Reply In Thread, create a new thread timeline

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/events/model/Event.kt

@@ -96,6 +96,9 @@ data class Event(
     @Transient
     var sendStateDetails: String? = null
 
+    @Transient
+    var isRootThread: Boolean = false
+
     fun sendStateError(): MatrixError? {
         return sendStateDetails?.let {
             val matrixErrorAdapter = MoshiProvider.providesMoshi().adapter(MatrixError::class.java)
@@ -299,12 +302,22 @@ fun Event.getRelationContent(): RelationDefaultContent? {
     }
 }
 
+/**
+ * Returns the relation content for a specific type or null otherwise
+ */
+fun Event.getRelationContentForType(type: String): RelationDefaultContent? =
+        getRelationContent()?.takeIf { it.type == type }
+
 fun Event.isReply(): Boolean {
     return getRelationContent()?.inReplyTo?.eventId != null
 }
 
+fun Event.isThread(): Boolean = getRelationContentForType(RelationType.THREAD)?.eventId != null
+
+fun Event.getRootThreadEventId(): String? = getRelationContentForType(RelationType.THREAD)?.eventId
+
 fun Event.isEdition(): Boolean {
-    return getRelationContent()?.takeIf { it.type == RelationType.REPLACE }?.eventId != null
+    return getRelationContentForType(RelationType.REPLACE)?.eventId != null
 }
 
 fun Event.getPresenceContent(): PresenceContent? {

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/RelationService.kt

@@ -131,11 +131,11 @@ interface RelationService {
      * Creates a thread reply for an existing timeline event
      * The replyInThreadText can be a Spannable and contains special spans (MatrixItemSpan) that will be translated
      * by the sdk into pills.
-     * @param eventToReplyInThread the event referenced by the thread reply
+     * @param rootThreadEventId the root thread eventId
      * @param replyInThreadText the reply text
      * @param autoMarkdown If true, the SDK will generate a formatted HTML message from the body text if markdown syntax is present
      */
-    fun replyInThread(eventToReplyInThread: TimelineEvent,
+    fun replyInThread(rootThreadEventId: String,
                        replyInThreadText: CharSequence,
                        autoMarkdown: Boolean = false): Cancelable?
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/threads/ThreadContent.kt

@@ -1,28 +0,0 @@
-/*
- * Copyright 2021 The Matrix.org Foundation C.I.C.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.matrix.android.sdk.api.session.room.model.relation.threads
-
-interface ThreadContent {
-
-    companion object {
-        const val MSG_TYPE_JSON_KEY = "msgtype"
-    }
-
-    val msgType: String
-    val body: String
-    val relatesTo: ThreadRelatesTo?
-}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/threads/ThreadRelatesTo.kt

@@ -1,31 +0,0 @@
-/*
- * Copyright (c) 2021 New Vector Ltd
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.matrix.android.sdk.api.session.room.model.relation.threads
-
-import com.squareup.moshi.Json
-import com.squareup.moshi.JsonClass
-import org.matrix.android.sdk.api.session.events.model.RelationType
-import org.matrix.android.sdk.api.session.room.model.relation.RelationContent
-import org.matrix.android.sdk.api.session.room.model.relation.ReplyToContent
-
-@JsonClass(generateAdapter = true)
-data class ThreadRelatesTo(
-        @Json(name = "rel_type") override val type: String? = RelationType.THREAD,
-        @Json(name = "event_id") override val eventId: String,
-        @Json(name = "m.in_reply_to") override val inReplyTo: ReplyToContent? = null,
-        @Json(name = "option") override val option: Int? = null
-) : RelationContent

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/relation/threads/ThreadTextContent.kt

@@ -1,28 +0,0 @@
-/*
- * Copyright 2021 The Matrix.org Foundation C.I.C.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.matrix.android.sdk.api.session.room.model.relation.threads
-
-import com.squareup.moshi.Json
-import com.squareup.moshi.JsonClass
-import org.matrix.android.sdk.api.session.room.model.message.MessageContent
-
-@JsonClass(generateAdapter = true)
-data class ThreadTextContent(
-        @Json(name = MessageContent.MSG_TYPE_JSON_KEY) override val msgType: String,
-        @Json(name = "body") override val body: String,
-        @Json(name = "m.relates_to") override val relatesTo: ThreadRelatesTo? = null,
-) : ThreadContent

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/RealmSessionStoreMigration.kt

@@ -25,6 +25,7 @@ import org.matrix.android.sdk.api.session.room.model.RoomJoinRulesContent
 import org.matrix.android.sdk.api.session.room.model.VersioningState
 import org.matrix.android.sdk.api.session.room.model.create.RoomCreateContent
 import org.matrix.android.sdk.api.session.room.model.tag.RoomTag
+import org.matrix.android.sdk.internal.database.model.ChunkEntityFields
 import org.matrix.android.sdk.internal.database.model.CurrentStateEventEntityFields
 import org.matrix.android.sdk.internal.database.model.EditAggregatedSummaryEntityFields
 import org.matrix.android.sdk.internal.database.model.EditionOfEventFields
@@ -49,7 +50,7 @@ import timber.log.Timber
 
 internal object RealmSessionStoreMigration : RealmMigration {
 
-    const val SESSION_STORE_SCHEMA_VERSION = 18L
+    const val SESSION_STORE_SCHEMA_VERSION = 19L
 
