Move SwiftUI version of ViewModel to a subclass

Riot/Modules/Room/NotificationSettings/RoomNotificationSettingsCoordinator.swift

@@ -56,23 +56,30 @@ final class RoomNotificationSettingsCoordinator: RoomNotificationSettingsCoordin
             )) : nil
         }
         
-        let roomNotificationSettingsViewModel = RoomNotificationSettingsViewModel(
-            roomNotificationService: roomNotificationService,
-            avatarData: avatarData,
-            displayName: room.summary.displayname,
-            roomEncrypted: room.summary.isEncrypted)
         
+        let viewModel: RoomNotificationSettingsViewModel
         let viewController: UIViewController
         if #available(iOS 14.0.0, *) {
+            let swiftUIViewModel = RoomNotificationSettingsSwiftUIViewModel(
+                roomNotificationService: roomNotificationService,
+                avatarData: avatarData,
+                displayName: room.summary.displayname,
+                roomEncrypted: room.summary.isEncrypted)
             let avatarService: AvatarServiceType = AvatarService(mediaManager: room.mxSession.mediaManager)
-            let view = RoomNotificationSettings(viewModel: roomNotificationSettingsViewModel, presentedModally: presentedModally)
+            let view = RoomNotificationSettings(viewModel: swiftUIViewModel, presentedModally: presentedModally)
                 .addDependency(avatarService)
             let host = VectorHostingController(rootView: view)
+            viewModel = swiftUIViewModel
             viewController = host
         } else {
-            viewController = RoomNotificationSettingsViewController.instantiate(with: roomNotificationSettingsViewModel)
+            viewModel = RoomNotificationSettingsViewModel(
+                roomNotificationService: roomNotificationService,
+                avatarData: avatarData,
+                displayName: room.summary.displayname,
+                roomEncrypted: room.summary.isEncrypted)
+            viewController = RoomNotificationSettingsViewController.instantiate(with: viewModel)
         }
-        self.roomNotificationSettingsViewModel = roomNotificationSettingsViewModel
+        self.roomNotificationSettingsViewModel = viewModel
         self.roomNotificationSettingsViewController = viewController
     }
 

Riot/Modules/Room/NotificationSettings/RoomNotificationSettingsSwiftUIViewModel.swift

@@ -0,0 +1,37 @@
+// 
+// Copyright 2021 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 Foundation
+import SwiftUI
+import Combine
+
+@available(iOS 14.0, *)
+class RoomNotificationSettingsSwiftUIViewModel: RoomNotificationSettingsViewModel, ObservableObject {
+
+    @Published var viewState: RoomNotificationSettingsViewState
+    
+    lazy var cancellables = Set<AnyCancellable>()
+    
+    override init(roomNotificationService: RoomNotificationSettingsServiceType, initialState: RoomNotificationSettingsViewState) {
+    self.viewState = initialState
+        super.init(roomNotificationService: roomNotificationService, initialState: initialState)
+    }
+    
+    override func update(viewState: RoomNotificationSettingsViewState) {
+        super.update(viewState: viewState)
+        self.viewState = viewState
+    }
+}

Riot/Modules/Room/NotificationSettings/RoomNotificationSettingsViewModel.swift

@@ -20,23 +20,19 @@ import Foundation
 import SwiftUI
 import Combine
 
-final class RoomNotificationSettingsViewModel: RoomNotificationSettingsViewModelType {
+class RoomNotificationSettingsViewModel: RoomNotificationSettingsViewModelType {
     
     // MARK: - Properties
     
     // MARK: Private
     
     private let roomNotificationService: RoomNotificationSettingsServiceType
-    private var state: RoomNotificationSettingsViewState {
+    var state: RoomNotificationSettingsViewState {
         willSet {
             update(viewState: newValue)
         }
     }
-    @available(iOS 14.0, *)
-    @Published var viewState: RoomNotificationSettingsViewState!
-    @available(iOS 14.0, *)
-    lazy var cancellables = Set<AnyCancellable>()
-    
+
     // MARK: Public
     
     weak var viewDelegate: RoomNotificationSettingsViewModelViewDelegate?
@@ -46,14 +42,26 @@ final class RoomNotificationSettingsViewModel: RoomNotificationSettingsViewModel
     // MARK: - Setup
     
     init(
+        roomNotificationService: RoomNotificationSettingsServiceType,
+        initialState: RoomNotificationSettingsViewState
+    ) {
+        self.roomNotificationService = roomNotificationService
+        self.state = initialState
+        
+        self.roomNotificationService.observeNotificationState { [weak self] state in
+            guard let self = self else { return }
+            self.state.notificationState = Self.mapNotificationStateOnRead(encrypted: self.state.roomEncrypted, state: state)
+        }
+    }
+    
+    convenience init(
         roomNotificationService: RoomNotificationSettingsServiceType,
         avatarData: AvatarInputOption?,
         displayName: String?,
         roomEncrypted: Bool
     ) {
-        self.roomNotificationService = roomNotificationService
-        
         let notificationState = Self.mapNotificationStateOnRead(encrypted: roomEncrypted, state: roomNotificationService.notificationState)
+        
         let initialState = RoomNotificationSettingsViewState(
             roomEncrypted: roomEncrypted,
             saving: false,
@@ -61,16 +69,7 @@ final class RoomNotificationSettingsViewModel: RoomNotificationSettingsViewModel
             avatarData: avatarData,
             displayName: displayName
         )
-        self.state = initialState
-        
-        if #available(iOS 14.0, *) {
-            self.viewState = initialState
-        }
-        
-        self.roomNotificationService.observeNotificationState { [weak self] state in
-            guard let self = self else { return }
-            self.state.notificationState = Self.mapNotificationStateOnRead(encrypted: roomEncrypted, state: state)
-        }
+        self.init(roomNotificationService: roomNotificationService, initialState: initialState)
     }
     
     // MARK: - Public 
@@ -104,14 +103,7 @@ final class RoomNotificationSettingsViewModel: RoomNotificationSettingsViewModel
         }
     }
     
-    private func update(viewState: RoomNotificationSettingsViewState) {
+    func update(viewState: RoomNotificationSettingsViewState) {
         self.viewDelegate?.roomNotificationSettingsViewModel(self, didUpdateViewState: viewState)
-        
-        if #available(iOS 14.0, *) {
-            self.viewState = viewState
-        }
     }
 }
-
-@available(iOS 14.0, *)
-extension RoomNotificationSettingsViewModel: ObservableObject {}

Riot/Modules/Room/NotificationSettings/SwiftUI/RoomNotificationSettings.swift

@@ -20,7 +20,7 @@ import SwiftUI
 struct RoomNotificationSettings: View {
     
     @Environment(\.theme) var theme: Theme
-    @ObservedObject var viewModel: RoomNotificationSettingsViewModel
+    @ObservedObject var viewModel: RoomNotificationSettingsSwiftUIViewModel
     
     let presentedModally: Bool
     
@@ -74,7 +74,7 @@ struct RoomNotificationSettings: View {
 @available(iOS 14.0, *)
 struct RoomNotificationSettings_Previews: PreviewProvider {
     
-    static let mockViewModel = RoomNotificationSettingsViewModel(
+    static let mockViewModel = RoomNotificationSettingsSwiftUIViewModel(
         roomNotificationService: MockRoomNotificationSettingsService.example,
         avatarData: .swiftUI(MockAvatarInput.example),
         displayName: MockAvatarInput.example.displayName,