Investigate if iOS sdk callbacks can be made "async" to support Swift concurrency

Basic-Video-Chat/Basic-Video-Chat/OTPublisherSync.swift

@@ -0,0 +1,98 @@
+//
+//  OTPublisherSync.swift
+//  Basic-Video-Chat
+//
+//  Created by Jaideep Shah on 8/30/24.
+//  Copyright © 2024 tokbox. All rights reserved.
+//
+
+
+
+import Foundation
+import OpenTok
+import ObjectiveC
+
+
+extension OTPublisherKit {
+
+    // Define the unique key for associated objects
+    private static var associatedObjectHandle: UInt8 = 0
+
+    // Method to set the associated object (e.g., wrapper)
+    private func setAssociatedWrapper(_ wrapper: PublisherKitDelegateWrapper?) {
+        objc_setAssociatedObject(self, &Self.associatedObjectHandle, wrapper, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+    }
+
+    // Method to get the associated object
+    private func associatedWrapper() -> PublisherKitDelegateWrapper? {
+        return objc_getAssociatedObject(self, &Self.associatedObjectHandle) as? PublisherKitDelegateWrapper
+    }
+}
+
+
+
+extension OTPublisherKit {
+    // Internal wrapper class to handle the Objective-C callbacks
+      private class PublisherKitDelegateWrapper: NSObject, OTPublisherDelegate {
+          let continuation: CheckedContinuation<OTStream, Error>
+
+          init(continuation: CheckedContinuation<OTStream, Error>) {
+              self.continuation = continuation
+          }
+
+          func publisher(_ publisher: OTPublisherKit, streamCreated stream: OTStream) {
+                  print("Wrapper Publishing")
+                  continuation.resume(returning: stream)
+          }
+
+          func publisher(_ publisher: OTPublisherKit, streamDestroyed stream: OTStream) {
+                  print("Wrapper Publishing stream destroyed")
+                  continuation.resume(returning: stream)
+          }
+
+          func publisher(_ publisher: OTPublisherKit, didFailWithError error: OTError) {
+              print("Wrapper Publisher failed: \(error.localizedDescription)")
+              continuation.resume(throwing: error)
+          }
+      }
+
+
+    // Async function to wait for a stream to be created
+    func waitForStreamCreated() async throws -> OTStream {
+        try await withCheckedThrowingContinuation { continuation in
+            let wrapper = PublisherKitDelegateWrapper(continuation: continuation)
+            setAssociatedWrapper(wrapper)
+            self.delegate = wrapper
+        }
+    }
+
+    // Async function to wait for a stream to be destroyed
+    //TODO: Make sure stream destroyed do not overlap between diff pubs
+    func waitForStreamDestroyed(completion: @escaping (Result<OTStream, Error>) -> Void) {
+        Task {
+            do {
+                let stream = try await withCheckedThrowingContinuation { continuation in
+                    let wrapper = PublisherKitDelegateWrapper(continuation: continuation)
+                    self.delegate = wrapper
+                    setAssociatedWrapper(nil)
+                }
+                completion(.success(stream))
+            } catch {
+                completion(.failure(error))
+            }
+        }
+    }
+}
+
+class OTPublisherSync : OTPublisher {
+    // Custom initializer
+    init?(settings: OTPublisherSettings) {
+        super.init(delegate: nil, settings: OTPublisherSettings())
+    }
+
+    // Hide the inherited initializer by providing an empty implementation
+    @available(*, unavailable, message: "Use custom initialization instead.")
+    override init(delegate: OTPublisherKitDelegate?, settings: OTPublisherSettings?) {
+        fatalError("This initializer is not available. Use the custom initializer.")
+    }
+}

Basic-Video-Chat/Basic-Video-Chat/ViewController.swift

@@ -12,11 +12,11 @@ import OpenTok
 // *** Fill the following variables using your own Project info  ***
 // ***            https://tokbox.com/account/#/                  ***
 // Replace with your OpenTok API key
-let kApiKey = ""
+let kApiKey = "28415832"
 // Replace with your generated session ID
-let kSessionId = ""
+let kSessionId = "2_MX4yODQxNTgzMn5-MTcyNTA0ODQ5ODQzN35ueTZwWTl2WFAwM1AvMi82YUpPd2wzTkp-fn4"
 // Replace with your generated token
-let kToken = ""
+let kToken = "T1==cGFydG5lcl9pZD0yODQxNTgzMiZzaWc9NGE0MDRiZjU4M2E4ODVlZTY5YWViZTFjMGEwZTliOWE1MDk0NDdiMzpzZXNzaW9uX2lkPTJfTVg0eU9EUXhOVGd6TW41LU1UY3lOVEEwT0RRNU9EUXpOMzV1ZVRad1dUbDJXRkF3TTFBdk1pODJZVXBQZDJ3elRrcC1mbjQmY3JlYXRlX3RpbWU9MTcyNTA0ODQ5OCZub25jZT0wLjE3NTUxMTYzNjkwMjkzMTI2JnJvbGU9bW9kZXJhdG9yJmV4cGlyZV90aW1lPTE3Mjc2NDA0OTgmaW5pdGlhbF9sYXlvdXRfY2xhc3NfbGlzdD0="
 
 let kWidgetHeight = 240
 let kWidgetWidth = 320
@@ -26,7 +26,7 @@ class ViewController: UIViewController {
         return OTSession(apiKey: kApiKey, sessionId: kSessionId, delegate: self)!
     }()
 
-    var publisher: OTPublisher?
+    var publisher: OTPublisherSync?
     var subscriber: OTSubscriber?
 
     override func viewDidLoad() {
@@ -53,6 +53,26 @@ class ViewController: UIViewController {
      * binds to the device camera and microphone, and will provide A/V streams
      * to the OpenTok session.
      */
+    func capturePublishingLifeCycle() async {
+        do {
+            let createdStream = try await publisher!.waitForStreamCreated()
+            print("Stream created after await: \(createdStream)")
+            session.unpublish(publisher!, error: nil)
+            // After stream creation, you might want to wait for stream destruction
+
+            publisher!.waitForStreamDestroyed { result in
+                switch result {
+                case .success(let stream):
+                    print("Stream destroyed after await: \(stream)")
+                case .failure(let error):
+                    print("Error occurred after await: \(error)")
+                }
+            }
+        } catch {
+            print("Error occurred after await: \(error)")
+        }
+    }
+
     fileprivate func doPublish() {
         var error: OTError?
         defer {
@@ -61,14 +81,17 @@ class ViewController: UIViewController {
 
         let settings = OTPublisherSettings()
         settings.name = UIDevice.current.name
-        publisher =  OTPublisher(delegate: self, settings: settings)!
+        publisher =  OTPublisherSync(settings: settings)
 
         session.publish(publisher!, error: &error)
 
         if let pubView = publisher!.view {
             pubView.frame = CGRect(x: 0, y: 0, width: kWidgetWidth, height: kWidgetHeight)
             view.addSubview(pubView)
         }
+        Task {
+            await self.capturePublishingLifeCycle()
+        }
     }
 
     /**