Read receipts : add a listener to know when data have been updated.

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

@@ -23,18 +23,20 @@ import im.vector.matrix.android.api.Matrix
 import im.vector.matrix.android.api.MatrixCallback
 import im.vector.matrix.android.api.session.Session
 import im.vector.matrix.android.api.session.events.model.Event
+import im.vector.matrix.android.api.session.room.Room
 import im.vector.matrix.rx.rx
 import im.vector.riotredesign.core.extensions.lastMinBy
 import im.vector.riotredesign.core.platform.RiotViewModel
 import im.vector.riotredesign.features.home.room.VisibleRoomHolder
 import io.reactivex.rxkotlin.subscribeBy
 import org.koin.android.ext.android.get
+import timber.log.Timber
 import java.util.concurrent.TimeUnit
 
 class RoomDetailViewModel(initialState: RoomDetailViewState,
                           private val session: Session,
                           private val visibleRoomHolder: VisibleRoomHolder
-) : RiotViewModel<RoomDetailViewState>(initialState) {
+) : RiotViewModel<RoomDetailViewState>(initialState), Room.Listener {
 
     private val room = session.getRoom(initialState.roomId)!!
     private val roomId = initialState.roomId
@@ -57,6 +59,7 @@ class RoomDetailViewModel(initialState: RoomDetailViewState,
         observeTimeline()
         observeDisplayedEvents()
         room.loadRoomMembersIfNeeded()
+        room.addListener(this)
     }
 
     fun process(action: RoomDetailActions) {
@@ -67,6 +70,17 @@ class RoomDetailViewModel(initialState: RoomDetailViewState,
         }
     }
 
+    override fun onCleared() {
+        room.removeListener(this)
+        super.onCleared()
+    }
+
+    // Room.Listener *******************************************************************************
+
+    override fun onReadReceiptsUpdated() {
+        Timber.v("On read receipts updated")
+    }
+
     // PRIVATE METHODS *****************************************************************************
 
     private fun handleSendMessage(action: RoomDetailActions.SendMessage) {

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

@@ -22,7 +22,6 @@ import im.vector.matrix.android.api.session.room.model.RoomSummary
 import im.vector.matrix.android.api.session.room.read.ReadService
 import im.vector.matrix.android.api.session.room.send.SendService
 import im.vector.matrix.android.api.session.room.timeline.TimelineService
-import im.vector.matrix.android.api.util.Cancelable
 
 /**
  * This interface defines methods to interact within a room.
@@ -40,4 +39,26 @@ interface Room : TimelineService, SendService, ReadService, RoomMembersService {
      */
     val roomSummary: LiveData<RoomSummary>
 
+    /**
+     * Add a listener to the room.
+     * @param listener the listener to add.
+     */
+    fun addListener(listener: Listener)
+
+    /**
+     * Remove a listener from the room.
+     * @param listener the listener to remove.
+     */
+    fun removeListener(listener: Listener)
+
+    /**
+     * A listener defined at the room level to listen for some events from the different room services.
+     */
+    interface Listener : ReadService.Listener {
+
+        override fun onReadReceiptsUpdated() {
+            // no-op
+        }
+    }
+
 }

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

@@ -46,9 +46,19 @@ interface ReadService {
     fun readReceipts(): LiveData<List<ReadReceipt>>
 
     /**
-     * @param the eventId to look for receipt.
+     * @param eventId to look for receipt.
      * * @return the receipt associated or null
      */
     fun readReceipt(eventId: String): ReadReceipt?
 
+    /**
+     * A listener defined at the room level to listen for some read events.
+     */
+    interface Listener {
+        /**
+         * Called when read receipts are updated in this room.
+         */
+        fun onReadReceiptsUpdated()
+    }
+
 }

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

@@ -29,16 +29,20 @@ import im.vector.matrix.android.internal.database.mapper.asDomain
 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.where
+import im.vector.matrix.android.internal.session.room.members.DefaultRoomMembersService
+import im.vector.matrix.android.internal.session.room.read.DefaultReadService
+import im.vector.matrix.android.internal.session.room.read.ReadServiceListeners
+import im.vector.matrix.android.internal.session.room.send.DefaultSendService
+import im.vector.matrix.android.internal.session.room.timeline.DefaultTimelineService
 
-internal data class DefaultRoom(
+internal class DefaultRoom(
         override val roomId: String,
         private val monarchy: Monarchy,
-        private val timelineService: TimelineService,
+        private val timelineService: DefaultTimelineService,
-        private val sendService: SendService,
+        private val sendService: DefaultSendService,
-        private val readService: ReadService,
+        private val readService: DefaultReadService,
-        private val roomMembersService: RoomMembersService
+        private val readServiceListeners: ReadServiceListeners,
-
+        private val roomMembersService: DefaultRoomMembersService
-
 ) : Room,
     TimelineService by timelineService,
     SendService by sendService,
@@ -56,5 +60,12 @@ internal data class DefaultRoom(
         }
     }
 
