Show redactions in qml timeline

resources/qml/TimelineView.qml

@@ -23,7 +23,7 @@ Rectangle {
 	ListView {
 		id: chat
 
-		cacheBuffer: 4*parent.height
+		cacheBuffer: parent.height
 
 		visible: timelineManager.timeline != null
 		anchors.fill: parent
@@ -65,6 +65,7 @@ Rectangle {
 					case MtxEvent.TextMessage: return "delegates/TextMessage.qml"
 					case MtxEvent.ImageMessage: return "delegates/ImageMessage.qml"
 					case MtxEvent.VideoMessage: return "delegates/VideoMessage.qml"
+					case MtxEvent.Redacted: return "delegates/Redacted.qml"
 					default: return "delegates/placeholder.qml"
 				}
 				property variant eventData: model

resources/qml/delegates/Redacted.qml

@@ -0,0 +1,15 @@
+import QtQuick 2.5
+import QtQuick.Controls 2.5
+
+Label {
+	text: qsTr("redacted")
+	color: inactiveColors.text
+	horizontalAlignment: Text.AlignHCenter
+
+	height: contentHeight * 1.2
+	width: contentWidth * 1.2
+	background: Rectangle {
+		radius: parent.height / 2
+		color: colors.dark
+	}
+}

resources/res.qrc

@@ -120,5 +120,6 @@
         <file>qml/delegates/TextMessage.qml</file>
         <file>qml/delegates/NoticeMessage.qml</file>
         <file>qml/delegates/ImageMessage.qml</file>
+        <file>qml/delegates/Redacted.qml</file>
     </qresource>
 </RCC>

src/timeline2/TimelineModel.cpp

@@ -1,5 +1,6 @@
 #include "TimelineModel.h"
 
+#include <algorithm>
 #include <type_traits>
 
 #include <QRegularExpression>
@@ -160,6 +161,12 @@ toRoomEventType(const mtx::events::Event<mtx::events::msg::Video> &)
 {
         return qml_mtx_events::EventType::VideoMessage;
 }
+
+qml_mtx_events::EventType
+toRoomEventType(const mtx::events::Event<mtx::events::msg::Redacted> &)
+{
+        return qml_mtx_events::EventType::Redacted;
+}
 // ::EventType::Type toRoomEventType(const Event<mtx::events::msg::Location> &e) { return
 // ::EventType::LocationMessage; }
 
@@ -319,26 +326,62 @@ TimelineModel::addEvents(const mtx::responses::Timeline &timeline)
         if (timeline.events.empty())
                 return;
 
+        std::vector<QString> ids = internalAddEvents(timeline.events);
+
+        if (ids.empty())
+                return;
+
+        beginInsertRows(QModelIndex(),
+                        static_cast<int>(this->eventOrder.size()),
+                        static_cast<int>(this->eventOrder.size() + ids.size() - 1));
+        this->eventOrder.insert(this->eventOrder.end(), ids.begin(), ids.end());
+        endInsertRows();
+}
+
+std::vector<QString>
+TimelineModel::internalAddEvents(
+  const std::vector<mtx::events::collections::TimelineEvents> &timeline)
+{
         std::vector<QString> ids;
-        for (const auto &e : timeline.events) {
+        for (const auto &e : timeline) {
                 QString id =
                   boost::apply_visitor([](const auto &e) -> QString { return eventId(e); }, e);
 
                 if (this->events.contains(id))
                         continue;
 
+                if (auto redaction =
+                      boost::get<mtx::events::RedactionEvent<mtx::events::msg::Redaction>>(&e)) {
+                        QString redacts = QString::fromStdString(redaction->redacts);
+                        auto redacted   = std::find(eventOrder.begin(), eventOrder.end(), redacts);
+
+                        if (redacted != eventOrder.end()) {
+                                auto redactedEvent = boost::apply_visitor(
+                                  [](const auto &ev)
+                                    -> mtx::events::RoomEvent<mtx::events::msg::Redacted> {
+                                          mtx::events::RoomEvent<mtx::events::msg::Redacted>
+                                            replacement                = {};
+                                          replacement.event_id         = ev.event_id;
+                                          replacement.room_id          = ev.room_id;
+                                          replacement.sender           = ev.sender;
+                                          replacement.origin_server_ts = ev.origin_server_ts;
+                                          replacement.type             = ev.type;
+                                          return replacement;
+                                  },
+                                  e);
+                                events.insert(redacts, redactedEvent);
+
+                                int row = (int)std::distance(eventOrder.begin(), redacted);
+                                emit dataChanged(index(row, 0), index(row, 0));
+                        }
+
+                        continue; // don't insert redaction into timeline
+                }
+
                 this->events.insert(id, e);
                 ids.push_back(id);
         }
-
-        if (ids.empty)
-                return;
-
-        beginInsertRows(QModelIndex(),
-                        static_cast<int>(this->eventOrder.size()),
-                        static_cast<int>(this->eventOrder.size() + ids.size() - 1));
-        this->eventOrder.insert(this->eventOrder.end(), ids.begin(), ids.end());
-        endInsertRows();
+        return ids;
 }
 
 void
@@ -373,17 +416,7 @@ TimelineModel::fetchHistory()
 void
 TimelineModel::addBackwardsEvents(const mtx::responses::Messages &msgs)
 {
-        std::vector<QString> ids;
-        for (const auto &e : msgs.chunk) {
-                QString id =
-                  boost::apply_visitor([](const auto &e) -> QString { return eventId(e); }, e);
-
-                if (this->events.contains(id))
-                        continue;
-
-                this->events.insert(id, e);
-                ids.push_back(id);
-        }
+        std::vector<QString> ids = internalAddEvents(msgs.chunk);
 
         if (!ids.empty()) {
                 beginInsertRows(QModelIndex(), 0, static_cast<int>(ids.size() - 1));

src/timeline2/TimelineModel.h

@@ -61,6 +61,7 @@ enum EventType
         NoticeMessage,
         TextMessage,
         VideoMessage,
+        Redacted,
         UnknownMessage,
 };
 Q_ENUM_NS(EventType)
@@ -124,6 +125,8 @@ signals:
 private:
         DecryptionResult decryptEvent(
           const mtx::events::EncryptedEvent<mtx::events::msg::Encrypted> &e) const;
+        std::vector<QString> internalAddEvents(
+          const std::vector<mtx::events::collections::TimelineEvents> &timeline);
 
         QHash<QString, mtx::events::collections::TimelineEvents> events;
         std::vector<QString> eventOrder;