Remove HomeViewModel and dispatch in multiple view models (one for each fragment)

app/build.gradle

@@ -47,7 +47,7 @@ configurations.all { strategy ->
 dependencies {
 
     def epoxy_version = "2.19.0"
-
+    def arrow_version = "0.8.0"
 
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation project(":matrix-sdk-android")
@@ -58,22 +58,30 @@ dependencies {
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
 
     implementation 'com.jakewharton.threetenabp:threetenabp:1.1.1'
-
     implementation 'com.jakewharton.timber:timber:4.7.1'
 
+    // rx
+    implementation 'io.reactivex.rxjava2:rxkotlin:2.3.0'
+    implementation 'io.reactivex.rxjava2:rxandroid:2.0.2'
+
     implementation("com.airbnb.android:epoxy:$epoxy_version")
     kapt "com.airbnb.android:epoxy-processor:$epoxy_version"
     implementation "com.airbnb.android:epoxy-paging:$epoxy_version"
     implementation 'com.airbnb.android:mvrx:0.6.0'
 
+    // FP
+    implementation "io.arrow-kt:arrow-core:$arrow_version"
+
+    // UI
     implementation 'com.github.bumptech.glide:glide:4.8.0'
     kapt 'com.github.bumptech.glide:compiler:4.8.0'
     implementation 'com.amulyakhare:com.amulyakhare.textdrawable:1.0.1'
 
-
+    // DI
     implementation "org.koin:koin-android:$koin_version"
     implementation "org.koin:koin-android-scope:$koin_version"
 
+    // TESTS
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

app/src/main/java/im/vector/riotredesign/core/platform/RiotViewModel.kt

@@ -0,0 +1,7 @@
+package im.vector.riotredesign.core.platform
+
+import com.airbnb.mvrx.BaseMvRxViewModel
+import com.airbnb.mvrx.MvRxState
+
+abstract class RiotViewModel<S : MvRxState>(initialState: S)
+    : BaseMvRxViewModel<S>(initialState, debugMode = false)

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

@@ -1,17 +0,0 @@
-package im.vector.riotredesign.features.home
-
-import im.vector.matrix.android.api.permalinks.PermalinkData
-import im.vector.matrix.android.api.session.group.model.GroupSummary
-import im.vector.matrix.android.api.session.room.model.RoomSummary
-
-sealed class HomeActions {
-
-    data class SelectRoom(val roomSummary: RoomSummary) : HomeActions()
-
-    data class SelectGroup(val groupSummary: GroupSummary) : HomeActions()
-
-    data class PermalinkClicked(val permalinkData: PermalinkData) : HomeActions()
-
-    object RoomDisplayed : HomeActions()
-
-}

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

@@ -5,12 +5,10 @@ import android.content.Intent
 import android.os.Bundle
 import android.support.v4.app.FragmentManager
 import android.support.v4.view.GravityCompat
-import android.support.v4.widget.DrawerLayout
 import android.support.v7.app.ActionBarDrawerToggle
 import android.support.v7.widget.Toolbar
 import android.view.Gravity
 import android.view.MenuItem
-import android.view.View
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.extensions.replaceFragment
 import im.vector.riotredesign.core.platform.OnBackPressed
@@ -91,11 +89,8 @@ class HomeActivity : RiotActivity(), HomeNavigator, ToolbarConfigurable {
     override fun openRoomDetail(roomId: String, eventId: String?) {
         val args = RoomDetailArgs(roomId, eventId)
         val roomDetailFragment = RoomDetailFragment.newInstance(args)
-        if (drawerLayout.isDrawerOpen(Gravity.LEFT)) {
-            closeDrawerLayout(Gravity.LEFT) { replaceFragment(roomDetailFragment, R.id.homeDetailFragmentContainer) }
-        } else {
-            replaceFragment(roomDetailFragment, R.id.homeDetailFragmentContainer)
-        }
+        drawerLayout.closeDrawer(Gravity.LEFT)
+        replaceFragment(roomDetailFragment, R.id.homeDetailFragmentContainer)
     }
 
     override fun openGroupDetail(groupId: String) {
@@ -106,16 +101,6 @@ class HomeActivity : RiotActivity(), HomeNavigator, ToolbarConfigurable {
         Timber.v("Open user detail $userId")
     }
 
