Timeline\ReadMarker: continue fixing issues

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/timeline/Timeline.kt

@@ -45,7 +45,7 @@ interface Timeline {
     fun dispose()
 
 
-    fun restartWithEventId(eventId: String)
+    fun restartWithEventId(eventId: String?)
 
 
     /**

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/read/SetReadMarkersTask.kt

@@ -26,7 +26,6 @@ import im.vector.matrix.android.internal.database.model.RoomSummaryEntity
 import im.vector.matrix.android.internal.database.model.TimelineEventEntity
 import im.vector.matrix.android.internal.database.query.find
 import im.vector.matrix.android.internal.database.query.findLastLiveChunkFromRoom
-import im.vector.matrix.android.internal.database.query.getOrCreate
 import im.vector.matrix.android.internal.database.query.latestEvent
 import im.vector.matrix.android.internal.database.query.where
 import im.vector.matrix.android.internal.network.executeRequest
@@ -36,7 +35,6 @@ import im.vector.matrix.android.internal.session.sync.RoomFullyReadHandler
 import im.vector.matrix.android.internal.task.Task
 import im.vector.matrix.android.internal.util.awaitTransaction
 import io.realm.Realm
-import io.realm.RealmConfiguration
 import timber.log.Timber
 import javax.inject.Inject
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimeline.kt

@@ -114,7 +114,7 @@ internal class DefaultTimeline(
     private val timelineID = UUID.randomUUID().toString()
 
     override val isLive
-        get() = initialEventId == null
+        get() = !hasMoreToLoad(Timeline.Direction.FORWARDS)
 
     private val eventDecryptor = TimelineEventDecryptor(realmConfiguration, timelineID, cryptoService)
 
@@ -260,7 +260,7 @@ internal class DefaultTimeline(
         }
     }
 
-    override fun restartWithEventId(eventId: String) {
+    override fun restartWithEventId(eventId: String?) {
         dispose()
         initialEventId = eventId
         start()
@@ -415,7 +415,7 @@ internal class DefaultTimeline(
      */
     private fun handleInitialLoad() {
         var shouldFetchInitialEvent = false
-        val initialDisplayIndex = if (isLive) {
+        val initialDisplayIndex = if (initialEventId == null) {
             liveEvents.firstOrNull()?.root?.displayIndex
         } else {
             val initialEvent = liveEvents.where()
@@ -431,7 +431,7 @@ internal class DefaultTimeline(
             fetchEvent(currentInitialEventId)
         } else {
             val count = min(settings.initialSize, liveEvents.size)
-            if (isLive) {
+            if (initialEventId == null) {
                 paginateInternal(initialDisplayIndex, Timeline.Direction.BACKWARDS, count, strict = false)
             } else {
                 paginateInternal(initialDisplayIndex, Timeline.Direction.FORWARDS, count / 2, strict = false)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/RoomFullyReadHandler.kt

@@ -17,6 +17,7 @@
 package im.vector.matrix.android.internal.session.sync
 
 import im.vector.matrix.android.api.session.room.read.FullyReadContent
+import im.vector.matrix.android.internal.database.model.EventEntity
 import im.vector.matrix.android.internal.database.model.ReadMarkerEntity
 import im.vector.matrix.android.internal.database.model.RoomSummaryEntity
 import im.vector.matrix.android.internal.database.model.TimelineEventEntity
@@ -37,12 +38,13 @@ internal class RoomFullyReadHandler @Inject constructor() {
         RoomSummaryEntity.getOrCreate(realm, roomId).apply {
             readMarkerId = content.eventId
         }
-        val readMarkerEntity = ReadMarkerEntity.getOrCreate(realm, roomId).apply {
+        val readMarkerEntity = ReadMarkerEntity.getOrCreate(realm, roomId)
-            eventId = content.eventId
-        }
-
         // Remove the old marker if any
-        readMarkerEntity.timelineEvent?.firstOrNull()?.readMarker = null
+        if (readMarkerEntity.eventId.isNotEmpty()) {
+            val oldReadMarkerEvent = TimelineEventEntity.where(realm, eventId = readMarkerEntity.eventId).findFirst()
+            oldReadMarkerEvent?.readMarker = null
+        }
+        readMarkerEntity.eventId = content.eventId
         // Attach to timelineEvent if known
         val timelineEventEntity = TimelineEventEntity.where(realm, eventId = content.eventId).findFirst()
         timelineEventEntity?.readMarker = readMarkerEntity

vector/src/main/java/im/vector/riotx/core/extensions/TimelineEvent.kt

@@ -23,3 +23,7 @@ fun TimelineEvent.canReact(): Boolean {
     // Only event of type Event.EVENT_TYPE_MESSAGE are supported for the moment
     return root.getClearType() == EventType.MESSAGE && root.sendState.isSent() && !root.isRedacted()
 }
+
+fun TimelineEvent.displayReadMarker(myUserId: String): Boolean {
+    return hasReadMarker && readReceipts.find { it.user.userId == myUserId } == null
+}

vector/src/main/java/im/vector/riotx/core/ui/views/ReadMarkerView.kt

@@ -42,9 +42,9 @@ class ReadMarkerView @JvmOverloads constructor(
     private var callback: Callback? = null
     private var callbackDispatcherJob: Job? = null
 
