Makes back pagination work. Still need to refine but ok for proto.

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

@@ -17,7 +17,7 @@ import im.vector.riotredesign.core.utils.FragmentArgumentDelegate
 import kotlinx.android.synthetic.main.fragment_room_detail.*
 import org.koin.android.ext.android.inject
 
-class RoomDetailFragment : RiotFragment(), TimelineAdapter.Callback {
+class RoomDetailFragment : RiotFragment(), TimelineEventAdapter.Callback {
 
     companion object {
 
@@ -31,7 +31,8 @@ class RoomDetailFragment : RiotFragment(), TimelineAdapter.Callback {
     private val matrix by inject<Matrix>()
     private val currentSession = matrix.currentSession!!
     private var roomId by FragmentArgumentDelegate<String>()
-    private val adapter = TimelineAdapter(this)
+    private val timelineAdapter = TimelineEventAdapter(this)
+    private val timelineEventController = TimelineEventController()
     private lateinit var room: Room
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
@@ -46,26 +47,27 @@ class RoomDetailFragment : RiotFragment(), TimelineAdapter.Callback {
     }
 
     private fun renderEvents(events: PagedList<Event>?) {
-        adapter.submitList(events)
+        timelineAdapter.submitList(events)
     }
 
     private fun setupRecyclerView() {
-        val layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
+        val layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, true)
-        adapter.registerAdapterDataObserver(object : RecyclerView.AdapterDataObserver() {
+        layoutManager.stackFromEnd = true
+        timelineAdapter.registerAdapterDataObserver(object : RecyclerView.AdapterDataObserver() {
             override fun onItemRangeInserted(positionStart: Int, itemCount: Int) {
-                if (layoutManager.findLastCompletelyVisibleItemPosition() == positionStart - itemCount) {
+                if (layoutManager.findFirstVisibleItemPosition() == 0) {
-                    layoutManager.scrollToPosition(adapter.itemCount - 1)
+                    layoutManager.scrollToPosition(0)
                 }
             }
         })
         recyclerView.layoutManager = layoutManager
-        recyclerView.adapter = adapter
+        recyclerView.adapter = timelineAdapter
-        recyclerView.setHasFixedSize(true)
+        //recyclerView.setController(timelineEventController)
     }
 
     override fun onEventsListChanged(oldList: List<Event>?, newList: List<Event>?) {
         if (oldList == null && newList != null) {
-            recyclerView.scrollToPosition(newList.size - 1)
+            recyclerView.scrollToPosition(0)
         }
     }
 

app/src/main/java/im/vector/riotredesign/features/home/TimelineEventAdapter.kt

@@ -14,8 +14,8 @@ import im.vector.riotredesign.R
  * Created by francois on 14/05/2018.
  */
 
-class TimelineAdapter(private val callback: Callback? = null)
+class TimelineEventAdapter(private val callback: Callback? = null)
-    : PagedListAdapter<Event, TimelineAdapter.ViewHolder>(EventDiffUtilCallback()) {
+    : PagedListAdapter<Event, TimelineEventAdapter.ViewHolder>(EventDiffUtilCallback()) {
 
 
     private var currentList: List<Event>? = null

app/src/main/res/layout/fragment_room_detail.xml

@@ -3,7 +3,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <android.support.v7.widget.RecyclerView
+    <com.airbnb.epoxy.EpoxyRecyclerView
         android:id="@+id/recyclerView"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />

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

@@ -7,7 +7,6 @@ import io.realm.annotations.LinkingObjects
 
 open class ChunkEntity(var prevToken: String? = null,
                        var nextToken: String? = null,
-                       var isLimited: Boolean = true,
                        var events: RealmList<EventEntity> = RealmList()
 ) : RealmObject() {
 

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

@@ -33,7 +33,7 @@ fun ChunkEntity.Companion.findWithNextToken(realm: Realm, roomId: String, nextTo
             .findFirst()
 }
 
-fun ChunkEntity.Companion.findLastFromRoom(realm: Realm, roomId: String): ChunkEntity? {
+fun ChunkEntity.Companion.findLastLiveChunkFromRoom(realm: Realm, roomId: String): ChunkEntity? {
     return where(realm, roomId)
             .and()
             .isNull("nextToken")

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

@@ -5,6 +5,7 @@ import im.vector.matrix.android.internal.database.model.EventEntity
 import io.realm.Realm
 import io.realm.RealmQuery
 import io.realm.RealmResults
+import io.realm.Sort
 
 fun EventEntity.Companion.where(realm: Realm, roomId: String): RealmQuery<EventEntity> {
     return realm.where(EventEntity::class.java)
@@ -23,9 +24,9 @@ fun EventEntity.Companion.where(realm: Realm, chunk: ChunkEntity?): RealmQuery<E
 }
 
 fun RealmResults<EventEntity>.getLast(type: String? = null): EventEntity? {
-    var query = this.where()
+    var query = this.where().sort("originServerTs", Sort.DESCENDING)
     if (type != null) {
         query = query.equalTo("type", type)
     }
-    return query.findAll().last(null)
+    return query.findFirst()
 }