     override fun migrate(realm: DynamicRealm, oldVersion: Long, newVersion: Long) {
         Timber.v("Migrating Realm Session from $oldVersion to $newVersion")
@@ -72,6 +73,7 @@ internal object RealmSessionStoreMigration : RealmMigration {
         if (oldVersion <= 15) migrateTo16(realm)
         if (oldVersion <= 16) migrateTo17(realm)
         if (oldVersion <= 17) migrateTo18(realm)
+        if (oldVersion <= 18) migrateTo19(realm)
     }
 
     private fun migrateTo1(realm: DynamicRealm) {
@@ -364,4 +366,13 @@ internal object RealmSessionStoreMigration : RealmMigration {
         realm.schema.get("RoomMemberSummaryEntity")
                 ?.addRealmObjectField(RoomMemberSummaryEntityFields.USER_PRESENCE_ENTITY.`$`, userPresenceEntity)
     }
+
+    private fun migrateTo19(realm: DynamicRealm) {
+        Timber.d("Step 18 -> 19")
+        realm.schema.get("EventEntity")
+                ?.addField(EventEntityFields.IS_THREAD, Boolean::class.java, FieldAttribute.INDEXED)
+                ?.addField(EventEntityFields.ROOT_THREAD_EVENT_ID, String::class.java)
+        realm.schema.get("ChunkEntity")
+                ?.addField(ChunkEntityFields.ROOT_THREAD_EVENT_ID, String::class.java, FieldAttribute.INDEXED)
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/mapper/EventMapper.kt

@@ -21,6 +21,8 @@ import org.matrix.android.sdk.api.session.crypto.MXCryptoError
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.events.model.EventType
 import org.matrix.android.sdk.api.session.events.model.UnsignedData
+import org.matrix.android.sdk.api.session.events.model.getRootThreadEventId
+import org.matrix.android.sdk.api.session.events.model.isThread
 import org.matrix.android.sdk.api.session.room.send.SendState
 import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
 import org.matrix.android.sdk.internal.database.model.EventEntity
@@ -39,6 +41,8 @@ internal object EventMapper {
         eventEntity.isUseless = IsUselessResolver.isUseless(event)
         eventEntity.stateKey = event.stateKey
         eventEntity.type = event.type ?: EventType.MISSING_TYPE
+        eventEntity.isThread = if(event.isRootThread) true else event.isThread()
+        eventEntity.rootThreadEventId = if(event.isRootThread) null else event.getRootThreadEventId()
         eventEntity.sender = event.senderId
         eventEntity.originServerTs = event.originServerTs
         eventEntity.redacts = event.redacts
@@ -93,6 +97,7 @@ internal object EventMapper {
                 MXCryptoError.ErrorType.valueOf(errorCode)
             }
             it.mCryptoErrorReason = eventEntity.decryptionErrorReason
+            it.isRootThread = eventEntity.isRootThread()
         }
     }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/ChunkEntity.kt

@@ -27,6 +27,7 @@ import org.matrix.android.sdk.internal.extensions.clearWith
 internal open class ChunkEntity(@Index var prevToken: String? = null,
         // Because of gaps we can have several chunks with nextToken == null
                                 @Index var nextToken: String? = null,
+                                @Index var rootThreadEventId: String? = null,
                                 var stateEvents: RealmList<EventEntity> = RealmList(),
                                 var timelineEvents: RealmList<TimelineEventEntity> = RealmList(),
                                 var numberOfTimelineEvents: Long = 0,
@@ -44,6 +45,8 @@ internal open class ChunkEntity(@Index var prevToken: String? = null,
     val room: RealmResults<RoomEntity>? = null
 
     companion object
+
+    fun isThreadChunk() = rootThreadEventId != null
 }
 
 internal fun ChunkEntity.deleteOnCascade(deleteStateEvents: Boolean, canDeleteRoot: Boolean) {

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/EventEntity.kt

@@ -27,6 +27,8 @@ import org.matrix.android.sdk.internal.extensions.assertIsManaged
 internal open class EventEntity(@Index var eventId: String = "",
                                 @Index var roomId: String = "",
                                 @Index var type: String = "",
+                                @Index var isThread: Boolean = false,
+                                var rootThreadEventId: String? = null,
                                 var content: String? = null,
                                 var prevContent: String? = null,
                                 var isUseless: Boolean = false,
@@ -75,4 +77,10 @@ internal open class EventEntity(@Index var eventId: String = "",
                 .findFirst()
                 ?.canBeProcessed = true
     }
+
+    /**
+     * Returns true if the current event is a thread root event
+     */
+    fun isRootThread(): Boolean = isThread && rootThreadEventId == null
+
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/query/ChunkEntityQueries.kt

@@ -33,9 +33,11 @@ internal fun ChunkEntity.Companion.find(realm: Realm, roomId: String, prevToken:
     val query = where(realm, roomId)
     if (prevToken != null) {
         query.equalTo(ChunkEntityFields.PREV_TOKEN, prevToken)
+        query.isNull(ChunkEntityFields.ROOT_THREAD_EVENT_ID)
     }
     if (nextToken != null) {
         query.equalTo(ChunkEntityFields.NEXT_TOKEN, nextToken)
+        query.isNull(ChunkEntityFields.ROOT_THREAD_EVENT_ID)
     }
     return query.findFirst()
 }
@@ -43,12 +45,15 @@ internal fun ChunkEntity.Companion.find(realm: Realm, roomId: String, prevToken:
 internal fun ChunkEntity.Companion.findLastForwardChunkOfRoom(realm: Realm, roomId: String): ChunkEntity? {
     return where(realm, roomId)
             .equalTo(ChunkEntityFields.IS_LAST_FORWARD, true)
+            .isNull(ChunkEntityFields.ROOT_THREAD_EVENT_ID)
             .findFirst()
 }
 