-    fun bindView(informationData: MessageInformationData, readMarkerCallback: Callback) {
+    fun bindView(displayReadMarker: Boolean, readMarkerCallback: Callback) {
         this.callback = readMarkerCallback
-        if (informationData.displayReadMarker) {
+        if (displayReadMarker) {
             visibility = VISIBLE
             callbackDispatcherJob = GlobalScope.launch(Dispatchers.Main) {
                 delay(DELAY_IN_MS)

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailFragment.kt

@@ -44,6 +44,7 @@ import androidx.core.content.ContextCompat
 import androidx.core.util.Pair
 import androidx.core.view.ViewCompat
 import androidx.core.view.forEach
+import androidx.core.view.isVisible
 import androidx.lifecycle.ViewModelProviders
 import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -57,6 +58,7 @@ import com.airbnb.mvrx.Loading
 import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.args
 import com.airbnb.mvrx.fragmentViewModel
+import com.airbnb.mvrx.withState
 import com.github.piasy.biv.BigImageViewer
 import com.github.piasy.biv.loader.ImageLoader
 import com.google.android.material.snackbar.Snackbar
@@ -78,6 +80,7 @@ import im.vector.matrix.android.api.session.room.model.message.MessageTextConten
 import im.vector.matrix.android.api.session.room.model.message.MessageType
 import im.vector.matrix.android.api.session.room.model.message.MessageVideoContent
 import im.vector.matrix.android.api.session.room.send.SendState
+import im.vector.matrix.android.api.session.room.timeline.Timeline
 import im.vector.matrix.android.api.session.room.timeline.TimelineEvent
 import im.vector.matrix.android.api.session.room.timeline.getLastMessageContent
 import im.vector.matrix.android.api.session.room.timeline.getTextEditableContent
@@ -96,6 +99,7 @@ import im.vector.riotx.core.glide.GlideApp
 import im.vector.riotx.core.platform.VectorBaseFragment
 import im.vector.riotx.core.ui.views.JumpToReadMarkerView
 import im.vector.riotx.core.ui.views.NotificationAreaView
+import im.vector.riotx.core.utils.Debouncer
 import im.vector.riotx.core.utils.PERMISSIONS_FOR_TAKING_PHOTO
 import im.vector.riotx.core.utils.PERMISSIONS_FOR_WRITING_FILES
 import im.vector.riotx.core.utils.PERMISSION_REQUEST_CODE_DOWNLOAD_FILE
@@ -105,6 +109,7 @@ import im.vector.riotx.core.utils.PERMISSION_REQUEST_CODE_LAUNCH_NATIVE_VIDEO_CA
 import im.vector.riotx.core.utils.allGranted
 import im.vector.riotx.core.utils.checkPermissions
 import im.vector.riotx.core.utils.copyToClipboard
+import im.vector.riotx.core.utils.createUIHandler
 import im.vector.riotx.core.utils.openCamera
 import im.vector.riotx.core.utils.shareMedia
 import im.vector.riotx.core.utils.toast
@@ -127,7 +132,6 @@ import im.vector.riotx.features.home.room.detail.timeline.action.MessageActionsB
 import im.vector.riotx.features.home.room.detail.timeline.action.SimpleAction
 import im.vector.riotx.features.home.room.detail.timeline.action.ViewEditHistoryBottomSheet
 import im.vector.riotx.features.home.room.detail.timeline.action.ViewReactionBottomSheet
-import im.vector.riotx.features.home.room.detail.timeline.helper.EndlessRecyclerViewScrollListener
 import im.vector.riotx.features.home.room.detail.timeline.item.AbsMessageItem
 import im.vector.riotx.features.home.room.detail.timeline.item.MessageFileItem
 import im.vector.riotx.features.home.room.detail.timeline.item.MessageImageVideoItem
@@ -211,6 +215,8 @@ class RoomDetailFragment :
     private val roomDetailViewModel: RoomDetailViewModel by fragmentViewModel()
     private val textComposerViewModel: TextComposerViewModel by fragmentViewModel()
 