-    private fun closeDrawerLayout(gravity: Int, actionOnClose: () -> Unit) {
-        drawerLayout.addDrawerListener(object : DrawerLayout.SimpleDrawerListener() {
-            override fun onDrawerClosed(p0: View) {
-                drawerLayout.removeDrawerListener(this)
-                actionOnClose()
-            }
-        })
-        drawerLayout.closeDrawer(gravity)
-    }
-
     companion object {
         fun newIntent(context: Context): Intent {
             return Intent(context, HomeActivity::class.java)

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

@@ -1,5 +1,6 @@
 package im.vector.riotredesign.features.home
 
+import im.vector.riotredesign.features.home.group.SelectedGroupHolder
 import im.vector.riotredesign.features.home.room.detail.timeline.MessageItemFactory
 import im.vector.riotredesign.features.home.room.detail.timeline.TextItemFactory
 import im.vector.riotredesign.features.home.room.detail.timeline.TimelineDateFormatter
@@ -30,5 +31,9 @@ class HomeModule(private val homeActivity: HomeActivity) {
             TimelineEventController(roomId, get(), get(), get())
         }
 
+        single {
+            SelectedGroupHolder()
+        }
+
     }
 }

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

@@ -1,107 +0,0 @@
-package im.vector.riotredesign.features.home
-
-import android.support.v4.app.FragmentActivity
-import com.airbnb.mvrx.BaseMvRxViewModel
-import com.airbnb.mvrx.MvRxViewModelFactory
-import im.vector.matrix.android.api.Matrix
-import im.vector.matrix.android.api.permalinks.PermalinkData
-import im.vector.matrix.android.api.session.Session
-import im.vector.matrix.rx.rx
-import im.vector.riotredesign.features.home.room.list.RoomSelectionRepository
-import org.koin.android.ext.android.get
-
-class HomeViewModel(initialState: HomeViewState,
-                    private val session: Session,
-                    private val roomSelectionRepository: RoomSelectionRepository) : BaseMvRxViewModel<HomeViewState>(initialState) {
-
-    companion object : MvRxViewModelFactory<HomeViewState> {
-
-        @JvmStatic
-        override fun create(activity: FragmentActivity, state: HomeViewState): HomeViewModel {
-            val currentSession = Matrix.getInstance().currentSession
-            val roomSelectionRepository = activity.get<RoomSelectionRepository>()
-            return HomeViewModel(state, currentSession, roomSelectionRepository)
-        }
-    }
-
-    init {
-        observeRoomSummaries()
-        observeGroupSummaries()
-    }
-
-    fun accept(action: HomeActions) {
-        when (action) {
-            is HomeActions.SelectRoom -> handleSelectRoom(action)
-            is HomeActions.SelectGroup -> handleSelectGroup(action)
-            is HomeActions.RoomDisplayed -> setState { copy(shouldOpenRoomDetail = false) }
-            is HomeActions.PermalinkClicked -> handlePermalinkClicked(action)
-        }
-    }
-
-    // PRIVATE METHODS *****************************************************************************
-
-    private fun handlePermalinkClicked(action: HomeActions.PermalinkClicked) = withState { state ->
-        when (action.permalinkData) {
-            is PermalinkData.EventLink -> {
-
-            }
-            is PermalinkData.RoomLink -> {
-
-            }
-            is PermalinkData.GroupLink -> {
-
-            }
-            is PermalinkData.UserLink -> {
-
-            }
-            is PermalinkData.FallbackLink -> {
-
-            }
-        }
-    }
-
-    private fun handleSelectRoom(action: HomeActions.SelectRoom) = withState { state ->
-        if (state.selectedRoomId != action.roomSummary.roomId) {
-            roomSelectionRepository.saveLastSelectedRoom(action.roomSummary.roomId)
-            setState { copy(selectedRoomId = action.roomSummary.roomId, shouldOpenRoomDetail = true) }
-        }
-    }
-
-    private fun handleSelectGroup(action: HomeActions.SelectGroup) = withState { state ->
-        if (state.selectedGroup?.groupId != action.groupSummary.groupId) {
-            setState { copy(selectedGroup = action.groupSummary) }
-        } else {
-            setState { copy(selectedGroup = null) }
-        }
-    }
-
-    private fun observeRoomSummaries() {
-        session
-                .rx().liveRoomSummaries()
-                .execute { async ->
-                    val summaries = async()
-                    val directRooms = summaries?.filter { it.isDirect } ?: emptyList()
-                    val groupRooms = summaries?.filter { !it.isDirect } ?: emptyList()
-
-                    val selectedRoomId = selectedRoomId
-                            ?: roomSelectionRepository.lastSelectedRoom()
-                            ?: directRooms.firstOrNull()?.roomId
-                            ?: groupRooms.firstOrNull()?.roomId
-
-                    copy(
-                            asyncRooms = async,
-                            directRooms = directRooms,
-                            groupRooms = groupRooms,
-                            selectedRoomId = selectedRoomId
-                    )
-                }
-    }
-
-    private fun observeGroupSummaries() {
-        session
-                .rx().liveGroupSummaries()
-                .execute { async ->
-                    copy(asyncGroups = async)
-                }
-    }
-}

