Line to indicate first unread message (#1147)

* First draft of unread line feature.

* Minor visual fix.

* Removed unnecessary ternary operator.

* Extended unread line functionality to work on minimised window or focusing another window.

* Fix for unread line not showing when last read message is hidden.

* Minor performance improvement. Fix for misbehaving event2order DB at application start.

* Fix for possible performance issues when user has joined a large number of rooms.

* Fix for breaking macos and clazy builds.

* Changed on windows focus function to refresh unread line if room is unread.

* Unread line is removed when user sends a message.

* Linting.

* Fixed unread line to work in standalone room windows.

* Switch isRoomUnread for index 0.

* Merged try/catch blocks.

* Fix for crash on opening a room invite.

* Call fullyReadEventId function when used instead of storing it and passing it through.

* Function that was meant to sync the unread line was relying on an async function, oops.

* Linting again.

* More linting...

* Minor changes.

4 files changed, 72 insertions, 8 deletions

diff --git a/src/timeline/RoomlistModel.cpp b/src/timeline/RoomlistModel.cpp

index 03abd3d5..6e95ef8e 100644
--- a/src/timeline/RoomlistModel.cpp
+++ b/src/timeline/RoomlistModel.cpp
@@ -283,6 +283,14 @@ RoomlistModel::addRoom(const QString &room_id, bool suppressInsertNotification)
         QSharedPointer<TimelineModel> newRoom(new TimelineModel(manager, room_id));
         newRoom->setDecryptDescription(ChatPage::instance()->userSettings()->decryptSidebar());
 
+        connect(this,
+                &RoomlistModel::currentRoomChanged,
+                newRoom.data(),
+                &TimelineModel::updateLastReadId);
+        connect(MainWindow::instance(),
+                &MainWindow::activeChanged,
+                newRoom.data(),
+                &TimelineModel::lastReadIdOnWindowFocus);
         connect(newRoom.data(),
                 &TimelineModel::newEncryptedImage,
                 MainWindow::instance()->imageProvider(),
@@ -383,7 +391,7 @@ RoomlistModel::addRoom(const QString &room_id, bool suppressInsertNotification)
             currentRoomPreview_->roomid() == room_id) {
             currentRoom_ = models.value(room_id);
             currentRoomPreview_.reset();
-            emit currentRoomChanged();
+            emit currentRoomChanged(room_id);
         }
 
         for (auto p : previewsToAdd) {
@@ -644,7 +652,7 @@ RoomlistModel::clear()
     invites.clear();
     roomids.clear();
     currentRoom_ = nullptr;
-    emit currentRoomChanged();
+    emit currentRoomChanged("");
     endResetModel();
 }
 
@@ -743,14 +751,14 @@ RoomlistModel::setCurrentRoom(QString roomid)
     if (roomid.isEmpty()) {
         currentRoom_        = nullptr;
         currentRoomPreview_ = {};
-        emit currentRoomChanged();
+        emit currentRoomChanged("");
     }
 
     nhlog::ui()->debug("Trying to switch to: {}", roomid.toStdString());
     if (models.contains(roomid)) {
         currentRoom_ = models.value(roomid);
         currentRoomPreview_.reset();
-        emit currentRoomChanged();
+        emit currentRoomChanged(currentRoom_->roomId());
         nhlog::ui()->debug("Switched to: {}", roomid.toStdString());
     } else if (invites.contains(roomid) || previewedRooms.contains(roomid)) {
         currentRoom_ = nullptr;
@@ -781,7 +789,7 @@ RoomlistModel::setCurrentRoom(QString roomid)
                                currentRoomPreview_->roomid_.toStdString());
         }
 
-        emit currentRoomChanged();
+        emit currentRoomChanged("");
     }
 }
 
diff --git a/src/timeline/RoomlistModel.h b/src/timeline/RoomlistModel.h

index 61bf2e7c..2f2ea066 100644
--- a/src/timeline/RoomlistModel.h
+++ b/src/timeline/RoomlistModel.h
@@ -116,7 +116,7 @@ public slots:
     {
         currentRoom_ = nullptr;
         currentRoomPreview_.reset();
-        emit currentRoomChanged();
+        emit currentRoomChanged("");
     }
 
 private slots:
@@ -124,7 +124,7 @@ private slots:
 
 signals:
     void totalUnreadMessageCountUpdated(int unreadMessages);
-    void currentRoomChanged();
+    void currentRoomChanged(QString currentRoomId);
     void fetchedPreview(QString roomid, RoomInfo info);
 
 private:
@@ -218,7 +218,7 @@ public slots:
     void updateHiddenTagsAndSpaces();
 
 signals:
-    void currentRoomChanged();
+    void currentRoomChanged(QString currentRoomId);
 
 private:
     short int calculateImportance(const QModelIndex &idx) const;
diff --git a/src/timeline/TimelineModel.cpp b/src/timeline/TimelineModel.cpp

index b7122db1..eaf85b2a 100644
--- a/src/timeline/TimelineModel.cpp
+++ b/src/timeline/TimelineModel.cpp
@@ -427,6 +427,7 @@ TimelineModel::TimelineModel(TimelineViewManager *manager, QString room_id, QObj
         setPaginationInProgress(false);
         updateLastMessage();
     });
+    connect(&events, &EventStore::fetchedMore, this, &TimelineModel::checkAfterFetch);
     connect(&events,
             &EventStore::startDMVerification,
             this,
@@ -977,6 +978,7 @@ TimelineModel::addEvents(const mtx::responses::Timeline &timeline)
             emit encryptionChanged();
         }
     }
+
     updateLastMessage();
 }
 
