App Layout invites empty state

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

@@ -199,6 +199,9 @@ class HomeRoomListFragment :
                 ).also { controller ->
                     controller.listener = this
                     controller.onFilterChanged = ::onRoomFilterChanged
+                    roomListViewModel.emptyStateFlow.onEach { emptyStateOptional ->
+                        controller.submitEmptyStateData(emptyStateOptional.getOrNull())
+                    }.launchIn(lifecycleScope)
                     section.filtersData.onEach {
                         controller.submitFiltersData(it.getOrNull())
                     }.launchIn(lifecycleScope)

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

@@ -23,11 +23,14 @@ import com.airbnb.mvrx.MavericksViewModelFactory
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
+import im.vector.app.R
 import im.vector.app.SpaceStateHandler
 import im.vector.app.core.di.MavericksAssistedViewModelFactory
 import im.vector.app.core.di.hiltMavericksViewModelFactory
 import im.vector.app.core.platform.StateView
 import im.vector.app.core.platform.VectorViewModel
+import im.vector.app.core.resources.StringProvider
+import im.vector.app.features.displayname.getBestName
 import im.vector.app.features.home.room.list.home.filter.HomeRoomFilter
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableSharedFlow
@@ -52,17 +55,20 @@ import org.matrix.android.sdk.api.session.room.RoomSortOrder
 import org.matrix.android.sdk.api.session.room.RoomSummaryQueryParams
 import org.matrix.android.sdk.api.session.room.UpdatableLivePageResult
 import org.matrix.android.sdk.api.session.room.model.Membership
+import org.matrix.android.sdk.api.session.room.model.RoomSummary
 import org.matrix.android.sdk.api.session.room.model.tag.RoomTag
 import org.matrix.android.sdk.api.session.room.roomSummaryQueryParams
 import org.matrix.android.sdk.api.session.room.state.isPublic
 import org.matrix.android.sdk.api.util.Optional
+import org.matrix.android.sdk.api.util.toMatrixItem
 import org.matrix.android.sdk.flow.flow
 
 class HomeRoomListViewModel @AssistedInject constructor(
         @Assisted initialState: HomeRoomListViewState,
         private val session: Session,
         private val spaceStateHandler: SpaceStateHandler,
         private val preferencesStore: HomeLayoutPreferencesStore,
+        private val stringProvider: StringProvider,
 ) : VectorViewModel<HomeRoomListViewState, HomeRoomListAction, HomeRoomListViewEvents>(initialState) {
 
     @AssistedFactory
@@ -82,6 +88,9 @@ class HomeRoomListViewModel @AssistedInject constructor(
     private val _sections = MutableSharedFlow<Set<HomeRoomSection>>(replay = 1)
     val sections = _sections.asSharedFlow()
 
+    private val _emptyStateFlow = MutableSharedFlow<Optional<StateView.State.Empty>>(replay = 1)
+    val emptyStateFlow = _emptyStateFlow.asSharedFlow()
+
     private var filteredPagedRoomSummariesLive: UpdatableLivePageResult? = null
 
     init {
@@ -230,11 +239,11 @@ class HomeRoomListViewModel @AssistedInject constructor(
 
     private fun getFilteredQueryParams(filter: HomeRoomFilter, currentParams: RoomSummaryQueryParams): RoomSummaryQueryParams {
         return when (filter) {
-            HomeRoomFilter.ALL -> currentParams.copy(
+            HomeRoomFilter.ALL        -> currentParams.copy(
                     roomCategoryFilter = null,
                     roomTagQueryFilter = null
             )
-            HomeRoomFilter.UNREADS -> currentParams.copy(
+            HomeRoomFilter.UNREADS    -> currentParams.copy(
                     roomCategoryFilter = RoomCategoryFilter.ONLY_WITH_NOTIFICATIONS,
                     roomTagQueryFilter = RoomTagQueryFilter(null, false, null)
             )
@@ -243,27 +252,57 @@ class HomeRoomListViewModel @AssistedInject constructor(
                         roomCategoryFilter = null,
                         roomTagQueryFilter = RoomTagQueryFilter(true, null, null)
                 )
-            HomeRoomFilter.PEOPlE -> currentParams.copy(
+            HomeRoomFilter.PEOPlE     -> currentParams.copy(
                     roomCategoryFilter = RoomCategoryFilter.ONLY_DM,
                     roomTagQueryFilter = null
             )
         }
     }
 