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

@@ -11,6 +11,7 @@ import im.vector.matrix.android.internal.database.model.ChunkEntity
 import im.vector.matrix.android.internal.database.query.where
 import im.vector.matrix.android.internal.session.room.timeline.PaginationRequest
 import im.vector.matrix.android.internal.session.room.timeline.TimelineBoundaryCallback
+import io.realm.Sort
 import org.koin.standalone.KoinComponent
 import org.koin.standalone.inject
 import java.util.concurrent.Executors
@@ -28,17 +29,16 @@ data class DefaultRoom(
             ChunkEntity.where(realm, roomId)
                     .findAll()
                     .last(null)
-                    ?.let { it.events }
+                    ?.let {
-                    ?.where()
+                        it.events.where().sort("originServerTs", Sort.DESCENDING)
-                    ?.sort("originServerTs")
+                    }
         }
         val domainSourceFactory = realmDataSourceFactory.map { EventMapper.map(it) }
 
         val pagedListConfig = PagedList.Config.Builder()
                 .setEnablePlaceholders(false)
                 .setPageSize(10)
-                .setInitialLoadSizeHint(30)
+                .setPrefetchDistance(10)
-                .setPrefetchDistance(5)
                 .build()
 
         val livePagedListBuilder = LivePagedListBuilder(domainSourceFactory, pagedListConfig).setBoundaryCallback(boundaryCallback)

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

@@ -7,6 +7,7 @@ import com.zhuinden.monarchy.Monarchy
 import im.vector.matrix.android.api.MatrixCallback
 import im.vector.matrix.android.api.failure.Failure
 import im.vector.matrix.android.api.util.Cancelable
+import im.vector.matrix.android.internal.database.DBConstants
 import im.vector.matrix.android.internal.database.mapper.asEntity
 import im.vector.matrix.android.internal.database.model.ChunkEntity
 import im.vector.matrix.android.internal.database.model.RoomEntity
@@ -14,6 +15,7 @@ import im.vector.matrix.android.internal.database.query.findAllIncludingEvents
 import im.vector.matrix.android.internal.database.query.findWithNextToken
 import im.vector.matrix.android.internal.database.query.findWithPrevToken
 import im.vector.matrix.android.internal.database.query.where
+import im.vector.matrix.android.internal.legacy.util.FilterUtil
 import im.vector.matrix.android.internal.network.executeRequest
 import im.vector.matrix.android.internal.session.room.RoomAPI
 import im.vector.matrix.android.internal.session.room.model.PaginationDirection
@@ -32,10 +34,10 @@ class PaginationRequest(private val roomAPI: RoomAPI,
                 from: String?,
                 direction: PaginationDirection,
                 limit: Int = 10,
-                filter: String? = null,
                 callback: MatrixCallback<TokenChunkEvent>
     ): Cancelable {
         val job = GlobalScope.launch(coroutineDispatchers.main) {
+            val filter = FilterUtil.createRoomEventFilter(true)?.toJSONString()
             val chunkOrFailure = execute(roomId, from, direction, limit, filter)
             chunkOrFailure.bimap({ callback.onFailure(it) }, { callback.onSuccess(it) })
         }
@@ -70,14 +72,13 @@ class PaginationRequest(private val roomAPI: RoomAPI,
     private fun insertInDb(chunkEvent: TokenChunkEvent, roomId: String) {
         monarchy.runTransactionSync { realm ->
             val roomEntity = RoomEntity.where(realm, roomId).findFirst()
-                    ?: return@runTransactionSync
+                             ?: return@runTransactionSync
 
             val nextChunk = ChunkEntity.findWithPrevToken(realm, roomId, chunkEvent.nextToken)
             val prevChunk = ChunkEntity.findWithNextToken(realm, roomId, chunkEvent.prevToken)
 
