
-        if (!evt.isStateEvent() && !evt.id().isEmpty()) {
-            return QVariant::fromValue<MessageContentModel *>(new MessageContentModel(m_currentRoom, &evt));
-        }
-        if (evt.isStateEvent()) {
-            if (evt.matrixType() == QStringLiteral("org.matrix.msc3672.beacon_info")) {
-                return QVariant::fromValue<MessageContentModel *>(new MessageContentModel(m_currentRoom, &evt));
-            }
+        if (m_contentModels.contains(evt.id())) {
+            return QVariant::fromValue<MessageContentModel *>(m_contentModels.at(evt.id()).get());
         }
         return {};
     }
@@ -634,6 +631,12 @@ void MessageEventModel::createEventObjects(const Quotient::RoomEvent *event)
         m_memberObjects[senderId] = std::unique_ptr<NeochatRoomMember>(new NeochatRoomMember(m_currentRoom, senderId));
     }
 
+    if (!m_contentModels.contains(eventId)) {
+        if (!event->isStateEvent() || event->matrixType() == QStringLiteral("org.matrix.msc3672.beacon_info")) {
+            m_contentModels[eventId] = std::unique_ptr<MessageContentModel>(new MessageContentModel(m_currentRoom, event));
+        }
+    }
+
     // ReadMarkerModel handles updates to add and remove markers, we only need to
     // handle adding and removing whole models here.
     if (m_readMarkerModels.contains(eventId)) {

src/models/messageeventmodel.h

@@ -8,6 +8,7 @@
 #include <QQmlEngine>
 
 #include "linkpreviewer.h"
+#include "messagecontentmodel.h"
 #include "neochatroom.h"
 #include "neochatroommember.h"
 #include "pollhandler.h"
@@ -117,6 +118,7 @@ private:
     KFormat m_format;
 
     std::map<QString, std::unique_ptr<NeochatRoomMember>> m_memberObjects;
+    std::map<QString, std::unique_ptr<MessageContentModel>> m_contentModels;
     QMap<QString, QSharedPointer<ReadMarkerModel>> m_readMarkerModels;
     QMap<QString, QSharedPointer<ReactionModel>> m_reactionModels;