Cherrypick Other user read markers 23.04

Add the ability to see other user's read markers. 

![image](/uploads/a4bdc35a60ab10685c7d3ea4d9b13c87/image.png)

Implements network/neochat#133


(cherry picked from commit 23303c0483)

src/models/messageeventmodel.cpp

@@ -54,6 +54,9 @@ QHash<int, QByteArray> MessageEventModel::roleNames() const
     roles[UserMarkerRole] = "userMarker";
     roles[ShowAuthorRole] = "showAuthor";
     roles[ShowSectionRole] = "showSection";
+    roles[ReadMarkersRole] = "readMarkers";
+    roles[ReadMarkersStringRole] = "readMarkersString";
+    roles[ShowReadMarkersRole] = "showReadMarkers";
     roles[ReactionRole] = "reaction";
     roles[IsEditedRole] = "isEdited";
     roles[SourceRole] = "source";
@@ -216,6 +219,12 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
             }
             refreshEventRoles(eventId, {ReactionRole, Qt::DisplayRole});
         });
+        connect(m_currentRoom, &Room::changed, this, [this]() {
+            for (auto it = m_currentRoom->messageEvents().rbegin(); it != m_currentRoom->messageEvents().rend(); ++it) {
+                auto event = it->event();
+                refreshEventRoles(event->id(), {ReadMarkersRole, ReadMarkersStringRole});
+            }
+        });
         connect(m_currentRoom, &Room::newFileTransfer, this, &MessageEventModel::refreshEvent);
         connect(m_currentRoom, &Room::fileTransferProgress, this, &MessageEventModel::refreshEvent);
         connect(m_currentRoom, &Room::fileTransferCompleted, this, &MessageEventModel::refreshEvent);
@@ -791,6 +800,65 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
         return false;
     }
 
+    if (role == ReadMarkersRole) {
+#ifdef QUOTIENT_07
+        auto userIds = room()->userIdsAtEvent(evt.id());
+        userIds.remove(m_currentRoom->localUser()->id());
+#else
+        auto userIds = room()->usersAtEventId(evt.id());
+        userIds.removeAll(m_currentRoom->localUser());
+#endif
+
+        QVariantList users;
+        users.reserve(userIds.size());
+        for (const auto &userId : userIds) {
+#ifdef QUOTIENT_07
+            auto user = static_cast<NeoChatUser *>(m_currentRoom->user(userId));
+#else
+            auto user = static_cast<NeoChatUser *>(userId);
+#endif
+            users += userAtEvent(user, m_currentRoom, evt);
+        }
+
+        return users;
+    }
+
+    if (role == ReadMarkersStringRole) {
+#ifdef QUOTIENT_07
+        auto userIds = room()->userIdsAtEvent(evt.id());
+        userIds.remove(m_currentRoom->localUser()->id());
+#else
+        auto userIds = room()->usersAtEventId(evt.id());
+        userIds.removeAll(m_currentRoom->localUser());
+#endif
+        /**
+         * The string ends up in the form
+         * "x users: user1DisplayName, user2DisplayName, etc."
+         */
+        QString readMarkersString = i18np("1 user: ", "%1 users: ", userIds.size());
+        for (const auto &userId : userIds) {
+#ifdef QUOTIENT_07
+            auto user = static_cast<NeoChatUser *>(m_currentRoom->user(userId));
+#else
+            auto user = static_cast<NeoChatUser *>(userId);
+#endif
+            readMarkersString += user->displayname(m_currentRoom) + i18nc("list separator", ", ");
+        }
+        readMarkersString.chop(2);
+        return readMarkersString;
+    }
+
+    if (role == ShowReadMarkersRole) {
+#ifdef QUOTIENT_07
+        auto userIds = room()->userIdsAtEvent(evt.id());
+        userIds.remove(m_currentRoom->localUser()->id());
+#else
+        auto userIds = room()->usersAtEventId(evt.id());
+        userIds.removeAll(m_currentRoom->localUser());
+#endif
+        return userIds.size() > 0;
+    }
+
     if (role == ReactionRole) {
         const auto &annotations = m_currentRoom->relatedEvents(evt, EventRelation::Annotation());
         if (annotations.isEmpty()) {

src/models/messageeventmodel.h

@@ -57,6 +57,9 @@ public:
         ShowAuthorRole,
         ShowSectionRole,
 
+        ReadMarkersRole, /**< QVariantList of users at the event for read marker tracking. */
+        ReadMarkersStringRole, /**< QString with the display name and mxID of the users at the event. */
+        ShowReadMarkersRole, /**< bool with whether there are any other user read markers to be shown. */
         ReactionRole,
 
         IsEditedRole,

src/qml/Component/Timeline/AvatarFlow.qml

@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2022 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15 as QQC2
+
+import org.kde.kirigami 2.15 as Kirigami
+
+Flow {
+    id: root
+
+    property var avatarSize: Kirigami.Units.iconSizes.small
+    property alias model: avatarFlowRepeater.model
+    property string toolTipText
+
+    spacing: -avatarSize / 2
+    Repeater {
+        id: avatarFlowRepeater
+        delegate: Kirigami.Avatar {
+            implicitWidth: avatarSize
+            implicitHeight: avatarSize
+
+            name: modelData.displayName
+            source: modelData.avatarMediaId ? ("image://mxc/" + modelData.avatarMediaId) : ""
+            color: modelData.color
+        }
+    }
+
+    QQC2.ToolTip.text: toolTipText
+    QQC2.ToolTip.visible: hoverHandler.hovered
+    QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
+
+    HoverHandler {
+        id: hoverHandler
+        margin: Kirigami.Units.smallSpacing
+    }
+}

src/qml/Component/Timeline/StateDelegate.qml

@@ -134,5 +134,12 @@ QQC2.Control {
             folded = !folded
             foldedChanged()
         }
+        AvatarFlow {
+            Layout.alignment: Qt.AlignRight
+            Layout.rightMargin: Kirigami.Units.largeSpacing
+            visible: showReadMarkers
+            model: readMarkers
+            toolTipText: readMarkersString
+        }
     }
 }

src/qml/Component/Timeline/TimelineContainer.qml

@@ -338,6 +338,13 @@ ColumnLayout {
 
         visible: eventType !== MessageEventModel.State && eventType !== MessageEventModel.Notice && reaction != undefined && reaction.length > 0
     }
+    AvatarFlow {
+        Layout.alignment: Qt.AlignRight
+        Layout.rightMargin: Kirigami.Units.largeSpacing
+        visible: showReadMarkers
+        model: readMarkers
+        toolTipText: readMarkersString
+    }
 
     function isVisibleInTimeline() {
         let yoff = Math.round(y - ListView.view.contentY);

src/res.qrc

@@ -49,6 +49,7 @@
         <file alias="MimeComponent.qml">qml/Component/Timeline/MimeComponent.qml</file>
         <file alias="StateComponent.qml">qml/Component/Timeline/StateComponent.qml</file>
         <file alias="MessageEditComponent.qml">qml/Component/Timeline/MessageEditComponent.qml</file>
+        <file alias="AvatarFlow.qml">qml/Component/Timeline/AvatarFlow.qml</file>
         <file alias="LoginStep.qml">qml/Component/Login/LoginStep.qml</file>
         <file alias="Login.qml">qml/Component/Login/Login.qml</file>
         <file alias="Password.qml">qml/Component/Login/Password.qml</file>