timeline: include the remote event's origin in the timeline position/end

and don't assume inserting to the end means it's coming from sync — as
it won't be true for forward pagination anymore.

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

@@ -213,16 +213,11 @@ impl TimelineEventKind {
 pub(super) enum TimelineItemPosition {
     /// One or more items are prepended to the timeline (i.e. they're the
     /// oldest).
-    ///
-    /// Usually this means items coming from back-pagination.
-    Start,
+    Start { origin: RemoteEventOrigin },
 
     /// One or more items are appended to the timeline (i.e. they're the most
     /// recent).
-    End {
-        /// Whether this event is coming from a local cache.
-        from_cache: bool,
-    },
+    End { origin: RemoteEventOrigin },
 
     /// A single item is updated.
     ///
@@ -832,16 +827,13 @@ impl<'a, 'o> TimelineEventHandler<'a, 'o> {
                     }
                 }
 
-                let origin = match position {
-                    TimelineItemPosition::Start => RemoteEventOrigin::Pagination,
-
-                    // We only paginate backwards for now, so End only happens for syncs
-                    TimelineItemPosition::End { from_cache: true } => RemoteEventOrigin::Cache,
-
-                    TimelineItemPosition::End { from_cache: false } => RemoteEventOrigin::Sync,
+                let origin = match *position {
+                    TimelineItemPosition::Start { origin }
+                    | TimelineItemPosition::End { origin } => origin,
 
+                    // For updates, reuse the origin of the encrypted event.
                     #[cfg(feature = "e2e-encryption")]
-                    TimelineItemPosition::Update(idx) => self.items[*idx]
+                    TimelineItemPosition::Update(idx) => self.items[idx]
                         .as_event()
                         .and_then(|ev| Some(ev.as_remote()?.origin))
                         .unwrap_or_else(|| {
@@ -875,7 +867,7 @@ impl<'a, 'o> TimelineEventHandler<'a, 'o> {
                 self.items.push_back(item);
             }
 
-            Flow::Remote { position: TimelineItemPosition::Start, event_id, .. } => {
+            Flow::Remote { position: TimelineItemPosition::Start { .. }, event_id, .. } => {
                 if self
                     .items
                     .iter()

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

@@ -52,6 +52,7 @@ use tracing::{field, info_span, Instrument as _};
 use super::traits::Decryptor;
 use super::{
     event_handler::TimelineEventKind,
+    event_item::RemoteEventOrigin,
     reactions::ReactionToggleResult,
     traits::RoomDataProvider,
     util::{rfind_event_by_id, rfind_event_item, RelativePosition},
@@ -396,13 +397,16 @@ impl<P: RoomDataProvider> TimelineInner<P> {
         &self,
         events: Vec<impl Into<SyncTimelineEvent>>,
         position: TimelineEnd,
+        origin: RemoteEventOrigin,
     ) -> HandleManyEventsResult {
         if events.is_empty() {
             return Default::default();
         }
 
         let mut state = self.state.write().await;
-        state.add_events_at(events, position, &self.room_data_provider, &self.settings).await
+        state
+            .add_events_at(events, position, origin, &self.room_data_provider, &self.settings)
+            .await
     }
 
     pub(super) async fn clear(&self) {
@@ -433,7 +437,8 @@ impl<P: RoomDataProvider> TimelineInner<P> {
             state
                 .add_events_at(
                     events,
-                    TimelineEnd::Back { from_cache: true },
+                    TimelineEnd::Back,
+                    RemoteEventOrigin::Cache,
                     &self.room_data_provider,
                     &self.settings,
                 )
@@ -468,7 +473,8 @@ impl<P: RoomDataProvider> TimelineInner<P> {
         state
             .add_events_at(
                 vec![event],
-                TimelineEnd::Back { from_cache: false },
+                TimelineEnd::Back,
+                RemoteEventOrigin::Sync,
                 &self.room_data_provider,
                 &self.settings,
             )

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

@@ -38,7 +38,7 @@ use crate::{
             Flow, HandleEventResult, TimelineEventContext, TimelineEventHandler, TimelineEventKind,
             TimelineItemPosition,
         },
-        event_item::EventItemIdentifier,
+        event_item::{EventItemIdentifier, RemoteEventOrigin},
         polls::PollPendingEvents,
         reactions::{ReactionToggleResult, Reactions},
         read_receipts::ReadReceipts,
@@ -59,10 +59,7 @@ pub(crate) enum TimelineEnd {
     /// Event should be prepended to the front of the timeline.
     Front,
     /// Event should appended to the back of the timeline.
-    Back {
-        /// Did the event come from the cache?
-        from_cache: bool,
-    },
+    Back,
 }
 
