Merge pull request #741 from vector-im/feature/breadcrumbs

Breadcrumbs

CHANGES.md

@@ -2,7 +2,7 @@ Changes in RiotX 0.10.0 (2019-XX-XX)
 ===================================================
 
 Features ✨:
- -
+ - Breadcrumbs: switch from one room to another quickly (#571)
 
 Improvements 🙌:
  -

docs/signup.md

@@ -17,7 +17,7 @@ Client request the sign-up flows, once the homeserver is chosen by the user and
 }
 ```
 
-We get the flows with a 401, which also means the the registration is possible on this homeserver.
+We get the flows with a 401, which also means that the registration is possible on this homeserver.
 
 ```json
 {

matrix-sdk-android-rx/src/main/java/im/vector/matrix/rx/RxSession.kt

@@ -38,6 +38,10 @@ class RxSession(private val session: Session) {
         return session.liveGroupSummaries().asObservable()
     }
 
+    fun liveBreadcrumbs(): Observable<List<RoomSummary>> {
+        return session.liveBreadcrumbs().asObservable()
+    }
+
     fun liveSyncState(): Observable<SyncState> {
         return session.syncState().asObservable()
     }

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/RoomService.kt

@@ -54,6 +54,18 @@ interface RoomService {
      */
     fun liveRoomSummaries(): LiveData<List<RoomSummary>>
 
+    /**
+     * Get a live list of Breadcrumbs
+     * @return the [LiveData] of [RoomSummary]
+     */
+    fun liveBreadcrumbs(): LiveData<List<RoomSummary>>
+
+    /**
+     * Inform the Matrix SDK that a room is displayed.
+     * The SDK will update the breadcrumbs in the user account data
+     */
+    fun onRoomDisplayed(roomId: String): Cancelable
+
     /**
      * Mark all rooms as read
      */

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/query/CryptoRoomEntityQueries.kt

@@ -19,16 +19,14 @@ package im.vector.matrix.android.internal.crypto.store.db.query
 import im.vector.matrix.android.internal.crypto.store.db.model.CryptoRoomEntity
 import im.vector.matrix.android.internal.crypto.store.db.model.CryptoRoomEntityFields
 import io.realm.Realm
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 /**
  * Get or create a room
  */
 internal fun CryptoRoomEntity.Companion.getOrCreate(realm: Realm, roomId: String): CryptoRoomEntity {
-    return getById(realm, roomId)
+    return getById(realm, roomId) ?: realm.createObject(roomId)
-            ?: let {
-                realm.createObject(CryptoRoomEntity::class.java, roomId)
-            }
 }
 
 /**

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/query/DeviceInfoEntityQueries.kt

@@ -20,18 +20,20 @@ import im.vector.matrix.android.internal.crypto.store.db.model.DeviceInfoEntity
 import im.vector.matrix.android.internal.crypto.store.db.model.DeviceInfoEntityFields
 import im.vector.matrix.android.internal.crypto.store.db.model.createPrimaryKey
 import io.realm.Realm
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 /**
  * Get or create a device info
  */
 internal fun DeviceInfoEntity.Companion.getOrCreate(realm: Realm, userId: String, deviceId: String): DeviceInfoEntity {
+    val key = DeviceInfoEntity.createPrimaryKey(userId, deviceId)
+
     return realm.where<DeviceInfoEntity>()
-            .equalTo(DeviceInfoEntityFields.PRIMARY_KEY, DeviceInfoEntity.createPrimaryKey(userId, deviceId))
+            .equalTo(DeviceInfoEntityFields.PRIMARY_KEY, key)
             .findFirst()
-            ?: let {
+            ?: realm.createObject<DeviceInfoEntity>(key)
-                realm.createObject(DeviceInfoEntity::class.java, DeviceInfoEntity.createPrimaryKey(userId, deviceId)).apply {
+                    .apply {
-                    this.deviceId = deviceId
+                        this.deviceId = deviceId
-                }
+                    }
-            }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/query/UserEntitiesQueries.kt

@@ -19,6 +19,7 @@ package im.vector.matrix.android.internal.crypto.store.db.query
 import im.vector.matrix.android.internal.crypto.store.db.model.UserEntity
 import im.vector.matrix.android.internal.crypto.store.db.model.UserEntityFields
 import io.realm.Realm
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 /**
@@ -28,9 +29,7 @@ internal fun UserEntity.Companion.getOrCreate(realm: Realm, userId: String): Use
     return realm.where<UserEntity>()
             .equalTo(UserEntityFields.USER_ID, userId)
             .findFirst()
-            ?: let {
+            ?: realm.createObject(userId)
-                realm.createObject(UserEntity::class.java, userId)
-            }
 }
 
 /**

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/model/BreadcrumbsEntity.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2019 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 im.vector.matrix.android.internal.database.model
+
+import io.realm.RealmList
+import io.realm.RealmObject
+
+internal open class BreadcrumbsEntity(
+        var recentRoomIds: RealmList<String> = RealmList()
+) : RealmObject() {
+
+    companion object
+}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/model/RoomSummaryEntity.kt

@@ -38,7 +38,8 @@ internal open class RoomSummaryEntity(@PrimaryKey var roomId: String = "",
                                       var readMarkerId: String? = null,
                                       var hasUnreadMessages: Boolean = false,
                                       var tags: RealmList<RoomTagEntity> = RealmList(),
-                                      var userDrafts: UserDraftsEntity? = null
+                                      var userDrafts: UserDraftsEntity? = null,
+                                      var breadcrumbsIndex: Int = NOT_IN_BREADCRUMBS
 ) : RealmObject() {
 
     private var membershipStr: String = Membership.NONE.name
@@ -59,5 +60,7 @@ internal open class RoomSummaryEntity(@PrimaryKey var roomId: String = "",
             versioningStateStr = value.name
         }
 