+    private fun getEmptyStateData(filter: HomeRoomFilter, selectedSpace: RoomSummary?): StateView.State.Empty? {
+        return when (filter) {
+            HomeRoomFilter.ALL     ->
+                if (selectedSpace != null) {
+                    StateView.State.Empty(
+                            title = stringProvider.getString(R.string.home_empty_space_no_rooms_title, selectedSpace.displayName),
+                            message = stringProvider.getString(R.string.home_empty_space_no_rooms_message)
+                    )
+                } else {
+                    val userName = session.userService().getUser(session.myUserId)?.displayName ?: ""
+                    StateView.State.Empty(
+                            title = stringProvider.getString(R.string.home_empty_no_rooms_title, userName),
+                            message = stringProvider.getString(R.string.home_empty_no_rooms_message)
+                    )
+                }
+            HomeRoomFilter.UNREADS ->
+                StateView.State.Empty(
+                        title = stringProvider.getString(R.string.home_empty_no_unreads_title),
+                        message = stringProvider.getString(R.string.home_empty_no_unreads_message)
+                )
+            else                   ->
+                null
+        }
+    }
+
     override fun handle(action: HomeRoomListAction) {
         when (action) {
-            is HomeRoomListAction.SelectRoom -> handleSelectRoom(action)
-            is HomeRoomListAction.LeaveRoom -> handleLeaveRoom(action)
+            is HomeRoomListAction.SelectRoom                  -> handleSelectRoom(action)
+            is HomeRoomListAction.LeaveRoom                   -> handleLeaveRoom(action)
             is HomeRoomListAction.ChangeRoomNotificationState -> handleChangeNotificationMode(action)
-            is HomeRoomListAction.ToggleTag -> handleToggleTag(action)
-            is HomeRoomListAction.ChangeRoomFilter -> handleChangeRoomFilter(action)
+            is HomeRoomListAction.ToggleTag                   -> handleToggleTag(action)
+            is HomeRoomListAction.ChangeRoomFilter            -> handleChangeRoomFilter(action)
         }
     }
 
     private fun handleChangeRoomFilter(action: HomeRoomListAction.ChangeRoomFilter) {
         filteredPagedRoomSummariesLive?.let { liveResults ->
             liveResults.queryParams = getFilteredQueryParams(action.filter, liveResults.queryParams)
         }
+
+        viewModelScope.launch {
+            val emptyState = getEmptyStateData(action.filter, spaceStateHandler.getCurrentSpace())
+            _emptyStateFlow.emit(Optional.from(emptyState))
+        }
     }
 
     fun isPublicRoom(roomId: String): Boolean {
@@ -322,9 +361,9 @@ class HomeRoomListViewModel @AssistedInject constructor(
 
     private fun String.otherTag(): String? {
         return when (this) {
-            RoomTag.ROOM_TAG_FAVOURITE -> RoomTag.ROOM_TAG_LOW_PRIORITY
+            RoomTag.ROOM_TAG_FAVOURITE    -> RoomTag.ROOM_TAG_LOW_PRIORITY
             RoomTag.ROOM_TAG_LOW_PRIORITY -> RoomTag.ROOM_TAG_FAVOURITE
-            else -> null
+            else                          -> null
         }
     }
 }

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

@@ -18,6 +18,7 @@ package im.vector.app.features.home.room.list.home
 
 import androidx.lifecycle.LiveData
 import androidx.paging.PagedList
+import im.vector.app.core.platform.StateView
 import im.vector.app.features.home.room.list.home.filter.HomeRoomFilter
 import kotlinx.coroutines.flow.SharedFlow
 import org.matrix.android.sdk.api.session.room.model.RoomSummary

