send queue: handle reactions in the send queue

crates/matrix-sdk-base/src/store/traits.rs

@@ -1252,6 +1252,18 @@ pub enum DependentQueuedEventKind {
 
     /// The event should be redacted/aborted/removed.
     Redact,
+
+    /// The event should be reacted to, with the given key.
+    React {
+        /// Key used for the reaction.
+        key: String,
+
+        /// The transaction id to use for sending the reaction.
+        ///
+        /// Note: it's not the one for the local echo of the event we're
+        /// reacting to.
+        transaction_id: OwnedTransactionId,
+    },
 }
 
 /// An event to be sent, depending on a [`QueuedEvent`] to be sent first.

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

@@ -1161,6 +1161,10 @@ impl<P: RoomDataProvider> TimelineInner<P> {
                     .await;
                 }
             }
+
+            LocalEchoContent::React { key, send_handle } => {
+                todo!();
+            }
         }
     }