Update OIDC presentation (#987)

* Present OIDC directly on the ServerConfirmationScreen.

Read the actual window from the view.

* Pop back to the confirmation screen when a user enters an MXID that needs OIDC.

* Remove OIDC error handling from the login screen.

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/ServerConfirmationScreenCoordinator.swift

@@ -23,7 +23,7 @@ struct ServerConfirmationScreenCoordinatorParameters {
 }
 
 enum ServerConfirmationScreenCoordinatorAction {
-    case confirm
+    case `continue`(UIWindow?)
     case changeServer
 }
 
@@ -50,7 +50,7 @@ final class ServerConfirmationScreenCoordinator: CoordinatorProtocol {
             
             switch action {
             case .confirm:
-                self.actionsSubject.send(.confirm)
+                self.actionsSubject.send(.continue(viewModel.context.viewState.window))
             case .changeServer:
                 self.actionsSubject.send(.changeServer)
             }

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/ServerConfirmationScreenModels.swift

@@ -14,7 +14,7 @@
 // limitations under the License.
 //
 
-import Foundation
+import SwiftUI
 
 enum ServerConfirmationScreenViewModelAction {
     /// The user would like to continue with the current homeserver.
@@ -28,6 +28,8 @@ struct ServerConfirmationScreenViewState: BindableState {
     var homeserverAddress: String
     /// The flow being attempted on the selected homeserver.
     let authenticationFlow: AuthenticationFlow
+    /// The presentation anchor used for OIDC authentication.
+    var window: UIWindow?
     
     /// The screen's title.
     var title: String {
@@ -57,6 +59,8 @@ struct ServerConfirmationScreenViewState: BindableState {
 }
 
 enum ServerConfirmationScreenViewAction {
+    /// Updates the window used as the OIDC presentation anchor.
+    case updateWindow(UIWindow)
     /// The user would like to continue with the current homeserver.
     case confirm
     /// The user would like to change to a different homeserver.

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/ServerConfirmationScreenViewModel.swift

@@ -43,6 +43,9 @@ class ServerConfirmationScreenViewModel: ServerConfirmationScreenViewModelType,
     
     override func process(viewAction: ServerConfirmationScreenViewAction) {
         switch viewAction {
+        case .updateWindow(let window):
+            guard state.window != window else { return }
+            Task { state.window = window }
         case .confirm:
             actionsSubject.send(.confirm)
         case .changeServer:

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/View/ServerConfirmationScreen.swift

@@ -34,6 +34,10 @@ struct ServerConfirmationScreen: View {
                 .readableFrame()
                 .background(Color.element.background.ignoresSafeArea())
         }
+        .introspectViewController { viewController in
+            guard let window = viewController.view.window else { return }
+            context.send(viewAction: .updateWindow(window))
+        }
     }
     
     /// The main content of the view to be shown in a scroll view.