Stop delaying ElementCall until the next sync loop and only notify other participants when presumed to already be up to date.

ElementX/Sources/FlowCoordinators/UserSessionFlowCoordinator.swift

@@ -201,7 +201,7 @@ class UserSessionFlowCoordinator: FlowCoordinatorProtocol {
         case .userProfile(let userID):
             stateMachine.processEvent(.showUserProfileScreen(userID: userID), userInfo: .init(animated: animated))
         case .call(let roomID):
-            Task { await presentCallScreen(roomID: roomID) }
+            Task { await presentCallScreen(roomID: roomID, notifyOtherParticipants: false) }
         case .genericCallLink(let url):
             presentCallScreen(genericCallLink: url)
         case .settings, .chatBackupSettings:
@@ -579,7 +579,8 @@ class UserSessionFlowCoordinator: FlowCoordinatorProtocol {
 
             switch action {
             case .presentCallScreen(let roomProxy):
-                presentCallScreen(roomProxy: roomProxy)
+                // Here we assume that the app is running and the call state is already up to date
+                presentCallScreen(roomProxy: roomProxy, notifyOtherParticipants: !roomProxy.infoPublisher.value.hasRoomCall)
             case .finished:
                 stateMachine.processEvent(.deselectRoom)
             }
@@ -657,22 +658,23 @@ class UserSessionFlowCoordinator: FlowCoordinatorProtocol {
         presentCallScreen(configuration: .init(genericCallLink: url))
     }
 
-    private func presentCallScreen(roomID: String) async {
+    private func presentCallScreen(roomID: String, notifyOtherParticipants: Bool) async {
         guard case let .joined(roomProxy) = await userSession.clientProxy.roomForIdentifier(roomID) else {
             return
         }
 
-        presentCallScreen(roomProxy: roomProxy)
+        presentCallScreen(roomProxy: roomProxy, notifyOtherParticipants: notifyOtherParticipants)
     }
 
-    private func presentCallScreen(roomProxy: JoinedRoomProxyProtocol) {
+    private func presentCallScreen(roomProxy: JoinedRoomProxyProtocol, notifyOtherParticipants: Bool) {
         let colorScheme: ColorScheme = appMediator.windowManager.mainWindow.traitCollection.userInterfaceStyle == .light ? .light : .dark
         presentCallScreen(configuration: .init(roomProxy: roomProxy,
                                                clientProxy: userSession.clientProxy,
                                                clientID: InfoPlistReader.main.bundleIdentifier,
                                                elementCallBaseURL: appSettings.elementCallBaseURL,
                                                elementCallBaseURLOverride: appSettings.elementCallBaseURLOverride,
-                                               colorScheme: colorScheme))
+                                               colorScheme: colorScheme,
+                                               notifyOtherParticipants: notifyOtherParticipants))
     }
 
     private var callScreenPictureInPictureController: AVPictureInPictureController?
@@ -899,7 +901,7 @@ class UserSessionFlowCoordinator: FlowCoordinatorProtocol {
                 navigationSplitCoordinator.setSheetCoordinator(nil)
                 stateMachine.processEvent(.selectRoom(roomID: roomID, via: [], entryPoint: .room))
             case .startCall(let roomID):
-                Task { await self.presentCallScreen(roomID: roomID) }
+                Task { await self.presentCallScreen(roomID: roomID, notifyOtherParticipants: false) }
             case .dismiss:
                 navigationSplitCoordinator.setSheetCoordinator(nil)
             }

ElementX/Sources/Screens/CallScreen/CallScreenViewModel.swift

@@ -24,8 +24,6 @@ class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol
         actionsSubject.eraseToAnyPublisher()
     }
 
