[Amazon] StopConnect for UDC in iOS tv-casting-app

Updated iOS tv-casting-app to send stopConnect command when user exits
UDC before confirming passcode

Changes
1. MCConnectionExampleViewModel track if user confirmed passcode or not
2. MCConnectionExampleView trigger stopConnect when Connecting view
   dissapear

Test
1. Verified stopConnect works for normal UDC and commissioner generated
   passcode UDC
2. Verified alternating attempt of normal UDC and commissioner generated
   passcode UDC
3. Verified stopConnect is not called in other states other than pending
   passcode confirmation

Author: yuenton-amazon

examples/tv-casting-app/darwin/TvCasting/TvCasting/MCConnectionExampleView.swift

@@ -88,6 +88,9 @@ struct MCConnectionExampleView: View {
                 viewModel.connect(selectedCastingPlayer: self.selectedCastingPlayer, useCommissionerGeneratedPasscode: self.useCommissionerGeneratedPasscode)
             }
         })
+        .onDisappear(perform: {
+            viewModel.cancelConnectionAttempt(selectedCastingPlayer: self.selectedCastingPlayer)
+        })
     }
 }
 

examples/tv-casting-app/darwin/TvCasting/TvCasting/MCConnectionExampleViewModel.swift

@@ -25,6 +25,8 @@ class MCConnectionExampleViewModel: ObservableObject {
 
     var passcodeAlertController: UIAlertController?
 
+    var pendingPasscodeConfirmation: Bool = true;
+    
     // VendorId of the MCEndpoint on the MCCastingPlayer that the MCCastingApp desires to interact with after connection
     let kDesiredEndpointVendorId: UInt16 = 65521;
 
@@ -42,13 +44,33 @@ class MCConnectionExampleViewModel: ObservableObject {
 
     @Published var errorCodeDescription: String?
 
+    func cancelConnectionAttempt(selectedCastingPlayer: MCCastingPlayer?) {
+        DispatchQueue.main.async {
+            // Only stop connection if we are pending passcode confirmation
+            // We cannot stop connection once continueConnecting() is called
+            if self.pendingPasscodeConfirmation {
+                self.Log.info("MCConnectionExampleViewModel cancelConnect(). User navigating back from ConnectionView")
+                let err = selectedCastingPlayer?.stopConnecting()
+                if err == nil {
+                    self.pendingPasscodeConfirmation = false;
+                    self.connectionStatus = "User cancelled the connection attempt with CastingPlayer.stopConnecting()."
+                    self.Log.info("MCConnectionExampleViewModel cancelConnect() MCCastingPlayer.stopConnecting() succeeded.")
+                } else {
+                    self.connectionStatus = "Cancel connection failed due to: \(String(describing: err))."
+                    self.Log.error("MCConnectionExampleViewModel cancelConnect() MCCastingPlayer.stopConnecting() failed due to: \(err)")
+                }
+            }
+        }
+    }
+
     func connect(selectedCastingPlayer: MCCastingPlayer?, useCommissionerGeneratedPasscode: Bool) {
         self.Log.info("MCConnectionExampleViewModel.connect() useCommissionerGeneratedPasscode: \(String(describing: useCommissionerGeneratedPasscode))")
 
         let connectionCompleteCallback: (Swift.Error?) -> Void = { err in
             self.Log.error("MCConnectionExampleViewModel connect() completed with: \(err)")
             DispatchQueue.main.async {
                 if err == nil {
+                    self.pendingPasscodeConfirmation = false;
                     self.connectionSuccess = true
                     if useCommissionerGeneratedPasscode {
                         self.connectionStatus = "Successfully connected to Casting Player using the Casting Player/Commissioner-Generated passcode!"
@@ -125,6 +147,7 @@ class MCConnectionExampleViewModel: ObservableObject {
                             self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, calling MCCastingPlayer.continueConnecting()")
                             let errContinue = selectedCastingPlayer?.continueConnecting()
                             if errContinue == nil {
+                                self.pendingPasscodeConfirmation = false;
                                 self.connectionStatus = "Continuing to connect with user entered passcode: \(userEnteredPasscode)"
                             } else {
                                 self.connectionStatus = "Continue Connecting to Casting Player failed with: \(String(describing: errContinue)) \n\nRoute back and try again."
@@ -142,6 +165,7 @@ class MCConnectionExampleViewModel: ObservableObject {
                             self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, Connection attempt cancelled by the user, calling MCCastingPlayer.stopConnecting()")
                             let err = selectedCastingPlayer?.stopConnecting()
                             self.connectionSuccess = false
+                            self.pendingPasscodeConfirmation = false;
                             if err == nil {
                                 self.connectionStatus = "User cancelled the connection attempt with CastingPlayer. \n\nRoute back to exit."
                                 self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, User cancelled the connection attempt with MCCastingPlayer, MCCastingPlayer.stopConnecting() succeeded.")
@@ -180,7 +204,10 @@ class MCConnectionExampleViewModel: ObservableObject {
 
         self.Log.info("MCConnectionExampleViewModel.connect() calling MCCastingPlayer.verifyOrEstablishConnection()")
         let err = selectedCastingPlayer?.verifyOrEstablishConnection(with: connectionCallbacks, identificationDeclarationOptions: identificationDeclarationOptions)
-        if err != nil {
+        if err == nil {
+            self.pendingPasscodeConfirmation = true;
+        } else {
+            self.pendingPasscodeConfirmation = false;
             self.Log.error("MCConnectionExampleViewModel connect(), MCCastingPlayer.verifyOrEstablishConnection() failed due to: \(err)")
         }
     }