Make Scala OnCompleted Notification an object

language-adaptors/rxjava-scala/src/examples/scala/rx/lang/scala/examples/RxScalaDemo.scala

@@ -404,7 +404,7 @@ class RxScalaDemo extends JUnitSuite {
       import Notification._
       o.materialize.subscribe(n => n match {
         case OnNext(v) => println("Got value " + v)
-        case OnCompleted() => println("Completed")
+        case OnCompleted => println("Completed")
         case OnError(err) => println("Error: " + err.getMessage)
       })
     }
@@ -420,11 +420,19 @@ class RxScalaDemo extends JUnitSuite {
     import Notification._
     List(1, 2, 3).toObservable.materialize.subscribe(n => n match {
       case OnNext(v) => println("Got value " + v)
-      case OnCompleted() => println("Completed")
+      case OnCompleted => println("Completed")
       case OnError(err) => println("Error: " + err.getMessage)
     })
   }
 
+  @Test def notificationSubtyping() {
+    import Notification._
+    val oc1: Notification[Nothing] = OnCompleted
+    val oc2: Notification[Int] = OnCompleted
+    val oc3: rx.Notification[_ <: Int] = oc2.asJavaNotification
+    val oc4: rx.Notification[_ <: Any] = oc2.asJavaNotification
+  }
+
   @Test def elementAtReplacement() {
     assertEquals("b", List("a", "b", "c").toObservable.drop(1).first.toBlockingObservable.single)
   }

language-adaptors/rxjava-scala/src/main/scala/rx/lang/scala/Notification.scala

@@ -41,7 +41,7 @@ sealed trait Notification[+T] {
     this match {
       case Notification.OnNext(value)  => onNext(value)
       case Notification.OnError(error) => onError(error)
-      case Notification.OnCompleted()  => onCompleted()
+      case Notification.OnCompleted  => onCompleted()
     }
   }
 
@@ -58,7 +58,7 @@ sealed trait Notification[+T] {
     this match {
       case Notification.OnNext(value)  => observer.onNext(value)
       case Notification.OnError(error) => observer.onError(error)
-      case Notification.OnCompleted()  => observer.onCompleted()
+      case Notification.OnCompleted  => observer.onCompleted()
     }
   }
 
@@ -82,7 +82,7 @@ object Notification {
 
   private [scala] def apply[T](n: rx.Notification[_ <: T]): Notification[T] = n.getKind match {
     case rx.Notification.Kind.OnNext => new OnNext(n)
-    case rx.Notification.Kind.OnCompleted => new OnCompleted(n)
+    case rx.Notification.Kind.OnCompleted => OnCompleted
     case rx.Notification.Kind.OnError => new OnError(n)
   }
 
@@ -150,26 +150,9 @@ object Notification {
     override def toString = s"OnError($error)"
   }
 
-  object OnCompleted {
-
-    /**
-     * Constructor for onCompleted notifications.
-     */
-    def apply[T](): Notification[T] = {
-      Notification(rx.Notification.createOnCompleted[T]())
-    }
-
-    /**
-     * Extractor for onCompleted notifications.
-     */
-    def unapply[U](notification: Notification[U]): Option[Unit] = notification match {
-      case onCompleted: OnCompleted[U] => Some()
-      case _ => None
-    }
-  }
-
-  class OnCompleted[T] private[scala](val asJavaNotification: rx.Notification[_ <: T]) extends Notification[T] {
-    override def toString = "OnCompleted()"
+  object OnCompleted extends Notification[Nothing] {
+    override def toString = "OnCompleted"
+    val asJavaNotification = rx.Notification.createOnCompleted[Nothing]()
   }
 
 }

language-adaptors/rxjava-scala/src/test/scala/rx/lang/scala/NotificationTests.scala

@@ -37,8 +37,8 @@ class NotificationTests extends JUnitSuite {
     val onError = OnError(oops)
       assertEquals(oops, onError match { case OnError(error) => error })
 
-    val onCompleted = OnCompleted()
-      assertEquals((), onCompleted match { case OnCompleted() => () })
+    val onCompleted = OnCompleted
+      assertEquals((), onCompleted match { case OnCompleted => () })
   }
 
   @Test
@@ -51,7 +51,7 @@ class NotificationTests extends JUnitSuite {
     val onError = OnError(oops)
       assertEquals(4711, onError(x=>42, e=>4711,()=>13))
 
-    val onCompleted = OnCompleted()
+    val onCompleted = OnCompleted
       assertEquals(13, onCompleted(x=>42, e=>4711,()=>13))
 
   }