Using flow to show items counter

dependencies.gradle

@@ -58,6 +58,7 @@ ext.libs = [
                 'lifecycleCommon'         : "androidx.lifecycle:lifecycle-common:$lifecycle",
                 'lifecycleLivedata'       : "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle",
                 'lifecycleProcess'        : "androidx.lifecycle:lifecycle-process:$lifecycle",
+                'lifecycleRuntimeKtx'     : "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle",
                 'datastore'               : "androidx.datastore:datastore:1.0.0",
                 'datastorepreferences'    : "androidx.datastore:datastore-preferences:1.0.0",
                 'pagingRuntimeKtx'        : "androidx.paging:paging-runtime-ktx:2.1.2",
@@ -141,4 +142,4 @@ ext.libs = [
                 'timberJunitRule'        : "net.lachlanmckee:timber-junit-rule:1.0.1",
                 'junit'                  : "junit:junit:4.13.2"
         ]
-]
+]

matrix-sdk-android/build.gradle

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

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

@@ -29,8 +29,10 @@ import io.realm.kotlin.toFlow
 import io.realm.kotlin.where
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
+import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
 import org.matrix.android.sdk.api.query.ActiveSpaceFilter
 import org.matrix.android.sdk.api.query.RoomCategoryFilter
 import org.matrix.android.sdk.api.query.isNormalized
@@ -63,7 +65,8 @@ internal class RoomSummaryDataSource @Inject constructor(
         @SessionDatabase private val monarchy: Monarchy,
         private val realmSessionProvider: RealmSessionProvider,
         private val roomSummaryMapper: RoomSummaryMapper,
-        private val queryStringValueProcessor: QueryStringValueProcessor
+        private val queryStringValueProcessor: QueryStringValueProcessor,
+        private val coroutineDispatchers: MatrixCoroutineDispatchers
 ) {
 
     fun getRoomSummary(roomIdOrAlias: String): RoomSummary? {
@@ -237,28 +240,16 @@ 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()
+                    // need to create the flow on a context dispatcher with a thread with attached Looper
+                    .flowOn(coroutineDispatchers.main)
                     .map { it.size }
-                    .flowOn(Dispatchers.IO)
+                    .flowOn(coroutineDispatchers.io)
+                    .distinctUntilChanged()
 
-    // TODO should we improve how we update notification count with flow ??
     fun getNotificationCountForRooms(queryParams: RoomSummaryQueryParams): RoomAggregateNotificationCount {
         var notificationCount: RoomAggregateNotificationCount? = null
         monarchy.doWithRealm { realm ->

vector/build.gradle

@@ -355,6 +355,7 @@ dependencies {
     // Lifecycle
     implementation libs.androidx.lifecycleLivedata
     implementation libs.androidx.lifecycleProcess
+    implementation libs.androidx.lifecycleRuntimeKtx
 
     implementation libs.androidx.datastore
     implementation libs.androidx.datastorepreferences

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

@@ -23,6 +23,8 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.core.content.ContextCompat
 import androidx.core.view.isVisible
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.ConcatAdapter
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -50,8 +52,10 @@ import im.vector.app.features.home.room.list.actions.RoomListQuickActionsSharedA
 import im.vector.app.features.home.room.list.actions.RoomListQuickActionsSharedActionViewModel
 import im.vector.app.features.home.room.list.widget.NotifsFabMenuView
 import im.vector.app.features.notifications.NotificationDrawerManager
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.launch
 import kotlinx.parcelize.Parcelize
 import org.matrix.android.sdk.api.extensions.orTrue
 import org.matrix.android.sdk.api.session.room.model.RoomSummary
@@ -287,11 +291,14 @@ class RoomListFragment @Inject constructor(
                                             ))
                                             checkEmptyState()
                                         }
-                                        // TODO use flow if possible ?
+                                        lifecycleScope.launch {
-                                        section.itemCount.observe(viewLifecycleOwner) { count ->
+                                            section.itemCount
-                                            sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
+                                                    .flowWithLifecycle(lifecycle, Lifecycle.State.STARTED)
-                                                    itemCount = count
+                                                    .collect { count ->
-                                            ))
+                                                        sectionAdapter.updateSection(
+                                                                sectionAdapter.roomsSectionData.copy(itemCount = count)
+                                                        )
+                                                    }
                                         }
                                         section.notificationCount.observe(viewLifecycleOwner) { counts ->
                                             sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
@@ -332,11 +339,14 @@ class RoomListFragment @Inject constructor(
                                                     isLoading = false))
                                             checkEmptyState()
                                         }
-                                        // TODO use flow instead ?
+                                        lifecycleScope.launch {
-                                        section.itemCount.observe(viewLifecycleOwner) { count ->
+                                            section.itemCount
-                                            sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(
+                                                    .flowWithLifecycle(lifecycle, Lifecycle.State.STARTED)
-                                                    itemCount = count
+                                                    .collect { count ->
-                                            ))
+                                                        sectionAdapter.updateSection(
+                                                                sectionAdapter.roomsSectionData.copy(itemCount = count)
+                                                        )
+                                                    }
                                         }
                                         section.notificationCount.observe(viewLifecycleOwner) { counts ->
                                             sectionAdapter.updateSection(sectionAdapter.roomsSectionData.copy(

