Timeline : add a mode to differentiate between live/focused/pinned

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/timeline/Timeline.kt

@@ -46,6 +46,12 @@ interface Timeline : AutoCloseable {
         FORWARDS
     }
 
+    enum class Mode {
+        LIVE,
+        FOCUSED_ON_EVENT,
+        FOCUSED_ON_PINNED_EVENTS
+    }
+
     val membershipChangeEventReceived: Flow<Unit>
     suspend fun sendReadReceipt(eventId: EventId, receiptType: ReceiptType): Result<Unit>
     suspend fun paginate(direction: PaginationDirection): Result<Boolean>

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/RustMatrixRoom.kt

@@ -153,7 +153,7 @@ class RustMatrixRoom(
     private val _roomNotificationSettingsStateFlow = MutableStateFlow<MatrixRoomNotificationSettingsState>(MatrixRoomNotificationSettingsState.Unknown)
     override val roomNotificationSettingsStateFlow: StateFlow<MatrixRoomNotificationSettingsState> = _roomNotificationSettingsStateFlow
 
-    override val liveTimeline = createTimeline(innerTimeline, isLive = true) {
+    override val liveTimeline = createTimeline(innerTimeline, mode = Timeline.Mode.LIVE) {
         _syncUpdateFlow.value = systemClock.epochMillis()
     }
 
@@ -181,7 +181,7 @@ class RustMatrixRoom(
                 numContextEvents = 50u,
                 internalIdPrefix = "focus_$eventId",
             ).let { inner ->
-                createTimeline(inner, isLive = false)
+                createTimeline(inner, mode = Timeline.Mode.FOCUSED_ON_EVENT)
             }
         }.mapFailure {
             it.toFocusEventException()
@@ -198,7 +198,7 @@ class RustMatrixRoom(
                 internalIdPrefix = "pinned_events",
                 maxEventsToLoad = 100u,
             ).let { inner ->
-                createTimeline(inner, isLive = false)
+                createTimeline(inner, mode = Timeline.Mode.FOCUSED_ON_PINNED_EVENTS)
             }
         }.onFailure {
             if (it is CancellationException) {
@@ -655,13 +655,13 @@ class RustMatrixRoom(
 
     private fun createTimeline(
         timeline: InnerTimeline,
-        isLive: Boolean,
+        mode: Timeline.Mode,
         onNewSyncedEvent: () -> Unit = {},
     ): Timeline {
         val timelineCoroutineScope = roomCoroutineScope.childScope(coroutineDispatchers.main, "TimelineScope-$roomId-$timeline")
         return RustTimeline(
             isKeyBackupEnabled = isKeyBackupEnabled,
-            isLive = isLive,
+            mode = mode,
             matrixRoom = this,
             systemClock = systemClock,
             coroutineScope = timelineCoroutineScope,

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

@@ -85,7 +85,7 @@ private const val PAGINATION_SIZE = 50
 
 class RustTimeline(
     private val inner: InnerTimeline,
-    private val isLive: Boolean,
+    mode: Timeline.Mode,
     systemClock: SystemClock,
     isKeyBackupEnabled: Boolean,
     private val matrixRoom: MatrixRoom,
@@ -131,21 +131,21 @@ class RustTimeline(
         onNewSyncedEvent = onNewSyncedEvent,
     )
 
-    private val roomBeginningPostProcessor = RoomBeginningPostProcessor()
+    private val roomBeginningPostProcessor = RoomBeginningPostProcessor(mode)
     private val loadingIndicatorsPostProcessor = LoadingIndicatorsPostProcessor(systemClock)
-    private val lastForwardIndicatorsPostProcessor = LastForwardIndicatorsPostProcessor(isLive)
+    private val lastForwardIndicatorsPostProcessor = LastForwardIndicatorsPostProcessor(mode)
 
     private val backPaginationStatus = MutableStateFlow(
-        Timeline.PaginationStatus(isPaginating = false, hasMoreToLoad = true)
+        Timeline.PaginationStatus(isPaginating = false, hasMoreToLoad = mode != Timeline.Mode.FOCUSED_ON_PINNED_EVENTS)
     )
 
     private val forwardPaginationStatus = MutableStateFlow(
-        Timeline.PaginationStatus(isPaginating = false, hasMoreToLoad = !isLive)
+        Timeline.PaginationStatus(isPaginating = false, hasMoreToLoad = mode == Timeline.Mode.FOCUSED_ON_EVENT)
     )
 
     init {
         coroutineScope.fetchMembers()
-        if (isLive) {
+        if (mode == Timeline.Mode.LIVE) {
             // When timeline is live, we need to listen to the back pagination status as
             // sdk can automatically paginate backwards.
             coroutineScope.registerBackPaginationStatusListener()

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

@@ -17,21 +17,22 @@
 package io.element.android.libraries.matrix.impl.timeline.postprocessor
 
 import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
+import io.element.android.libraries.matrix.api.timeline.Timeline
 import io.element.android.libraries.matrix.api.timeline.item.virtual.VirtualTimelineItem
 