+    private val debouncer = Debouncer(createUIHandler())
+
     @Inject lateinit var session: Session
     @Inject lateinit var avatarRenderer: AvatarRenderer
     @Inject lateinit var timelineEventController: TimelineEventController
@@ -227,7 +233,6 @@ class RoomDetailFragment :
 
     private lateinit var scrollOnNewMessageCallback: ScrollOnNewMessageCallback
     private lateinit var scrollOnHighlightedEventCallback: ScrollOnHighlightedEventCallback
-    private lateinit var endlessScrollListener: EndlessRecyclerViewScrollListener
 
 
     override fun getLayoutResId() = R.layout.fragment_room_detail
@@ -254,6 +259,7 @@ class RoomDetailFragment :
         setupInviteView()
         setupNotificationView()
         setupJumpToReadMarkerView()
+        setupJumpToBottomView()
         roomDetailViewModel.subscribe { renderState(it) }
         textComposerViewModel.subscribe { renderTextComposerState(it) }
         roomDetailViewModel.sendMessageResultLiveData.observeEvent(this) { renderSendMessageResult(it) }
@@ -306,6 +312,21 @@ class RoomDetailFragment :
         }
     }
 
+    private fun setupJumpToBottomView() {
+        jumpToBottomView.isVisible = false
+        jumpToBottomView.setOnClickListener {
+            withState(roomDetailViewModel) { state ->
+                recyclerView.stopScroll()
+                if (state.timeline?.isLive == false) {
+                    state.timeline.restartWithEventId(null)
+                } else {
+                    layoutManager.scrollToPosition(0)
+                }
+                jumpToBottomView.isVisible = false
+            }
+        }
+    }
+
     private fun setupJumpToReadMarkerView() {
         jumpToReadMarkerView.callback = this
     }
@@ -377,17 +398,17 @@ class RoomDetailFragment :
         if (messageContent is MessageTextContent && messageContent.format == MessageType.FORMAT_MATRIX_HTML) {
             val parser = Parser.builder().build()
             val document = parser.parse(messageContent.formattedBody
-                    ?: messageContent.body)
+                                        ?: messageContent.body)
             formattedBody = eventHtmlRenderer.render(document)
         }
         composerLayout.composerRelatedMessageContent.text = formattedBody
-                ?: nonFormattedBody
+                                                            ?: nonFormattedBody
 
         composerLayout.composerEditText.setText(if (useText) event.getTextEditableContent() else "")
         composerLayout.composerRelatedMessageActionIcon.setImageDrawable(ContextCompat.getDrawable(requireContext(), iconRes))
 
         avatarRenderer.render(event.senderAvatar, event.root.senderId
-                ?: "", event.senderName, composerLayout.composerRelatedMessageAvatar)
+                                                  ?: "", event.senderName, composerLayout.composerRelatedMessageAvatar)
 
         composerLayout.composerEditText.setSelection(composerLayout.composerEditText.text.length)
         composerLayout.expand {
@@ -416,9 +437,9 @@ class RoomDetailFragment :
                 REQUEST_FILES_REQUEST_CODE, TAKE_IMAGE_REQUEST_CODE -> handleMediaIntent(data)
                 REACTION_SELECT_REQUEST_CODE                        -> {
                     val eventId = data.getStringExtra(EmojiReactionPickerActivity.EXTRA_EVENT_ID)
-                            ?: return
+                                  ?: return
                     val reaction = data.getStringExtra(EmojiReactionPickerActivity.EXTRA_REACTION_RESULT)
-                            ?: return
+                                   ?: return
                     //TODO check if already reacted with that?
                     roomDetailViewModel.process(RoomDetailActions.SendReaction(reaction, eventId))
                 }
@@ -428,14 +449,12 @@ class RoomDetailFragment :
 
 // PRIVATE METHODS *****************************************************************************
 
+
     private fun setupRecyclerView() {
         val epoxyVisibilityTracker = EpoxyVisibilityTracker()
         epoxyVisibilityTracker.attach(recyclerView)
         layoutManager = LinearLayoutManager(context, RecyclerView.VERTICAL, true)
         val stateRestorer = LayoutManagerStateRestorer(layoutManager).register()
-        endlessScrollListener = EndlessRecyclerViewScrollListener(layoutManager, RoomDetailViewModel.PAGINATION_COUNT) { direction ->
-            roomDetailViewModel.process(RoomDetailActions.LoadMoreTimelineEvents(direction))
-        }
         scrollOnNewMessageCallback = ScrollOnNewMessageCallback(layoutManager, timelineEventController)
         scrollOnHighlightedEventCallback = ScrollOnHighlightedEventCallback(layoutManager, timelineEventController)
         recyclerView.layoutManager = layoutManager
@@ -446,38 +465,67 @@ class RoomDetailFragment :
             it.dispatchTo(scrollOnNewMessageCallback)
             it.dispatchTo(scrollOnHighlightedEventCallback)
         }
-
-        recyclerView.addOnScrollListener(endlessScrollListener)
         recyclerView.setController(timelineEventController)
+        recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                if (recyclerView.scrollState == RecyclerView.SCROLL_STATE_IDLE) {
+                    updateJumpToBottomViewVisibility()
+                }
+            }
+
+            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+                when (newState) {
+                    RecyclerView.SCROLL_STATE_IDLE     -> {
+                        updateJumpToBottomViewVisibility()
+                    }
+                    RecyclerView.SCROLL_STATE_DRAGGING,
+                    RecyclerView.SCROLL_STATE_SETTLING -> {
+                        jumpToBottomView.hide()
+                    }
+                }
+            }
+        })
         timelineEventController.callback = this
 
