Fix incorrect read state causing stale notifications and tweak scroll to bottom behavior.

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt

@@ -373,6 +373,11 @@ class ConversationFragment :
       adapter.unregisterAdapterDataObserver(it)
     }
 
+    scrollListener?.let {
+      _binding.conversationItemRecycler.removeOnScrollListener(it)
+    }
+    scrollListener = null
+
     _binding.conversationItemRecycler.adapter = null
 
     textDraftSaveDebouncer.clear()
@@ -473,6 +478,7 @@ class ConversationFragment :
   private var composeTextEventsListener: ComposeTextEventsListener? = null
   private var dataObserver: DataObserver? = null
   private var menuProvider: ConversationOptionsMenu.Provider? = null
+  private var scrollListener: ScrollListener? = null
 
   private val jumpAndPulseScrollStrategy = object : ScrollToPositionDelegate.ScrollStrategy {
     override fun performScroll(recyclerView: RecyclerView, layoutManager: LinearLayoutManager, position: Int, smooth: Boolean) {
@@ -830,10 +836,6 @@ class ConversationFragment :
       .distinctUntilChanged { r1, r2 -> r1 === r2 || r1.hasSameContent(r2) }
       .subscribeBy(onNext = this::onRecipientChanged)
 
-    disposables += viewModel.markReadRequests
-      .observeOn(AndroidSchedulers.mainThread())
-      .subscribeBy(onNext = markReadHelper::onViewsRevealed)
-
     disposables += viewModel.scrollButtonState
       .subscribeBy(onNext = this::presentScrollButtons)
 
@@ -1448,7 +1450,8 @@ class ConversationFragment :
     layoutManager = ConversationLayoutManager(requireContext())
     binding.conversationItemRecycler.setHasFixedSize(false)
     binding.conversationItemRecycler.layoutManager = layoutManager
-    binding.conversationItemRecycler.addOnScrollListener(ScrollListener())
+    scrollListener = ScrollListener()
+    binding.conversationItemRecycler.addOnScrollListener(scrollListener!!)
 
     adapter = ConversationAdapterV2(
       lifecycleOwner = viewLifecycleOwner,
@@ -2248,6 +2251,10 @@ class ConversationFragment :
     return layoutManager.findFirstCompletelyVisibleItemPosition() > 4
   }
 
+  private fun shouldScrollToBottom(): Boolean {
+    return isScrolledToBottom() || layoutManager.findFirstVisibleItemPosition() <= 0
+  }
+
   /**
    * Controls animation and visibility of the scrollDateHeader.
    */
@@ -2308,9 +2315,11 @@ class ConversationFragment :
 
     override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
       if (isScrolledToBottom()) {
-        viewModel.setShowScrollButtons(false)
+        viewModel.setShowScrollButtonsForScrollPosition(showScrollButtons = false, willScrollToBottomOnNewMessage = true)
       } else if (isScrolledPastButtonThreshold()) {
-        viewModel.setShowScrollButtons(true)
+        viewModel.setShowScrollButtonsForScrollPosition(showScrollButtons = true, willScrollToBottomOnNewMessage = false)
+      } else {
+        viewModel.setShowScrollButtonsForScrollPosition(showScrollButtons = false, willScrollToBottomOnNewMessage = shouldScrollToBottom())
       }
 
       presentComposeDivider()
@@ -2344,10 +2353,9 @@ class ConversationFragment :
 
   private inner class DataObserver : RecyclerView.AdapterDataObserver() {
     override fun onItemRangeInserted(positionStart: Int, itemCount: Int) {
-      Log.d(TAG, "onItemRangeInserted $positionStart $itemCount")
-      if (positionStart == 0 && itemCount == 1 && !binding.conversationItemRecycler.canScrollVertically(1)) {
-        Log.d(TAG, "Requesting scroll to bottom.")
+      if (positionStart == 0 && itemCount == 1 && shouldScrollToBottom()) {
         layoutManager.scrollToPositionWithOffset(0, 0)
+        scrollListener?.onScrolled(binding.conversationItemRecycler, 0, 0)
       }
     }
 
@@ -2369,6 +2377,10 @@ class ConversationFragment :
         actionMode?.setTitle(calculateSelectedItemCount())
       }
     }
+
+    override fun onItemRangeChanged(positionStart: Int, itemCount: Int) {
+      scrollListener?.onScrolled(binding.conversationItemRecycler, 0, 0)
+    }
   }
 
   //endregion Scroll Handling
@@ -2820,10 +2832,7 @@ class ConversationFragment :
 
           ViewUtil.hideKeyboard(requireContext(), itemView)
 
