Scroll to first unread message in conversation upon entering it

app/src/main/java/org/linphone/ui/main/chat/adapter/ConversationEventAdapter.kt

@@ -28,6 +28,7 @@ import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListAdapter
 import androidx.recyclerview.widget.RecyclerView
 import org.linphone.R
+import org.linphone.core.tools.Log
 import org.linphone.databinding.ChatBubbleIncomingBinding
 import org.linphone.databinding.ChatBubbleOutgoingBinding
 import org.linphone.databinding.ChatConversationEventBinding
@@ -41,6 +42,8 @@ class ConversationEventAdapter : ListAdapter<EventLogModel, RecyclerView.ViewHol
     EventLogDiffCallback()
 ) {
     companion object {
+        private const val TAG = "[Conversation Event Adapter]"
+
         const val INCOMING_CHAT_MESSAGE = 1
         const val OUTGOING_CHAT_MESSAGE = 2
         const val EVENT = 3
@@ -76,6 +79,21 @@ class ConversationEventAdapter : ListAdapter<EventLogModel, RecyclerView.ViewHol
         return INCOMING_CHAT_MESSAGE
     }
 
+    fun getFirstUnreadMessagePosition(): Int {
+        var index = 0
+        for (eventLog in currentList) {
+            if (eventLog.model is MessageModel) {
+                if (!eventLog.model.isRead) {
+                    Log.i("$TAG First unread message is [${eventLog.model.id}] at index [$index]")
+                    return index
+                }
+            }
+            index += 1
+        }
+        Log.i("$TAG No unread message found in list of [${currentList.size}] events")
+        return -1
+    }
+
     private fun createIncomingChatBubble(parent: ViewGroup): IncomingBubbleViewHolder {
         val binding: ChatBubbleIncomingBinding = DataBindingUtil.inflate(
             LayoutInflater.from(parent.context),

app/src/main/java/org/linphone/ui/main/chat/fragment/ConversationFragment.kt

@@ -127,11 +127,15 @@ class ConversationFragment : GenericFragment() {
         override fun onItemRangeInserted(positionStart: Int, itemCount: Int) {
             if (positionStart == 0 && adapter.itemCount == itemCount) {
                 // First time we fill the list with messages
-                Log.i("$TAG [$itemCount] events have been loaded")
-                binding.eventsList.scrollToPosition(adapter.itemCount - 1)
+                Log.i(
+                    "$TAG [$itemCount] events have been loaded, scrolling to first unread message"
+                )
+                scrollToFirstUnreadMessageOrBottom(false)
             } else {
-                Log.i("$TAG [$itemCount] new events have been loaded, scrolling to bottom")
-                binding.eventsList.smoothScrollToPosition(adapter.itemCount - 1)
+                Log.i(
+                    "$TAG [$itemCount] new events have been loaded, scrolling to first unread message"
+                )
+                scrollToFirstUnreadMessageOrBottom(true)
             }
         }
     }
@@ -565,6 +569,36 @@ class ConversationFragment : GenericFragment() {
         super.onPause()
     }
 
+    private fun scrollToFirstUnreadMessageOrBottom(smooth: Boolean): Boolean {
+        if (adapter.itemCount > 0) {
+            val recyclerView = binding.eventsList
+
+            // Scroll to first unread message if any, unless we are already on it
+            val firstUnreadMessagePosition = adapter.getFirstUnreadMessagePosition()
+            val currentPosition = (recyclerView.layoutManager as LinearLayoutManager).findFirstCompletelyVisibleItemPosition()
+            val indexToScrollTo = if (firstUnreadMessagePosition != -1 && firstUnreadMessagePosition != currentPosition) {
+                firstUnreadMessagePosition
+            } else {
+                adapter.itemCount - 1
+            }
+
+            Log.i(
+                "$TAG Scrolling to position $indexToScrollTo, first unread message is at $firstUnreadMessagePosition"
+            )
+            if (smooth) {
+                recyclerView.smoothScrollToPosition(indexToScrollTo)
+            } else {
+                recyclerView.scrollToPosition(indexToScrollTo)
+            }
+
+            if (firstUnreadMessagePosition == 0) {
+                // Return true only if all unread messages don't fit in the recyclerview height
+                return recyclerView.computeVerticalScrollRange() > recyclerView.height
+            }
+        }
+        return false
+    }
+
     private fun showChatMessageLongPressMenu(chatMessageModel: MessageModel) {
         Compatibility.setBlurRenderEffect(binding.root)
 

app/src/main/java/org/linphone/ui/main/chat/model/MessageModel.kt

@@ -82,6 +82,8 @@ class MessageModel @WorkerThread constructor(
 
     val id = chatMessage.messageId
 
+    val isRead = chatMessage.isRead
+
     val isOutgoing = chatMessage.isOutgoing
 
     val isInError = chatMessage.state == ChatMessage.State.NotDelivered