-    companion object
+    companion object {
+        const val NOT_IN_BREADCRUMBS = -1
+    }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/model/SessionRealmModule.kt

@@ -36,6 +36,7 @@ import io.realm.annotations.RealmModule
                  SyncEntity::class,
                  UserEntity::class,
                  IgnoredUserEntity::class,
+                 BreadcrumbsEntity::class,
                  EventAnnotationsSummaryEntity::class,
                  ReactionAggregatedSummaryEntity::class,
                  EditAggregatedSummaryEntity::class,

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/query/BreadcrumbsEntityQuery.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 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 im.vector.matrix.android.internal.database.query
+
+import im.vector.matrix.android.internal.database.model.BreadcrumbsEntity
+import io.realm.Realm
+import io.realm.kotlin.createObject
+import io.realm.kotlin.where
+
+internal fun BreadcrumbsEntity.Companion.get(realm: Realm): BreadcrumbsEntity? {
+    return realm.where<BreadcrumbsEntity>().findFirst()
+}
+
+internal fun BreadcrumbsEntity.Companion.getOrCreate(realm: Realm): BreadcrumbsEntity {
+    return get(realm) ?: realm.createObject()
+}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/query/ReadMarkerEntityQueries.kt

@@ -20,6 +20,7 @@ import im.vector.matrix.android.internal.database.model.ReadMarkerEntity
 import im.vector.matrix.android.internal.database.model.ReadMarkerEntityFields
 import io.realm.Realm
 import io.realm.RealmQuery
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 internal fun ReadMarkerEntity.Companion.where(realm: Realm, roomId: String): RealmQuery<ReadMarkerEntity> {
@@ -28,6 +29,5 @@ internal fun ReadMarkerEntity.Companion.where(realm: Realm, roomId: String): Rea
 }
 
 internal fun ReadMarkerEntity.Companion.getOrCreate(realm: Realm, roomId: String): ReadMarkerEntity {
-    return where(realm, roomId).findFirst()
+    return where(realm, roomId).findFirst() ?: realm.createObject(roomId)
-           ?: realm.createObject(ReadMarkerEntity::class.java, roomId)
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/query/ReadReceiptEntityQueries.kt

@@ -20,6 +20,7 @@ import im.vector.matrix.android.internal.database.model.ReadReceiptEntity
 import im.vector.matrix.android.internal.database.model.ReadReceiptEntityFields
 import io.realm.Realm
 import io.realm.RealmQuery
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 internal fun ReadReceiptEntity.Companion.where(realm: Realm, roomId: String, userId: String): RealmQuery<ReadReceiptEntity> {
@@ -44,10 +45,11 @@ internal fun ReadReceiptEntity.Companion.createUnmanaged(roomId: String, eventId
 
 internal fun ReadReceiptEntity.Companion.getOrCreate(realm: Realm, roomId: String, userId: String): ReadReceiptEntity {
     return ReadReceiptEntity.where(realm, roomId, userId).findFirst()
-           ?: realm.createObject(ReadReceiptEntity::class.java, buildPrimaryKey(roomId, userId)).apply {
+            ?: realm.createObject<ReadReceiptEntity>(buildPrimaryKey(roomId, userId))
-               this.roomId = roomId
+                    .apply {
-               this.userId = userId
+                        this.roomId = roomId
-           }
+                        this.userId = userId
+                    }
 }
 
 private fun buildPrimaryKey(roomId: String, userId: String) = "${roomId}_$userId"

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/query/RoomSummaryEntityQueries.kt

@@ -21,6 +21,7 @@ import im.vector.matrix.android.internal.database.model.RoomSummaryEntityFields
 import io.realm.Realm
 import io.realm.RealmQuery
 import io.realm.RealmResults
+import io.realm.kotlin.createObject
 import io.realm.kotlin.where
 
 internal fun RoomSummaryEntity.Companion.where(realm: Realm, roomId: String? = null): RealmQuery<RoomSummaryEntity> {
@@ -32,8 +33,7 @@ internal fun RoomSummaryEntity.Companion.where(realm: Realm, roomId: String? = n
 }
 
 internal fun RoomSummaryEntity.Companion.getOrCreate(realm: Realm, roomId: String): RoomSummaryEntity {
-    return where(realm, roomId).findFirst()
+    return where(realm, roomId).findFirst() ?: realm.createObject(roomId)
-           ?: realm.createObject(RoomSummaryEntity::class.java, roomId)
 }
 
 internal fun RoomSummaryEntity.Companion.getDirectRooms(realm: Realm): RealmResults<RoomSummaryEntity> {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/di/MoshiProvider.kt

@@ -21,6 +21,7 @@ import im.vector.matrix.android.api.session.room.model.message.*
 import im.vector.matrix.android.internal.network.parsing.RuntimeJsonAdapterFactory
 import im.vector.matrix.android.internal.network.parsing.UriMoshiAdapter
 import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountData
+import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountDataBreadcrumbs
 import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountDataDirectMessages
 import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountDataFallback
 import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountDataIgnoredUsers
@@ -34,6 +35,7 @@ object MoshiProvider {
                     .registerSubtype(UserAccountDataDirectMessages::class.java, UserAccountData.TYPE_DIRECT_MESSAGES)
                     .registerSubtype(UserAccountDataIgnoredUsers::class.java, UserAccountData.TYPE_IGNORED_USER_LIST)
                     .registerSubtype(UserAccountDataPushRules::class.java, UserAccountData.TYPE_PUSH_RULES)
+                    .registerSubtype(UserAccountDataBreadcrumbs::class.java, UserAccountData.TYPE_BREADCRUMBS)
             )
             .add(RuntimeJsonAdapterFactory.of(MessageContent::class.java, "msgtype", MessageDefaultContent::class.java)
                     .registerSubtype(MessageTextContent::class.java, MessageType.MSGTYPE_TEXT)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/DefaultRoomService.kt