@@ -1370,6 +1372,48 @@ TimelineModel::markEventsAsRead(const std::vector<QString> &event_ids)
     }
 }
 
+void
+TimelineModel::updateLastReadId(QString currentRoomId)
+{
+    if (currentRoomId == room_id_) {
+        last_event_id = cache::getFullyReadEventId(room_id_.toStdString());
+        auto lastVisibleEventIndexAndId =
+          cache::lastVisibleEvent(room_id_.toStdString(), last_event_id);
+        if (lastVisibleEventIndexAndId) {
+            fullyReadEventId_ = lastVisibleEventIndexAndId->second;
+            emit fullyReadEventIdChanged();
+        }
+    }
+}
+
+void
+TimelineModel::lastReadIdOnWindowFocus()
+{
+    /* this stops it from removing the line when focusing another window
+     * and from removing the line when refocusing nheko */
+    if (ChatPage::instance()->isRoomActive(room_id_) &&
+        cache::calculateRoomReadStatus(room_id_.toStdString())) {
+        updateLastReadId(room_id_);
+    }
+}
+
+/*
+ * if the event2order db didn't have the messages we needed when the room was opened
+ * try again after these new messages were fetched
+ */
+void
+TimelineModel::checkAfterFetch()
+{
+    if (fullyReadEventId_.empty()) {
+        auto lastVisibleEventIndexAndId =
+          cache::lastVisibleEvent(room_id_.toStdString(), last_event_id);
+        if (lastVisibleEventIndexAndId) {
+            fullyReadEventId_ = lastVisibleEventIndexAndId->second;
+            emit fullyReadEventIdChanged();
+        }
+    }
+}
+
 template<typename T>
 void
 TimelineModel::sendEncryptedMessage(mtx::events::RoomEvent<T> msg, mtx::events::EventType eventType)
@@ -1550,6 +1594,9 @@ TimelineModel::addPendingMessage(mtx::events::collections::TimelineEvents event)
       event);
 
     std::visit(SendMessageVisitor{this}, event);
+
+    fullyReadEventId_ = this->EventId;
+    emit fullyReadEventIdChanged();
 }
 
 void
diff --git a/src/timeline/TimelineModel.h b/src/timeline/TimelineModel.h

index 47fd27f1..295bc69b 100644
--- a/src/timeline/TimelineModel.h
+++ b/src/timeline/TimelineModel.h
@@ -189,6 +189,7 @@ class TimelineModel : public QAbstractListModel
     Q_PROPERTY(QStringList widgetLinks READ widgetLinks NOTIFY widgetLinksChanged)
     Q_PROPERTY(int roomMemberCount READ roomMemberCount NOTIFY roomMemberCountChanged)
     Q_PROPERTY(bool isEncrypted READ isEncrypted NOTIFY encryptionChanged)
+    Q_PROPERTY(QString fullyReadEventId READ fullyReadEventId NOTIFY fullyReadEventIdChanged)
     Q_PROPERTY(bool isSpace READ isSpace CONSTANT)
     Q_PROPERTY(int trustlevel READ trustlevel NOTIFY trustlevelChanged)
     Q_PROPERTY(bool isDirect READ isDirect NOTIFY isDirectChanged)
@@ -325,6 +326,7 @@ public:
 
     bool isSpace() const { return isSpace_; }
     bool isEncrypted() const { return isEncrypted_; }
+    QString fullyReadEventId() const { return QString::fromStdString(fullyReadEventId_); }
     crypto::Trust trustlevel() const;
     int roomMemberCount() const;
     bool isDirect() const { return roomMemberCount() <= 2; }
@@ -344,6 +346,9 @@ public slots:
     int currentIndex() const { return idToIndex(currentId); }
     void eventShown();
     void markEventsAsRead(const std::vector<QString> &event_ids);
+    void updateLastReadId(QString currentRoomId);
+    void lastReadIdOnWindowFocus();
+    void checkAfterFetch();
     QVariantMap getDump(const QString &eventId, const QString &relatedTo) const;
     void updateTypingUsers(const std::vector<QString> &users)
     {
@@ -427,6 +432,7 @@ signals:
     void updateFlowEventId(std::string event_id);
 
     void encryptionChanged();
+    void fullyReadEventIdChanged();
     void trustlevelChanged();
     void roomNameChanged();
     void roomTopicChanged();
@@ -480,6 +486,8 @@ private:
     bool m_paginationInProgress = false;
     bool isSpace_               = false;
     bool isEncrypted_           = false;
+    std::string last_event_id;
+    std::string fullyReadEventId_;
 };
 
 template<class T>
@@ -497,6 +505,7 @@ TimelineModel::sendMessageEvent(const T &content, mtx::events::EventType eventTy
         msgCopy.type                      = eventType;
         emit newMessageToSend(msgCopy);
     }
+
     resetReply();
     resetEdit();
 }