adding a helper function for updating conversations, if necessary

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/MainActivity.kt

@@ -165,16 +165,7 @@ class MainActivity : SimpleActivity() {
                 conversations_list.beVisibleIf(hasConversations)
                 no_conversations_placeholder.beVisibleIf(!hasConversations)
                 no_conversations_placeholder_2.beVisibleIf(!hasConversations)
-
-                ConversationsAdapter(this, conversations, conversations_list, conversations_fastscroller) {
-                    Intent(this, ThreadActivity::class.java).apply {
-                        putExtra(THREAD_ID, (it as Conversation).system_id)
-                        putExtra(THREAD_TITLE, it.title)
-                        startActivity(this)
-                    }
-                }.apply {
-                    conversations_list.adapter = this
-                }
+                updateConversations(conversations)
             }
         }
 
@@ -187,6 +178,23 @@ class MainActivity : SimpleActivity() {
         }
     }
 
+    private fun updateConversations(conversations: ArrayList<Conversation>) {
+        val currAdapter = conversations_list.adapter
+        if (currAdapter == null) {
+            ConversationsAdapter(this, conversations, conversations_list, conversations_fastscroller) {
+                Intent(this, ThreadActivity::class.java).apply {
+                    putExtra(THREAD_ID, (it as Conversation).system_id)
+                    putExtra(THREAD_TITLE, it.title)
+                    startActivity(this)
+                }
+            }.apply {
+                conversations_list.adapter = this
+            }
+        } else {
+            (currAdapter as ConversationsAdapter).updateConversations(conversations)
+        }
+    }
+
     private fun launchNewConversation() {
         Intent(this, NewConversationActivity::class.java).apply {
             startActivity(this)

app/src/main/kotlin/com/simplemobiletools/smsmessenger/adapters/ConversationsAdapter.kt

@@ -173,6 +173,15 @@ class ConversationsAdapter(activity: SimpleActivity, var conversations: ArrayLis
         }
     }
 
+    fun updateConversations(newConversations: ArrayList<Conversation>) {
+        val oldHashCode = conversations.hashCode()
+        val newHashCode = newConversations.hashCode()
+        if (newHashCode != oldHashCode) {
+            conversations = newConversations
+            notifyDataSetChanged()
+        }
+    }
+
     private fun setupView(view: View, conversation: Conversation) {
         view.apply {
             conversation_frame.isSelected = selectedKeys.contains(conversation.system_id)