path: root/include/timeline/TimelineView.h

/*
 * nheko Copyright (C) 2017  Konstantinos Sideris <siderisk@auth.gr>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <QApplication>
#include <QDebug>
#include <QLayout>
#include <QList>
#include <QQueue>
#include <QScrollArea>
#include <QStyle>
#include <QStyleOption>

#include <mtx/events.hpp>
#include <mtx/responses/messages.hpp>

#include "MatrixClient.h"
#include "ScrollBar.h"
#include "TimelineItem.h"

class FloatingButton;
struct DescInfo;

// Contains info about a message shown in the history view
// but not yet confirmed by the homeserver through sync.
struct PendingMessage
{
        mtx::events::MessageType ty;
        int txn_id;
        QString body;
        QString filename;
        QString mime;
        uint64_t media_size;
        QString event_id;
        TimelineItem *widget;

        PendingMessage(mtx::events::MessageType ty,
                       int txn_id,
                       QString body,
                       QString filename,
                       QString mime,
                       uint64_t media_size,
                       QString event_id,
                       TimelineItem *widget)
          : ty(ty)
          , txn_id(txn_id)
          , body(body)
          , filename(filename)
          , mime(mime)
          , media_size(media_size)
          , event_id(event_id)
          , widget(widget)
        {}
};

// In which place new TimelineItems should be inserted.
enum class TimelineDirection
{
        Top,
        Bottom,
};

class DateSeparator : public QWidget
{
        Q_OBJECT

        Q_PROPERTY(QColor textColor WRITE setTextColor READ textColor)
        Q_PROPERTY(QColor boxColor WRITE setBoxColor READ boxColor)

public:
        DateSeparator(QDateTime datetime, QWidget *parent = nullptr);

        QSize sizeHint() const override { return QSize(width(), height_ + 2 * HMargin); }

        void setTextColor(QColor color) { textColor_ = color; }
        void setBoxColor(QColor color) { boxColor_ = color; }

        QColor textColor() const { return textColor_; }
        QColor boxColor() const { return boxColor_; }

protected:
        void paintEvent(QPaintEvent *event) override;

private:
        static constexpr int VPadding = 6;
        static constexpr int HPadding = 12;
        static constexpr int HMargin  = 20;

        int width_;
        int height_;

        QString msg_;
        QFont font_;

        QColor textColor_ = QColor("black");
        QColor boxColor_  = QColor("white");
};

class TimelineView : public QWidget
{
        Q_OBJECT

public:
        TimelineView(const mtx::responses::Timeline &timeline,
                     QSharedPointer<MatrixClient> client,
                     const QString &room_id,
                     QWidget *parent = 0);
        TimelineView(QSharedPointer<MatrixClient> client,
                     const QString &room_id,
                     QWidget *parent = 0);

        // Add new events at the end of the timeline.
        void addEvents(const mtx::responses::Timeline &timeline);
        void addUserMessage(mtx::events::MessageType ty, const QString &msg);

        template<class Widget, mtx::events::MessageType MsgType>
        void addUserMessage(const QString &url,
                            const QString &filename,
                            const QString &mime,
                            uint64_t size);
        void updatePendingMessage(int txn_id, QString event_id);
        void scrollDown();
        QLabel *createDateSeparator(QDateTime datetime);

        //! Remove an item from the timeline with the given Event ID.
        void removeEvent(const QString &event_id);

public slots:
        void sliderRangeChanged(int min, int max);
        void sliderMoved(int position);
        void fetchHistory();

        // Add old events at the top of the timeline.
        void addBackwardsEvents(const QString &room_id, const mtx::responses::Messages &msgs);

        // Whether or not the initial batch has been loaded.
        bool hasLoaded() { return scroll_layout_->count() > 1 || isTimelineFinished; }

        void handleFailedMessage(int txnid);

private slots:
        void sendNextPendingMessage();

signals:
        void updateLastTimelineMessage(const QString &user, const DescInfo &info);

protected:
        void paintEvent(QPaintEvent *event) override;
        void showEvent(QShowEvent *event) override;
        bool event(QEvent *event) override;

private:
        using TimelineEvent = mtx::events::collections::TimelineEvents;

        QWidget *relativeWidget(TimelineItem *item, int dt) const;

        //! HACK: Fixing layout flickering when adding to the bottom
        //! of the timeline.
        void pushTimelineItem(TimelineItem *item)
        {
                item->hide();
                scroll_layout_->addWidget(item);
                QTimer::singleShot(0, this, [item]() { item->show(); });
        };

        //! Decides whether or not to show or hide the scroll down button.
        void toggleScrollDownButton();
        void init();
        void addTimelineItem(TimelineItem *item,
                             TimelineDirection direction = TimelineDirection::Bottom);
        void updateLastSender(const QString &user_id, TimelineDirection direction);
        void notifyForLastEvent();
        void notifyForLastEvent(const TimelineEvent &event);
        //! Keep track of the sender and the timestamp of the current message.
        void saveLastMessageInfo(const QString &sender, const QDateTime &datetime)
        {
                lastSender_       = sender;
                lastMsgTimestamp_ = datetime;
        }
        void saveFirstMessageInfo(const QString &sender, const QDateTime &datetime)
        {
                firstSender_       = sender;
                firstMsgTimestamp_ = datetime;
        }
        //! Keep track of the sender and the timestamp of the current message.
        void saveMessageInfo(const QString &sender,
                             uint64_t origin_server_ts,
                             TimelineDirection direction);

        TimelineEvent findFirstViewableEvent(const std::vector<TimelineEvent> &events);
        TimelineEvent findLastViewableEvent(const std::vector<TimelineEvent> &events);

        //! Mark the last event as read.
        void readLastEvent() const;
        //! Whether or not the scrollbar is visible (non-zero height).
        bool isScrollbarActivated() { return scroll_area_->verticalScrollBar()->value() != 0; }
        //! Retrieve the event id of the last item.
        QString getLastEventId() const;

        template<class Event, class Widget>
        TimelineItem *processMessageEvent(const Event &event, TimelineDirection direction);

        // TODO: Remove this eventually.
        template<class Event>
        TimelineItem *processMessageEvent(const Event &event, TimelineDirection direction);

        // For events with custom display widgets.
        template<class Event, class Widget>
        TimelineItem *createTimelineItem(const Event &event, bool withSender);

        // For events without custom display widgets.
        // TODO: All events should have custom widgets.
        template<class Event>
        TimelineItem *createTimelineItem(const Event &event, bool withSender);

        // Used to determine whether or not we should prefix a message with the
        // sender's name.
        bool isSenderRendered(const QString &user_id,
                              uint64_t origin_server_ts,
                              TimelineDirection direction