+
 internal fun ChunkEntity.Companion.findAllIncludingEvents(realm: Realm, eventIds: List<String>): RealmResults<ChunkEntity> {
     return realm.where<ChunkEntity>()
             .`in`(ChunkEntityFields.TIMELINE_EVENTS.EVENT_ID, eventIds.toTypedArray())
+            .isNull(ChunkEntityFields.ROOT_THREAD_EVENT_ID)
             .findAll()
 }
 
@@ -56,6 +61,7 @@ internal fun ChunkEntity.Companion.findIncludingEvent(realm: Realm, eventId: Str
     return findAllIncludingEvents(realm, listOf(eventId)).firstOrNull()
 }
 
+
 internal fun ChunkEntity.Companion.create(
         realm: Realm,
         prevToken: String?,
@@ -66,3 +72,16 @@ internal fun ChunkEntity.Companion.create(
         this.nextToken = nextToken
     }
 }
+
+// Threads
+internal fun ChunkEntity.Companion.findThreadChunkOfRoom(realm: Realm, roomId: String, rootThreadEventId: String): ChunkEntity? {
+    return where(realm, roomId)
+            .equalTo(ChunkEntityFields.ROOT_THREAD_EVENT_ID, rootThreadEventId)
+            .findFirst()
+}
+
+internal fun ChunkEntity.Companion.findAllThreadChunkOfRoom(realm: Realm, roomId: String): RealmResults<ChunkEntity> {
+    return where(realm, roomId)
+            .isNotNull(ChunkEntityFields.ROOT_THREAD_EVENT_ID)
+            .findAll()
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/relation/DefaultRelationService.kt

@@ -159,11 +159,15 @@ internal class DefaultRelationService @AssistedInject constructor(
         }
     }
 
-    override fun replyInThread(eventToReplyInThread: TimelineEvent, replyInThreadText: CharSequence, autoMarkdown: Boolean): Cancelable? {
+    override fun replyInThread(rootThreadEventId: String, replyInThreadText: CharSequence, autoMarkdown: Boolean): Cancelable {
-        val event = eventFactory.createThreadTextEvent(eventToReplyInThread, TextContent(replyInThreadText.toString()))
+        val event = eventFactory.createThreadTextEvent(
-                .also {
+                rootThreadEventId = rootThreadEventId,
-                    saveLocalEcho(it)
+                roomId = roomId,
-                }
+                text = replyInThreadText.toString(),
+                autoMarkdown = autoMarkdown)
+//                .also {
+//                    saveLocalEcho(it)
+//                }
         return eventSenderProcessor.postEvent(event, cryptoSessionInfoProvider.isRoomEncrypted(roomId))
     }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/LocalEchoEventFactory.kt

@@ -51,8 +51,6 @@ import org.matrix.android.sdk.api.session.room.model.relation.ReactionContent
 import org.matrix.android.sdk.api.session.room.model.relation.ReactionInfo
 import org.matrix.android.sdk.api.session.room.model.relation.RelationDefaultContent
 import org.matrix.android.sdk.api.session.room.model.relation.ReplyToContent
-import org.matrix.android.sdk.api.session.room.model.relation.threads.ThreadTextContent
-import org.matrix.android.sdk.api.session.room.model.relation.threads.ThreadRelatesTo
 import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.api.session.room.timeline.getLastMessageContent
 import org.matrix.android.sdk.api.session.room.timeline.isReply
@@ -60,7 +58,6 @@ import org.matrix.android.sdk.internal.di.UserId
 import org.matrix.android.sdk.internal.session.content.ThumbnailExtractor
 import org.matrix.android.sdk.internal.session.permalinks.PermalinkFactory
 import org.matrix.android.sdk.internal.session.room.send.pills.TextPillsUtils
-import timber.log.Timber
 import javax.inject.Inject
 
 /**
@@ -346,11 +343,13 @@ internal class LocalEchoEventFactory @Inject constructor(
     /**
      * Creates a thread event related to the already existing event
      */
-    fun createThreadTextEvent(eventToReplyInThread: TimelineEvent, textContent: TextContent): Event =
+    fun createThreadTextEvent(rootThreadEventId: String, roomId:String, text: String, autoMarkdown: Boolean): Event =
             createEvent(
-                    eventToReplyInThread.roomId,
+                    roomId,
                     EventType.MESSAGE,
-                    textContent.toThreadTextContent(eventToReplyInThread).toContent())
+                    createTextContent(text, autoMarkdown)
+                            .toThreadTextContent(rootThreadEventId)
+                            .toContent())
 
     private fun dummyOriginServerTs(): Long {
         return System.currentTimeMillis()

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/send/TextContent.kt

@@ -16,13 +16,11 @@
 
 package org.matrix.android.sdk.internal.session.room.send
 
-import org.matrix.android.sdk.api.session.events.model.toContent
+import org.matrix.android.sdk.api.session.events.model.RelationType
 import org.matrix.android.sdk.api.session.room.model.message.MessageFormat
 import org.matrix.android.sdk.api.session.room.model.message.MessageTextContent
 import org.matrix.android.sdk.api.session.room.model.message.MessageType
-import org.matrix.android.sdk.api.session.room.model.relation.threads.ThreadTextContent
+import org.matrix.android.sdk.api.session.room.model.relation.RelationDefaultContent
-import org.matrix.android.sdk.api.session.room.model.relation.threads.ThreadRelatesTo
-import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.api.util.ContentUtils.extractUsefulTextFromHtmlReply
 import org.matrix.android.sdk.api.util.ContentUtils.extractUsefulTextFromReply
 