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

@@ -68,11 +68,18 @@ class RoomListSectionBuilderGroup(
                             it.memberships = Membership.activeMemberships()
                         },
                         { qpm ->
+                            // TODO find a way to show the filtered rooms count ?
                             val name = stringProvider.getString(R.string.bottom_action_rooms)
                             session.getFilteredPagedRoomSummariesLive(qpm)
                                     .let { updatableFilterLivePageResult ->
                                         onUpdatable(updatableFilterLivePageResult)
-                                        sections.add(RoomsSection(name, updatableFilterLivePageResult.livePagedList))
+                                        sections.add(
+                                                RoomsSection(
+                                                        sectionName = name,
+                                                        livePages = updatableFilterLivePageResult.livePagedList,
+                                                        itemCount = session.getRoomCountFlow(qpm)
+                                                )
+                                        )
                                     }
                         }
                 )
@@ -242,7 +249,6 @@ 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 ->
@@ -252,7 +258,6 @@ 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 {
@@ -267,7 +272,8 @@ class RoomListSectionBuilderGroup(
                                         RoomsSection(
                                                 sectionName = name,
                                                 livePages = livePagedList,
-                                                notifyOfLocalEcho = notifyOfLocalEcho
+                                                notifyOfLocalEcho = notifyOfLocalEcho,
+                                                itemCount = session.getRoomCountFlow(roomQueryParams)
                                         )
                                 )
                             }

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

@@ -38,6 +38,7 @@ import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
 import org.matrix.android.sdk.api.extensions.tryOrNull
 import org.matrix.android.sdk.api.query.ActiveSpaceFilter
@@ -87,11 +88,18 @@ class RoomListSectionBuilderSpace(
                             it.memberships = Membership.activeMemberships()
                         },
                         { qpm ->
+                            // TODO find a way to show the filtered rooms count ?
                             val name = stringProvider.getString(R.string.bottom_action_rooms)
                             session.getFilteredPagedRoomSummariesLive(qpm)
                                     .let { updatableFilterLivePageResult ->
                                         onUpdatable(updatableFilterLivePageResult)
-                                        sections.add(RoomsSection(name, updatableFilterLivePageResult.livePagedList))
+                                        sections.add(
+                                                RoomsSection(
+                                                        sectionName = name,
+                                                        livePages = updatableFilterLivePageResult.livePagedList,
+                                                        itemCount = session.getRoomCountFlow(qpm)
+                                                )
+                                        )
                                     }
                         }
                 )
@@ -261,7 +269,8 @@ class RoomListSectionBuilderSpace(
                 RoomsSection(
                         sectionName = stringProvider.getString(R.string.suggested_header),
                         liveSuggested = liveSuggestedRooms,
-                        notifyOfLocalEcho = false
+                        notifyOfLocalEcho = false,
+                        itemCount = suggestedRoomsFlow.map { suggestions -> suggestions.size }
                 )
         )
     }
@@ -374,7 +383,6 @@ 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
@@ -395,16 +403,11 @@ class RoomListSectionBuilderSpace(
                                         RoomsSection(
                                                 sectionName = name,
                                                 livePages = livePagedList,
-                                                notifyOfLocalEcho = notifyOfLocalEcho
+                                                notifyOfLocalEcho = notifyOfLocalEcho,
+                                                itemCount = session.getRoomCountFlow(roomQueryParams)
                                         )
                                 )
                             }
-
-                    // 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

@@ -19,6 +19,7 @@ package im.vector.app.features.home.room.list
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.paging.PagedList
+import kotlinx.coroutines.flow.Flow
 import org.matrix.android.sdk.api.session.room.model.RoomSummary
 import org.matrix.android.sdk.api.session.room.summary.RoomAggregateNotificationCount
 
@@ -30,8 +31,7 @@ data class RoomsSection(
         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: Flow<Int>,
-        val itemCount: MutableLiveData<Int> = MutableLiveData(0),
         val notificationCount: MutableLiveData<RoomAggregateNotificationCount> = MutableLiveData(RoomAggregateNotificationCount(0, 0)),
         val notifyOfLocalEcho: Boolean = false
 )