@@ -33,6 +33,7 @@ import im.vector.matrix.android.internal.database.query.where
 import im.vector.matrix.android.internal.session.room.create.CreateRoomTask
 import im.vector.matrix.android.internal.session.room.membership.joining.JoinRoomTask
 import im.vector.matrix.android.internal.session.room.read.MarkAllRoomsReadTask
+import im.vector.matrix.android.internal.session.user.accountdata.UpdateBreadcrumbsTask
 import im.vector.matrix.android.internal.task.TaskExecutor
 import im.vector.matrix.android.internal.task.configureWith
 import io.realm.Realm
@@ -43,6 +44,7 @@ internal class DefaultRoomService @Inject constructor(private val monarchy: Mona
                                                       private val createRoomTask: CreateRoomTask,
                                                       private val joinRoomTask: JoinRoomTask,
                                                       private val markAllRoomsReadTask: MarkAllRoomsReadTask,
+                                                      private val updateBreadcrumbsTask: UpdateBreadcrumbsTask,
                                                       private val roomFactory: RoomFactory,
                                                       private val taskExecutor: TaskExecutor) : RoomService {
 
@@ -75,6 +77,25 @@ internal class DefaultRoomService @Inject constructor(private val monarchy: Mona
         )
     }
 
+    override fun liveBreadcrumbs(): LiveData<List<RoomSummary>> {
+        return monarchy.findAllMappedWithChanges(
+                { realm ->
+                    RoomSummaryEntity.where(realm)
+                            .isNotEmpty(RoomSummaryEntityFields.DISPLAY_NAME)
+                            .notEqualTo(RoomSummaryEntityFields.VERSIONING_STATE_STR, VersioningState.UPGRADED_ROOM_JOINED.name)
+                            .greaterThan(RoomSummaryEntityFields.BREADCRUMBS_INDEX, RoomSummaryEntity.NOT_IN_BREADCRUMBS)
+                            .sort(RoomSummaryEntityFields.BREADCRUMBS_INDEX)
+                },
+                { roomSummaryMapper.map(it) }
+        )
+    }
+
+    override fun onRoomDisplayed(roomId: String): Cancelable {
+        return updateBreadcrumbsTask
+                .configureWith(UpdateBreadcrumbsTask.Params(roomId))
+                .executeBy(taskExecutor)
+    }
+
     override fun joinRoom(roomId: String, viaServers: List<String>, callback: MatrixCallback<Unit>): Cancelable {
         return joinRoomTask
                 .configureWith(JoinRoomTask.Params(roomId, viaServers)) {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/UserAccountDataSyncHandler.kt

@@ -29,6 +29,7 @@ import im.vector.matrix.android.internal.session.room.membership.RoomMembers
 import im.vector.matrix.android.internal.session.sync.model.InvitedRoomSync
 import im.vector.matrix.android.internal.session.sync.model.accountdata.*
 import im.vector.matrix.android.internal.session.user.accountdata.DirectChatsHelper
+import im.vector.matrix.android.internal.session.user.accountdata.SaveBreadcrumbsTask
 import im.vector.matrix.android.internal.session.user.accountdata.SaveIgnoredUsersTask
 import im.vector.matrix.android.internal.session.user.accountdata.UpdateUserAccountDataTask
 import im.vector.matrix.android.internal.task.TaskExecutor
@@ -44,6 +45,7 @@ internal class UserAccountDataSyncHandler @Inject constructor(private val monarc
                                                               private val updateUserAccountDataTask: UpdateUserAccountDataTask,
                                                               private val savePushRulesTask: SavePushRulesTask,
                                                               private val saveIgnoredUsersTask: SaveIgnoredUsersTask,
+                                                              private val saveBreadcrumbsTask: SaveBreadcrumbsTask,
                                                               private val taskExecutor: TaskExecutor) {
 
     suspend fun handle(accountData: UserAccountDataSync?, invites: Map<String, InvitedRoomSync>?) {
@@ -52,6 +54,7 @@ internal class UserAccountDataSyncHandler @Inject constructor(private val monarc
                 is UserAccountDataDirectMessages -> handleDirectChatRooms(it)
                 is UserAccountDataPushRules      -> handlePushRules(it)
                 is UserAccountDataIgnoredUsers   -> handleIgnoredUsers(it)
+                is UserAccountDataBreadcrumbs    -> handleBreadcrumbs(it)
                 is UserAccountDataFallback       -> Timber.d("Receive account data of unhandled type ${it.type}")
                 else                             -> error("Missing code here!")
             }
@@ -130,4 +133,10 @@ internal class UserAccountDataSyncHandler @Inject constructor(private val monarc
                 .executeBy(taskExecutor)
         // TODO If not initial sync, we should execute a init sync
     }
+
+    private fun handleBreadcrumbs(userAccountDataBreadcrumbs: UserAccountDataBreadcrumbs) {
+        saveBreadcrumbsTask
+                .configureWith(SaveBreadcrumbsTask.Params(userAccountDataBreadcrumbs.content.recentRoomIds))
+                .executeBy(taskExecutor)
+    }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/model/accountdata/UserAccountData.kt