@@ -45,11 +43,13 @@ fun TextContent.toMessageTextContent(msgType: String = MessageType.MSGTYPE_TEXT)
     )
 }
 
-fun TextContent.toThreadTextContent(eventToReplyInThread: TimelineEvent, msgType: String = MessageType.MSGTYPE_TEXT): ThreadTextContent {
+fun TextContent.toThreadTextContent(rootThreadEventId: String, msgType: String = MessageType.MSGTYPE_TEXT): MessageTextContent {
-    return ThreadTextContent(
+    return MessageTextContent(
             msgType = msgType,
+            format = MessageFormat.FORMAT_MATRIX_HTML.takeIf { formattedText != null },
             body = text,
-            relatesTo = ThreadRelatesTo(eventId = eventToReplyInThread.eventId)
+            relatesTo = RelationDefaultContent(RelationType.THREAD, rootThreadEventId),
+            formattedBody = formattedText
     )
 }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEventPersistor.kt

@@ -18,7 +18,9 @@ package org.matrix.android.sdk.internal.session.room.timeline
 
 import com.zhuinden.monarchy.Monarchy
 import io.realm.Realm
+import io.realm.kotlin.createObject
 import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.isThread
 import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.room.model.RoomMemberContent
 import org.matrix.android.sdk.api.session.room.send.SendState
@@ -28,6 +30,8 @@ import org.matrix.android.sdk.internal.database.helper.addTimelineEvent
 import org.matrix.android.sdk.internal.database.helper.merge
 import org.matrix.android.sdk.internal.database.mapper.toEntity
 import org.matrix.android.sdk.internal.database.model.ChunkEntity
+import org.matrix.android.sdk.internal.database.model.EventEntity
+import org.matrix.android.sdk.internal.database.model.EventEntityFields
 import org.matrix.android.sdk.internal.database.model.EventInsertType
 import org.matrix.android.sdk.internal.database.model.RoomEntity
 import org.matrix.android.sdk.internal.database.model.RoomSummaryEntity
@@ -37,6 +41,7 @@ import org.matrix.android.sdk.internal.database.query.create
 import org.matrix.android.sdk.internal.database.query.find
 import org.matrix.android.sdk.internal.database.query.findAllIncludingEvents
 import org.matrix.android.sdk.internal.database.query.findLastForwardChunkOfRoom
+import org.matrix.android.sdk.internal.database.query.findThreadChunkOfRoom
 import org.matrix.android.sdk.internal.database.query.getOrCreate
 import org.matrix.android.sdk.internal.database.query.where
 import org.matrix.android.sdk.internal.di.SessionDatabase
@@ -221,7 +226,15 @@ internal class TokenChunkEventPersistor @Inject constructor(@SessionDatabase pri
                 roomMemberContentsByUser[event.stateKey] = contentToUse.toModel<RoomMemberContent>()
             }
 
-            currentChunk.addTimelineEvent(roomId, eventEntity, direction, roomMemberContentsByUser)
+            Timber.i("------> [TokenChunkEventPersistor] Add TimelineEvent to chunkEntity event[${event.eventId}] ${if (event.isThread()) "is Thread" else ""}")
+
+            addTimelineEventToChunk(
+                    realm = realm,
+                    roomId = roomId,
+                    eventEntity = eventEntity,
+                    currentChunk = currentChunk,
+                    direction = direction,
+                    roomMemberContentsByUser = roomMemberContentsByUser)
         }
         // Find all the chunks which contain at least one event from the list of eventIds
         val chunks = ChunkEntity.findAllIncludingEvents(realm, eventIds)
@@ -247,4 +260,43 @@ internal class TokenChunkEventPersistor @Inject constructor(@SessionDatabase pri
             RoomEntity.where(realm, roomId).findFirst()?.addIfNecessary(currentChunk)
         }
     }
+
+    /**
+     * Adds a timeline event to the correct chunk. If there is a thread detected will be added
+     * to a specific chunk
+     */
+    private fun addTimelineEventToChunk(realm: Realm,
+                                        roomId: String,
+                                        eventEntity: EventEntity,
+                                        currentChunk: ChunkEntity,
+                                        direction: PaginationDirection,
+                                        roomMemberContentsByUser: Map<String, RoomMemberContent?>) {
+        val rootThreadEventId = eventEntity.rootThreadEventId
+        if (eventEntity.isThread && rootThreadEventId != null) {
+            val threadChunk = getOrCreateThreadChunk(realm, roomId, rootThreadEventId)
+            threadChunk.addTimelineEvent(roomId, eventEntity, direction, roomMemberContentsByUser)
+            markEventAsRootEvent(realm, rootThreadEventId)
+            if (threadChunk.isValid)
+                RoomEntity.where(realm, roomId).findFirst()?.addIfNecessary(threadChunk)
+        } else {
+            currentChunk.addTimelineEvent(roomId, eventEntity, direction, roomMemberContentsByUser)
+        }
+    }
+
+    private fun markEventAsRootEvent(realm: Realm, rootThreadEventId: String) {
+        val rootThreadEvent = EventEntity
+                .where(realm, rootThreadEventId)
+                .equalTo(EventEntityFields.IS_THREAD, false).findFirst() ?: return
+        rootThreadEvent.isThread = true
+    }
+
+    /**
+     * Returns the chunk for the current room if exists, otherwise it creates a new ChunkEntity
+     */
+    private fun getOrCreateThreadChunk(realm: Realm, roomId: String, rootThreadEventId: String): ChunkEntity {
+        return ChunkEntity.findThreadChunkOfRoom(realm, roomId, rootThreadEventId)
+                ?: realm.createObject<ChunkEntity>().apply {
+                    this.rootThreadEventId = rootThreadEventId
+                }
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/handler/room/RoomSyncHandler.kt