         if (vectorPreferences.swipeToReplyIsEnabled()) {
             val swipeCallback = RoomMessageTouchHelperCallback(requireContext(),
-                    R.drawable.ic_reply,
+                                                               R.drawable.ic_reply,
-                    object : RoomMessageTouchHelperCallback.QuickReplayHandler {
+                                                               object : RoomMessageTouchHelperCallback.QuickReplayHandler {
-                        override fun performQuickReplyOnHolder(model: EpoxyModel<*>) {
+                                                                   override fun performQuickReplyOnHolder(model: EpoxyModel<*>) {
-                            (model as? AbsMessageItem)?.attributes?.informationData?.let {
+                                                                       (model as? AbsMessageItem)?.attributes?.informationData?.let {
-                                val eventId = it.eventId
+                                                                           val eventId = it.eventId
-                                roomDetailViewModel.process(RoomDetailActions.EnterReplyMode(eventId))
+                                                                           roomDetailViewModel.process(RoomDetailActions.EnterReplyMode(eventId))
-                            }
+                                                                       }
-                        }
+                                                                   }
 
-                        override fun canSwipeModel(model: EpoxyModel<*>): Boolean {
+                                                                   override fun canSwipeModel(model: EpoxyModel<*>): Boolean {
-                            return when (model) {
+                                                                       return when (model) {
-                                is MessageFileItem,
+                                                                           is MessageFileItem,
-                                is MessageImageVideoItem,
+                                                                           is MessageImageVideoItem,
-                                is MessageTextItem -> {
+                                                                           is MessageTextItem -> {
-                                    return (model as AbsMessageItem).attributes.informationData.sendState == SendState.SYNCED
+                                                                               return (model as AbsMessageItem).attributes.informationData.sendState == SendState.SYNCED
-                                }
+                                                                           }
-                                else               -> false
+                                                                           else               -> false
-                            }
+                                                                       }
-                        }
+                                                                   }
-                    })
+                                                               })
             val touchHelper = ItemTouchHelper(swipeCallback)
             touchHelper.attachToRecyclerView(recyclerView)
         }
     }
 
+    private fun updateJumpToBottomViewVisibility() {
+        debouncer.debounce("jump_to_bottom_visibility", 100, Runnable {
+            Timber.v("First visible: ${layoutManager.findFirstCompletelyVisibleItemPosition()}")
+            if (layoutManager.findFirstCompletelyVisibleItemPosition() != 0) {
+                jumpToBottomView.show()
+            } else {
+                jumpToBottomView.hide()
+            }
+        })
+    }
+
     private fun setupComposer() {
         val elevation = 6f
         val backgroundDrawable = ColorDrawable(ThemeUtils.getColor(requireContext(), R.attr.riotx_background))
@@ -737,7 +785,7 @@ class RoomDetailFragment :
                 .show()
     }
 
-    // TimelineEventController.Callback ************************************************************
+// TimelineEventController.Callback ************************************************************
 
     override fun onUrlClicked(url: String): Boolean {
         return permalinkHandler.launch(requireActivity(), url, object : NavigateToRoomInterceptor {
@@ -835,6 +883,10 @@ class RoomDetailFragment :
         vectorBaseActivity.notImplemented("open audio file")
     }
 
+    override fun onLoadMore(direction: Timeline.Direction) {
+        roomDetailViewModel.process(RoomDetailActions.LoadMoreTimelineEvents(direction))
+    }
+
     override fun onEventCellClicked(informationData: MessageInformationData, messageContent: MessageContent?, view: View) {
 
     }
@@ -901,7 +953,7 @@ class RoomDetailFragment :
         }
     }
 
-    // AutocompleteUserPresenter.Callback
+// AutocompleteUserPresenter.Callback
 
     override fun onQueryUsers(query: CharSequence?) {
         textComposerViewModel.process(TextComposerActions.QueryUsers(query))
@@ -1066,6 +1118,7 @@ class RoomDetailFragment :
         snack.show()
     }
 
+
     // VectorInviteView.Callback
 
     override fun onAcceptInvite() {
@@ -1078,7 +1131,7 @@ class RoomDetailFragment :
         roomDetailViewModel.process(RoomDetailActions.RejectInvite)
     }
 