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

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2022 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.app.features.home.room.list.home
+
+import com.airbnb.epoxy.EpoxyAttribute
+import com.airbnb.epoxy.EpoxyModelClass
+import com.google.android.material.tabs.TabLayout
+import im.vector.app.R
+import im.vector.app.core.epoxy.VectorEpoxyHolder
+import im.vector.app.core.epoxy.VectorEpoxyModel
+import im.vector.app.core.platform.StateView
+import im.vector.app.features.home.room.list.home.filter.HomeRoomFilter
+import im.vector.app.features.home.room.list.home.filter.RoomFilterHeaderItem
+
+@EpoxyModelClass
+abstract class RoomListEmptyItem : VectorEpoxyModel<RoomListEmptyItem.Holder>(R.layout.item_room_list_empty) {
+
+    @EpoxyAttribute
+    var emptyData: StateView.State.Empty? = null
+
+    override fun bind(holder: Holder) {
+        super.bind(holder)
+        holder.stateView.state = emptyData ?: StateView.State.Content
+    }
+
+    class Holder : VectorEpoxyHolder() {
+        val stateView by bind<StateView>(R.id.stateView)
+    }
+}

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

@@ -18,11 +18,13 @@ package im.vector.app.features.home.room.list.home.filter
 
 import com.airbnb.epoxy.EpoxyModel
 import com.airbnb.epoxy.paging.PagedListEpoxyController
+import im.vector.app.core.platform.StateView
 import im.vector.app.core.utils.createUIHandler
 import im.vector.app.features.home.RoomListDisplayMode
 import im.vector.app.features.home.room.list.RoomListListener
 import im.vector.app.features.home.room.list.RoomSummaryItemFactory
 import im.vector.app.features.home.room.list.RoomSummaryItemPlaceHolder_
+import im.vector.app.features.home.room.list.home.roomListEmptyItem
 import org.matrix.android.sdk.api.session.room.members.ChangeMembershipState
 import org.matrix.android.sdk.api.session.room.model.RoomSummary
 
@@ -44,6 +46,8 @@ class HomeFilteredRoomsController(
     var onFilterChanged: ((HomeRoomFilter) -> Unit)? = null
 
     private var filtersData: List<HomeRoomFilter>? = null
+    private var emptyStateData: StateView.State.Empty? = null
+    private var currentState: StateView.State = StateView.State.Content
 
     override fun addModels(models: List<EpoxyModel<*>>) {
         val host = this
@@ -54,14 +58,32 @@ class HomeFilteredRoomsController(
                 onFilterChangedListener(host.onFilterChanged)
             }
         }
-        super.addModels(models)
+
+        if (models.isEmpty() && emptyStateData != null) {
+            emptyStateData?.let { emptyState ->
+                roomListEmptyItem {
+                    id("state_item")
+                    emptyData(emptyState)
+                }
+                currentState = emptyState
+            }
+        } else {
+            currentState = StateView.State.Content
+            super.addModels(models)
+        }
+    }
+
+    fun submitEmptyStateData(state: StateView.State.Empty?) {
+        this.emptyStateData = state
+        if (currentState is StateView.State.Empty) {
+            requestModelBuild()
+        }
     }
 
     fun submitFiltersData(data: List<HomeRoomFilter>?) {
         this.filtersData = data
         requestForcedModelBuild()
     }
-
     override fun buildItemModel(currentPosition: Int, item: RoomSummary?): EpoxyModel<*> {
         item ?: return RoomSummaryItemPlaceHolder_().apply { id(currentPosition) }
         return roomSummaryItemFactory.create(item, roomChangeMembershipStates.orEmpty(), emptySet(), RoomListDisplayMode.ROOMS, listener)

vector/src/main/res/layout/item_room_list_empty.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<im.vector.app.core.platform.StateView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/stateView"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?android:colorBackground">
+
+</im.vector.app.core.platform.StateView>