Remove unnecessary TimelineAction via an immediate action handling

Now that Timeline and RoomScreen have been merged, we don't need to
emit multiple separate redundant actions for showing the message
being replied to. Instead, we can handle it immediately once
a message widget broadcasts the action that its reply button
has been pressed.

src/home/room_screen.rs

@@ -1173,24 +1173,20 @@ impl Widget for RoomScreen {
         }
 
         if let Event::Actions(actions) = event {
-            self.send_user_read_receipts_based_on_scroll_pos(cx, actions);
             for action in actions {
                 // Handle actions on a message, e.g., clicking the reply button or clicking the reply preview.
                 match action.as_widget_action().cast() {
                     MessageAction::MessageReply(item_id) => {
                         let Some(tl) = self.tl_state.as_mut() else {
                             continue;
                         };
-                        let tl_idx = item_id as usize;
-                        if let Some(tl_item) = tl.items.get(tl_idx) {
-                            if let Some(tl_event_item) = tl_item.as_event() {
-                                // TODO: this is ugly, but i couldnt find a clean way of making the Message
-                                // dispatch the action itself, it would need access to the timeline state or data
-                                cx.widget_action(
-                                    widget_uid,
-                                    &scope.path,
-                                    TimelineAction::MessageReply(tl_event_item.clone()),
-                                );
+
+                        if let Some(event_tl_item) = tl.items
+                            .get(item_id)
+                            .and_then(|tl_item| tl_item.as_event().cloned())
+                        {
+                            if let Ok(replied_to_info) = event_tl_item.replied_to_info() {
+                                self.show_replying_to(cx, (event_tl_item, replied_to_info));
                             }
                         }
                     }
@@ -1251,15 +1247,6 @@ impl Widget for RoomScreen {
                     }
                 }
 
-                // Handle message reply action
-                if let TimelineAction::MessageReply(message_to_reply_to) = action.as_widget_action().cast() {
-                    if let Ok(replied_to_info) = message_to_reply_to.replied_to_info() {
-                        self.show_replying_to(cx, (message_to_reply_to, replied_to_info));
-                    } else {
-                        error!("Failed to get replied-to info for message {:?}", message_to_reply_to);
-                    }
-                }
-
                 // Handle the action that requests to show the user profile sliding pane.
                 if let ShowUserProfileAction::ShowUserProfile(profile_and_room_id) = action.as_widget_action().cast() {
                     self.show_user_profile(
@@ -1352,6 +1339,9 @@ impl Widget for RoomScreen {
                 }
             }
 
+            // Handle sending any read receipts for the current logged-in user.
+            self.send_user_read_receipts_based_on_scroll_pos(cx, actions);
+
             // Handle the cancel reply button being clicked.
             if self.button(id!(cancel_reply_button)).clicked(&actions) {
                 self.clear_replying_to();
@@ -1803,11 +1793,6 @@ impl RoomScreenRef {
     }
 }
 
-#[derive(Clone, DefaultNone, Debug)]
-pub enum TimelineAction {
-    MessageReply(EventTimelineItem),
-    None,
-}
 
 /// A message that is sent from a background async task to a room's timeline view
 /// for the purpose of update the Timeline UI contents or metadata.
@@ -2183,6 +2168,7 @@ fn populate_message_view(
         return (item, new_drawn_status);
     }
 
+    // Set the Message widget's metatdata for reply-handling purposes.
     item.as_message().set_data(
         event_tl_item.can_be_replied_to(),
         item_id,