-    // JumpToReadMarkerView.Callback
+// JumpToReadMarkerView.Callback
 
     override fun onJumpToReadMarkerClicked(readMarkerId: String) {
         roomDetailViewModel.process(RoomDetailActions.NavigateToEvent(readMarkerId, false))

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt

@@ -21,6 +21,8 @@ import android.text.TextUtils
 import androidx.annotation.IdRes
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
+import arrow.core.Option
+import arrow.core.getOrElse
 import com.airbnb.mvrx.FragmentViewModelContext
 import com.airbnb.mvrx.MvRxViewModelFactory
 import com.airbnb.mvrx.Success
@@ -635,16 +637,22 @@ class RoomDetailViewModel @AssistedInject constructor(@Assisted initialState: Ro
     private fun observeJumpToReadMarkerViewVisibility() {
         Observable
                 .combineLatest(
-                        room.rx().liveRoomSummary(),
+                        room.rx().liveRoomSummary().map {
+                            val readMarkerId = it.readMarkerId
+                            if (readMarkerId == null) {
+                                Option.empty()
+                            } else {
+                                val timelineEvent = room.getTimeLineEvent(readMarkerId)
+                                Option.fromNullable(timelineEvent)
+                            }
+                        }.distinctUntilChanged(),
                         visibleEventsObservable.distinctUntilChanged(),
-                        isEventVisibleObservable { it.hasReadMarker }.startWith(false).takeUntil { it },
+                        isEventVisibleObservable { it.hasReadMarker }.startWith(false),
-                        Function3<RoomSummary, RoomDetailActions.TimelineEventTurnsVisible, Boolean, Boolean> { roomSummary, currentVisibleEvent, isReadMarkerViewVisible ->
+                        Function3<Option<TimelineEvent>, RoomDetailActions.TimelineEventTurnsVisible, Boolean, Boolean> { readMarkerEvent, currentVisibleEvent, isReadMarkerViewVisible ->
-                            val readMarkerId = roomSummary.readMarkerId
+                            if (readMarkerEvent.isEmpty() || isReadMarkerViewVisible) {
-                            if (readMarkerId == null || isReadMarkerViewVisible || !timeline.isLive) {
                                 false
                             } else {
-                                val readMarkerPosition = timeline.getTimelineEventWithId(readMarkerId)?.displayIndex
+                                val readMarkerPosition = readMarkerEvent.map { it.displayIndex }.getOrElse { Int.MIN_VALUE }
-                                                         ?: Int.MIN_VALUE
                                 val currentVisibleEventPosition = currentVisibleEvent.event.displayIndex
                                 readMarkerPosition < currentVisibleEventPosition
                             }

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/TimelineEventController.kt

@@ -24,6 +24,7 @@ import androidx.recyclerview.widget.ListUpdateCallback
 import androidx.recyclerview.widget.RecyclerView
 import com.airbnb.epoxy.EpoxyController
 import com.airbnb.epoxy.EpoxyModel
+import com.airbnb.epoxy.VisibilityState
 import im.vector.matrix.android.api.session.room.model.message.*
 import im.vector.matrix.android.api.session.room.timeline.Timeline
 import im.vector.matrix.android.api.session.room.timeline.TimelineEvent
@@ -50,6 +51,7 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
 ) : EpoxyController(backgroundHandler, backgroundHandler), Timeline.Listener {
 
     interface Callback : BaseCallback, ReactionPillCallback, AvatarCallback, UrlClickCallback, ReadReceiptsCallback {
+        fun onLoadMore(direction: Timeline.Direction)
         fun onEventInvisible(event: TimelineEvent)
         fun onEventVisible(event: TimelineEvent)
         fun onRoomCreateLinkClicked(url: String)
@@ -158,7 +160,7 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
             synchronized(modelCache) {
                 for (i in 0 until modelCache.size) {
                     if (modelCache[i]?.eventId == eventIdToHighlight
-                            || modelCache[i]?.eventId == this.eventIdToHighlight) {
+                        || modelCache[i]?.eventId == this.eventIdToHighlight) {
                         modelCache[i] = null
                     }
                 }
@@ -180,6 +182,7 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
         val timestamp = System.currentTimeMillis()
         showingForwardLoader = LoadingItem_()
                 .id("forward_loading_item_$timestamp")
+                .setVisibilityStateChangedListener(Timeline.Direction.FORWARDS)
                 .addWhen(Timeline.Direction.FORWARDS)
 