 #[derive(Debug)]
@@ -100,6 +97,7 @@ impl TimelineInnerState {
         &mut self,
         events: Vec<impl Into<SyncTimelineEvent>>,
         position: TimelineEnd,
+        origin: RemoteEventOrigin,
         room_data_provider: &P,
         settings: &TimelineInnerSettings,
     ) -> HandleManyEventsResult {
@@ -109,7 +107,7 @@ impl TimelineInnerState {
 
         let mut txn = self.transaction();
         let handle_many_res =
-            txn.add_events_at(events, position, room_data_provider, settings).await;
+            txn.add_events_at(events, position, origin, room_data_provider, settings).await;
         txn.commit();
 
         handle_many_res
@@ -135,7 +133,8 @@ impl TimelineInnerState {
 
         txn.add_events_at(
             events,
-            TimelineEnd::Back { from_cache: false },
+            TimelineEnd::Back,
+            RemoteEventOrigin::Sync,
             room_data_provider,
             settings,
         )
@@ -398,14 +397,15 @@ impl TimelineInnerStateTransaction<'_> {
         &mut self,
         events: Vec<impl Into<SyncTimelineEvent>>,
         position: TimelineEnd,
+        origin: RemoteEventOrigin,
         room_data_provider: &P,
         settings: &TimelineInnerSettings,
     ) -> HandleManyEventsResult {
         let mut total = HandleManyEventsResult::default();
 
         let position = match position {
-            TimelineEnd::Front => TimelineItemPosition::Start,
-            TimelineEnd::Back { from_cache } => TimelineItemPosition::End { from_cache },
+            TimelineEnd::Front => TimelineItemPosition::Start { origin },
+            TimelineEnd::Back => TimelineItemPosition::End { origin },
         };
 
         let mut day_divider_adjuster = DayDividerAdjuster::default();
@@ -630,7 +630,9 @@ impl TimelineInnerStateTransaction<'_> {
         settings: &TimelineInnerSettings,
     ) {
         match position {
-            TimelineItemPosition::Start => self.meta.all_events.push_front(event_meta.base_meta()),
+            TimelineItemPosition::Start { .. } => {
+                self.meta.all_events.push_front(event_meta.base_meta())
+            }
             TimelineItemPosition::End { .. } => {
                 // Handle duplicated event.
                 if let Some(pos) =
@@ -660,7 +662,10 @@ impl TimelineInnerStateTransaction<'_> {
         }
 
         if settings.track_read_receipts
-            && matches!(position, TimelineItemPosition::Start | TimelineItemPosition::End { .. })
+            && matches!(
+                position,
+                TimelineItemPosition::Start { .. } | TimelineItemPosition::End { .. }
+            )
         {
             self.load_read_receipts_for_event(event_meta.event_id, room_data_provider).await;
 

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

@@ -17,7 +17,7 @@ use std::{fmt, ops::ControlFlow, sync::Arc, time::Duration};
 use matrix_sdk::event_cache::{self, BackPaginationOutcome};
 use tracing::{instrument, trace, warn};
 
-use crate::timeline::inner::TimelineEnd;
+use crate::timeline::{event_item::RemoteEventOrigin, inner::TimelineEnd};
 
 impl super::Timeline {
     /// Add more events to the start of the timeline.
@@ -53,8 +53,14 @@ impl super::Timeline {
                         let num_events = events.len();
                         trace!("Back-pagination succeeded with {num_events} events");
 
-                        let handle_many_res =
-                            self.inner.add_events_at(events, TimelineEnd::Front).await;
+                        let handle_many_res = self
+                            .inner
+                            .add_events_at(
+                                events,
+                                TimelineEnd::Front,
+                                RemoteEventOrigin::Pagination,
+                            )
+                            .await;
 
                         if reached_start {
                             self.back_pagination_status

crates/matrix-sdk-ui/src/timeline/tests/basic.rs

@@ -37,7 +37,7 @@ use stream_assert::assert_next_matches;
 
 use super::TestTimeline;
 use crate::timeline::{
-    event_item::AnyOtherFullStateEventContent,
+    event_item::{AnyOtherFullStateEventContent, RemoteEventOrigin},
     inner::{TimelineEnd, TimelineInnerSettings},
     tests::{ReadReceiptMap, TestRoomDataProvider},
     MembershipChange, TimelineDetails, TimelineItemContent, TimelineItemKind, VirtualTimelineItem,
@@ -63,7 +63,8 @@ async fn test_initial_events() {
                         .make_sync_message_event(*BOB, RoomMessageEventContent::text_plain("B")),
                 ),
             ],
-            TimelineEnd::Back { from_cache: false },
+            TimelineEnd::Back,
+            RemoteEventOrigin::Sync,
         )
         .await;
 