-            val mergedEvents = chunkEvent.chunk + chunkEvent.stateEvents
+            val eventIds = chunkEvent.chunk.filter { it.eventId != null }.map { it.eventId!! }
-            val mergedEventIds = mergedEvents.filter { it.eventId != null }.map { it.eventId!! }
+            val chunksOverlapped = ChunkEntity.findAllIncludingEvents(realm, eventIds)
-            val chunksOverlapped = ChunkEntity.findAllIncludingEvents(realm, mergedEventIds)
             val hasOverlapped = chunksOverlapped.isNotEmpty()
 
             val currentChunk = if (nextChunk != null) {
@@ -85,9 +86,25 @@ class PaginationRequest(private val roomAPI: RoomAPI,
             } else {
                 ChunkEntity()
             }
-
             currentChunk.prevToken = chunkEvent.prevToken
-            mergedEvents.forEach { event ->
+
+
+            val stateEventsChunk = ChunkEntity.findWithNextToken(realm, roomId, DBConstants.STATE_EVENTS_CHUNK_TOKEN)
+                                   ?: ChunkEntity().apply {
+                                       this.prevToken = DBConstants.STATE_EVENTS_CHUNK_TOKEN
+                                       this.nextToken = DBConstants.STATE_EVENTS_CHUNK_TOKEN
+                                   }
+
+            chunkEvent.stateEvents.forEach { stateEvent ->
+                val eventEntity = stateEvent.asEntity().let {
+                    realm.copyToRealmOrUpdate(it)
+                }
+                if (!stateEventsChunk.events.contains(eventEntity)) {
+                    stateEventsChunk.events.add(0, eventEntity)
+                }
+            }
+
+            chunkEvent.chunk.forEach { event ->
                 val eventEntity = event.asEntity().let {
                     realm.copyToRealmOrUpdate(it)
                 }
@@ -101,13 +118,14 @@ class PaginationRequest(private val roomAPI: RoomAPI,
                 roomEntity.chunks.remove(prevChunk)
 
             } else if (hasOverlapped) {
-                chunksOverlapped.forEach { chunk ->
+                chunksOverlapped.forEach { overlapped ->
-                    chunk.events.forEach { event ->
+                    overlapped.events.forEach { event ->
                         if (!currentChunk.events.contains(event)) {
                             currentChunk.events.add(0, event)
                         }
                     }
-                    roomEntity.chunks.remove(chunk)
+                    currentChunk.prevToken = overlapped.prevToken
+                    roomEntity.chunks.remove(overlapped)
                 }
             }
             if (!roomEntity.chunks.contains(currentChunk)) {

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

@@ -32,7 +32,7 @@ class TimelineBoundaryCallback(private val paginationRequest: PaginationRequest,
                     return@doWithRealm
                 }
                 val chunkEntity = ChunkEntity.findAllIncludingEvents(realm, Collections.singletonList(itemAtEnd.eventId)).firstOrNull()
-                paginationRequest.execute(roomId, chunkEntity?.nextToken, PaginationDirection.FORWARDS, callback = createCallback(it))
+                paginationRequest.execute(roomId, chunkEntity?.prevToken, PaginationDirection.BACKWARDS, callback = createCallback(it))
             }
         }
     }
@@ -44,7 +44,7 @@ class TimelineBoundaryCallback(private val paginationRequest: PaginationRequest,
                     return@doWithRealm
                 }
                 val chunkEntity = ChunkEntity.findAllIncludingEvents(realm, Collections.singletonList(itemAtFront.eventId)).firstOrNull()
-                paginationRequest.execute(roomId, chunkEntity?.prevToken, PaginationDirection.BACKWARDS, callback = createCallback(it))
+                paginationRequest.execute(roomId, chunkEntity?.nextToken, PaginationDirection.FORWARDS, callback = createCallback(it))
             }
         }
     }

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

@@ -7,7 +7,7 @@ import im.vector.matrix.android.internal.database.mapper.asEntity
 import im.vector.matrix.android.internal.database.model.ChunkEntity
 import im.vector.matrix.android.internal.database.model.RoomEntity
 import im.vector.matrix.android.internal.database.query.findAllIncludingEvents
-import im.vector.matrix.android.internal.database.query.findLastFromRoom
+import im.vector.matrix.android.internal.database.query.findLastLiveChunkFromRoom
 import im.vector.matrix.android.internal.database.query.where
 import im.vector.matrix.android.internal.session.sync.model.InvitedRoomSync
 import im.vector.matrix.android.internal.session.sync.model.RoomSync
@@ -95,14 +95,13 @@ class RoomSyncHandler(private val monarchy: Monarchy) {
                                  isLimited: Boolean = true): ChunkEntity {
 
         val chunkEntity = if (!isLimited) {
-            ChunkEntity.findLastFromRoom(realm, roomId)
+            ChunkEntity.findLastLiveChunkFromRoom(realm, roomId)
         } else {
             val eventIds = eventList.filter { it.eventId != null }.map { it.eventId!! }
             ChunkEntity.findAllIncludingEvents(realm, eventIds).firstOrNull()
         } ?: ChunkEntity().apply { this.prevToken = prevToken }
 
         chunkEntity.nextToken = nextToken
-        chunkEntity.isLimited = isLimited
 
         eventList.forEach { event ->
             val eventEntity = event.asEntity().let {