         val timelineModels = getModels()
@@ -189,6 +192,7 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
         if (!showingForwardLoader || timelineModels.isNotEmpty()) {
             LoadingItem_()
                     .id("backward_loading_item_$timestamp")
+                    .setVisibilityStateChangedListener(Timeline.Direction.BACKWARDS)
                     .addWhen(Timeline.Direction.BACKWARDS)
         }
     }
@@ -220,8 +224,8 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
                 // Should be build if not cached or if cached but contains mergedHeader or formattedDay
                 // We then are sure we always have items up to date.
                 if (modelCache[position] == null
-                        || modelCache[position]?.mergedHeaderModel != null
+                    || modelCache[position]?.mergedHeaderModel != null
-                        || modelCache[position]?.formattedDayModel != null) {
+                    || modelCache[position]?.formattedDayModel != null) {
                     modelCache[position] = buildItemModels(position, currentSnapshot)
                 }
             }
@@ -251,7 +255,7 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
             it.id(event.localId)
             it.setOnVisibilityStateChanged(TimelineEventVisibilityStateChangedListener(callback, event))
         }
-        val mergedHeaderModel = mergedHeaderItemFactory.create(event, nextEvent, items, addDaySeparator, currentPosition, callback) {
+        val mergedHeaderModel = mergedHeaderItemFactory.create(event, nextEvent, items, addDaySeparator, currentPosition, eventIdToHighlight, callback) {
             requestModelBuild()
         }
         val daySeparatorItem = buildDaySeparatorItem(addDaySeparator, date)
@@ -277,6 +281,18 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
         return shouldAdd
     }
 
+    /**
+     * Return true if added
+     */
+    private fun LoadingItem_.setVisibilityStateChangedListener(direction: Timeline.Direction): LoadingItem_ {
+        return onVisibilityStateChanged { model, view, visibilityState ->
+            if (visibilityState == VisibilityState.VISIBLE) {
+                callback?.onLoadMore(direction)
+            }
+        }
+    }
+
+
     fun searchPositionOfEvent(eventId: String): Int? = synchronized(modelCache) {
         // Search in the cache
         var realPosition = 0

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/factory/MergedHeaderItemFactory.kt

@@ -17,6 +17,8 @@
 package im.vector.riotx.features.home.room.detail.timeline.factory
 
 import im.vector.matrix.android.api.session.room.timeline.TimelineEvent
+import im.vector.riotx.core.di.ActiveSessionHolder
+import im.vector.riotx.core.extensions.displayReadMarker
 import im.vector.riotx.features.home.AvatarRenderer
 import im.vector.riotx.features.home.room.detail.timeline.TimelineEventController
 import im.vector.riotx.features.home.room.detail.timeline.helper.AvatarSizeProvider
@@ -29,7 +31,8 @@ import im.vector.riotx.features.home.room.detail.timeline.item.MergedHeaderItem
 import im.vector.riotx.features.home.room.detail.timeline.item.MergedHeaderItem_
 import javax.inject.Inject
 
-class MergedHeaderItemFactory @Inject constructor(private val avatarRenderer: AvatarRenderer,
+class MergedHeaderItemFactory @Inject constructor(private val sessionHolder: ActiveSessionHolder,
+                                                  private val avatarRenderer: AvatarRenderer,
                                                   private val avatarSizeProvider: AvatarSizeProvider) {
 
     private val collapsedEventIds = linkedSetOf<Long>()
@@ -40,6 +43,7 @@ class MergedHeaderItemFactory @Inject constructor(private val avatarRenderer: Av
                items: List<TimelineEvent>,
                addDaySeparator: Boolean,
                currentPosition: Int,
+               eventIdToHighlight: String?,
                callback: TimelineEventController.Callback?,
                requestModelBuild: () -> Unit)
             : MergedHeaderItem? {
@@ -47,20 +51,30 @@ class MergedHeaderItemFactory @Inject constructor(private val avatarRenderer: Av
         return if (!event.canBeMerged() || (nextEvent?.root?.getClearType() == event.root.getClearType() && !addDaySeparator)) {
             null
         } else {
+            var highlighted = false
+            var showReadMarker = false
             val prevSameTypeEvents = items.prevSameTypeEvents(currentPosition, 2)
             if (prevSameTypeEvents.isEmpty()) {
                 null
             } else {
                 val mergedEvents = (prevSameTypeEvents + listOf(event)).asReversed()
-                val mergedData = mergedEvents.map { mergedEvent ->
+                val mergedData = ArrayList<MergedHeaderItem.Data>(mergedEvents.size)
+                mergedEvents.forEach { mergedEvent ->
+                    if (!highlighted && mergedEvent.root.eventId == eventIdToHighlight) {
+                        highlighted = true
+                    }
+                    if (!showReadMarker && mergedEvent.displayReadMarker(sessionHolder.getActiveSession().myUserId)) {
+                        showReadMarker = true
+                    }
                     val senderAvatar = mergedEvent.senderAvatar()
                     val senderName = mergedEvent.senderName()
-                    MergedHeaderItem.Data(
+                    val data = MergedHeaderItem.Data(
                             userId = mergedEvent.root.senderId ?: "",
                             avatarUrl = senderAvatar,
                             memberName = senderName ?: "",
                             eventId = mergedEvent.localId
                     )
+                    mergedData.add(data)
                 }
                 val mergedEventIds = mergedEvents.map { it.localId }
                 // We try to find if one of the item id were used as mergeItemCollapseStates key
@@ -82,11 +96,13 @@ class MergedHeaderItemFactory @Inject constructor(private val avatarRenderer: Av
                         onCollapsedStateChanged = {
                             mergeItemCollapseStates[event.localId] = it
                             requestModelBuild()
-                        }
+                        },
+                        showReadMarker = showReadMarker
                 )
                 MergedHeaderItem_()
                         .id(mergeId)
                         .leftGuideline(avatarSizeProvider.leftGuideline)
+                        .highlighted(highlighted)
                         .attributes(attributes)
                         .also {
                             it.setOnVisibilityStateChanged(MergedTimelineEventVisibilityStateChangedListener(callback, mergedEvents))

