refactor(ui): Move TimelineStream into the new subscriber module.

This patch moves the `TimelineStream` type into the new `subscriber`
module. The idea is to add more code related to subscribers in the next
patches.

Author: Hywan

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

@@ -16,7 +16,7 @@
 //!
 //! See [`Timeline`] for details.
 
-use std::{fs, path::PathBuf, pin::Pin, sync::Arc, task::Poll};
+use std::{fs, path::PathBuf, sync::Arc};
 
 use algorithms::rfind_event_by_item_id;
 use event_item::{extract_room_msg_edit_content, TimelineItemHandle};
@@ -33,7 +33,7 @@ use matrix_sdk::{
     Client, Result,
 };
 use mime::Mime;
-use pin_project_lite::pin_project;
+use pinned_events_loader::PinnedEventsRoom;
 use ruma::{
     api::client::receipt::create_receipt::v3::ReceiptType,
     events::{
@@ -52,13 +52,13 @@ use ruma::{
     serde::Raw,
     EventId, MilliSecondsSinceUnixEpoch, OwnedEventId, OwnedUserId, RoomVersionId, UserId,
 };
+use subscriber::TimelineStream;
 use thiserror::Error;
 use tracing::{error, instrument, trace, warn};
 
 use self::{
     algorithms::rfind_event_by_id, controller::TimelineController, futures::SendAttachment,
 };
-use crate::timeline::pinned_events_loader::PinnedEventsRoom;
 
 mod algorithms;
 mod builder;
@@ -73,6 +73,7 @@ mod item;
 mod pagination;
 mod pinned_events_loader;
 mod reactions;
+mod subscriber;
 #[cfg(test)]
 mod tests;
 mod to_device;
@@ -848,31 +849,6 @@ impl Drop for TimelineDropHandle {
     }
 }
 
-pin_project! {
-    struct TimelineStream<S> {
-        #[pin]
-        inner: S,
-        drop_handle: Arc<TimelineDropHandle>,
-    }
-}
-
-impl<S> TimelineStream<S> {
-    fn new(inner: S, drop_handle: Arc<TimelineDropHandle>) -> Self {
-        Self { inner, drop_handle }
-    }
-}
-
-impl<S: Stream> Stream for TimelineStream<S> {
-    type Item = S::Item;
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut std::task::Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
-        self.project().inner.poll_next(cx)
-    }
-}
-
 pub type TimelineEventFilterFn =
     dyn Fn(&AnySyncTimelineEvent, &RoomVersionId) -> bool + Send + Sync;
 

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

@@ -0,0 +1,49 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::{
+    pin::Pin,
+    sync::Arc,
+    task::{Context, Poll},
+};
+
+use futures_core::Stream;
+use pin_project_lite::pin_project;
+
+use super::TimelineDropHandle;
+
+pin_project! {
+    pub(super) struct TimelineStream<S> {
+        #[pin]
+        inner: S,
+        drop_handle: Arc<TimelineDropHandle>,
+    }
+}
+
+impl<S> TimelineStream<S> {
+    pub fn new(inner: S, drop_handle: Arc<TimelineDropHandle>) -> Self {
+        Self { inner, drop_handle }
+    }
+}
+
+impl<S> Stream for TimelineStream<S>
+where
+    S: Stream,
+{
+    type Item = S::Item;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        self.project().inner.poll_next(cx)
+    }
+}