Add RedactionEvent support on backend

src/backend/matrix_client.py

@@ -1208,6 +1208,11 @@ class MatrixClient(nio.AsyncClient):
                 content, inline=True, room_id=room.room_id,
             )
 
+        age = 0
+        with suppress(Exception):
+            age = ev.source.get("age")
+        age = age or 0
+
         # Create Event ModelItem
 
         item = Event(
@@ -1215,7 +1220,12 @@ class MatrixClient(nio.AsyncClient):
             event_id      = ev.event_id,
             event_type    = type(ev),
             source        = ev,
-            date          = datetime.fromtimestamp(ev.server_timestamp / 1000),
+            date          = datetime.fromtimestamp(
+                (
+                    datetime.fromtimestamp(ev.server_timestamp / 1000) -
+                    datetime.fromtimestamp(age / 1000)
+                ).total_seconds()
+            ),
             sender_id     = ev.sender,
             sender_name   = sender_name,
             sender_avatar = sender_avatar,
@@ -1242,5 +1252,61 @@ class MatrixClient(nio.AsyncClient):
             AlertRequested()
 
         model[item.id] = item
-
         await self.set_room_last_event(room.room_id, item)
+
+
+    async def register_redact_event(
+        self, room: nio.MatrixRoom, ev: nio.Event, **fields
+    ) -> None:
+        """Register a `nio.events.room_events.RedactionEvent` in our model.
+
+        If .redacts attribute points to an existing model, it should get replaced.
+        Else register as a new Event.
+        """
+
+        model = self.models[self.user_id, room.room_id, "events"]
+        event = model.get_event_id(ev.redacts)
+
+        if event:
+            sender_name, sender_avatar = \
+            await self.get_member_name_avatar(room.room_id, ev.sender)
+
+            target_id = getattr(ev, "state_key", "") or ""
+
+            target_name, target_avatar = \
+                await self.get_member_name_avatar(room.room_id, target_id) \
+                if target_id else ("", "")
+
+            content = fields.get("content", "").strip()
+
+            if content and "inline_content" not in fields:
+                fields["inline_content"] = HTML.filter(
+                    content, inline=True, room_id=room.room_id,
+                )
+
+            age = ev.source["unsigned"]["age"]
+
+            item = Event(
+                id            = ev.event_id,
+                event_id      = ev.event_id,
+                event_type    = type(ev),
+                source        = ev,
+                date          = datetime.fromtimestamp(
+                    (
+                        datetime.fromtimestamp(ev.server_timestamp / 1000) -
+                        datetime.fromtimestamp(age / 1000)
+                    ).total_seconds()
+                ),
+                sender_id     = ev.sender,
+                sender_name   = sender_name,
+                sender_avatar = sender_avatar,
+                target_id     = target_id,
+                target_name   = target_name,
+                target_avatar = target_avatar,
+                links         = Event.parse_links(content),
+                **fields,
+            )
+
+            model[event.id] = item
+        else:
+            await self.register_nio_event(room, ev, **fields)

src/backend/models/items.py

@@ -177,6 +177,7 @@ class Event(ModelItem):
 
     content:        str                   = ""
     inline_content: str                   = ""
+    redacts:        str                   = ""
     reason:         str                   = ""
     links:          List[str]             = field(default_factory=list)
     mentions:       List[Tuple[str, str]] = field(default_factory=list)

src/backend/models/model.py

@@ -129,3 +129,21 @@ class Model(MutableMapping):
         new = type(self)(sync_id=sync_id)
         new.update(self)
         return new
+
+
+    def get_event_id(self, event_id: str) -> "Model":
+        """Get an event from the internal dict by event_id field.
+
+        This function exists because not every event is indexed with its
+        event_id field.
+        """
+
+        event = self._data.get(event_id)
+        if event and event.event_id == event_id:
+            return event
+
+        for event in self._data.values():
+            if event.event_id == event_id:
+                return event
+
+        return None

src/backend/nio_callbacks.py

@@ -161,6 +161,12 @@ class NioCallbacks:
         await self.onRoomMessageMedia(room, ev)
 
 
+    async def onRedactionEvent(self, room, ev) -> None:
+        await self.client.register_redact_event(
+            room, ev, redacts=ev.redacts, reason=ev.reason
+        )
+
+
     async def onRoomCreateEvent(self, room, ev) -> None:
         co = "%1 allowed users on other matrix servers to join this room" \
              if ev.federate else \

src/gui/Pages/Chat/Timeline/EventDelegate.qml

@@ -33,6 +33,7 @@ HColumnLayout {
     readonly property bool smallAvatar: compact
     readonly property bool collapseAvatar: combine
     readonly property bool hideAvatar: onRight
+    readonly property bool isRedacted: model.event_type === "RedactionEvent"
 
     readonly property bool hideNameLine:
         model.event_type === "RoomMessageEmote" ||
@@ -221,6 +222,7 @@ HColumnLayout {
         HMenuItemPopupSpawner {
             icon.name: "remove-message"
             text: qsTr("Remove")
+            enabled: ! isRedacted
 
             popup: "Popups/RedactEvents.qml"
             popupParent: chat

src/gui/Utils.qml

@@ -200,6 +200,14 @@ QtObject {
             return qsTr(ev.content).arg(sender).arg(target)
         }
 
+        if (type === "RedactionEvent") {
+            return qsTr(
+                "<i>Removed message" +
+                `${ev.reason ? ". Reason: " + ev.reason : ""}` +
+                "</i>"
+            )
+        }
+
         return qsTr(ev.content).arg(sender)
     }