Add compose divider to CFV2.

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

@@ -1949,6 +1949,9 @@ class ConversationFragment :
   }
 
   private inner class ScrollListener : RecyclerView.OnScrollListener() {
+
+    private var wasAtBottom = true
+
     override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
       if (isScrolledToBottom()) {
         viewModel.setShowScrollButtons(false)
@@ -1956,9 +1959,22 @@ class ConversationFragment :
         viewModel.setShowScrollButtons(true)
       }
 
+      presentComposeDivider()
+
       val timestamp = MarkReadHelper.getLatestTimestamp(adapter, layoutManager)
       timestamp.ifPresent(markReadHelper::onViewsRevealed)
     }
+
+    private fun presentComposeDivider() {
+      val isAtBottom = isScrolledToBottom()
+      if (isAtBottom && !wasAtBottom) {
+        ViewUtil.fadeOut(binding.composeDivider, 50, View.INVISIBLE)
+      } else if (wasAtBottom && !isAtBottom) {
+        ViewUtil.fadeIn(binding.composeDivider, 500)
+      }
+      
+      wasAtBottom = isAtBottom
+    }
   }
 
   private inner class DataObserver(

app/src/main/res/layout/v2_conversation_fragment.xml

@@ -160,10 +160,10 @@
         android:id="@+id/mention_fragment_container"
         android:layout_width="0dp"
         android:layout_height="0dp"
-        app:layout_constraintStart_toStartOf="@id/parent_start_guideline"
-        app:layout_constraintTop_toBottomOf="@id/toolbar"
+        app:layout_constraintBottom_toTopOf="@id/conversation_bottom_panel_barrier"
         app:layout_constraintEnd_toEndOf="@id/parent_end_guideline"
-        app:layout_constraintBottom_toTopOf="@id/conversation_bottom_panel_barrier"/>
+        app:layout_constraintStart_toStartOf="@id/parent_start_guideline"
+        app:layout_constraintTop_toBottomOf="@id/toolbar" />
 
     <androidx.constraintlayout.widget.Barrier
         android:id="@+id/conversation_bottom_panel_barrier"
@@ -225,7 +225,7 @@
         android:layout_height="wrap_content"
         app:barrierDirection="top"
         app:constraint_referenced_ids="emoji_search_container,keyboard_guideline" />
-    
+
     <TextView
         android:id="@+id/conversation_input_space_left"
         android:layout_width="0dp"
@@ -240,6 +240,16 @@
         tools:text="160/160 (1)"
         tools:visibility="visible" />
 
+    <View
+        android:id="@+id/compose_divider"
+        android:layout_width="match_parent"
+        android:layout_height="2dp"
+        android:alpha="1"
+        android:background="@drawable/compose_divider_background"
+        android:visibility="invisible"
+        app:layout_constraintBottom_toTopOf="@id/conversation_input_panel"
+        tools:visibility="visible" />
+
     <androidx.fragment.app.FragmentContainerView
         android:id="@+id/input_container"
         android:layout_width="0dp"