Move all timeline relevant models and classes to the module

src/timeline/models/messagemodel.h

@@ -0,0 +1,162 @@
+// SPDX-FileCopyrightText: 2024 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+#pragma once
+
+#include <QAbstractListModel>
+#include <QQmlEngine>
+#include <functional>
+
+#include "neochatroom.h"
+#include "readmarkermodel.h"
+#include "threadmodel.h"
+
+class ReactionModel;
+
+/**
+ * @class MessageModel
+ *
+ * This class defines a base model for visualising the room events.
+ *
+ * On its own MessageModel will result in an empty timeline as there is no mechanism
+ * to retrieve events. This is by design as it allows the model to be inherited from
+ * and the user can specify their own source of events, e.g. a room timeline or a
+ * search result.
+ *
+ * The inherited model MUST do the following:
+ *  - Define methods for retrieving events
+ *  - Call newEventAdded() for each new event in the model so that all the required
+ *    event objects are created.
+ *  - Override getEventForIndex() so that the data() function can get an event for a
+ *    given index
+ *  - Override rowCount()
+ *
+ * Optionally the new model can:
+ *  - override timelineServerIndex() if dealing with pending events otherwise the default
+ *    function returns 0 which is correct for other use cases.
+ *  - m_lastReadEventIndex is available to track a read marker location (so that the
+ *    data function can output the appropriate values). The new class must implement
+ *    the functionality to add, move, remove, etc though.
+ *
+ * @sa NeoChatRoom
+ */
+class MessageModel : public QAbstractListModel
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_UNCREATABLE("")
+
+    /**
+     * @brief The current room that the model is getting its messages from.
+     */
+    Q_PROPERTY(NeoChatRoom *room READ room WRITE setRoom NOTIFY roomChanged)
+
+public:
+    /**
+     * @brief Defines the model roles.
+     */
+    enum EventRoles {
+        DelegateTypeRole = Qt::UserRole + 1, /**< The delegate type of the message. */
+        EventIdRole, /**< The matrix event ID of the event. */
+        TimeRole, /**< The timestamp for when the event was sent (as a QDateTime). */
+        SectionRole, /**< The date of the event as a string. */
+        AuthorRole, /**< The author of the event. */
+        HighlightRole, /**< Whether the event should be highlighted. */
+        SpecialMarksRole, /**< Whether the event is hidden or not. */
+        ProgressInfoRole, /**< Progress info when downloading files. */
+        GenericDisplayRole, /**< A generic string based upon the message type. */
+        MediaInfoRole, /**< The media info for the event. */
+
+        ContentModelRole, /**< The MessageContentModel for the event. */
+
+        IsThreadedRole, /**< Whether the message is in a thread. */
+        ThreadRootRole, /**< The Matrix ID of the thread root message, if any . */
+        IsPollRole, /**< Whether the message is a poll. */
+
+        ShowSectionRole, /**< Whether the section header should be shown. */
+
+        ReadMarkersRole, /**< The first 5 other users at the event for read marker tracking. */
+        ShowReadMarkersRole, /**< Whether there are any other user read markers to be shown. */
+
+        VerifiedRole, /**< Whether an encrypted message is sent in a verified session. */
+        AuthorDisplayNameRole, /**< The displayname for the event's sender; for name change events, the old displayname. */
+        IsRedactedRole, /**< Whether an event has been deleted. */
+        IsPendingRole, /**< Whether an event is waiting to be accepted by the server. */
+        IsEditableRole, /**< Whether the event can be edited by the user. */
+        ShowAuthorRole, /**< Whether the author of a message should be shown. */
+        LastRole, // Keep this last
+    };
+    Q_ENUM(EventRoles)
+
+    explicit MessageModel(QObject *parent = nullptr);
+
+    [[nodiscard]] NeoChatRoom *room() const;
+    void setRoom(NeoChatRoom *room);
+
+    /**
+     * @brief Get the given role value at the given index.
+     *
+     * @sa QAbstractItemModel::data
+     */
+    [[nodiscard]] QVariant data(const QModelIndex &idx, int role = Qt::DisplayRole) const override;
+
+    /**
+     * @brief Returns a mapping from Role enum values to role names.
+     *
+     * @sa EventRoles, QAbstractItemModel::roleNames()
+     */
+    [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
+
+    /**
+     * @brief Get the row number of the given event ID in the model.
+     */
+    Q_INVOKABLE [[nodiscard]] int eventIdToRow(const QString &eventID) const;
+
+    static void setHiddenFilter(std::function<bool(const Quotient::RoomEvent *)> hiddenFilter);
+
+    static void setThreadsEnabled(bool enableThreads);
+
+Q_SIGNALS:
+    /**
+     * @brief Emitted when the room is changed.
+     */
+    void roomChanged();
+
+    /**
+     * @brief A signal to tell the MessageModel that a new event has been added.
+     *
+     * Any model inheriting from MessageModel needs to emit this signal for every
+     * new event it adds.
+     */
+    void newEventAdded(const Quotient::RoomEvent *event);
+
+    void threadsEnabledChanged();
+
+protected:
+    QPointer<NeoChatRoom> m_room;
+    QPersistentModelIndex m_lastReadEventIndex;
+
+    virtual int timelineServerIndex() const;
+    virtual std::optional<std::reference_wrapper<const Quotient::RoomEvent>> getEventForIndex(QModelIndex index) const;
+
+    void fullEventRefresh(int row);
+    int refreshEventRoles(const QString &eventId, const QList<int> &roles = {});
+    void refreshEventRoles(int row, const QList<int> &roles = {});
+    void refreshLastUserEvents(int baseTimelineRow);
+
+    void clearModel();
+    void clearEventObjects();
+
+    bool event(QEvent *event) override;
+
+private:
+    bool resetting = false;
+    bool movingEvent = false;
+
+    QMap<QString, QSharedPointer<ReadMarkerModel>> m_readMarkerModels;
+
+    void createEventObjects(const Quotient::RoomEvent *event);
+
+    static std::function<bool(const Quotient::RoomEvent *)> m_hiddenFilter;
+    static bool m_threadsEnabled;
+};