@@ -21,31 +21,41 @@ import io.realm.kotlin.createObject
 import org.matrix.android.sdk.api.session.crypto.MXCryptoError
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.isThread
 import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.initsync.InitSyncStep
 import org.matrix.android.sdk.api.session.room.model.Membership
 import org.matrix.android.sdk.api.session.room.model.RoomMemberContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageRelationContent
 import org.matrix.android.sdk.api.session.room.send.SendState
 import org.matrix.android.sdk.api.session.sync.model.InvitedRoomSync
 import org.matrix.android.sdk.api.session.sync.model.LazyRoomSyncEphemeral
 import org.matrix.android.sdk.api.session.sync.model.RoomSync
 import org.matrix.android.sdk.api.session.sync.model.RoomsSyncResponse
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.crypto.CryptoSessionInfoProvider
 import org.matrix.android.sdk.internal.crypto.DefaultCryptoService
 import org.matrix.android.sdk.internal.crypto.MXCRYPTO_ALGORITHM_MEGOLM
 import org.matrix.android.sdk.internal.crypto.algorithms.olm.OlmDecryptionResult
 import org.matrix.android.sdk.internal.database.helper.addIfNecessary
 import org.matrix.android.sdk.internal.database.helper.addTimelineEvent
+import org.matrix.android.sdk.internal.database.mapper.EventMapper
 import org.matrix.android.sdk.internal.database.mapper.asDomain
 import org.matrix.android.sdk.internal.database.mapper.toEntity
 import org.matrix.android.sdk.internal.database.model.ChunkEntity
 import org.matrix.android.sdk.internal.database.model.CurrentStateEventEntity
+import org.matrix.android.sdk.internal.database.model.EventEntity
+import org.matrix.android.sdk.internal.database.model.EventEntityFields
 import org.matrix.android.sdk.internal.database.model.EventInsertType
 import org.matrix.android.sdk.internal.database.model.RoomEntity
 import org.matrix.android.sdk.internal.database.model.RoomMemberSummaryEntity
+import org.matrix.android.sdk.internal.database.model.TimelineEventEntity
 import org.matrix.android.sdk.internal.database.model.deleteOnCascade
 import org.matrix.android.sdk.internal.database.query.copyToRealmOrIgnore
 import org.matrix.android.sdk.internal.database.query.find
+import org.matrix.android.sdk.internal.database.query.findAllThreadChunkOfRoom
 import org.matrix.android.sdk.internal.database.query.findLastForwardChunkOfRoom
+import org.matrix.android.sdk.internal.database.query.findThreadChunkOfRoom
 import org.matrix.android.sdk.internal.database.query.getOrCreate
 import org.matrix.android.sdk.internal.database.query.getOrNull
 import org.matrix.android.sdk.internal.database.query.where
@@ -58,8 +68,11 @@ import org.matrix.android.sdk.internal.session.initsync.mapWithProgress
 import org.matrix.android.sdk.internal.session.initsync.reportSubtask
 import org.matrix.android.sdk.internal.session.room.membership.RoomChangeMembershipStateDataSource
 import org.matrix.android.sdk.internal.session.room.membership.RoomMemberEventHandler
+import org.matrix.android.sdk.internal.session.room.send.LocalEchoEventFactory
+import org.matrix.android.sdk.internal.session.room.send.queue.EventSenderProcessor
 import org.matrix.android.sdk.internal.session.room.summary.RoomSummaryUpdater
 import org.matrix.android.sdk.internal.session.room.timeline.PaginationDirection
+import org.matrix.android.sdk.internal.session.room.timeline.TimelineEventDecryptor
 import org.matrix.android.sdk.internal.session.room.timeline.TimelineInput
 import org.matrix.android.sdk.internal.session.room.typing.TypingEventContent
 import org.matrix.android.sdk.internal.session.sync.InitialSyncStrategy
@@ -356,6 +369,21 @@ internal class RoomSyncHandler @Inject constructor(private val readReceiptHandle
         val eventIds = ArrayList<String>(eventList.size)
         val roomMemberContentsByUser = HashMap<String, RoomMemberContent?>()
 
+/////////////////////
+        // There is only one chunk per room
+
+        val threadChunks = ChunkEntity.findAllThreadChunkOfRoom(realm, roomId)
+
+        val tc = threadChunks.joinToString { chunk ->
+            var output = "\n----------------\n------> [${chunk.timelineEvents.size}] rootThreadEventId = ${chunk.rootThreadEventId}" + "\n"
+            output += chunk.timelineEvents
+                    .joinToString("") {
+                        "------>          " + "eventId:[${it?.eventId}] payload:[${getValueFromPayload(it.root?.let { root -> EventMapper.map(root).mxDecryptionResult }?.payload, "body")}]\n"
+            }
+            output
+        }
+        Timber.i("------> Chunks (${threadChunks.size})$tc")
+/////////////////////
         for (event in eventList) {
             if (event.eventId == null || event.senderId == null || event.type == null) {
                 continue
@@ -385,7 +413,16 @@ internal class RoomSyncHandler @Inject constructor(private val readReceiptHandle
                 rootStateEvent?.asDomain()?.getFixedRoomMemberContent()
             }
 
