Room List Filters Empty State View (#2522)

ElementX/Sources/Screens/HomeScreen/HomeScreenModels.swift

@@ -118,6 +118,10 @@ struct HomeScreenViewState: BindableState {
     var shouldHideRoomList: Bool {
         bindings.isSearchFieldFocused && bindings.searchQuery.isEmpty
     }
+    
+    var shouldShowEmptyFilterState: Bool {
+        shouldShowFilters && bindings.filtersState.isFiltering && visibleRooms.isEmpty
+    }
 }
 
 struct HomeScreenViewStateBindings {

ElementX/Sources/Screens/HomeScreen/View/Filters/RoomListFiltersEmptyStateView.swift

@@ -0,0 +1,71 @@
+//
+// Copyright 2024 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.
+//
+
+import SwiftUI
+
+struct RoomListFiltersEmptyStateView: View {
+    let state: RoomListFiltersState
+    
+    private var emptyStateTitle: String {
+        if state.activeFilters.count == 1 {
+            switch state.activeFilters[0] {
+            case .unreads:
+                return L10n.screenRoomlistFilterUnreadsEmptyStateTitle
+            case .people:
+                return L10n.screenRoomlistFilterPeopleEmptyStateTitle
+            case .rooms:
+                return L10n.screenRoomlistFilterRoomsEmptyStateTitle
+            case .favourites:
+                return L10n.screenRoomlistFilterFavouritesEmptyStateTitle
+            }
+        }
+        return L10n.screenRoomlistFilterMixedEmptyStateTitle
+    }
+    
+    private var emptyStateSubtitle: String {
+        if state.activeFilters.first == .favourites {
+            return L10n.screenRoomlistFilterFavouritesEmptyStateSubtitle
+        }
+        return L10n.screenRoomlistFilterMixedEmptyStateSubtitle
+    }
+
+    var body: some View {
+        VStack(spacing: 24) {
+            Text(emptyStateTitle)
+                .multilineTextAlignment(.center)
+                .font(.compound.headingSMSemibold)
+                .foregroundColor(.compound.textPrimary)
+            
+            Text(emptyStateSubtitle)
+                .multilineTextAlignment(.center)
+                .font(.compound.bodyMD)
+                .foregroundColor(.compound.textSecondary)
+        }
+        .padding(.horizontal, 60)
+    }
+}
+
+struct RoomListFiltersEmptyStateView_Previews: PreviewProvider, TestablePreview {
+    static var previews: some View {
+        VStack(spacing: 24) {
+            ForEach(RoomListFilter.allCases) { filter in
+                RoomListFiltersEmptyStateView(state: .init(activeFilters: [filter]))
+            }
+            RoomListFiltersEmptyStateView(state: .init(activeFilters: [.people, .favourites]))
+        }
+        .previewLayout(.sizeThatFits)
+    }
+}

ElementX/Sources/Screens/HomeScreen/View/HomeScreenContent.swift

@@ -20,6 +20,7 @@ struct HomeScreenContent: View {
     @Environment(\.verticalSizeClass) private var verticalSizeClass
     
     @ObservedObject var context: HomeScreenViewModel.Context
+    @State private var topSectionFrame: CGRect = .zero
     let scrollViewAdapter: ScrollViewAdapter
     
     var body: some View {
@@ -56,9 +57,15 @@ struct HomeScreenContent: View {
                         // Showing empty views in pinned headers makes the room list spasm when reaching the top
                         LazyVStack(spacing: 0, pinnedViews: [.sectionHeaders]) {
                             Section {
-                                HomeScreenRoomList(context: context)
+                                if context.viewState.shouldShowEmptyFilterState {
+                                    RoomListFiltersEmptyStateView(state: context.filtersState)
+                                        .frame(height: geometry.size.height - topSectionFrame.height)
+                                } else {
+                                    HomeScreenRoomList(context: context)
+                                }
                             } header: {
                                 topSection
+                                    .readFrame($topSectionFrame)
                             }
                         }
                         .searchable(text: $context.searchQuery)