@@ -25,6 +25,7 @@ internal abstract class UserAccountData {
     companion object {
         const val TYPE_IGNORED_USER_LIST = "m.ignored_user_list"
         const val TYPE_DIRECT_MESSAGES = "m.direct"
+        const val TYPE_BREADCRUMBS = "im.vector.setting.breadcrumbs" // Was previously "im.vector.riot.breadcrumb_rooms"
         const val TYPE_PREVIEW_URLS = "org.matrix.preview_urls"
         const val TYPE_WIDGETS = "m.widgets"
         const val TYPE_PUSH_RULES = "m.push_rules"

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/model/accountdata/UserAccountDataBreadcrumbs.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 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 im.vector.matrix.android.internal.session.sync.model.accountdata
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+internal data class UserAccountDataBreadcrumbs(
+        @Json(name = "type") override val type: String = TYPE_BREADCRUMBS,
+        @Json(name = "content") val content: BreadcrumbsContent
+) : UserAccountData()
+
+@JsonClass(generateAdapter = true)
+internal data class BreadcrumbsContent(
+        @Json(name = "recent_rooms") val recentRoomIds: List<String> = emptyList()
+)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/user/accountdata/AccountDataModule.kt

@@ -35,5 +35,11 @@ internal abstract class AccountDataModule {
     }
 
     @Binds
-    abstract fun bindUpdateUserAccountDataTask(updateUserAccountDataTask: DefaultUpdateUserAccountDataTask): UpdateUserAccountDataTask
+    abstract fun bindUpdateUserAccountDataTask(task: DefaultUpdateUserAccountDataTask): UpdateUserAccountDataTask
+
+    @Binds
+    abstract fun bindSaveBreadcrumbsTask(task: DefaultSaveBreadcrumbsTask): SaveBreadcrumbsTask
+
+    @Binds
+    abstract fun bindUpdateBreadcrumsTask(task: DefaultUpdateBreadcrumbsTask): UpdateBreadcrumbsTask
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/user/accountdata/SaveBreadcrumbsTask.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2019 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 im.vector.matrix.android.internal.session.user.accountdata
+
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.internal.database.model.BreadcrumbsEntity
+import im.vector.matrix.android.internal.database.model.RoomSummaryEntity
+import im.vector.matrix.android.internal.database.model.RoomSummaryEntityFields
+import im.vector.matrix.android.internal.database.query.getOrCreate
+import im.vector.matrix.android.internal.database.query.where
+import im.vector.matrix.android.internal.task.Task
+import im.vector.matrix.android.internal.util.awaitTransaction
+import io.realm.RealmList
+import javax.inject.Inject
+
+/**
+ * Save the Breadcrumbs roomId list in DB, either from the sync, or updated locally
+ */
+internal interface SaveBreadcrumbsTask : Task<SaveBreadcrumbsTask.Params, Unit> {
+    data class Params(
+            val recentRoomIds: List<String>
+    )
+}
+
+internal class DefaultSaveBreadcrumbsTask @Inject constructor(
+        private val monarchy: Monarchy
+) : SaveBreadcrumbsTask {
+
+    override suspend fun execute(params: SaveBreadcrumbsTask.Params) {
+        monarchy.awaitTransaction { realm ->
+            // Get or create a breadcrumbs entity
+            val entity = BreadcrumbsEntity.getOrCreate(realm)
+
+            // And save the new received list
+            entity.recentRoomIds = RealmList<String>().apply { addAll(params.recentRoomIds) }
+
+            // Update the room summaries
+            // Reset all the indexes...
+            RoomSummaryEntity.where(realm)
+                    .greaterThan(RoomSummaryEntityFields.BREADCRUMBS_INDEX, RoomSummaryEntity.NOT_IN_BREADCRUMBS)
+                    .findAll()
+                    .forEach {
+                        it.breadcrumbsIndex = RoomSummaryEntity.NOT_IN_BREADCRUMBS
+                    }
+
+            // ...and apply new indexes
+            params.recentRoomIds.forEachIndexed { index, roomId ->
+                RoomSummaryEntity.where(realm, roomId)
+                        .findFirst()
+                        ?.breadcrumbsIndex = index
+            }
+        }
+    }
+}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/user/accountdata/UpdateBreadcrumbsTask.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2019 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 im.vector.matrix.android.internal.session.user.accountdata
+
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.internal.database.model.BreadcrumbsEntity
+import im.vector.matrix.android.internal.database.query.get
+import im.vector.matrix.android.internal.session.sync.model.accountdata.BreadcrumbsContent
+import im.vector.matrix.android.internal.task.Task
+import im.vector.matrix.android.internal.util.fetchCopied
+import javax.inject.Inject
+
+// Use the same arbitrary value than Riot-Web
+private const val MAX_BREADCRUMBS_ROOMS_NUMBER = 20
+
+internal interface UpdateBreadcrumbsTask : Task<UpdateBreadcrumbsTask.Params, Unit> {
+    data class Params(
+            val newTopRoomId: String
+    )
+}
+
+internal class DefaultUpdateBreadcrumbsTask @Inject constructor(
+        private val saveBreadcrumbsTask: SaveBreadcrumbsTask,
+        private val updateUserAccountDataTask: UpdateUserAccountDataTask,
+        private val monarchy: Monarchy
+) : UpdateBreadcrumbsTask {
+
+    override suspend fun execute(params: UpdateBreadcrumbsTask.Params) {
+        val newBreadcrumbs =
+                // Get the breadcrumbs entity, if any
+                monarchy.fetchCopied { BreadcrumbsEntity.get(it) }
+                        ?.recentRoomIds
+                        ?.apply {
+                            // Modify the list to add the newTopRoomId first
+                            // Ensure the newTopRoomId is not already in the list
+                            remove(params.newTopRoomId)
+                            // Add the newTopRoomId at first position
+                            add(0, params.newTopRoomId)
+                        }
+                        ?.take(MAX_BREADCRUMBS_ROOMS_NUMBER)
+                        ?: listOf(params.newTopRoomId)
+
+        // Update the DB locally, do not wait for the sync
+        saveBreadcrumbsTask.execute(SaveBreadcrumbsTask.Params(newBreadcrumbs))
+
+        // FIXME It can remove the previous breadcrumbs, if not synced yet
+        // And update account data
+        updateUserAccountDataTask.execute(UpdateUserAccountDataTask.BreadcrumbsParams(
+                breadcrumbsContent = BreadcrumbsContent(newBreadcrumbs)
+        ))
+    }
+}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/user/accountdata/UpdateUserAccountDataTask.kt

