(DRAFT) Room counter flow

matrix-sdk-android/build.gradle

@@ -73,6 +73,9 @@ android {
 
     kotlinOptions {
         jvmTarget = "11"
+        freeCompilerArgs += [
+                "-Xopt-in=kotlin.RequiresOptIn"
+        ]
     }
 
     sourceSets {

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

@@ -18,6 +18,7 @@ package org.matrix.android.sdk.api.session.room
 
 import androidx.lifecycle.LiveData
 import androidx.paging.PagedList
+import kotlinx.coroutines.flow.Flow
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.members.ChangeMembershipState
 import org.matrix.android.sdk.api.session.room.model.Membership
@@ -216,6 +217,11 @@ interface RoomService {
                                           pagedListConfig: PagedList.Config = defaultPagedListConfig,
                                           sortOrder: RoomSortOrder = RoomSortOrder.ACTIVITY): UpdatableLivePageResult
 
+    /**
+     * Retrieve a flow on the the number of rooms.
+     */
+    fun getRoomCountFlow(queryParams: RoomSummaryQueryParams): Flow<Int>
+
     /**
      * TODO Doc
      */

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

@@ -20,6 +20,7 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.Transformations
 import androidx.paging.PagedList
 import com.zhuinden.monarchy.Monarchy
+import kotlinx.coroutines.flow.Flow
 import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.Room
 import org.matrix.android.sdk.api.session.room.RoomService
@@ -109,6 +110,10 @@ internal class DefaultRoomService @Inject constructor(
         return roomSummaryDataSource.getUpdatablePagedRoomSummariesLive(queryParams, pagedListConfig, sortOrder)
     }
 
+    override fun getRoomCountFlow(queryParams: RoomSummaryQueryParams): Flow<Int> {
+        return roomSummaryDataSource.getCountFlow(queryParams)
+    }
+
     override fun getNotificationCountForRooms(queryParams: RoomSummaryQueryParams): RoomAggregateNotificationCount {
         return roomSummaryDataSource.getNotificationCountForRooms(queryParams)
     }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/summary/RoomSummaryDataSource.kt

@@ -25,7 +25,12 @@ import androidx.paging.PagedList
 import com.zhuinden.monarchy.Monarchy
 import io.realm.Realm
 import io.realm.RealmQuery
+import io.realm.kotlin.toFlow
 import io.realm.kotlin.where
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
 import org.matrix.android.sdk.api.query.ActiveSpaceFilter
 import org.matrix.android.sdk.api.query.RoomCategoryFilter
 import org.matrix.android.sdk.api.query.isNormalized
@@ -42,6 +47,7 @@ import org.matrix.android.sdk.api.session.room.summary.RoomAggregateNotification
 import org.matrix.android.sdk.api.session.space.SpaceSummaryQueryParams
 import org.matrix.android.sdk.api.util.Optional
 import org.matrix.android.sdk.api.util.toOptional
+import org.matrix.android.sdk.internal.database.RealmSessionProvider
 import org.matrix.android.sdk.internal.database.mapper.RoomSummaryMapper
 import org.matrix.android.sdk.internal.database.model.RoomSummaryEntity
 import org.matrix.android.sdk.internal.database.model.RoomSummaryEntityFields
@@ -55,6 +61,7 @@ import javax.inject.Inject
 
 internal class RoomSummaryDataSource @Inject constructor(
         @SessionDatabase private val monarchy: Monarchy,
+        private val realmSessionProvider: RealmSessionProvider,
         private val roomSummaryMapper: RoomSummaryMapper,
         private val queryStringValueProcessor: QueryStringValueProcessor
 ) {
@@ -230,6 +237,28 @@ internal class RoomSummaryDataSource @Inject constructor(
         }
     }
 
+//    @OptIn(ExperimentalCoroutinesApi::class)
+//    fun getCountFlow(queryParams: RoomSummaryQueryParams): Flow<Int> = callbackFlow {
+//        val realmResult = realmSessionProvider.withRealm { realm ->
+//            roomSummariesQuery(realm, queryParams).findAllAsync()
+//        }
+//        val changeListener = RealmChangeListener<RealmResults<RoomSummaryEntity>> {
+//            trySendBlocking(it.size)
+//                    .onFailure { throwable -> Timber.e(throwable) }
+//        }
+//        realmResult.addChangeListener(changeListener)
+//        awaitClose { realmResult.removeChangeListener(changeListener) }
+//    }
+
+    fun getCountFlow(queryParams: RoomSummaryQueryParams): Flow<Int> =
+            // TODO handle properly threads and dispatchers otherwise use livedata of monarchy
+            realmSessionProvider
+                    .withRealm { realm -> roomSummariesQuery(realm, queryParams).findAllAsync() }
+                    .toFlow()
+                    .map { it.size }
+                    .flowOn(Dispatchers.IO)
+
+    // TODO should we improve how we update notification count with flow ??
     fun getNotificationCountForRooms(queryParams: RoomSummaryQueryParams): RoomAggregateNotificationCount {
         var notificationCount: RoomAggregateNotificationCount? = null
         monarchy.doWithRealm { realm ->