@@ -102,7 +103,7 @@ async fn test_replace_with_initial_events_and_read_marker() {
     let factory = EventFactory::new();
     let ev = factory.text_msg("hey").sender(*ALICE).into_sync();
 
-    timeline.inner.add_events_at(vec![ev], TimelineEnd::Back { from_cache: false }).await;
+    timeline.inner.add_events_at(vec![ev], TimelineEnd::Back, RemoteEventOrigin::Sync).await;
 
     let items = timeline.inner.items().await;
     assert_eq!(items.len(), 2);
@@ -286,7 +287,8 @@ async fn test_dedup_initial() {
                 // … and a new event also came in
                 event_c,
             ],
-            TimelineEnd::Back { from_cache: false },
+            TimelineEnd::Back,
+            RemoteEventOrigin::Sync,
         )
         .await;
 
@@ -322,7 +324,7 @@ async fn test_internal_id_prefix() {
 
     timeline
         .inner
-        .add_events_at(vec![ev_a, ev_b, ev_c], TimelineEnd::Back { from_cache: false })
+        .add_events_at(vec![ev_a, ev_b, ev_c], TimelineEnd::Back, RemoteEventOrigin::Sync)
         .await;
 
     let timeline_items = timeline.inner.items().await;

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

@@ -48,6 +48,7 @@ use ruma::{
 
 use super::{
     event_handler::TimelineEventKind,
+    event_item::RemoteEventOrigin,
     inner::{ReactionAction, TimelineEnd, TimelineInnerSettings},
     reactions::ReactionToggleResult,
     traits::RoomDataProvider,
@@ -255,7 +256,9 @@ impl TestTimeline {
 
     async fn handle_back_paginated_custom_event(&self, event: Raw<AnyTimelineEvent>) {
         let timeline_event = TimelineEvent::new(event.cast());
-        self.inner.add_events_at(vec![timeline_event], TimelineEnd::Front).await;
+        self.inner
+            .add_events_at(vec![timeline_event], TimelineEnd::Front, RemoteEventOrigin::Pagination)
+            .await;
     }
 
     async fn handle_read_receipts(

crates/matrix-sdk-ui/src/timeline/tests/reactions.rs

@@ -27,7 +27,8 @@ use ruma::{
 use stream_assert::assert_next_matches;
 
 use crate::timeline::{
-    inner::ReactionAction,
+    event_item::RemoteEventOrigin,
+    inner::{ReactionAction, TimelineEnd},
     reactions::ReactionToggleResult,
     tests::{assert_event_is_updated, assert_no_more_updates, TestTimeline},
     TimelineItem,
@@ -256,7 +257,8 @@ async fn test_initial_reaction_timestamp_is_stored() {
                     RoomMessageEventContent::text_plain("A"),
                 )),
             ],
-            crate::timeline::inner::TimelineEnd::Back { from_cache: false },
+            TimelineEnd::Back,
+            RemoteEventOrigin::Sync,
         )
         .await;
 

crates/matrix-sdk-ui/src/timeline/tests/redaction.rs

@@ -35,7 +35,10 @@ use ruma::{
 use stream_assert::assert_next_matches;
 
 use super::TestTimeline;
-use crate::timeline::{AnyOtherFullStateEventContent, TimelineDetails, TimelineItemContent};
+use crate::timeline::{
+    event_item::RemoteEventOrigin, inner::TimelineEnd, AnyOtherFullStateEventContent,
+    TimelineDetails, TimelineItemContent,
+};
 
 #[async_test]
 async fn test_redact_state_event() {
@@ -152,7 +155,8 @@ async fn test_reaction_redaction_timeline_filter() {
                     .event_builder
                     .make_sync_redacted_message_event(*ALICE, RedactedReactionEventContent::new()),
             )],
-            crate::timeline::inner::TimelineEnd::Back { from_cache: false },
+            TimelineEnd::Back,
+            RemoteEventOrigin::Sync,
         )
         .await;
     // Timeline items are actually empty.