iOS: MessageChannel handling;

SendText Message handling;
ReceivedText Message handling;

ios/Classes/MessageCastingChannel.swift

@@ -0,0 +1,67 @@
+//
+//  MessageCastingChannel.swift
+//  flutter_cast_framework
+//
+//  Created by Gianluca Paradiso on 16/11/2019.
+//
+
+import Foundation
+import GoogleCast
+
+class MessageCastingChannel : GCKCastChannel {
+    
+    let channel: FlutterMethodChannel
+    let namespace: String
+    
+    init(namespace: String, channel: FlutterMethodChannel) {
+        self.channel = channel
+        self.namespace = namespace
+        super.init(namespace: namespace)
+    }
+    
+    override func didReceiveTextMessage(_ message: String) {
+        print("Message received: .\(message)")
+        let argsMap: NSDictionary = [
+            "namespace": namespace,
+            "message": message
+        ]
+
+        channel.invokeMethod(MethodNames.onMessageReceived.rawValue, arguments: argsMap)
+    }
+    
+    public static func sendMessage(allCastingChannels: Dictionary<String, MessageCastingChannel>, arguments: Any?) {
+        let argsMap = arguments as? NSDictionary
+        if (argsMap == nil) {
+            print("Arguments not valid: can't send message")
+            return
+        }
+        
+        let namespaceRaw = argsMap?.value(forKey: "namespace") as? String
+        let messageRaw = argsMap?.value(forKey: "message") as? String
+        
+        if (namespaceRaw == nil) {
+            print("Namespace not valid: can't send message")
+            return
+        }
+        
+        let namespace = namespaceRaw!
+        let message = messageRaw ?? ""
+        
+        let castingChannel = allCastingChannels[namespace]
+        
+        if (castingChannel == nil) {
+            print("Namespace not registered: can't send message")
+        }
+        
+        castingChannel?.sendMessage(message: message)
+    }
+    
+    private func sendMessage(message: String) {
+        var error: GCKError?
+        self.sendTextMessage(message, error: &error)
+        
+        if error != nil {
+          print("Error sending text message \(error.debugDescription)")
+        }
+    }
+}

ios/Classes/MethodNames.swift

@@ -22,4 +22,8 @@ enum MethodNames : String {
     case onSessionResumeFailed = "SessionManager.onSessionResumeFailed"
     case onSessionSuspended = "SessionManager.onSessionSuspended"
     // end-region
+
+    case getSessionMessageNamespaces = "CastSession.getSessionMessageNamespaces"
+    case onMessageReceived = "CastSession.onMessageReceived"
+    case sendMessage = "CastSession.sendMessage"
 }

ios/Classes/SwiftFlutterCastFrameworkPlugin.swift

@@ -15,18 +15,48 @@ public class SwiftFlutterCastFrameworkPlugin: NSObject, FlutterPlugin, GCKSessio
     
     private let sessionManager: GCKSessionManager
     
+    private var castingChannels: Dictionary<String, MessageCastingChannel> = [:]
+    
     var _castSession: GCKCastSession?
     var castSession: GCKCastSession? {
         get { return _castSession }
         set {
             print("Updating castSession - castSession changed: \(_castSession != newValue)")
-            // if (_castSession == newValue) return // Despite the instances are the same, I need to re-attach the listener to every new session instance
             
-            // val result = NamespaceResult(oldSession = field, newSession = value)
+            let oldSession = _castSession
+            let newSession = newValue
             
             _castSession = newValue
 
-            // channel.invokeMethod(MethodNames.getSessionMessageNamespaces, null, result)
+            channel.invokeMethod(MethodNames.getSessionMessageNamespaces.rawValue, arguments: nil) { (args) in
+                print("Updating castSession - success - param: \(args ?? "-")")
+                if (oldSession == nil && newSession == nil) {
+                    return // nothing to do here
+                }
+                
+                let namespaces = args as? NSArray
+                if (namespaces == nil || namespaces?.count == 0) {
+                    return  // nothing to do here
+                }
+                
+                // removing castingChannels from old session
+                if (oldSession != nil && self.castingChannels.count != 0) {
+                    self.castingChannels.values.forEach { (castingChannel) in
+                        oldSession?.remove(castingChannel)
+                    }
+                }
+
+                namespaces?.forEach({ (namespaceRaw) in
+                    if (!(namespaceRaw is String)) {
+                        return
+                    }
+                    
+                    let namespace = namespaceRaw as! String
+                    let castingChannel = MessageCastingChannel.init(namespace: namespace, channel: self.channel)
+                    self.castingChannels[namespace] = castingChannel
+                    newSession?.add(castingChannel)
+                })
+            }
         }
     }
     
@@ -44,9 +74,9 @@ public class SwiftFlutterCastFrameworkPlugin: NSObject, FlutterPlugin, GCKSessio
         let app = UIApplication.shared
         notificationCenter.addObserver(self, selector: #selector(appDidBecomeActive), name: NSNotification.Name.UIApplicationDidBecomeActive, object: app)
         notificationCenter.addObserver(self, selector: #selector(appWillResignActive), name: NSNotification.Name.UIApplicationWillResignActive, object: app)
-        notificationCenter.addObserver(self, selector: #selector(appDidEnterBackground), name: NSNotification.Name.UIApplicationDidEnterBackground, object: app)
+        //notificationCenter.addObserver(self, selector: #selector(appDidEnterBackground), name: NSNotification.Name.UIApplicationDidEnterBackground, object: app)
-        notificationCenter.addObserver(self, selector: #selector(appWillEnterForeground), name: NSNotification.Name.UIApplicationWillEnterForeground, object: app)
+        //notificationCenter.addObserver(self, selector: #selector(appWillEnterForeground), name: NSNotification.Name.UIApplicationWillEnterForeground, object: app)
-        notificationCenter.addObserver(self, selector: #selector(appWillTerminate), name: NSNotification.Name.UIApplicationWillTerminate, object: app)
+        //notificationCenter.addObserver(self, selector: #selector(appWillTerminate), name: NSNotification.Name.UIApplicationWillTerminate, object: app)
     }
     
     @objc func appDidBecomeActive() {
@@ -63,18 +93,6 @@ public class SwiftFlutterCastFrameworkPlugin: NSObject, FlutterPlugin, GCKSessio
         self.castSession = nil
     }
     
-    @objc func appDidEnterBackground() {
-        print("AppLife: appDidEnterBackground")
-    }
-    
-    @objc func appWillEnterForeground() {
-        print("AppLife: appWillEnterForeground")
-    }
-    
-    @objc func appWillTerminate() {
-        print("AppLife: appWillTerminate")
-    }
-    
     private func onCastStateChanged(state: GCKCastContext, change: NSKeyValueObservedChange<GCKCastState>) {
         let castState = GCKCastContext.sharedInstance().castState
         print("cast state change to: \(castState.rawValue)")
@@ -92,6 +110,8 @@ public class SwiftFlutterCastFrameworkPlugin: NSObject, FlutterPlugin, GCKSessio
         switch call.method {
         case MethodNames.showCastDialog.rawValue:
             castContext.presentCastDialog()
+        case MethodNames.sendMessage.rawValue:
+            MessageCastingChannel.sendMessage(allCastingChannels: self.castingChannels, arguments: call.arguments)
         default:
             print("Method [\(call.method)] is not implemented.")
         }