-            chunkEntity.addTimelineEvent(roomId, eventEntity, PaginationDirection.FORWARDS, roomMemberContentsByUser)
+            Timber.i("------> [RoomSyncHandler] Add TimelineEvent to chunkEntity event[${event.eventId}] ${if (event.isThread()) "is Thread" else ""}")
+
+            addTimelineEventToChunk(
+                    realm = realm,
+                    roomId = roomId,
+                    eventEntity = eventEntity,
+                    chunkEntity = chunkEntity,
+                    roomEntity = roomEntity,
+                    roomMemberContentsByUser = roomMemberContentsByUser)
+
             // Give info to crypto module
             cryptoService.onLiveEvent(roomEntity.roomId, event)
 
@@ -412,9 +449,54 @@ internal class RoomSyncHandler @Inject constructor(private val readReceiptHandle
         }
         // posting new events to timeline if any is registered
         timelineInput.onNewTimelineEvents(roomId = roomId, eventIds = eventIds)
+
         return chunkEntity
     }
 
+    /**
+     * Adds a timeline event to the correct chunk. If there is a thread detected will be added
+     * to a specific chunk
+     */
+    private fun addTimelineEventToChunk(realm: Realm,
+                                        roomId: String,
+                                        eventEntity: EventEntity,
+                                        chunkEntity: ChunkEntity,
+                                        roomEntity: RoomEntity,
+                                        roomMemberContentsByUser: Map<String, RoomMemberContent?>) {
+        val rootThreadEventId = eventEntity.rootThreadEventId
+        if (eventEntity.isThread && rootThreadEventId != null) {
+            val threadChunk = getOrCreateThreadChunk(realm, roomId, rootThreadEventId)
+            threadChunk.addTimelineEvent(roomId, eventEntity, PaginationDirection.FORWARDS, roomMemberContentsByUser)
+            markEventAsRootEvent(realm, rootThreadEventId)
+            roomEntity.addIfNecessary(threadChunk)
+        } else {
+            chunkEntity.addTimelineEvent(roomId, eventEntity, PaginationDirection.FORWARDS, roomMemberContentsByUser)
+        }
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    private fun getValueFromPayload(payload: JsonDict?, key: String): String? {
+        val content = payload?.get("content") as? JsonDict
+        return content?.get(key) as? String
+    }
+
+    /**
+     * Returns the chunk for the current room if exists, otherwise it creates a new ChunkEntity
+     */
+    private fun getOrCreateThreadChunk(realm: Realm, roomId: String, rootThreadEventId: String): ChunkEntity {
+        return ChunkEntity.findThreadChunkOfRoom(realm, roomId, rootThreadEventId)
+                ?: realm.createObject<ChunkEntity>().apply {
+                    this.rootThreadEventId = rootThreadEventId
+                }
+    }
+
+    private fun markEventAsRootEvent(realm: Realm, rootThreadEventId: String){
+        val rootThreadEvent = EventEntity
+                .where(realm, rootThreadEventId)
+                .equalTo(EventEntityFields.IS_THREAD, false).findFirst() ?: return
+        rootThreadEvent.isThread = true
+    }
+
     private fun decryptIfNeeded(event: Event, roomId: String) {
         try {
             // Event from sync does not have roomId, so add it to the event first

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailFragment.kt

@@ -49,6 +49,7 @@ import androidx.core.text.toSpannable
 import androidx.core.util.Pair
 import androidx.core.view.ViewCompat
 import androidx.core.view.forEach
+import androidx.core.view.isGone
 import androidx.core.view.isInvisible
 import androidx.core.view.isVisible
 import androidx.fragment.app.setFragmentResultListener
@@ -228,7 +229,8 @@ data class RoomDetailArgs(
         val roomId: String,
         val eventId: String? = null,
         val sharedData: SharedData? = null,
-        val openShareSpaceForId: String? = null
+        val openShareSpaceForId: String? = null,
+        val roomThreadDetailArgs: RoomThreadDetailArgs? = null
 ) : Parcelable
 
 class RoomDetailFragment @Inject constructor(
@@ -352,7 +354,12 @@ class RoomDetailFragment @Inject constructor(
         )
         keyboardStateUtils = KeyboardStateUtils(requireActivity())
         lazyLoadedViews.bind(views)
+        if (isThreadTimeLine()) {
+            views.roomToolbar.isGone = true
+        } else {
             setupToolbar(views.roomToolbar)
+        }
+        setupThreadIfNeeded()
         setupRecyclerView()
         setupComposer()
         setupNotificationView()
@@ -902,6 +909,7 @@ class RoomDetailFragment @Inject constructor(
 
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
         super.onCreateOptionsMenu(menu, inflater)
+        if (isThreadTimeLine()) return
         // We use a custom layout for this menu item, so we need to set a ClickListener
         menu.findItem(R.id.open_matrix_apps)?.let { menuItem ->
             menuItem.actionView.setOnClickListener {
@@ -915,6 +923,12 @@ class RoomDetailFragment @Inject constructor(
     }
 
     override fun onPrepareOptionsMenu(menu: Menu) {
+        if (isThreadTimeLine()) {
+            menu.forEach {
+                it.isVisible = false
+            }
+            return
+        }
         menu.forEach {
             it.isVisible = roomDetailViewModel.isMenuItemVisible(it.itemId)
         }
@@ -1180,6 +1194,12 @@ class RoomDetailFragment @Inject constructor(
 
