Properly update last chat room message for when going back to chat rooms list

app/src/main/java/org/linphone/activities/main/chat/adapters/ChatMessagesListAdapter.kt

@@ -451,12 +451,18 @@ private class ChatMessageDiffCallback : DiffUtil.ItemCallback<EventLogData>() {
         oldItem: EventLogData,
         newItem: EventLogData
     ): Boolean {
-        return if (newItem.eventLog.type == EventLog.Type.ConferenceChatMessage) {
+        return if (oldItem.eventLog.type == EventLog.Type.ConferenceChatMessage &&
+            newItem.eventLog.type == EventLog.Type.ConferenceChatMessage
+        ) {
             val oldData = (oldItem.data as ChatMessageData)
             val newData = (newItem.data as ChatMessageData)
+
             val previous = oldData.hasPreviousMessage == newData.hasPreviousMessage
             val next = oldData.hasNextMessage == newData.hasNextMessage
             newItem.eventLog.chatMessage?.state == ChatMessage.State.Displayed && previous && next
-        } else true
+        } else {
+            oldItem.eventLog.type != EventLog.Type.ConferenceChatMessage &&
+                newItem.eventLog.type != EventLog.Type.ConferenceChatMessage
+        }
     }
 }

app/src/main/java/org/linphone/activities/main/chat/fragments/DetailChatRoomFragment.kt

@@ -175,10 +175,20 @@ class DetailChatRoomFragment : MasterFragment<ChatRoomDetailFragmentBinding, Cha
 
         isSecure = chatRoom.currentParams.isEncryptionEnabled
 
-        viewModel = ViewModelProvider(
+        val chatRoomsListViewModel: ChatRoomsListViewModel = requireActivity().run {
+            ViewModelProvider(this)[ChatRoomsListViewModel::class.java]
+        }
+        val chatRoomViewModel = chatRoomsListViewModel.chatRooms.value.orEmpty().find {
+            it.chatRoom == chatRoom
+        }
+        if (chatRoomViewModel == null) {
+            Log.w("[Chat Room] Couldn't find existing view model, will create a new one!")
+        }
+        viewModel = chatRoomViewModel ?: ViewModelProvider(
             this,
             ChatRoomViewModelFactory(chatRoom)
         )[ChatRoomViewModel::class.java]
+
         binding.viewModel = viewModel
 
         chatSendingViewModel = ViewModelProvider(
@@ -331,6 +341,7 @@ class DetailChatRoomFragment : MasterFragment<ChatRoomDetailFragmentBinding, Cha
             {
                 it.consume { chatMessage ->
                     listViewModel.deleteMessage(chatMessage)
+                    viewModel.updateLastMessageToDisplay()
                 }
             }
         )
@@ -607,6 +618,7 @@ class DetailChatRoomFragment : MasterFragment<ChatRoomDetailFragmentBinding, Cha
             list.add(eventLog)
         }
         listViewModel.deleteEventLogs(list)
+        viewModel.updateLastMessageToDisplay()
     }
 
     override fun onRequestPermissionsResult(
@@ -849,6 +861,7 @@ class DetailChatRoomFragment : MasterFragment<ChatRoomDetailFragmentBinding, Cha
                         Log.i("[Chat Room] Deleting event $eventLog at position $position")
                         listViewModel.deleteEventLogs(arrayListOf(eventLog))
                     }
+                    viewModel.updateLastMessageToDisplay()
                 }
             }
         }

app/src/main/java/org/linphone/activities/main/chat/fragments/MasterChatRoomsFragment.kt

@@ -98,7 +98,9 @@ class MasterChatRoomsFragment : MasterFragment<ChatRoomMasterFragmentBinding, Ch
         isSecure = true
         binding.lifecycleOwner = viewLifecycleOwner
 
-        listViewModel = ViewModelProvider(this)[ChatRoomsListViewModel::class.java]
+        listViewModel = requireActivity().run {
+            ViewModelProvider(this)[ChatRoomsListViewModel::class.java]
+        }
         binding.viewModel = listViewModel
 
         /* Shared view model & sliding pane related */

app/src/main/java/org/linphone/activities/main/chat/viewmodels/ChatRoomViewModel.kt

@@ -276,7 +276,7 @@ class ChatRoomViewModel(val chatRoom: ChatRoom) : ViewModel(), ContactDataInterf
         }
     }
 
-    private fun updateLastMessageToDisplay() {
+    fun updateLastMessageToDisplay() {
         lastMessageText.value = formatLastMessage(chatRoom.lastMessageInHistory)
     }
 

app/src/main/java/org/linphone/activities/main/chat/viewmodels/ChatRoomsListViewModel.kt

@@ -142,9 +142,7 @@ class ChatRoomsListViewModel : ErrorReportingViewModel() {
     }
 
     private fun updateChatRooms() {
-        for (chatRoomViewModel in chatRooms.value.orEmpty()) {
+        chatRooms.value.orEmpty().forEach(ChatRoomViewModel::destroy)
-            chatRoomViewModel.destroy()
-        }
 
         val list = arrayListOf<ChatRoomViewModel>()
         for (chatRoom in coreContext.core.chatRooms) {