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

@@ -1,18 +0,0 @@
-package im.vector.riotredesign.features.home
-
-import com.airbnb.mvrx.Async
-import com.airbnb.mvrx.MvRxState
-import com.airbnb.mvrx.Uninitialized
-import im.vector.matrix.android.api.session.group.model.GroupSummary
-import im.vector.matrix.android.api.session.room.model.RoomSummary
-
-data class HomeViewState(
-        val asyncRooms: Async<List<RoomSummary>> = Uninitialized,
-        val directRooms: List<RoomSummary> = emptyList(),
-        val groupRooms: List<RoomSummary> = emptyList(),
-        val selectedRoomId: String? = null,
-        val selectedEventId: String? = null,
-        val shouldOpenRoomDetail: Boolean = true,
-        val asyncGroups: Async<List<GroupSummary>> = Uninitialized,
-        val selectedGroup: GroupSummary? = null
-) : MvRxState

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

@@ -0,0 +1,9 @@
+package im.vector.riotredesign.features.home.group
+
+import im.vector.matrix.android.api.session.group.model.GroupSummary
+
+sealed class GroupListActions {
+
+    data class SelectGroup(val groupSummary: GroupSummary) : GroupListActions()
+
+}

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

@@ -6,14 +6,11 @@ import android.view.View
 import android.view.ViewGroup
 import com.airbnb.mvrx.Incomplete
 import com.airbnb.mvrx.Success
-import com.airbnb.mvrx.activityViewModel
+import com.airbnb.mvrx.fragmentViewModel
 import im.vector.matrix.android.api.session.group.model.GroupSummary
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.platform.RiotFragment
 import im.vector.riotredesign.core.platform.StateView
-import im.vector.riotredesign.features.home.HomeActions
-import im.vector.riotredesign.features.home.HomeViewModel
-import im.vector.riotredesign.features.home.HomeViewState
 import kotlinx.android.synthetic.main.fragment_group_list.*
 
 class GroupListFragment : RiotFragment(), GroupSummaryController.Callback {
@@ -24,7 +21,7 @@ class GroupListFragment : RiotFragment(), GroupSummaryController.Callback {
         }
     }
 
-    private val viewModel: HomeViewModel by activityViewModel()
+    private val viewModel: GroupListViewModel by fragmentViewModel()
 
     private lateinit var groupController: GroupSummaryController
 
@@ -40,14 +37,14 @@ class GroupListFragment : RiotFragment(), GroupSummaryController.Callback {
         viewModel.subscribe { renderState(it) }
     }
 
-    private fun renderState(state: HomeViewState) {
+    private fun renderState(state: GroupListViewState) {
         when (state.asyncGroups) {
             is Incomplete -> renderLoading()
             is Success -> renderSuccess(state)
         }
     }
 
-    private fun renderSuccess(state: HomeViewState) {
+    private fun renderSuccess(state: GroupListViewState) {
         stateView.state = StateView.State.Content
         groupController.setData(state)
     }
@@ -57,7 +54,7 @@ class GroupListFragment : RiotFragment(), GroupSummaryController.Callback {
     }
 
     override fun onGroupSelected(groupSummary: GroupSummary) {
-        viewModel.accept(HomeActions.SelectGroup(groupSummary))
+        viewModel.accept(GroupListActions.SelectGroup(groupSummary))
     }
 
