Mark all messages as read upon opening a conversation

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationActivityV2.kt

@@ -126,6 +126,7 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity(), InputBarDe
         setUpBlockedBanner()
         setUpLinkPreviewObserver()
         scrollToFirstUnreadMessage()
+        markAllAsRead()
     }
 
     private fun setUpRecyclerView() {
@@ -257,6 +258,10 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity(), InputBarDe
     // endregion
 
     // region Updating & Animation
+    private fun markAllAsRead() {
+        DatabaseFactory.getThreadDatabase(this).setRead(threadID, true)
+    }
+
     override fun inputBarHeightChanged(newValue: Int) {
         @Suppress("NAME_SHADOWING") val newValue = max(newValue, resources.getDimension(R.dimen.input_bar_height).roundToInt())
         // 36 DP is the exact height of the typing indicator view. It's also exactly 18 * 2, and 18 is the large message