feat(ui): RoomList dynamic entries simplifications

feat(ui): `RoomList` dynamic entries simplifications

crates/matrix-sdk-ui/src/room_list_service/room_list.rs

@@ -12,10 +12,7 @@
 // See the License for that specific language governing permissions and
 // limitations under the License.
 
-use std::{
-    future::ready,
-    sync::{Arc, Mutex},
-};
+use std::{future::ready, sync::Arc};
 
 use async_cell::sync::AsyncCell;
 use async_rx::StreamExt as _;
@@ -138,7 +135,7 @@ impl RoomList {
         let dynamic_entries_controller = RoomListDynamicEntriesController::new(
             filter_fn_cell.clone(),
             page_size,
-            limit.clone(),
+            limit,
             list.maximum_number_of_rooms_stream(),
         );
 
@@ -211,7 +208,7 @@ pub struct RoomListDynamicEntriesController {
     filter: Arc<AsyncCell<BoxedFilterFn>>,
     page_size: usize,
     limit: SharedObservable<usize>,
-    maximum_number_of_rooms: Mutex<Subscriber<Option<u32>>>,
+    maximum_number_of_rooms: Subscriber<Option<u32>>,
 }
 
 impl RoomListDynamicEntriesController {
@@ -221,12 +218,7 @@ impl RoomListDynamicEntriesController {
         limit_stream: SharedObservable<usize>,
         maximum_number_of_rooms: Subscriber<Option<u32>>,
     ) -> Self {
-        Self {
-            filter,
-            page_size,
-            limit: limit_stream,
-            maximum_number_of_rooms: Mutex::new(maximum_number_of_rooms),
-        }
+        Self { filter, page_size, limit: limit_stream, maximum_number_of_rooms }
     }
 
     /// Set the filter.
@@ -251,7 +243,7 @@ impl RoomListDynamicEntriesController {
     /// Add one page, i.e. view `page_size` more entries in the room list if
     /// any.
     pub fn add_one_page(&self) {
-        let Some(max) = self.maximum_number_of_rooms.lock().unwrap().next_now() else {
+        let Some(max) = self.maximum_number_of_rooms.get() else {
             return;
         };
 
@@ -263,13 +255,13 @@ impl RoomListDynamicEntriesController {
             // `max - limit < page_size`, and that's perfectly fine. It's OK to have a
             // `limit` greater than `max`, but it's not OK to increase the limit
             // indefinitely.
-            self.limit.set(limit + self.page_size);
+            self.limit.set_if_not_eq(limit + self.page_size);
         }
     }
 
     /// Reset the one page, i.e. forget all pages and move back to the first
     /// page.
     pub fn reset_to_one_page(&self) {
-        self.limit.set(self.page_size);
+        self.limit.set_if_not_eq(self.page_size);
     }
 }

crates/matrix-sdk-ui/tests/integration/room_list_service.rs

@@ -1851,6 +1851,10 @@ async fn test_dynamic_entries_stream() -> Result<(), Error> {
     }
     assert_pending!(dynamic_entries_stream);
 
+    // Let's reset to one page again, it should do nothing.
+    dynamic_entries.reset_to_one_page();
+    assert_pending!(dynamic_entries_stream);
+
     // Let's ask one more page again, because it's fun.
     dynamic_entries.add_one_page();