feat(WidgetDriver): Send state from state sync and not from timeline to widget (matrix-org#4254)

Author: toger5

crates/matrix-sdk/src/widget/matrix.rs

@@ -26,8 +26,9 @@ use ruma::{
     },
     assign,
     events::{
-        AnyMessageLikeEventContent, AnyStateEventContent, AnySyncTimelineEvent, AnyTimelineEvent,
-        MessageLikeEventType, StateEventType, TimelineEventType,
+        AnyMessageLikeEventContent, AnyStateEventContent, AnySyncMessageLikeEvent,
+        AnySyncStateEvent, AnySyncTimelineEvent, AnyTimelineEvent, MessageLikeEventType,
+        StateEventType, TimelineEventType,
     },
     serde::{from_raw_json_value, Raw},
     EventId, RoomId, TransactionId,
@@ -177,21 +178,39 @@ impl MatrixDriver {
     pub(crate) fn events(&self) -> EventReceiver {
         let (tx, rx) = unbounded_channel();
         let room_id = self.room.room_id().to_owned();
-        let handle = self.room.add_event_handler(move |raw: Raw<AnySyncTimelineEvent>| {
-            let _ = tx.send(attach_room_id(&raw, &room_id));
+
+        // Get only message like events from the timeline section of the sync.
+        let _tx = tx.clone();
+        let _room_id = room_id.clone();
+        let handle_msg_like =
+            self.room.add_event_handler(move |raw: Raw<AnySyncMessageLikeEvent>| {
+                let _ = _tx.send(attach_room_id(raw.cast_ref(), &_room_id));
+                async {}
+            });
+        let drop_guard_msg_like = self.room.client().event_handler_drop_guard(handle_msg_like);
+
+        // Get only all state events from the state section of the sync.
+        let handle_state = self.room.add_event_handler(move |raw: Raw<AnySyncStateEvent>| {
+            let _ = tx.send(attach_room_id(raw.cast_ref(), &room_id));
             async {}
         });
-
-        let drop_guard = self.room.client().event_handler_drop_guard(handle);
-        EventReceiver { rx, _drop_guard: drop_guard }
+        let drop_guard_state = self.room.client().event_handler_drop_guard(handle_state);
+
+        // The receiver will get a combination of state and message like events.
+        // The state events will come from the state section of the sync (to always
+        // represent current resolved state). All state events in the timeline
+        // section of the sync will not be forwarded to the widget.
+        // TODO annotate the events and send both timeline and state section state
+        // events.
+        EventReceiver { rx, _drop_guards: [drop_guard_msg_like, drop_guard_state] }
     }
 }
 
 /// A simple entity that wraps an `UnboundedReceiver`
 /// along with the drop guard for the room event handler.
 pub(crate) struct EventReceiver {
     rx: UnboundedReceiver<Raw<AnyTimelineEvent>>,
-    _drop_guard: EventHandlerDropGuard,
+    _drop_guards: [EventHandlerDropGuard; 2],
 }
 
 impl EventReceiver {