Move all timeline relevant models and classes to the module

src/timeline/models/timelinemessagemodel.h

@@ -0,0 +1,62 @@
+// SPDX-FileCopyrightText: 2018-2019 Black Hat <bhat@encom.eu.org>
+// SPDX-License-Identifier: GPL-3.0-only
+
+#pragma once
+
+#include <QAbstractListModel>
+#include <QQmlEngine>
+
+#include "messagemodel.h"
+
+class ReactionModel;
+
+namespace Quotient
+{
+class RoomEvent;
+}
+
+/**
+ * @class TimelineMessageModel
+ *
+ * This class defines the model for visualising the room timeline.
+ *
+ * This model covers all event types in the timeline with many of the roles being
+ * specific to a subset of events. This means the user needs to understand which
+ * roles will return useful information for a given event type.
+ *
+ * @sa NeoChatRoom
+ */
+class TimelineMessageModel : public MessageModel
+{
+    Q_OBJECT
+    QML_ELEMENT
+
+public:
+    explicit TimelineMessageModel(QObject *parent = nullptr);
+
+    /**
+     * @brief Number of rows in the model.
+     *
+     * @sa  QAbstractItemModel::rowCount
+     */
+    [[nodiscard]] int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+
+private:
+    void connectNewRoom();
+
+    std::optional<std::reference_wrapper<const Quotient::RoomEvent>> getEventForIndex(QModelIndex index) const override;
+
+    int rowBelowInserted = -1;
+    bool resetting = false;
+    bool movingEvent = false;
+
+    int timelineServerIndex() const override;
+
+    bool canFetchMore(const QModelIndex &parent) const override;
+    void fetchMore(const QModelIndex &parent) override;
+
+    void moveReadMarker(const QString &toEventId);
+
+    // Hack to ensure that we don't call endInsertRows when we haven't called beginInsertRows
+    bool m_initialized = false;
+};