fix(ui): Sending read receipt in thread timelines

Author: jmartinesp

crates/matrix-sdk-ui/src/timeline/controller/mod.rs

@@ -1764,6 +1764,18 @@ impl TimelineController {
         state.items.all_remote_events().last().map(|event_meta| &event_meta.event_id).cloned()
     }
 
+    /// Returns the latest event identifier from the visible timeline items.
+    pub(crate) async fn latest_visible_event_id(&self) -> Option<OwnedEventId> {
+        let state = self.state.read().await;
+        state
+            .items
+            .iter()
+            .filter(|item| item.is_event() && !item.is_local_echo())
+            .last()
+            .and_then(|event_meta| event_meta.as_event().unwrap().event_id())
+            .map(ToOwned::to_owned)
+    }
+
     #[instrument(skip(self), fields(room_id = ?self.room().room_id()))]
     pub(super) async fn retry_event_decryption(&self, session_ids: Option<BTreeSet<String>>) {
         self.retry_event_decryption_inner(session_ids).await

crates/matrix-sdk-ui/src/timeline/mod.rs

@@ -796,7 +796,7 @@ impl Timeline {
     /// Returns a boolean indicating if it sent the receipt or not.
     #[instrument(skip(self), fields(room_id = ?self.room().room_id()))]
     pub async fn mark_as_read(&self, receipt_type: ReceiptType) -> Result<bool> {
-        if let Some(event_id) = self.controller.latest_event_id().await {
+        if let Some(event_id) = self.controller.latest_visible_event_id().await {
             self.send_single_receipt(receipt_type, event_id).await
         } else {
             trace!("can't mark room as read because there's no latest event id");