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/EndlessRecyclerViewScrollListener.kt

@@ -1,63 +0,0 @@
-/*
- * Copyright 2019 New Vector Ltd
- *
- * 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.
- */
-
-package im.vector.riotx.features.home.room.detail.timeline.helper
-
-import androidx.recyclerview.widget.LinearLayoutManager
-import androidx.recyclerview.widget.RecyclerView
-import im.vector.matrix.android.api.session.room.timeline.Timeline
-
-class EndlessRecyclerViewScrollListener(private val layoutManager: LinearLayoutManager,
-                                        private val visibleThreshold: Int,
-                                        private val onLoadMore: (Timeline.Direction) -> Unit
-) : RecyclerView.OnScrollListener() {
-
-    // The total number of items in the dataset after the last load
-    private var previousTotalItemCount = 0
-    // True if we are still waiting for the last set of data to load.
-    private var loadingBackwards = true
-    private var loadingForwards = true
-
-    // This happens many times a second during a scroll, so be wary of the code you place here.
-    // We are given a few useful parameters to help us work out if we need to load some more data,
-    // but first we check if we are waiting for the previous load to finish.
-
-    override fun onScrolled(view: RecyclerView, dx: Int, dy: Int) {
-        val lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition()
-        val firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition()
-        val totalItemCount = layoutManager.itemCount
-
-        // We check to see if the dataset count has
-        // changed, if so we conclude it has finished loading
-        if (totalItemCount != previousTotalItemCount) {
-            previousTotalItemCount = totalItemCount
-            loadingBackwards = false
-            loadingForwards = false
-        }
-        // If it isn’t currently loading, we check to see if we have reached
-        // the visibleThreshold and need to reload more data.
-        if (!loadingBackwards && lastVisibleItemPosition + visibleThreshold > totalItemCount) {
-            loadingBackwards = true
-            onLoadMore(Timeline.Direction.BACKWARDS)
-        }
-        if (!loadingForwards && firstVisibleItemPosition < visibleThreshold) {
-            loadingForwards = true
-            onLoadMore(Timeline.Direction.FORWARDS)
-        }
-    }
-
-
-}

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/MessageInformationDataFactory.kt

@@ -27,6 +27,7 @@ import im.vector.riotx.core.resources.ColorProvider
 import im.vector.riotx.core.utils.isSingleEmoji
 import im.vector.riotx.features.home.getColorFromUserId
 import im.vector.riotx.core.date.VectorDateFormatter
+import im.vector.riotx.core.extensions.displayReadMarker
 import im.vector.riotx.features.home.room.detail.timeline.item.MessageInformationData
 import im.vector.riotx.features.home.room.detail.timeline.item.ReactionInfoData
 import im.vector.riotx.features.home.room.detail.timeline.item.ReadReceiptData
@@ -64,8 +65,7 @@ class MessageInformationDataFactory @Inject constructor(private val session: Ses
             textColor = colorProvider.getColor(getColorFromUserId(event.root.senderId ?: ""))
         }
 