+    override fun addListener(listener: Room.Listener) {
+        readServiceListeners.addListener(listener)
+    }
+
+    override fun removeListener(listener: Room.Listener) {
+        readServiceListeners.removeListener(listener)
+    }
 
 }

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

@@ -22,6 +22,7 @@ import im.vector.matrix.android.internal.session.room.members.DefaultRoomMembers
 import im.vector.matrix.android.internal.session.room.members.LoadRoomMembersTask
 import im.vector.matrix.android.internal.session.room.members.RoomMemberExtractor
 import im.vector.matrix.android.internal.session.room.read.DefaultReadService
+import im.vector.matrix.android.internal.session.room.read.ReadServiceListeners
 import im.vector.matrix.android.internal.session.room.read.SetReadMarkersTask
 import im.vector.matrix.android.internal.session.room.send.DefaultSendService
 import im.vector.matrix.android.internal.session.room.send.EventFactory
@@ -49,6 +50,7 @@ internal class RoomFactory(private val loadRoomMembersTask: LoadRoomMembersTask,
         val sendService = DefaultSendService(roomId, eventFactory, monarchy)
         val roomMembersService = DefaultRoomMembersService(roomId, monarchy, loadRoomMembersTask, taskExecutor)
         val readService = DefaultReadService(roomId, monarchy, roomMembersService, setReadMarkersTask, taskExecutor)
+        val readServiceListeners = ReadServiceListeners(roomId, monarchy)
 
         return DefaultRoom(
                 roomId,
@@ -56,6 +58,7 @@ internal class RoomFactory(private val loadRoomMembersTask: LoadRoomMembersTask,
                 timelineService,
                 sendService,
                 readService,
+                readServiceListeners,
                 roomMembersService
         )
     }

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

@@ -37,7 +37,7 @@ internal class DefaultReadService(private val roomId: String,
                                   private val taskExecutor: TaskExecutor) : ReadService {
 
     override fun markAllAsRead(callback: MatrixCallback<Void>) {
-        val latestEvent = getLatestEvent()
+        val latestEvent = monarchy.fetchCopied { EventEntity.latestEvent(it, roomId) }
         val params = SetReadMarkersTask.Params(roomId, fullyReadEventId = latestEvent?.eventId, readReceiptEventId = latestEvent?.eventId)
         setReadMarkersTask.configureWith(params).executeBy(taskExecutor)
     }
@@ -52,10 +52,6 @@ internal class DefaultReadService(private val roomId: String,
         setReadMarkersTask.configureWith(params).executeBy(taskExecutor)
     }
 
-    private fun getLatestEvent(): EventEntity? {
-        return monarchy.fetchCopied { EventEntity.latestEvent(it, roomId) }
-    }
-
     override fun readReceipts(): LiveData<List<ReadReceipt>> {
         return monarchy.findAllMappedWithChanges(
                 { realm -> ReadReceiptEntity.where(realm, roomId) },

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

@@ -0,0 +1,58 @@
+/*
+ * 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.room.read
+
+import androidx.lifecycle.Observer
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.api.session.room.read.ReadService
+import im.vector.matrix.android.internal.database.model.ReadReceiptEntity
+import im.vector.matrix.android.internal.database.query.where
+
+class ReadServiceListeners(private val roomId: String,
+                           private val monarchy: Monarchy
+) {
+
+    private val listeners = ArrayList<ReadService.Listener>()
+    private val readReceiptsLive by lazy {
+        monarchy.findAllManagedWithChanges { realm -> ReadReceiptEntity.where(realm, roomId) }
+    }
+    private val readReceiptLiveObserver = Observer<Monarchy.ManagedChangeSet<ReadReceiptEntity>> { listeners.forEach { it.onReadReceiptsUpdated() } }
+
+    fun addListener(listener: ReadService.Listener) {
+        if (listeners.isEmpty()) {
+            startObservingData()
+        }
+        listeners.add(listener)
+    }
+
+    fun removeListener(listener: ReadService.Listener) {
+        listeners.remove(listener)
+        if (listeners.isEmpty()) {
+            stopObservingData()
+        }
+    }
+
+    private fun startObservingData() {
+        readReceiptsLive.observeForever(readReceiptLiveObserver)
+    }
+
+    private fun stopObservingData() {
+        readReceiptsLive.removeObserver(readReceiptLiveObserver)
+    }
+
+
+}