Device Verification: Display the "The other party cancelled the verification." modal

Riot/Modules/DeviceVerification/Start/DeviceVerificationStartViewController.swift

@@ -157,7 +157,9 @@ final class DeviceVerificationStartViewController: UIViewController {
         case .loading:
             self.renderLoading()
         case .loaded:
-            self.renderLoaded()
+            self.renderStarted()
+        case .cancelled(let reason):
+            self.renderCancelled(reason: reason)
         case .error(let error):
             self.render(error: error)
         }
@@ -167,13 +169,21 @@ final class DeviceVerificationStartViewController: UIViewController {
         self.activityPresenter.presentActivityIndicator(on: self.view, animated: true)
     }
     
-    private func renderLoaded() {
+    private func renderStarted() {
         self.activityPresenter.removeCurrentActivityIndicator(animated: true)
 
         self.verifyButtonBackgroundView.isHidden = true
         self.waitingPartnerLabel.isHidden = false
         self.useLegacyVerificationLabel.isHidden = false
     }
+
+    private func renderCancelled(reason: MXTransactionCancelCode) {
+        self.activityPresenter.removeCurrentActivityIndicator(animated: true)
+
+        self.errorPresenter.presentError(from: self, title: "", message: VectorL10n.deviceVerificationCancelled, animated: true) {
+            self.viewModel.process(viewAction: .cancel)
+        }
+    }
     
     private func render(error: Error) {
         self.activityPresenter.removeCurrentActivityIndicator(animated: true)

Riot/Modules/DeviceVerification/Start/DeviceVerificationStartViewModel.swift

@@ -114,7 +114,10 @@ final class DeviceVerificationStartViewModel: DeviceVerificationStartViewModelTy
         case MXSASTransactionStateShowSAS:
             self.coordinatorDelegate?.deviceVerificationStartViewModel(self, didCompleteWithOutgoingTransaction: transaction)
         case MXSASTransactionStateCancelled:
-            self.coordinatorDelegate?.deviceVerificationStartViewModel(self, didTransactionCancelled: transaction)
+            guard let reason = transaction.reasonCancelCode else {
+                return
+            }
+            self.update(viewState: .cancelled(reason))
         default:
             break
         }

Riot/Modules/DeviceVerification/Start/DeviceVerificationStartViewState.swift

@@ -21,6 +21,7 @@ import Foundation
 /// DeviceVerificationStartViewController view state
 enum DeviceVerificationStartViewState {
     case loading
-    case loaded
+    case loaded     // started
+    case cancelled(MXTransactionCancelCode)
     case error(Error)
 }