vector/src/main/java/im/vector/app/features/home/room/list/RoomCategoryItem.kt

@@ -29,6 +29,7 @@ import im.vector.app.core.epoxy.VectorEpoxyModel
 import im.vector.app.core.epoxy.onClick
 import im.vector.app.features.themes.ThemeUtils
 
+// TODO check where it is used in the project
 @EpoxyModelClass(layout = R.layout.item_room_category)
 abstract class RoomCategoryItem : VectorEpoxyModel<RoomCategoryItem.Holder>() {
 

vector/src/main/java/im/vector/app/features/home/room/list/RoomListFragment.kt

@@ -287,6 +287,12 @@ class RoomListFragment @Inject constructor(
                                             ))
                                             checkEmptyState()
                                         }
+                                        // TODO use flow if possible ?
+                                        section.itemCount.observe(viewLifecycleOwner) { count ->
+                                            sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
+                                                    itemCount = count
+                                            ))
+                                        }
                                         section.notificationCount.observe(viewLifecycleOwner) { counts ->
                                             sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
                                                     notificationCount = counts.totalCount,
@@ -326,6 +332,12 @@ class RoomListFragment @Inject constructor(
                                                     isLoading = false))
                                             checkEmptyState()
                                         }
+                                        // TODO use flow instead ?
+                                        section.itemCount.observe(viewLifecycleOwner) { count ->
+                                            sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
+                                                    itemCount = count
+                                            ))
+                                        }
                                         section.notificationCount.observe(viewLifecycleOwner) { counts ->
                                             sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
                                                     notificationCount = counts.totalCount,

vector/src/main/java/im/vector/app/features/home/room/list/RoomListSectionBuilderGroup.kt

@@ -242,6 +242,7 @@ class RoomListSectionBuilderGroup(
                            @StringRes nameRes: Int,
                            notifyOfLocalEcho: Boolean = false,
                            query: (RoomSummaryQueryParams.Builder) -> Unit) {
+        // TODO check when this class is used: difference with RoomListSectionBuilderSpace ?
         withQueryParams(
                 { query.invoke(it) },
                 { roomQueryParams ->
@@ -251,6 +252,7 @@ class RoomListSectionBuilderGroup(
                                 activeSpaceUpdaters.add(it)
                             }.livePagedList
                             .let { livePagedList ->
+                                // TODO should we improve this ?
                                 // use it also as a source to update count
                                 livePagedList.asFlow()
                                         .onEach {

vector/src/main/java/im/vector/app/features/home/room/list/RoomListSectionBuilderSpace.kt

@@ -374,6 +374,7 @@ class RoomListSectionBuilderSpace(
                                 // use it also as a source to update count
                                 livePagedList.asFlow()
                                         .onEach {
+                                            // TODO should we improve this ?
                                             Timber.v("Thread space list: ${Thread.currentThread()}")
                                             sections.find { it.sectionName == name }
                                                     ?.notificationCount
@@ -398,6 +399,12 @@ class RoomListSectionBuilderSpace(
                                         )
                                 )
                             }
+
+                    // TODO extract into a dedicated private method
+                    session.getRoomCountFlow(roomQueryParams)
+                            .onEach { count -> sections.find { section -> section.sectionName == name }?.itemCount?.postValue(count) }
+                            .flowOn(Dispatchers.Default)
+                            .launchIn(viewModelScope)
                 }
 
         )

vector/src/main/java/im/vector/app/features/home/room/list/RoomsSection.kt

@@ -26,9 +26,12 @@ data class RoomsSection(
         val sectionName: String,
         // can be a paged list or a regular list
         val livePages: LiveData<PagedList<RoomSummary>>? = null,
+        // TODO liveList is not used : can we delete ?
         val liveList: LiveData<List<RoomSummary>>? = null,
         val liveSuggested: LiveData<SuggestedRoomInfo>? = null,
         val isExpanded: MutableLiveData<Boolean> = MutableLiveData(true),
+        // TODO expose a Flow<Int> instead ?
+        val itemCount: MutableLiveData<Int> = MutableLiveData(0),
         val notificationCount: MutableLiveData<RoomAggregateNotificationCount> = MutableLiveData(RoomAggregateNotificationCount(0, 0)),
         val notifyOfLocalEcho: Boolean = false
 )