reafactor(ffi): Have ffi::Timeline::latest_event_id use ui::Timeline::latest_event_id, instead of ui::Timeline::latest_event

This is important because `latest_event` would also return local events, which won't have an event id.

Author: jmartinesp

bindings/matrix-sdk-ffi/src/timeline/mod.rs

@@ -367,7 +367,7 @@ impl Timeline {
 
     /// Returns the [`EventId`] of the latest event in the timeline.
     pub async fn latest_event_id(&self) -> Option<String> {
-        self.inner.latest_event().await.and_then(|event| event.event_id().map(ToString::to_string))
+        self.inner.latest_event_id().await.as_deref().map(ToString::to_string)
     }
 
     /// Queues an event in the room's send queue so it's processed for

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

@@ -253,7 +253,7 @@ impl Timeline {
         Some(item.to_owned())
     }
 
-    /// Get the latest of the timeline's event items.
+    /// Get the latest of the timeline's event items, both remote and local.
     pub async fn latest_event(&self) -> Option<EventTimelineItem> {
         if self.controller.is_live() {
             self.controller.items().await.iter().rev().find_map(|item| {
@@ -268,6 +268,11 @@ impl Timeline {
         }
     }
 
+    /// Get the latest of the timeline's event ids.
+    pub async fn latest_event_id(&self) -> Option<OwnedEventId> {
+        self.controller.latest_event_id().await
+    }
+
     /// Get the current timeline items, along with a stream of updates of
     /// timeline items.
     ///