Thread decoration: add and branch isThreaded method

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/timeline/item/event/EventContent.kt

@@ -32,6 +32,7 @@ data class MessageContent(
     val body: String,
     val inReplyTo: InReplyTo?,
     val isEdited: Boolean,
+    val isThreaded: Boolean,
     val type: MessageType?
 ) : EventContent
 

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/timeline/item/event/EventTimelineItem.kt

@@ -40,6 +40,11 @@ data class EventTimelineItem(
     fun inReplyTo(): InReplyTo? {
         return (content as? MessageContent)?.inReplyTo
     }
+
+    fun isThreaded(): Boolean {
+        return (content as? MessageContent)?.isThreaded ?: false
+    }
+
     fun hasNotLoadedInReplyTo(): Boolean {
         val details = inReplyTo()
         return details is InReplyTo.NotLoaded

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/timeline/item/event/EventMessageMapper.kt

@@ -68,6 +68,7 @@ class EventMessageMapper {
             body = it.body(),
             inReplyTo = inReplyToEvent,
             isEdited = it.isEdited(),
+            isThreaded = it.isThreaded(),
             type = type
         )
     }

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/room/RoomSummaryFixture.kt

@@ -147,6 +147,7 @@ fun aMessageContent(
     body: String = "body",
     inReplyTo: InReplyTo? = null,
     isEdited: Boolean = false,
+    isThreaded: Boolean = false,
     messageType: MessageType = TextMessageType(
         body = body,
         formatted = null
@@ -155,6 +156,7 @@ fun aMessageContent(
     body = body,
     inReplyTo = inReplyTo,
     isEdited = isEdited,
+    isThreaded = isThreaded,
     type = messageType
 )