 }

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

@@ -0,0 +1,64 @@
+package im.vector.riotredesign.features.home.group
+
+import android.support.v4.app.FragmentActivity
+import com.airbnb.mvrx.BaseMvRxViewModel
+import com.airbnb.mvrx.MvRxViewModelFactory
+import im.vector.matrix.android.api.Matrix
+import im.vector.matrix.android.api.session.Session
+import im.vector.matrix.rx.rx
+import im.vector.riotredesign.core.platform.RiotViewModel
+import org.koin.android.ext.android.get
+
+class GroupListViewModel(initialState: GroupListViewState,
+                         private val selectedGroupHolder: SelectedGroupHolder,
+                         private val session: Session
+) : RiotViewModel<GroupListViewState>(initialState) {
+
+    companion object : MvRxViewModelFactory<GroupListViewState> {
+
+        @JvmStatic
+        override fun create(activity: FragmentActivity, state: GroupListViewState): GroupListViewModel {
+            val currentSession = Matrix.getInstance().currentSession
+            val selectedGroupHolder = activity.get<SelectedGroupHolder>()
+            return GroupListViewModel(state, selectedGroupHolder, currentSession)
+        }
+    }
+
+    init {
+        observeGroupSummaries()
+        observeState()
+    }
+
+    private fun observeState() {
+        subscribe {
+            selectedGroupHolder.setSelectedGroup(it.selectedGroup)
+        }
+    }
+
+    fun accept(action: GroupListActions) {
+        when (action) {
+            is GroupListActions.SelectGroup -> handleSelectGroup(action)
+        }
+    }
+
+    // PRIVATE METHODS *****************************************************************************
+
+    private fun handleSelectGroup(action: GroupListActions.SelectGroup) = withState { state ->
+        if (state.selectedGroup?.groupId != action.groupSummary.groupId) {
+            setState { copy(selectedGroup = action.groupSummary) }
+        } else {
+            setState { copy(selectedGroup = null) }
+        }
+    }
+
+
+    private fun observeGroupSummaries() {
+        session
+                .rx().liveGroupSummaries()
+                .execute { async ->
+                    copy(asyncGroups = async)
+                }
+    }
+
+
+}

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

@@ -0,0 +1,11 @@
+package im.vector.riotredesign.features.home.group
+
+import com.airbnb.mvrx.Async
+import com.airbnb.mvrx.MvRxState
+import com.airbnb.mvrx.Uninitialized
+import im.vector.matrix.android.api.session.group.model.GroupSummary
+
+data class GroupListViewState(
+        val asyncGroups: Async<List<GroupSummary>> = Uninitialized,
+        val selectedGroup: GroupSummary? = null
+) : MvRxState

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

@@ -2,12 +2,11 @@ package im.vector.riotredesign.features.home.group
 
 import com.airbnb.epoxy.TypedEpoxyController
 import im.vector.matrix.android.api.session.group.model.GroupSummary
-import im.vector.riotredesign.features.home.HomeViewState
 
 class GroupSummaryController(private val callback: Callback? = null
-) : TypedEpoxyController<HomeViewState>() {
+) : TypedEpoxyController<GroupListViewState>() {
 
-    override fun buildModels(viewState: HomeViewState) {
+    override fun buildModels(viewState: GroupListViewState) {
         buildGroupModels(viewState.asyncGroups(), viewState.selectedGroup)
     }
 

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

@@ -0,0 +1,22 @@
+package im.vector.riotredesign.features.home.group
+
+import arrow.core.Option
+import im.vector.matrix.android.api.session.group.model.GroupSummary
+import io.reactivex.Observable
+import io.reactivex.subjects.BehaviorSubject
+
+class SelectedGroupHolder {
+
+    private val selectedGroupStream = BehaviorSubject.createDefault<Option<GroupSummary>>(Option.empty())
+
+    fun setSelectedGroup(group: GroupSummary?) {
+        val optionValue = Option.fromNullable(group)
+        selectedGroupStream.onNext(optionValue)
+    }
+
+    fun selectedGroup(): Observable<Option<GroupSummary>> {
+        return selectedGroupStream.hide()
+    }
+
+
+}

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

@@ -6,8 +6,6 @@ import android.support.v7.widget.LinearLayoutManager
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import com.airbnb.mvrx.Success
-import com.airbnb.mvrx.activityViewModel
 import com.airbnb.mvrx.args
 import com.airbnb.mvrx.fragmentViewModel
 import im.vector.matrix.android.api.permalinks.PermalinkParser
@@ -16,8 +14,6 @@ import im.vector.riotredesign.R
 import im.vector.riotredesign.core.platform.RiotFragment
 import im.vector.riotredesign.core.platform.ToolbarConfigurable
 import im.vector.riotredesign.features.home.AvatarRenderer
-import im.vector.riotredesign.features.home.HomeActions
-import im.vector.riotredesign.features.home.HomeViewModel
 import im.vector.riotredesign.features.home.room.detail.timeline.TimelineEventController
 import kotlinx.android.parcel.Parcelize
 import kotlinx.android.synthetic.main.fragment_room_detail.*
@@ -41,7 +37,6 @@ class RoomDetailFragment : RiotFragment(), TimelineEventController.Callback {
         }
     }
 