-    private var syncUpdateCancellable: AnyCancellable?
-
     /// Designated initialiser
     /// - Parameters:
     ///   - elementCallService: service responsible for setting up CallKit
@@ -43,7 +41,7 @@ class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol
         switch configuration.kind {
         case .genericCallLink(let url):
             widgetDriver = GenericCallLinkWidgetDriver(url: url)
-        case .roomCall(let roomProxy, let clientProxy, _, _, _, _):
+        case .roomCall(let roomProxy, let clientProxy, _, _, _, _, _):
             guard let deviceID = clientProxy.deviceID else { fatalError("Missing device ID for the call.") }
             widgetDriver = roomProxy.elementCallWidgetDriver(deviceID: deviceID)
         }
@@ -137,47 +135,39 @@ class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol
         case .genericCallLink(let url):
             state.url = url
             // We need widget messaging to work before enabling CallKit, otherwise mute, hangup etc do nothing.
-
-        case .roomCall(let roomProxy, let clientProxy, let clientID, let elementCallBaseURL, let elementCallBaseURLOverride, let colorScheme):
-            // Wait for room states to be up to date before starting the call and notifying others
-            syncUpdateCancellable = clientProxy.actionsPublisher
-                .filter(\.isSyncUpdate)
-                .timeout(.seconds(5), scheduler: DispatchQueue.main)
-                .first() // Timeout will make the publisher complete, use first to handle both branches in the same place
-                .sink(receiveCompletion: { [weak self] _ in
-                    Task { [weak self] in
-                        guard let self else { return }
-
-                        let baseURL = if let elementCallBaseURLOverride {
-                            elementCallBaseURLOverride
-                        } else if case .success(let wellKnown) = await clientProxy.getElementWellKnown(), let wellKnownCall = wellKnown?.call {
-                            wellKnownCall.widgetURL
-                        } else {
-                            elementCallBaseURL
-                        }
-
-                        switch await widgetDriver.start(baseURL: baseURL, clientID: clientID, colorScheme: colorScheme) {
-                        case .success(let url):
-                            state.url = url
-                        case .failure(let error):
-                            MXLog.error("Failed starting ElementCall Widget Driver with error: \(error)")
-                            state.bindings.alertInfo = .init(id: UUID(),
-                                                             title: L10n.errorUnknown,
-                                                             primaryButton: .init(title: L10n.actionOk) {
-                                                                 self.actionsSubject.send(.dismiss)
-                                                             })
-
-                            return
-                        }
-
-                        await elementCallService.setupCallSession(roomID: roomProxy.id,
-                                                                  roomDisplayName: roomProxy.infoPublisher.value.displayName ?? roomProxy.id)
-
-                        _ = await roomProxy.sendCallNotificationIfNeeded()
-
-                        syncUpdateCancellable = nil
-                    }
-                }, receiveValue: { _ in })
+
+        case .roomCall(let roomProxy, let clientProxy, let clientID, let elementCallBaseURL, let elementCallBaseURLOverride, let colorScheme, let notifyOtherParticipants):
+            Task { [weak self] in
+                guard let self else { return }
+
+                let baseURL = if let elementCallBaseURLOverride {
+                    elementCallBaseURLOverride
+                } else if case .success(let wellKnown) = await clientProxy.getElementWellKnown(), let wellKnownCall = wellKnown?.call {
+                    wellKnownCall.widgetURL
+                } else {
+                    elementCallBaseURL
+                }
+
+                switch await widgetDriver.start(baseURL: baseURL, clientID: clientID, colorScheme: colorScheme) {
+                case .success(let url):
+                    state.url = url
+                case .failure(let error):
+                    MXLog.error("Failed starting ElementCall Widget Driver with error: \(error)")
+                    state.bindings.alertInfo = .init(id: UUID(),
+                                                     title: L10n.errorUnknown,
+                                                     primaryButton: .init(title: L10n.actionOk) {
+                                                         self.actionsSubject.send(.dismiss)
+                                                     })
+                    return
+                }
+
+                await elementCallService.setupCallSession(roomID: roomProxy.id,
+                                                          roomDisplayName: roomProxy.infoPublisher.value.displayName ?? roomProxy.id)
+
+                if notifyOtherParticipants {
+                    _ = await roomProxy.sendCallNotificationIfNeeded()
+                }
+            }
         }
     }
 

ElementX/Sources/Screens/CallScreen/View/CallScreen.swift

@@ -303,7 +303,8 @@ struct CallScreen_Previews: PreviewProvider {
                                                         clientID: "io.element.elementx",
                                                         elementCallBaseURL: "https://call.element.io",
                                                         elementCallBaseURLOverride: nil,
-                                                        colorScheme: .light),
+                                                        colorScheme: .light,
+                                                        notifyOtherParticipants: false),
                                    allowPictureInPicture: false,
                                    appHooks: AppHooks())
     }()

ElementX/Sources/Services/ElementCall/ElementCallConfiguration.swift

@@ -21,7 +21,8 @@ struct ElementCallConfiguration {
                       clientID: String,
                       elementCallBaseURL: URL,
                       elementCallBaseURLOverride: URL?,
-                      colorScheme: ColorScheme)
+                      colorScheme: ColorScheme,
+                      notifyOtherParticipants: Bool)
     }
 
     /// The type of call being configured i.e. whether it's an external URL or an internal room call.
@@ -58,21 +59,23 @@ struct ElementCallConfiguration {
          clientID: String,
          elementCallBaseURL: URL,
          elementCallBaseURLOverride: URL?,
-         colorScheme: ColorScheme) {
+         colorScheme: ColorScheme,
+         notifyOtherParticipants: Bool) {
         kind = .roomCall(roomProxy: roomProxy,
                          clientProxy: clientProxy,
                          clientID: clientID,
                          elementCallBaseURL: elementCallBaseURL,
                          elementCallBaseURLOverride: elementCallBaseURLOverride,
-                         colorScheme: colorScheme)
+                         colorScheme: colorScheme,
+                         notifyOtherParticipants: notifyOtherParticipants)
     }
 
     /// A string representing the call being configured.
     var callRoomID: String {
         switch kind {
         case .genericCallLink(let url):
             url.absoluteString
-        case .roomCall(let roomProxy, _, _, _, _, _):
+        case .roomCall(let roomProxy, _, _, _, _, _, _):
             roomProxy.id
         }
     }