 /**
  * This post processor is responsible for adding virtual items to indicate all the previous last forward item.
  */
 class LastForwardIndicatorsPostProcessor(
-    private val isTimelineLive: Boolean,
+    private val mode: Timeline.Mode,
 ) {
     private val lastForwardIdentifiers = LinkedHashSet<String>()
 
     fun process(
         items: List<MatrixTimelineItem>,
     ): List<MatrixTimelineItem> {
-        // If the timeline is live, we don't have any last forward indicator to display
+        // We don't need to add the last forward indicator if we are not in the FOCUSED_ON_EVENT mode
-        if (isTimelineLive) {
+        if (mode != Timeline.Mode.FOCUSED_ON_EVENT) {
             return items
         } else {
             return buildList {

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

@@ -18,6 +18,7 @@ package io.element.android.libraries.matrix.impl.timeline.postprocessor
 
 import androidx.annotation.VisibleForTesting
 import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
+import io.element.android.libraries.matrix.api.timeline.Timeline
 import io.element.android.libraries.matrix.api.timeline.item.event.MembershipChange
 import io.element.android.libraries.matrix.api.timeline.item.event.OtherState
 import io.element.android.libraries.matrix.api.timeline.item.event.RoomMembershipContent
@@ -28,13 +29,14 @@ import io.element.android.libraries.matrix.api.timeline.item.virtual.VirtualTime
  * This timeline post-processor removes the room creation event and the self-join event from the timeline for DMs
  * or add the RoomBeginning item for non DM room.
  */
-class RoomBeginningPostProcessor {
+class RoomBeginningPostProcessor(private val mode: Timeline.Mode) {
     fun process(
         items: List<MatrixTimelineItem>,
         isDm: Boolean,
         hasMoreToLoadBackwards: Boolean
     ): List<MatrixTimelineItem> {
         return when {
+            mode == Timeline.Mode.FOCUSED_ON_PINNED_EVENTS -> items
             hasMoreToLoadBackwards -> items
             isDm -> processForDM(items)
             else -> processForRoom(items)

libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/timeline/postprocessor/RoomBeginningPostProcessorTest.kt

@@ -36,7 +36,7 @@ class RoomBeginningPostProcessorTest {
             MatrixTimelineItem.Event("m.room.create", anEventTimelineItem(sender = A_USER_ID, content = StateContent("", OtherState.RoomCreate))),
             MatrixTimelineItem.Event("m.room.member", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID, null, MembershipChange.JOINED))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = true, hasMoreToLoadBackwards = false)
         assertThat(processedItems).isEmpty()
     }
@@ -53,7 +53,7 @@ class RoomBeginningPostProcessorTest {
             MatrixTimelineItem.Event("m.room.member_other", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID_2, null, MembershipChange.JOINED))),
             MatrixTimelineItem.Event("m.room.message", anEventTimelineItem(content = aMessageContent("hi"))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = true, hasMoreToLoadBackwards = false)
         assertThat(processedItems).isEqualTo(expected)
     }
@@ -64,7 +64,7 @@ class RoomBeginningPostProcessorTest {
             MatrixTimelineItem.Event("m.room.create", anEventTimelineItem(sender = A_USER_ID, content = StateContent("", OtherState.RoomCreate))),
             MatrixTimelineItem.Event("m.room.member", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID, null, MembershipChange.JOINED))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = false, hasMoreToLoadBackwards = false)
         assertThat(processedItems).isEqualTo(
             listOf(processor.createRoomBeginningItem()) + timelineItems
@@ -76,7 +76,7 @@ class RoomBeginningPostProcessorTest {
         val timelineItems = listOf(
             MatrixTimelineItem.Virtual("EncryptedHistoryBanner", VirtualTimelineItem.EncryptedHistoryBanner),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = false, hasMoreToLoadBackwards = false)
         assertThat(processedItems).isEqualTo(timelineItems)
     }
@@ -87,7 +87,7 @@ class RoomBeginningPostProcessorTest {
             MatrixTimelineItem.Event("m.room.create", anEventTimelineItem(sender = A_USER_ID, content = StateContent("", OtherState.RoomCreate))),
             MatrixTimelineItem.Event("m.room.member", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID, null, MembershipChange.JOINED))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = true, hasMoreToLoadBackwards = true)
         assertThat(processedItems).isEqualTo(timelineItems)
     }
@@ -97,7 +97,7 @@ class RoomBeginningPostProcessorTest {
         val timelineItems = listOf(
             MatrixTimelineItem.Event("m.room.member", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID, null, MembershipChange.JOINED))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = true, hasMoreToLoadBackwards = true)
         assertThat(processedItems).isEqualTo(timelineItems)
     }
@@ -108,7 +108,7 @@ class RoomBeginningPostProcessorTest {
             MatrixTimelineItem.Event("m.room.create", anEventTimelineItem(sender = A_USER_ID, content = StateContent("", OtherState.RoomCreate))),
             MatrixTimelineItem.Event("m.room.member", anEventTimelineItem(content = RoomMembershipContent(A_USER_ID_2, null, MembershipChange.JOINED))),
         )
-        val processor = RoomBeginningPostProcessor()
+        val processor = RoomBeginningPostProcessor(mode)
         val processedItems = processor.process(timelineItems, isDm = true, hasMoreToLoadBackwards = true)
         assertThat(processedItems).isEqualTo(timelineItems)
     }