-    private val homeViewModel: HomeViewModel by activityViewModel()
     private val roomDetailViewModel: RoomDetailViewModel by fragmentViewModel()
     private val roomDetailArgs: RoomDetailArgs by args()
 
@@ -83,12 +78,8 @@ class RoomDetailFragment : RiotFragment(), TimelineEventController.Callback {
     }
 
     private fun renderState(state: RoomDetailViewState) {
-        when (state.asyncTimeline) {
-            is Success -> renderTimeline(state.asyncTimeline())
-        }
-        when (state.asyncRoomSummary) {
-            is Success -> renderRoomSummary(state.asyncRoomSummary())
-        }
+        renderTimeline(state.asyncTimeline())
+        renderRoomSummary(state.asyncRoomSummary())
     }
 
     private fun renderRoomSummary(roomSummary: RoomSummary?) {
@@ -113,7 +104,7 @@ class RoomDetailFragment : RiotFragment(), TimelineEventController.Callback {
 
     override fun onUrlClicked(url: String) {
         val permalinkData = PermalinkParser.parse(url)
-        homeViewModel.accept(HomeActions.PermalinkClicked(permalinkData))
+
     }
 
 }

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

@@ -1,17 +1,17 @@
 package im.vector.riotredesign.features.home.room.detail
 
 import android.support.v4.app.FragmentActivity
-import com.airbnb.mvrx.BaseMvRxViewModel
 import com.airbnb.mvrx.MvRxViewModelFactory
 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.rx.rx
+import im.vector.riotredesign.core.platform.RiotViewModel
 
 class RoomDetailViewModel(initialState: RoomDetailViewState,
                           session: Session
-) : BaseMvRxViewModel<RoomDetailViewState>(initialState) {
+) : RiotViewModel<RoomDetailViewState>(initialState) {
 
     private val room = session.getRoom(initialState.roomId)!!
     private val roomId = initialState.roomId
@@ -53,10 +53,9 @@ class RoomDetailViewModel(initialState: RoomDetailViewState,
 
     private fun observeTimeline() {
         room.rx().timeline(eventId)
-                .execute { async ->
-                    copy(asyncTimeline = async)
+                .execute { asyncTimeline ->
+                    copy(asyncTimeline = asyncTimeline)
                 }
     }
 
-
 }

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

@@ -0,0 +1,11 @@
+package im.vector.riotredesign.features.home.room.list
+
+import im.vector.matrix.android.api.session.room.model.RoomSummary
+
+sealed class RoomListActions {
+
+    data class SelectRoom(val roomSummary: RoomSummary) : RoomListActions()
+
+    object RoomDisplayed : RoomListActions()
+
+}

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

@@ -13,10 +13,7 @@ import im.vector.matrix.android.api.session.room.model.RoomSummary
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.platform.RiotFragment
 import im.vector.riotredesign.core.platform.StateView
-import im.vector.riotredesign.features.home.HomeActions
 import im.vector.riotredesign.features.home.HomeNavigator
-import im.vector.riotredesign.features.home.HomeViewModel
-import im.vector.riotredesign.features.home.HomeViewState
 import kotlinx.android.synthetic.main.fragment_room_list.*
 import org.koin.android.ext.android.inject
 
@@ -29,7 +26,7 @@ class RoomListFragment : RiotFragment(), RoomSummaryController.Callback {
     }
 
     private val homeNavigator by inject<HomeNavigator>()
-    private val homeViewModel: HomeViewModel by activityViewModel()
+    private val homeViewModel: RoomListViewModel by activityViewModel()
     private lateinit var roomController: RoomSummaryController
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
@@ -44,19 +41,15 @@ class RoomListFragment : RiotFragment(), RoomSummaryController.Callback {
         homeViewModel.subscribe { renderState(it) }
     }
 