@@ -18,6 +18,7 @@ package im.vector.matrix.android.internal.session.user.accountdata
 
 import im.vector.matrix.android.internal.di.UserId
 import im.vector.matrix.android.internal.network.executeRequest
+import im.vector.matrix.android.internal.session.sync.model.accountdata.BreadcrumbsContent
 import im.vector.matrix.android.internal.session.sync.model.accountdata.UserAccountData
 import im.vector.matrix.android.internal.task.Task
 import javax.inject.Inject
@@ -38,6 +39,15 @@ internal interface UpdateUserAccountDataTask : Task<UpdateUserAccountDataTask.Pa
             return directMessages
         }
     }
+
+    data class BreadcrumbsParams(override val type: String = UserAccountData.TYPE_BREADCRUMBS,
+                                 private val breadcrumbsContent: BreadcrumbsContent
+    ) : Params {
+
+        override fun getData(): Any {
+            return breadcrumbsContent
+        }
+    }
 }
 
 internal class DefaultUpdateUserAccountDataTask @Inject constructor(private val accountDataApi: AccountDataAPI,

vector/src/main/java/im/vector/riotx/core/di/FragmentModule.kt

@@ -33,6 +33,7 @@ import im.vector.riotx.features.home.LoadingFragment
 import im.vector.riotx.features.home.createdirect.CreateDirectRoomDirectoryUsersFragment
 import im.vector.riotx.features.home.createdirect.CreateDirectRoomKnownUsersFragment
 import im.vector.riotx.features.home.group.GroupListFragment
+import im.vector.riotx.features.home.room.breadcrumbs.BreadcrumbsFragment
 import im.vector.riotx.features.home.room.detail.RoomDetailFragment
 import im.vector.riotx.features.home.room.list.RoomListFragment
 import im.vector.riotx.features.login.*
@@ -249,4 +250,9 @@ interface FragmentModule {
     @IntoMap
     @FragmentKey(PublicRoomsFragment::class)
     fun bindPublicRoomsFragment(fragment: PublicRoomsFragment): Fragment
+
+    @Binds
+    @IntoMap
+    @FragmentKey(BreadcrumbsFragment::class)
+    fun bindBreadcrumbsFragment(fragment: BreadcrumbsFragment): Fragment
 }

vector/src/main/java/im/vector/riotx/core/di/ViewModelModule.kt

@@ -29,6 +29,7 @@ import im.vector.riotx.features.crypto.keysbackup.setup.KeysBackupSetupSharedVie
 import im.vector.riotx.features.crypto.verification.SasVerificationViewModel
 import im.vector.riotx.features.home.HomeSharedActionViewModel
 import im.vector.riotx.features.home.createdirect.CreateDirectRoomSharedActionViewModel
+import im.vector.riotx.features.home.room.detail.RoomDetailSharedActionViewModel
 import im.vector.riotx.features.home.room.detail.timeline.action.MessageSharedActionViewModel
 import im.vector.riotx.features.home.room.list.actions.RoomListQuickActionsSharedActionViewModel
 import im.vector.riotx.features.login.LoginSharedActionViewModel
@@ -118,4 +119,9 @@ interface ViewModelModule {
     @IntoMap
     @ViewModelKey(LoginSharedActionViewModel::class)
     fun bindLoginSharedActionViewModel(viewModel: LoginSharedActionViewModel): ViewModel
+
+    @Binds
+    @IntoMap
+    @ViewModelKey(RoomDetailSharedActionViewModel::class)
+    fun bindRoomDetailSharedActionViewModel(viewModel: RoomDetailSharedActionViewModel): ViewModel
 }

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsAnimator.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import androidx.recyclerview.widget.DefaultItemAnimator
+
+private const val ANIM_DURATION_IN_MILLIS = 200L
+
+class BreadcrumbsAnimator : DefaultItemAnimator() {
+
+    init {
+        addDuration = ANIM_DURATION_IN_MILLIS
+        removeDuration = ANIM_DURATION_IN_MILLIS
+        moveDuration = ANIM_DURATION_IN_MILLIS
+        changeDuration = ANIM_DURATION_IN_MILLIS
+    }
+}

