Fix chat back button listener race condition

There was a race condition where sometimes the old instance of ChatView was accessing and destroying the ChatController *after* a newer instance of ChatView had just set up the ChatController (same instance) causing the broken state of ChatController.

MOB-3524

Author: gugalo

widgetssdk/src/main/java/com/glia/widgets/chat/ChatContract.kt

@@ -21,6 +21,7 @@ internal interface ChatContract {
         val isChatVisible: Boolean
 
         fun setView(view: View)
+        fun getView(): View?
         fun onDestroy(retain: Boolean)
         fun onMessageClicked(messageId: String)
         fun onGvaButtonClicked(button: GvaButton)

widgetssdk/src/main/java/com/glia/widgets/chat/ChatView.kt

@@ -593,7 +593,11 @@ internal class ChatView(context: Context, attrs: AttributeSet?, defStyleAttr: In
     }
 
     private fun destroyController() {
-        controller?.onDestroy(context.asActivity() is ChatActivity)
+        controller?.let {
+            if (it.getView() == this) {
+                it.onDestroy(context.asActivity() is ChatActivity)
+            }
+        }
         controller = null
     }
 

widgetssdk/src/main/java/com/glia/widgets/chat/controller/ChatController.kt

@@ -470,6 +470,11 @@ internal class ChatController(
         view.scrollToBottomImmediate()
     }
 
+    @Synchronized
+    override fun getView(): ChatContract.View? {
+        return this.view
+    }
+
     override fun setOnBackClickedListener(finishCallback: ChatView.OnBackClickedListener?) {
         this.backClickedListener = finishCallback
     }