 // PRIVATE METHODS *****************************************************************************
 
+    private fun setupThreadIfNeeded(){
+        getRootThreadEventId()?.let{
+            textComposerViewModel.handle(TextComposerAction.EnterReplyInThreadTimeline(it))
+        }
+    }
+
     private fun setupRecyclerView() {
         timelineEventController.callback = this
         timelineEventController.timeline = roomDetailViewModel.timeline
@@ -2203,4 +2223,7 @@ class RoomDetailFragment @Inject constructor(
             }
         }
     }
+
+    fun isThreadTimeLine(): Boolean = roomDetailArgs.roomThreadDetailArgs != null
+    fun getRootThreadEventId(): String? = roomDetailArgs.roomThreadDetailArgs?.eventId
 }

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewState.kt

@@ -65,7 +65,8 @@ data class RoomDetailViewState(
         val isAllowedToManageWidgets: Boolean = false,
         val isAllowedToStartWebRTCCall: Boolean = true,
         val hasFailedSending: Boolean = false,
-        val jitsiState: JitsiState = JitsiState()
+        val jitsiState: JitsiState = JitsiState(),
+        val rootThreadEventId: String? = null
         ) : MavericksState {
 
     constructor(args: RoomDetailArgs) : this(

vector/src/main/java/im/vector/app/features/home/room/detail/composer/TextComposerAction.kt

@@ -28,4 +28,6 @@ sealed class TextComposerAction : VectorViewModelAction {
     data class UserIsTyping(val isTyping: Boolean) : TextComposerAction()
     data class OnTextChanged(val text: CharSequence) : TextComposerAction()
     data class OnVoiceRecordingStateChanged(val isRecording: Boolean) : TextComposerAction()
+    data class EnterReplyInThreadTimeline(val rootThreadEventId: String) : TextComposerAction()
+
 }

vector/src/main/java/im/vector/app/features/home/room/detail/composer/TextComposerViewModel.kt

@@ -42,6 +42,7 @@ import org.commonmark.renderer.html.HtmlRenderer
 import org.matrix.android.sdk.api.query.QueryStringValue
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.getRootThreadEventId
 import org.matrix.android.sdk.api.session.events.model.toContent
 import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.room.model.PowerLevelsContent
@@ -88,6 +89,8 @@ class TextComposerViewModel @AssistedInject constructor(
             is TextComposerAction.UserIsTyping                 -> handleUserIsTyping(action)
             is TextComposerAction.OnTextChanged                -> handleOnTextChanged(action)
             is TextComposerAction.OnVoiceRecordingStateChanged -> handleOnVoiceRecordingStateChanged(action)
+            is TextComposerAction.EnterReplyInThreadTimeline   -> handleEnterReplyInThreadTimeline(action)
+
         }
     }
 
@@ -95,6 +98,10 @@ class TextComposerViewModel @AssistedInject constructor(
         copy(isVoiceRecording = action.isRecording)
     }
 
+    private fun handleEnterReplyInThreadTimeline(action: TextComposerAction.EnterReplyInThreadTimeline) = setState {
+        copy(rootThreadEventId = action.rootThreadEventId)
+    }
+
     private fun handleOnTextChanged(action: TextComposerAction.OnTextChanged) {
         setState {
             // Makes sure currentComposerText is upToDate when accessing further setState
@@ -155,7 +162,11 @@ class TextComposerViewModel @AssistedInject constructor(
                     when (val slashCommandResult = CommandParser.parseSplashCommand(action.text)) {
                         is ParsedCommand.ErrorNotACommand         -> {
                             // Send the text message to the room
+                            if (state.rootThreadEventId != null)
+                                room.replyInThread(state.rootThreadEventId, action.text.toString(), action.autoMarkdown)
+                            else
                                 room.sendTextMessage(action.text, autoMarkdown = action.autoMarkdown)
+
                             _viewEvents.post(TextComposerViewEvents.MessageSent)
                             popDraft()
                         }

vector/src/main/java/im/vector/app/features/home/room/detail/composer/TextComposerViewState.kt

@@ -46,6 +46,7 @@ data class TextComposerViewState(
         val canSendMessage: Boolean = true,
         val isVoiceRecording: Boolean = false,
         val isSendButtonVisible: Boolean = false,
+        val rootThreadEventId: String? = null,
         val sendMode: SendMode = SendMode.REGULAR("", false)
 ) : MavericksState {
 
@@ -53,4 +54,6 @@ data class TextComposerViewState(
         get() = canSendMessage && !isVoiceRecording
 
     constructor(args: RoomDetailArgs) : this(roomId = args.roomId)
+
+    fun isInThreadTimeline(): Boolean = rootThreadEventId != null
 }

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/factory/MessageItemFactory.kt

@@ -149,7 +149,7 @@ class MessageItemFactory @Inject constructor(
             // This is an edit event, we should display it when debugging as a notice event
             return noticeItemFactory.create(params)
         }
-        val attributes = messageItemAttributesFactory.create(messageContent, informationData, callback)
+        val attributes = messageItemAttributesFactory.create(messageContent, informationData, callback, event.root.isRootThread)
 
 //        val all = event.root.toContent()
 //        val ev = all.toModel<Event>()

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/helper/MessageItemAttributesFactory.kt