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsController.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import android.view.View
+import com.airbnb.epoxy.EpoxyController
+import im.vector.riotx.core.utils.DebouncedClickListener
+import im.vector.riotx.features.home.AvatarRenderer
+import javax.inject.Inject
+
+class BreadcrumbsController @Inject constructor(
+        private val avatarRenderer: AvatarRenderer
+) : EpoxyController() {
+
+    var listener: Listener? = null
+
+    private var viewState: BreadcrumbsViewState? = null
+
+    init {
+        // We are requesting a model build directly as the first build of epoxy is on the main thread.
+        // It avoids to build the whole list of breadcrumbs on the main thread.
+        requestModelBuild()
+    }
+
+    fun update(viewState: BreadcrumbsViewState) {
+        this.viewState = viewState
+        requestModelBuild()
+    }
+
+    override fun buildModels() {
+        val safeViewState = viewState ?: return
+
+        // An empty breadcrumbs list can only be temporary because when entering in a room,
+        // this one is added to the breadcrumbs
+
+        safeViewState.asyncBreadcrumbs.invoke()
+                ?.forEach {
+                    breadcrumbsItem {
+                        id(it.roomId)
+                        avatarRenderer(avatarRenderer)
+                        roomId(it.roomId)
+                        roomName(it.displayName)
+                        avatarUrl(it.avatarUrl)
+                        unreadNotificationCount(it.notificationCount)
+                        showHighlighted(it.highlightCount > 0)
+                        hasUnreadMessage(it.hasUnreadMessages)
+                        hasDraft(it.userDrafts.isNotEmpty())
+                        itemClickListener(
+                                DebouncedClickListener(View.OnClickListener { _ ->
+                                    listener?.onBreadcrumbClicked(it.roomId)
+                                })
+                        )
+                    }
+                }
+    }
+
+    interface Listener {
+        fun onBreadcrumbClicked(roomId: String)
+    }
+}

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsFragment.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import android.os.Bundle
+import android.view.View
+import androidx.recyclerview.widget.LinearLayoutManager
+import com.airbnb.mvrx.fragmentViewModel
+import im.vector.riotx.R
+import im.vector.riotx.core.platform.VectorBaseFragment
+import im.vector.riotx.features.home.room.detail.RoomDetailSharedAction
+import im.vector.riotx.features.home.room.detail.RoomDetailSharedActionViewModel
+import kotlinx.android.synthetic.main.fragment_breadcrumbs.*
+import javax.inject.Inject
+
+class BreadcrumbsFragment @Inject constructor(
+        private val breadcrumbsController: BreadcrumbsController,
+        val breadcrumbsViewModelFactory: BreadcrumbsViewModel.Factory
+) : VectorBaseFragment(), BreadcrumbsController.Listener {
+
+    private lateinit var sharedActionViewModel: RoomDetailSharedActionViewModel
+    private val breadcrumbsViewModel: BreadcrumbsViewModel by fragmentViewModel()
+
+    override fun getLayoutResId() = R.layout.fragment_breadcrumbs
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        setupRecyclerView()
+        sharedActionViewModel = activityViewModelProvider.get(RoomDetailSharedActionViewModel::class.java)
+
+        breadcrumbsViewModel.subscribe { renderState(it) }
+    }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        breadcrumbsRecyclerView.adapter = null
+    }
+
+    private fun setupRecyclerView() {
+        val layoutManager = LinearLayoutManager(context)
+        breadcrumbsRecyclerView.layoutManager = layoutManager
+        breadcrumbsRecyclerView.itemAnimator = BreadcrumbsAnimator()
+        breadcrumbsController.listener = this
+        breadcrumbsRecyclerView.setController(breadcrumbsController)
+    }
+
+    private fun renderState(state: BreadcrumbsViewState) {
+        breadcrumbsController.update(state)
+    }
+
+    // BreadcrumbsController.Listener **************************************************************
+
+    override fun onBreadcrumbClicked(roomId: String) {
+        sharedActionViewModel.post(RoomDetailSharedAction.SwitchToRoom(roomId))
+    }
+}

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsItem.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageView
+import androidx.core.view.isVisible
+import com.airbnb.epoxy.EpoxyAttribute
+import com.airbnb.epoxy.EpoxyModelClass
+import im.vector.riotx.R
+import im.vector.riotx.core.epoxy.VectorEpoxyHolder
+import im.vector.riotx.core.epoxy.VectorEpoxyModel
+import im.vector.riotx.features.home.AvatarRenderer
+import im.vector.riotx.features.home.room.list.UnreadCounterBadgeView
+
+@EpoxyModelClass(layout = R.layout.item_breadcrumbs)
+abstract class BreadcrumbsItem : VectorEpoxyModel<BreadcrumbsItem.Holder>() {
+
+    @EpoxyAttribute lateinit var avatarRenderer: AvatarRenderer
+    @EpoxyAttribute lateinit var roomId: String
+    @EpoxyAttribute lateinit var roomName: CharSequence
+    @EpoxyAttribute var avatarUrl: String? = null
+    @EpoxyAttribute var unreadNotificationCount: Int = 0
+    @EpoxyAttribute var showHighlighted: Boolean = false
+    @EpoxyAttribute var hasUnreadMessage: Boolean = false
+    @EpoxyAttribute var hasDraft: Boolean = false
+    @EpoxyAttribute var itemClickListener: View.OnClickListener? = null
+
+    override fun bind(holder: Holder) {
+        super.bind(holder)
+        holder.rootView.setOnClickListener(itemClickListener)
+        holder.unreadIndentIndicator.isVisible = hasUnreadMessage
+        avatarRenderer.render(avatarUrl, roomId, roomName.toString(), holder.avatarImageView)
+        holder.unreadCounterBadgeView.render(UnreadCounterBadgeView.State(unreadNotificationCount, showHighlighted))
+        holder.draftIndentIndicator.isVisible = hasDraft
+    }
+
+    class Holder : VectorEpoxyHolder() {
+        val unreadCounterBadgeView by bind<UnreadCounterBadgeView>(R.id.breadcrumbsUnreadCounterBadgeView)
+        val unreadIndentIndicator by bind<View>(R.id.breadcrumbsUnreadIndicator)
+        val draftIndentIndicator by bind<View>(R.id.breadcrumbsDraftBadge)
+        val avatarImageView by bind<ImageView>(R.id.breadcrumbsImageView)
+        val rootView by bind<ViewGroup>(R.id.breadcrumbsRoot)
+    }
+}