-        val displayReadMarker = event.hasReadMarker
+        val displayReadMarker = event.displayReadMarker(session.myUserId)
-                && event.readReceipts.find { it.user.userId == session.myUserId } == null
 
         return MessageInformationData(
                 eventId = eventId,

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/item/AbsMessageItem.kt

@@ -106,7 +106,7 @@ abstract class AbsMessageItem<H : AbsMessageItem.Holder> : BaseEventItem<H>() {
             holder.memberNameView.setOnLongClickListener(null)
         }
         holder.readReceiptsView.render(attributes.informationData.readReceipts, attributes.avatarRenderer, _readReceiptsClickListener)
-        holder.readMarkerView.bindView(attributes.informationData, _readMarkerCallback)
+        holder.readMarkerView.bindView(attributes.informationData.displayReadMarker, _readMarkerCallback)
 
         if (!shouldShowReactionAtBottom() || attributes.informationData.orderedReactionList.isNullOrEmpty()) {
             holder.reactionWrapper?.isVisible = false
@@ -162,7 +162,6 @@ abstract class AbsMessageItem<H : AbsMessageItem.Holder> : BaseEventItem<H>() {
         val avatarImageView by bind<ImageView>(R.id.messageAvatarImageView)
         val memberNameView by bind<TextView>(R.id.messageMemberNameView)
         val timeView by bind<TextView>(R.id.messageTimeView)
-        val readMarkerView by bind<ReadMarkerView>(R.id.readMarkerView)
         var reactionWrapper: ViewGroup? = null
         var reactionFlowHelper: Flow? = null
     }

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/item/BaseEventItem.kt

@@ -24,6 +24,7 @@ import im.vector.riotx.R
 import im.vector.riotx.core.epoxy.VectorEpoxyHolder
 import im.vector.riotx.core.epoxy.VectorEpoxyModel
 import im.vector.riotx.core.platform.CheckableView
+import im.vector.riotx.core.ui.views.ReadMarkerView
 import im.vector.riotx.core.ui.views.ReadReceiptsView
 import im.vector.riotx.core.utils.DimensionUtils.dpToPx
 import org.w3c.dom.Attr
@@ -49,6 +50,7 @@ abstract class BaseEventItem<H : BaseEventItem.BaseHolder> : VectorEpoxyModel<H>
         val leftGuideline by bind<Guideline>(R.id.messageStartGuideline)
         val checkableBackground by bind<CheckableView>(R.id.messageSelectedBackground)
         val readReceiptsView by bind<ReadReceiptsView>(R.id.readReceiptsView)
+        val readMarkerView by bind<ReadMarkerView>(R.id.readMarkerView)
 
         override fun bindView(itemView: View) {
             super.bindView(itemView)

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/item/MergedHeaderItem.kt

@@ -79,6 +79,7 @@ abstract class MergedHeaderItem : BaseEventItem<MergedHeaderItem.Holder>() {
 
     data class Attributes(
             val isCollapsed: Boolean,
+            val showReadMarker: Boolean,
             val mergeData: List<Data>,
             val avatarRenderer: AvatarRenderer,
             val onCollapsedStateChanged: (Boolean) -> Unit

vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/item/NoticeItem.kt

@@ -55,7 +55,7 @@ abstract class NoticeItem : BaseEventItem<NoticeItem.Holder>() {
         )
         holder.view.setOnLongClickListener(attributes.itemLongClickListener)
         holder.readReceiptsView.render(attributes.informationData.readReceipts, attributes.avatarRenderer, _readReceiptsClickListener)
-        holder.readMarkerView.bindView(attributes.informationData, _readMarkerCallback)
+        holder.readMarkerView.bindView(attributes.informationData.displayReadMarker, _readMarkerCallback)
     }
 
     override fun unbind(holder: Holder) {
@@ -68,7 +68,6 @@ abstract class NoticeItem : BaseEventItem<NoticeItem.Holder>() {
     class Holder : BaseHolder(STUB_ID) {
         val avatarImageView by bind<ImageView>(R.id.itemNoticeAvatarView)
         val noticeTextView by bind<TextView>(R.id.itemNoticeTextView)
-        val readMarkerView by bind<ReadMarkerView>(R.id.readMarkerView)
     }
 
     data class Attributes(

vector/src/main/res/layout/fragment_room_detail.xml

@@ -153,4 +153,17 @@
         app:layout_constraintTop_toBottomOf="@+id/roomToolbar"
         tools:visibility="visible" />
 
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/jumpToBottomView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="16dp"
+        android:src="@drawable/chevron_down"
+        app:backgroundTint="#FFFFFF"
+        app:layout_constraintBottom_toTopOf="@id/composerLayout"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:maxImageSize="16dp"
+        app:tint="@color/black" />
+
+
 </androidx.constraintlayout.widget.ConstraintLayout>

vector/src/main/res/layout/view_jump_to_read_marker.xml

@@ -11,11 +11,8 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
-        android:layout_marginLeft="16dp"
         android:layout_toStartOf="@+id/closeJumpToReadMarkerView"
-        android:layout_toLeftOf="@+id/closeJumpToReadMarkerView"
+        android:drawableStart="@drawable/arrow_up_circle"
-        android:drawableStart="@drawable/jump_to_unread"
-        android:drawableLeft="@drawable/jump_to_unread"
         android:drawablePadding="10dp"
         android:gravity="center_vertical"
         android:paddingTop="12dp"