-    private fun renderState(state: HomeViewState) {
+    private fun renderState(state: RoomListViewState) {
         when (state.asyncRooms) {
             is Incomplete -> renderLoading()
             is Success -> renderSuccess(state)
             is Fail -> renderFailure(state.asyncRooms.error)
         }
-        if (state.shouldOpenRoomDetail && state.selectedRoomId != null) {
-            homeNavigator.openRoomDetail(state.selectedRoomId, null)
-            homeViewModel.accept(HomeActions.RoomDisplayed)
-        }
     }
 
-    private fun renderSuccess(state: HomeViewState) {
+    private fun renderSuccess(state: RoomListViewState) {
         if (state.asyncRooms().isNullOrEmpty()) {
             stateView.state = StateView.State.Empty(getString(R.string.room_list_empty))
         } else {
@@ -78,7 +71,8 @@ class RoomListFragment : RiotFragment(), RoomSummaryController.Callback {
     }
 
     override fun onRoomSelected(room: RoomSummary) {
-        homeViewModel.accept(HomeActions.SelectRoom(room))
+        homeViewModel.accept(RoomListActions.SelectRoom(room))
+        homeNavigator.openRoomDetail(room.roomId, null)
     }
 
 }

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

@@ -0,0 +1,93 @@
+package im.vector.riotredesign.features.home.room.list
+
+import android.support.v4.app.FragmentActivity
+import arrow.core.Option
+import com.airbnb.mvrx.MvRxViewModelFactory
+import im.vector.matrix.android.api.Matrix
+import im.vector.matrix.android.api.session.Session
+import im.vector.matrix.android.api.session.group.model.GroupSummary
+import im.vector.matrix.android.api.session.room.model.RoomSummary
+import im.vector.matrix.rx.rx
+import im.vector.riotredesign.core.platform.RiotViewModel
+import im.vector.riotredesign.features.home.group.SelectedGroupHolder
+import io.reactivex.Observable
+import io.reactivex.functions.BiFunction
+import org.koin.android.ext.android.get
+
+class RoomListViewModel(initialState: RoomListViewState,
+                        private val session: Session,
+                        private val selectedGroupHolder: SelectedGroupHolder,
+                        private val roomSelectionRepository: RoomSelectionRepository)
+    : RiotViewModel<RoomListViewState>(initialState) {
+
+    companion object : MvRxViewModelFactory<RoomListViewState> {
+
+        @JvmStatic
+        override fun create(activity: FragmentActivity, state: RoomListViewState): RoomListViewModel {
+            val currentSession = Matrix.getInstance().currentSession
+            val roomSelectionRepository = activity.get<RoomSelectionRepository>()
+            val selectedGroupHolder = activity.get<SelectedGroupHolder>()
+            return RoomListViewModel(state, currentSession, selectedGroupHolder, roomSelectionRepository)
+        }
+    }
+
+    init {
+        observeRoomSummaries()
+    }
+
+    fun accept(action: RoomListActions) {
+        when (action) {
+            is RoomListActions.SelectRoom -> handleSelectRoom(action)
+        }
+    }
+
+    // PRIVATE METHODS *****************************************************************************
+
+    private fun handleSelectRoom(action: RoomListActions.SelectRoom) = withState { state ->
+        if (state.selectedRoomId != action.roomSummary.roomId) {
+            roomSelectionRepository.saveLastSelectedRoom(action.roomSummary.roomId)
+            setState { copy(selectedRoomId = action.roomSummary.roomId) }
+        }
+    }
+
+    private fun observeRoomSummaries() {
+        Observable.combineLatest<List<RoomSummary>, Option<GroupSummary>, RoomSummaries>(
+                session.rx().liveRoomSummaries(),
+                selectedGroupHolder.selectedGroup(),
+                BiFunction { rooms, selectedGroupOption ->
+                    val selectedGroup = selectedGroupOption.orNull()
+
+                    val filteredDirectRooms = rooms
+                            .filter { it.isDirect }
+                            .filter {
+                                if (selectedGroup == null) {
+                                    true
+                                } else {
+                                    it.otherMemberIds
+                                            .intersect(selectedGroup.userIds)
+                                            .isNotEmpty()
+                                }
+                            }
+
+                    val filteredGroupRooms = rooms
+                            .filter { !it.isDirect }
+                            .filter {
+                                selectedGroup?.roomIds?.contains(it.roomId) ?: true
+                            }
+                    RoomSummaries(filteredDirectRooms, filteredGroupRooms)
+                }
+        )
+                .execute { async ->
+                    val summaries = async()
+                    val selectedRoomId = selectedRoomId
+                            ?: roomSelectionRepository.lastSelectedRoom()
+                            ?: summaries?.directRooms?.firstOrNull()?.roomId
+                            ?: summaries?.groupRooms?.firstOrNull()?.roomId
+
+                    copy(
+                            asyncRooms = async,
+                            selectedRoomId = selectedRoomId
+                    )
+                }
+    }
+}