-          val showScrollButtons = viewModel.showScrollButtonsSnapshot
-          if (showScrollButtons) {
-            viewModel.setShowScrollButtons(false)
-          }
+          viewModel.setHideScrollButtonsForReactionOverlay(true)
 
           val targetViews: InteractiveConversationElement = target
           handleReaction(
@@ -2861,9 +2870,7 @@ class ConversationFragment :
                   ViewUtil.fadeIn(targetViews.quotedIndicatorView!!, 150)
                 }
 
-                if (showScrollButtons) {
-                  viewModel.setShowScrollButtons(true)
-                }
+                viewModel.setHideScrollButtonsForReactionOverlay(false)
               }
             }
           )

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationRepository.kt

@@ -288,15 +288,14 @@ class ConversationRepository(
   }
 
   fun getMessageCounts(threadId: Long): Flowable<MessageCounts> {
-    return RxDatabaseObserver.conversationList
+    return RxDatabaseObserver.conversation(threadId)
       .map { getUnreadCount(threadId) }
       .distinctUntilChanged()
       .map { MessageCounts(it, getUnreadMentionsCount(threadId)) }
   }
 
   private fun getUnreadCount(threadId: Long): Int {
-    val threadRecord = SignalDatabase.threads.getThreadRecord(threadId)
-    return threadRecord?.unreadCount ?: 0
+    return SignalDatabase.messages.getUnreadCount(threadId)
   }
 
   private fun getUnreadMentionsCount(threadId: Long): Int {

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationScrollButtonState.kt

@@ -1,7 +1,20 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 package org.thoughtcrime.securesms.conversation.v2
 
+/**
+ * State information used to display the scroll to next mention and scroll to bottom buttons.
+ */
 data class ConversationScrollButtonState(
-  val showScrollButtons: Boolean = false,
+  val hideScrollButtonsForReactionOverlay: Boolean = false,
+  val showScrollButtonsForScrollPosition: Boolean = false,
+  val willScrollToBottomOnNewMessage: Boolean = true,
   val unreadCount: Int = 0,
   val hasMentions: Boolean = false
-)
+) {
+  val showScrollButtons: Boolean
+    get() = !hideScrollButtonsForReactionOverlay && (showScrollButtonsForScrollPosition || (!willScrollToBottomOnNewMessage && unreadCount > 0))
+}

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationViewModel.kt

@@ -20,7 +20,6 @@ import io.reactivex.rxjava3.disposables.CompositeDisposable
 import io.reactivex.rxjava3.kotlin.addTo
 import io.reactivex.rxjava3.kotlin.plusAssign
 import io.reactivex.rxjava3.kotlin.subscribeBy
-import io.reactivex.rxjava3.processors.PublishProcessor
 import io.reactivex.rxjava3.schedulers.Schedulers
 import io.reactivex.rxjava3.subjects.BehaviorSubject
 import io.reactivex.rxjava3.subjects.PublishSubject
@@ -98,11 +97,6 @@ class ConversationViewModel(
   private val _conversationThreadState: Subject<ConversationThreadState> = BehaviorSubject.create()
   val conversationThreadState: Single<ConversationThreadState> = _conversationThreadState.firstOrError()
 
-  private val _markReadProcessor: PublishProcessor<Long> = PublishProcessor.create()
-  val markReadRequests: Flowable<Long> = _markReadProcessor
-    .onBackpressureBuffer()
-    .distinct()
-
   val pagingController = ProxyPagingController<ConversationElementKey>()
 
   val groupMemberServiceIds: Observable<List<ServiceId>> = recipientRepository
@@ -249,9 +243,18 @@ class ConversationViewModel(
     disposables.clear()
   }
 
-  fun setShowScrollButtons(showScrollButtons: Boolean) {
+  fun setShowScrollButtonsForScrollPosition(showScrollButtons: Boolean, willScrollToBottomOnNewMessage: Boolean) {
     scrollButtonStateStore.update {
-      it.copy(showScrollButtons = showScrollButtons)
+      it.copy(
+        showScrollButtonsForScrollPosition = showScrollButtons,
+        willScrollToBottomOnNewMessage = willScrollToBottomOnNewMessage
+      )
+    }
+  }
+
+  fun setHideScrollButtonsForReactionOverlay(hide: Boolean) {
+    scrollButtonStateStore.update {
+      it.copy(hideScrollButtonsForReactionOverlay = hide)
     }
   }
 

app/src/main/java/org/thoughtcrime/securesms/database/RxDatabaseObserver.kt

@@ -22,6 +22,12 @@ object RxDatabaseObserver {
     }
   }
 
+  fun conversation(threadId: Long): Flowable<Unit> {
+    return databaseFlowable { listener ->
+      ApplicationDependencies.getDatabaseObserver().registerVerboseConversationObserver(threadId, listener)
+    }
+  }
+
   @Suppress("RedundantUnitExpression")
   private fun notificationProfilesFlowable(): Flowable<Unit> {
     return Flowable.combineLatest(