Timeline : remove some code from main thread

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/timeline/MatrixTimelineItemMapper.kt

@@ -31,7 +31,7 @@ class MatrixTimelineItemMapper(
     private val eventTimelineItemMapper: EventTimelineItemMapper = EventTimelineItemMapper(),
 ) {
     fun map(timelineItem: TimelineItem): MatrixTimelineItem = timelineItem.use {
-        val uniqueId = timelineItem.uniqueId().toString()
+        val uniqueId = timelineItem.uniqueId()
         val asEvent = it.asEvent()
         if (asEvent != null) {
             val eventTimelineItem = eventTimelineItemMapper.map(asEvent)

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/timeline/RustTimeline.kt

@@ -174,6 +174,7 @@ class RustTimeline(
 
     // Use NonCancellable to avoid breaking the timeline when the coroutine is cancelled.
     override suspend fun paginate(direction: Timeline.PaginationDirection): Result<Boolean> = withContext(NonCancellable) {
+        withContext(dispatcher) {
             initLatch.await()
             runCatching {
                 if (!canPaginate(direction)) throw TimelineException.CannotPaginate
@@ -193,6 +194,7 @@ class RustTimeline(
                 updatePaginationStatus(direction) { it.copy(isPaginating = false, hasMoreToLoad = !hasReachedEnd) }
             }
         }
+    }
 
     private fun canPaginate(direction: Timeline.PaginationDirection): Boolean {
         if (!isInit.get()) return false
@@ -214,6 +216,7 @@ class RustTimeline(
         backPaginationStatus.map { it.hasMoreToLoad }.distinctUntilChanged(),
         forwardPaginationStatus.map { it.hasMoreToLoad }.distinctUntilChanged(),
     ) { timelineItems, hasMoreToLoadBackward, hasMoreToLoadForward ->
+        withContext(dispatcher) {
             timelineItems
                 .let { items -> encryptedHistoryPostProcessor.process(items) }
                 .let { items ->
@@ -227,6 +230,7 @@ class RustTimeline(
                 // Keep lastForwardIndicatorsPostProcessor last
                 .let { items -> lastForwardIndicatorsPostProcessor.process(items) }
         }
+    }
 
     override fun close() {
         inner.close()