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

@@ -0,0 +1,20 @@
+package im.vector.riotredesign.features.home.room.list
+
+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 RoomListViewState(
+        val asyncRooms: Async<RoomSummaries> = Uninitialized,
+        val selectedRoomId: String? = null
+) : MvRxState
+
+data class RoomSummaries(
+        val directRooms: List<RoomSummary>,
+        val groupRooms: List<RoomSummary>
+)
+
+fun RoomSummaries?.isNullOrEmpty(): Boolean {
+    return this == null || (directRooms.isEmpty() && groupRooms.isEmpty())
+}

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

@@ -2,17 +2,15 @@ package im.vector.riotredesign.features.home.room.list
 
 import com.airbnb.epoxy.TypedEpoxyController
 import im.vector.matrix.android.api.session.room.model.RoomSummary
-import im.vector.riotredesign.features.home.HomeViewState
 
 class RoomSummaryController(private val callback: Callback? = null
-) : TypedEpoxyController<HomeViewState>() {
-
+) : TypedEpoxyController<RoomListViewState>() {
 
     private var isDirectRoomsExpanded = true
     private var isGroupRoomsExpanded = true
 
-    override fun buildModels(viewState: HomeViewState) {
-
+    override fun buildModels(viewState: RoomListViewState) {
+        val roomSummaries = viewState.asyncRooms()
         RoomCategoryItem(
                 title = "DIRECT MESSAGES",
                 isExpanded = isDirectRoomsExpanded,
@@ -25,16 +23,7 @@ class RoomSummaryController(private val callback: Callback? = null
                 .addTo(this)
 
         if (isDirectRoomsExpanded) {
-            val filteredDirectRooms = viewState.directRooms.filter {
-                if (viewState.selectedGroup == null) {
-                    true
-                } else {
-                    it.otherMemberIds
-                            .intersect(viewState.selectedGroup.userIds)
-                            .isNotEmpty()
-                }
-            }
-            buildRoomModels(filteredDirectRooms, viewState.selectedRoomId)
+            buildRoomModels(roomSummaries?.directRooms ?: emptyList(), viewState.selectedRoomId)
         }
 
         RoomCategoryItem(
@@ -49,10 +38,7 @@ class RoomSummaryController(private val callback: Callback? = null
                 .addTo(this)
 
         if (isGroupRoomsExpanded) {
-            val filteredGroupRooms = viewState.groupRooms.filter {
-                viewState.selectedGroup?.roomIds?.contains(it.roomId) ?: true
-            }
-            buildRoomModels(filteredGroupRooms, viewState.selectedRoomId)
+            buildRoomModels(roomSummaries?.groupRooms ?: emptyList(), viewState.selectedRoomId)
         }
 
     }

matrix-sdk-android-rx/build.gradle

@@ -40,7 +40,7 @@ dependencies {
     implementation 'io.reactivex.rxjava2:rxandroid:2.0.2'
 
     // Paging
-    api "android.arch.paging:runtime:1.0.1"
+    implementation "android.arch.paging:runtime:1.0.1"
 
 
     testImplementation 'junit:junit:4.12'

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

@@ -2,10 +2,10 @@ package im.vector.matrix.rx
 
 import android.arch.paging.PagedList
 import im.vector.matrix.android.api.session.events.model.EnrichedEvent
-import im.vector.matrix.android.api.session.group.model.GroupSummary
 import im.vector.matrix.android.api.session.room.Room
 import im.vector.matrix.android.api.session.room.model.RoomSummary
 import io.reactivex.Observable
+import io.reactivex.schedulers.Schedulers
 
 class RxRoom(private val room: Room) {
 
@@ -15,6 +15,7 @@ class RxRoom(private val room: Room) {
 
     fun timeline(eventId: String? = null): Observable<PagedList<EnrichedEvent>> {
         return room.timeline(eventId).asObservable()
+                .subscribeOn(Schedulers.io())
     }
 
 }