@@ -31,7 +31,8 @@ class MessageItemAttributesFactory @Inject constructor(
 
     fun create(messageContent: Any?,
                informationData: MessageInformationData,
-               callback: TimelineEventController.Callback?): AbsMessageItem.Attributes {
+               callback: TimelineEventController.Callback?,
+               isRootThread: Boolean = false): AbsMessageItem.Attributes {
         return AbsMessageItem.Attributes(
                 avatarSize = avatarSizeProvider.avatarSize,
                 informationData = informationData,
@@ -49,7 +50,8 @@ class MessageItemAttributesFactory @Inject constructor(
                 reactionPillCallback = callback,
                 avatarCallback = callback,
                 readReceiptsCallback = callback,
-                emojiTypeFace = emojiCompatFontProvider.typeface
+                emojiTypeFace = emojiCompatFontProvider.typeface,
+                isRootThread = isRootThread
         )
     }
 }

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/item/AbsMessageItem.kt

@@ -98,6 +98,7 @@ abstract class AbsMessageItem<H : AbsMessageItem.Holder> : AbsBaseMessageItem<H>
         // Render send state indicator
         holder.sendStateImageView.render(attributes.informationData.sendStateDecoration)
         holder.eventSendingIndicator.isVisible = attributes.informationData.sendStateDecoration == SendStateDecoration.SENDING_MEDIA
+        holder.isThread.isVisible = attributes.isRootThread
     }
 
     override fun unbind(holder: H) {
@@ -117,6 +118,7 @@ abstract class AbsMessageItem<H : AbsMessageItem.Holder> : AbsBaseMessageItem<H>
         val timeView by bind<TextView>(R.id.messageTimeView)
         val sendStateImageView by bind<SendStateImageView>(R.id.messageSendStateImageView)
         val eventSendingIndicator by bind<ProgressBar>(R.id.eventSendingIndicator)
+        val isThread by bind<View>(R.id.messageIsThread)
     }
 
     /**
@@ -133,7 +135,8 @@ abstract class AbsMessageItem<H : AbsMessageItem.Holder> : AbsBaseMessageItem<H>
             override val reactionPillCallback: TimelineEventController.ReactionPillCallback? = null,
             val avatarCallback: TimelineEventController.AvatarCallback? = null,
             override val readReceiptsCallback: TimelineEventController.ReadReceiptsCallback? = null,
-            val emojiTypeFace: Typeface? = null
+            val emojiTypeFace: Typeface? = null,
+            val isRootThread: Boolean = false
     ) : AbsBaseMessageItem.Attributes {
 
         // Have to override as it's used to diff epoxy items

vector/src/main/java/im/vector/app/features/home/room/threads/detail/RoomThreadDetailActivity.kt

@@ -25,6 +25,8 @@ import im.vector.app.core.extensions.replaceFragment
 import im.vector.app.core.platform.VectorBaseActivity
 import im.vector.app.databinding.ActivityRoomThreadDetailBinding
 import im.vector.app.features.home.AvatarRenderer
+import im.vector.app.features.home.room.detail.RoomDetailArgs
+import im.vector.app.features.home.room.detail.RoomDetailFragment
 import im.vector.app.features.home.room.threads.detail.arguments.RoomThreadDetailArgs
 import org.matrix.android.sdk.api.util.MatrixItem
 import javax.inject.Inject
@@ -65,7 +67,16 @@ class RoomThreadDetailActivity : VectorBaseActivity<ActivityRoomThreadDetailBind
 
     private fun initFragment() {
         if (isFirstCreation()) {
-            replaceFragment(R.id.roomThreadDetailFragmentContainer, RoomThreadDetailFragment::class.java, getRoomThreadDetailArgs(), FRAGMENT_TAG)
+            getRoomThreadDetailArgs()?.let {
+                replaceFragment(
+                        R.id.roomThreadDetailFragmentContainer,
+                        RoomDetailFragment::class.java,
+                        RoomDetailArgs(
+                                roomId = it.roomId,
+                                roomThreadDetailArgs = it
+                        ))
+            }
+//            replaceFragment(R.id.roomThreadDetailFragmentContainer, RoomThreadDetailFragment::class.java, getRoomThreadDetailArgs(), FRAGMENT_TAG)
         }
     }
 

vector/src/main/java/im/vector/app/features/home/room/threads/detail/RoomThreadDetailFragment.kt

@@ -47,7 +47,15 @@ class RoomThreadDetailFragment @Inject constructor(
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         initTextComposer()
-//        views.testTextVeiwddasda.text = "${roomThreadDetailArgs.eventId}  --  ${roomThreadDetailArgs.roomId}"
+//        lifecycleScope.launch(Dispatchers.IO) {
+//            Realm.getInstance(realmConfiguration).executeTransaction {
+//                val eventId = roomThreadDetailArgs.eventId ?: return@executeTransaction
+//                val r = EventEntity.where(it, eventId = eventId)
+//                        .findFirst() ?: return@executeTransaction
+//                Timber.i("------> $eventId isThread: ${EventMapper.map(r).isThread()}")
+//            }
+//        }
+////        views.testTextVeiwddasda.text = "${roomThreadDetailArgs.eventId}  --  ${roomThreadDetailArgs.roomId}"
     }
 
     private fun initTextComposer(){

vector/src/main/res/layout/item_timeline_event_base.xml

@@ -200,4 +200,17 @@
         </com.google.android.flexbox.FlexboxLayout>
     </LinearLayout>
 
+    <View
+        android:id="@+id/messageIsThread"
+        android:layout_width="wrap_content"
+        android:background="#2653AE"
+        android:layout_height="2dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginEnd="20dp"
+        android:layout_marginBottom="4dp"
+        android:layout_below="@id/informationBottom"
+        android:layout_toStartOf="@id/messageSendStateImageView"
+        android:layout_toEndOf="@id/messageStartGuideline"
+        android:contentDescription="@string/room_threads_filter" />
+
 </RelativeLayout>