Create widgets on demand for messages added to the end of the timeline

include/Utils.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "RoomInfoListItem.h"
+
+#include <QDateTime>
+#include <mtx/events/collections.hpp>
+
+namespace utils {
+
+using TimelineEvent = mtx::events::collections::TimelineEvents;
+
+//! Human friendly timestamp representation.
+QString
+descriptiveTime(const QDateTime &then);
+
+//! Generate a message description from the event to be displayed
+//! in the RoomList.
+DescInfo
+getMessageDescription(const TimelineEvent &event, const QString &localUser);
+}

include/timeline/TimelineItem.h

@@ -28,6 +28,7 @@
 #include "AvatarProvider.h"
 #include "RoomInfoListItem.h"
 #include "TimelineViewManager.h"
+#include "Utils.h"
 
 class ImageItem;
 class AudioItem;
@@ -107,7 +108,6 @@ private:
         void generateBody(const QString &body);
         void generateBody(const QString &userid, const QString &body);
         void generateTimestamp(const QDateTime &time);
-        QString descriptiveTime(const QDateTime &then);
 
         void setupAvatarLayout(const QString &userName);
         void setupSimpleLayout();
@@ -145,8 +145,11 @@ TimelineItem::setupLocalWidgetLayout(Widget *widget,
         auto displayName = TimelineViewManager::displayName(userid);
         auto timestamp   = QDateTime::currentDateTime();
 
-        descriptionMsg_ = {
-          "You", userid, QString(" %1").arg(msgDescription), descriptiveTime(timestamp), timestamp};
+        descriptionMsg_ = {"You",
+                           userid,
+                           QString(" %1").arg(msgDescription),
+                           utils::descriptiveTime(timestamp),
+                           timestamp};
 
         generateTimestamp(timestamp);
 
@@ -187,7 +190,7 @@ TimelineItem::setupWidgetLayout(Widget *widget,
         descriptionMsg_ = {sender == settings.value("auth/user_id") ? "You" : displayName,
                            sender,
                            msgDescription,
-                           descriptiveTime(timestamp),
+                           utils::descriptiveTime(timestamp),
                            timestamp};
 
         generateTimestamp(timestamp);

include/timeline/TimelineView.h

@@ -23,7 +23,6 @@
 #include <QList>
 #include <QQueue>
 #include <QScrollArea>
-#include <QSettings>
 #include <QStyle>
 #include <QStyleOption>
 
@@ -119,10 +118,13 @@ protected:
         bool event(QEvent *event) override;
 
 private:
+        using TimelineEvent = mtx::events::collections::TimelineEvents;
+
         void init();
         void addTimelineItem(TimelineItem *item, TimelineDirection direction);
         void updateLastSender(const QString &user_id, TimelineDirection direction);
         void notifyForLastEvent();
+        void notifyForLastEvent(const TimelineEvent &event);
         void readLastEvent() const;
         bool isScrollbarActivated() { return scroll_area_->verticalScrollBar()->value() != 0; }
         QString getLastEventId() const;
@@ -193,6 +195,18 @@ private:
 
         TimelineDirection lastMessageDirection_;
 
+        //! Messages received by sync not added to the timeline.
+        std::vector<TimelineEvent> bottomMessages_;
+
+        //! Render the given timeline events to the bottom of the timeline.
+        void renderBottomEvents(const std::vector<TimelineEvent> &events);
+
+        //! Decide if the given timeline event can be rendered.
+        inline bool isViewable(const TimelineEvent &event) const;
+
+        //! Decide if the given event should trigger a notification.
+        inline bool isNotifiable(const TimelineEvent &event) const;
+
         // The events currently rendered. Used for duplicate detection.
         QMap<QString, bool> eventIds_;
         QQueue<PendingMessage> pending_msgs_;
@@ -204,20 +218,19 @@ template<class Widget, mtx::events::MessageType MsgType>
 void
 TimelineView::addUserMessage(const QString &url, const QString &filename)
 {
-        QSettings settings;
-        auto user_id     = settings.value("auth/user_id").toString();
-        auto with_sender = lastSender_ != user_id;
+        auto with_sender = lastSender_ != local_user_;
 
         auto widget = new Widget(client_, url, filename, this);
 
-        TimelineItem *view_item = new TimelineItem(widget, user_id, with_sender, scroll_widget_);
+        TimelineItem *view_item =
+          new TimelineItem(widget, local_user_, with_sender, scroll_widget_);
         scroll_layout_->addWidget(view_item);
 
         lastMessageDirection_ = TimelineDirection::Bottom;
 
         QApplication::processEvents();
 
-        lastSender_ = user_id;
+        lastSender_ = local_user_;
 
         int txn_id = client_->incrementTransactionId();