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsViewModel.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import com.airbnb.mvrx.FragmentViewModelContext
+import com.airbnb.mvrx.MvRxViewModelFactory
+import com.airbnb.mvrx.ViewModelContext
+import com.squareup.inject.assisted.Assisted
+import com.squareup.inject.assisted.AssistedInject
+import im.vector.matrix.android.api.session.Session
+import im.vector.matrix.rx.rx
+import im.vector.riotx.core.platform.EmptyAction
+import im.vector.riotx.core.platform.VectorViewModel
+import io.reactivex.schedulers.Schedulers
+
+class BreadcrumbsViewModel @AssistedInject constructor(@Assisted initialState: BreadcrumbsViewState,
+                                                       private val session: Session)
+    : VectorViewModel<BreadcrumbsViewState, EmptyAction>(initialState) {
+
+    @AssistedInject.Factory
+    interface Factory {
+        fun create(initialState: BreadcrumbsViewState): BreadcrumbsViewModel
+    }
+
+    companion object : MvRxViewModelFactory<BreadcrumbsViewModel, BreadcrumbsViewState> {
+
+        @JvmStatic
+        override fun create(viewModelContext: ViewModelContext, state: BreadcrumbsViewState): BreadcrumbsViewModel? {
+            val fragment: BreadcrumbsFragment = (viewModelContext as FragmentViewModelContext).fragment()
+            return fragment.breadcrumbsViewModelFactory.create(state)
+        }
+    }
+
+    init {
+        observeBreadcrumbs()
+    }
+
+    override fun handle(action: EmptyAction) {
+        // No op
+    }
+
+    // PRIVATE METHODS *****************************************************************************
+
+    private fun observeBreadcrumbs() {
+        session.rx()
+                .liveBreadcrumbs()
+                .observeOn(Schedulers.computation())
+                .execute { asyncBreadcrumbs ->
+                    copy(asyncBreadcrumbs = asyncBreadcrumbs)
+                }
+    }
+}

vector/src/main/java/im/vector/riotx/features/home/room/breadcrumbs/BreadcrumbsViewState.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.breadcrumbs
+
+import com.airbnb.mvrx.Async
+import com.airbnb.mvrx.MvRxState
+import com.airbnb.mvrx.Uninitialized
+import im.vector.matrix.android.api.session.room.model.RoomSummary
+
+data class BreadcrumbsViewState(
+        val asyncBreadcrumbs: Async<List<RoomSummary>> = Uninitialized
+) : MvRxState

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailActivity.kt

@@ -20,17 +20,25 @@ import android.content.Context
 import android.content.Intent
 import android.os.Bundle
 import androidx.appcompat.widget.Toolbar
+import androidx.core.view.GravityCompat
+import androidx.drawerlayout.widget.DrawerLayout
 import im.vector.riotx.R
+import im.vector.riotx.core.extensions.hideKeyboard
 import im.vector.riotx.core.extensions.replaceFragment
 import im.vector.riotx.core.platform.ToolbarConfigurable
 import im.vector.riotx.core.platform.VectorBaseActivity
+import im.vector.riotx.features.home.room.breadcrumbs.BreadcrumbsFragment
+import kotlinx.android.synthetic.main.activity_room_detail.*
 import kotlinx.android.synthetic.main.merge_overlay_waiting_view.*
 
 class RoomDetailActivity : VectorBaseActivity(), ToolbarConfigurable {
 
-    override fun getLayoutRes(): Int {
+    override fun getLayoutRes() = R.layout.activity_room_detail
-        return R.layout.activity_room_detail
+
-    }
+    private lateinit var sharedActionViewModel: RoomDetailSharedActionViewModel
+
+    // Simple filter
+    private var currentRoomId: String? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -38,14 +46,57 @@ class RoomDetailActivity : VectorBaseActivity(), ToolbarConfigurable {
         if (isFirstCreation()) {
             val roomDetailArgs: RoomDetailArgs = intent?.extras?.getParcelable(EXTRA_ROOM_DETAIL_ARGS)
                     ?: return
+            currentRoomId = roomDetailArgs.roomId
             replaceFragment(R.id.roomDetailContainer, RoomDetailFragment::class.java, roomDetailArgs)
+            replaceFragment(R.id.roomDetailDrawerContainer, BreadcrumbsFragment::class.java)
         }
+
+        sharedActionViewModel = viewModelProvider.get(RoomDetailSharedActionViewModel::class.java)
+
+        sharedActionViewModel
+                .observe()
+                .subscribe { sharedAction ->
+                    when (sharedAction) {
+                        is RoomDetailSharedAction.SwitchToRoom -> switchToRoom(sharedAction)
+                    }
+                }
+                .disposeOnDestroy()
+
+        drawerLayout.addDrawerListener(drawerListener)
+    }
+
+    private fun switchToRoom(switchToRoom: RoomDetailSharedAction.SwitchToRoom) {
+        drawerLayout.closeDrawer(GravityCompat.START)
+        // Do not replace the Fragment if it's the same roomId
+        if (currentRoomId != switchToRoom.roomId) {
+            currentRoomId = switchToRoom.roomId
+            replaceFragment(R.id.roomDetailContainer, RoomDetailFragment::class.java, RoomDetailArgs(switchToRoom.roomId))
+        }
+    }
+
+    override fun onDestroy() {
+        drawerLayout.removeDrawerListener(drawerListener)
+        super.onDestroy()
     }
 
     override fun configure(toolbar: Toolbar) {
         configureToolbar(toolbar)
     }
 
+    private val drawerListener = object : DrawerLayout.SimpleDrawerListener() {
+        override fun onDrawerStateChanged(newState: Int) {
+            hideKeyboard()
+        }
+    }
+
+    override fun onBackPressed() {
+        if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
+            drawerLayout.closeDrawer(GravityCompat.START)
+        } else {
+            super.onBackPressed()
+        }
+    }
+
     companion object {
 
         private const val EXTRA_ROOM_DETAIL_ARGS = "EXTRA_ROOM_DETAIL_ARGS"

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailSharedAction.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.detail
+
+import im.vector.riotx.core.platform.VectorSharedAction
+
+/**
+ * Supported navigation actions for [RoomDetailActivity]
+ */
+sealed class RoomDetailSharedAction : VectorSharedAction {
+    data class SwitchToRoom(val roomId: String) : RoomDetailSharedAction()
+}

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailSharedActionViewModel.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2019 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 im.vector.riotx.features.home.room.detail
+
+import im.vector.riotx.core.platform.VectorSharedActionViewModel
+import javax.inject.Inject
+
+/**
+ * Activity shared view model
+ */
+class RoomDetailSharedActionViewModel @Inject constructor() : VectorSharedActionViewModel<RoomDetailSharedAction>()

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt

@@ -143,6 +143,9 @@ class RoomDetailViewModel @AssistedInject constructor(@Assisted initialState: Ro
         timeline.addListener(this)
         timeline.start()
         setState { copy(timeline = this@RoomDetailViewModel.timeline) }
+
+        // Inform the SDK that the room is displayed
+        session.onRoomDisplayed(initialState.roomId)
     }
 
     override fun handle(action: RoomDetailAction) {

vector/src/main/java/im/vector/riotx/features/home/room/list/RoomSummaryController.kt

@@ -42,7 +42,7 @@ class RoomSummaryController @Inject constructor(private val stringProvider: Stri
 
     init {
         // We are requesting a model build directly as the first build of epoxy is on the main thread.
-        // It avoids to build the the whole list of rooms on the main thread.
+        // It avoids to build the whole list of rooms on the main thread.
         requestModelBuild()
     }
 

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

@@ -17,6 +17,7 @@
             android:layout_height="match_parent" />
 
         <include layout="@layout/merge_overlay_waiting_view" />
+
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
 

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

@@ -1,14 +1,36 @@
 <?xml version="1.0" encoding="utf-8"?>
-
+<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/drawerLayout"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:openDrawer="start">
+
+    <androidx.coordinatorlayout.widget.CoordinatorLayout
+        android:id="@+id/vector_coordinator_layout"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <FrameLayout
+            android:layout_width="match_parent"
+            android:layout_height="match_parent">
+
+            <androidx.fragment.app.FragmentContainerView
+                android:id="@+id/roomDetailContainer"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent" />
+
+            <include layout="@layout/merge_overlay_waiting_view" />
+
+        </FrameLayout>
+
+    </androidx.coordinatorlayout.widget.CoordinatorLayout>
+
 
     <androidx.fragment.app.FragmentContainerView
-        android:id="@+id/roomDetailContainer"
+        android:id="@+id/roomDetailDrawerContainer"
-        android:layout_width="match_parent"
+        android:layout_width="wrap_content"
-        android:layout_height="match_parent" />
+        android:layout_height="match_parent"
+        android:layout_gravity="start" />
 
-    <include layout="@layout/merge_overlay_waiting_view" />
+</androidx.drawerlayout.widget.DrawerLayout>
-
-</FrameLayout>

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

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<com.airbnb.epoxy.EpoxyRecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/breadcrumbsRecyclerView"
+    android:layout_width="wrap_content"
+    android:layout_height="match_parent"
+    android:background="?riotx_background"
+    tools:listitem="@layout/item_breadcrumbs" />

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

@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/breadcrumbsRoot"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:background="?riotx_background"
+    android:clickable="true"
+    android:focusable="true"
+    android:foreground="?attr/selectableItemBackground">
+
+    <View
+        android:id="@+id/breadcrumbsUnreadIndicator"
+        android:layout_width="4dp"
+        android:layout_height="0dp"
+        android:background="?attr/colorAccent"
+        android:visibility="gone"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:visibility="visible" />
+
+    <ImageView
+        android:id="@+id/breadcrumbsImageView"
+        android:layout_width="56dp"
+        android:layout_height="56dp"
+        android:layout_marginStart="12dp"
+        android:layout_marginTop="4dp"
+        android:layout_marginEnd="12dp"
+        android:layout_marginBottom="4dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:src="@tools:sample/avatars" />
+
+    <im.vector.riotx.features.home.room.list.UnreadCounterBadgeView
+        android:id="@+id/breadcrumbsUnreadCounterBadgeView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:minWidth="16dp"
+        android:minHeight="16dp"
+        android:textColor="@android:color/white"
+        android:textSize="10sp"
+        android:visibility="gone"
+        app:layout_constraintCircle="@+id/breadcrumbsImageView"
+        app:layout_constraintCircleAngle="45"
+        app:layout_constraintCircleRadius="28dp"
+        tools:background="@drawable/bg_unread_highlight"
+        tools:ignore="MissingConstraints"
+        tools:text="24"
+        tools:visibility="visible" />
+
+    <ImageView
+        android:id="@+id/breadcrumbsDraftBadge"
+        android:layout_width="20dp"
+        android:layout_height="20dp"
+        android:background="@drawable/circle"
+        android:padding="3dp"
+        android:src="@drawable/ic_edit"
+        android:visibility="gone"
+        app:layout_constraintCircle="@+id/breadcrumbsImageView"
+        app:layout_constraintCircleAngle="135"
+        app:layout_constraintCircleRadius="28dp"
+        tools:ignore="MissingConstraints"
+        tools:visibility="visible" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>