move Typed ActorMaterializer to scaladsl/javadsl, #24868

* add type alias for typed ActorMaterializer
* name it ActorMaterializerFactory in javadsl

Migration guide:
Scala:
import akka.stream.typed.ActorMaterializer -> akka.stream.typed.scaladsl.ActorMaterializer
Java:
import akka.stream.typed.ActorMaterializer -> akka.stream.typed.javadsl.ActorMaterializerFactory

akka-stream-typed/src/main/scala/akka/stream/typed/javadsl/ActorMaterializerFactory.scala

@@ -2,31 +2,16 @@
  * Copyright (C) 2018 Lightbend Inc. <https://www.lightbend.com>
  */
 
-package akka.stream.typed
+package akka.stream.typed.javadsl
 
 import akka.actor.typed.ActorSystem
 import akka.stream.ActorMaterializerSettings
 
-object ActorMaterializer {
+object ActorMaterializerFactory {
   import akka.actor.typed.scaladsl.adapter._
 
   /**
-   * Scala API: Creates an ActorMaterializer which will execute every step of a transformation
-   * pipeline within its own [[akka.actor.Actor]]. The required [[akka.actor.typed.ActorSystem]]
-   * will be used to create one actor that in turn creates actors for the transformation steps.
-   *
-   * The materializer's [[akka.stream.ActorMaterializerSettings]] will be obtained from the
-   * configuration of the `context`'s underlying [[akka.actor.typed.ActorSystem]].
-   *
-   * The `namePrefix` is used as the first part of the names of the actors running
-   * the processing steps. The default `namePrefix` is `"flow"`. The actor names are built up of
-   * `namePrefix-flowNumber-flowStepNumber-stepName`.
-   */
-  def apply[T](materializerSettings: Option[ActorMaterializerSettings] = None, namePrefix: Option[String] = None)(implicit actorSystem: ActorSystem[T]): akka.stream.ActorMaterializer =
-    akka.stream.ActorMaterializer(materializerSettings, namePrefix)(actorSystem.toUntyped)
-
-  /**
-   * Java API: Creates an ActorMaterializer which will execute every step of a transformation
+   * Creates an `ActorMaterializer` which will execute every step of a transformation
    * pipeline within its own [[akka.actor.Actor]]. The required [[akka.actor.typed.ActorSystem]]
    * will be used to create these actors, therefore it is *forbidden* to pass this object
    * to another actor if the factory is an ActorContext.
@@ -35,18 +20,18 @@ object ActorMaterializer {
    * The actor names are built up of `namePrefix-flowNumber-flowStepNumber-stepName`.
    */
   def create[T](actorSystem: ActorSystem[T]): akka.stream.ActorMaterializer =
-    apply()(actorSystem)
+    akka.stream.ActorMaterializer.create(actorSystem.toUntyped)
 
   /**
-   * Java API: Creates an ActorMaterializer which will execute every step of a transformation
+   * Creates an `ActorMaterializer` which will execute every step of a transformation
    * pipeline within its own [[akka.actor.Actor]]. The required [[akka.actor.typed.ActorSystem]]
    * will be used to create one actor that in turn creates actors for the transformation steps.
    */
   def create[T](settings: ActorMaterializerSettings, actorSystem: ActorSystem[T]): akka.stream.ActorMaterializer =
-    apply(Option(settings), None)(actorSystem)
+    akka.stream.ActorMaterializer.create(settings, actorSystem.toUntyped)
 
   /**
-   * Java API: Creates an ActorMaterializer which will execute every step of a transformation
+   * Creates an `ActorMaterializer` which will execute every step of a transformation
    * pipeline within its own [[akka.actor.Actor]]. The required [[akka.actor.typed.ActorSystem]]
    * will be used to create these actors, therefore it is *forbidden* to pass this object
    * to another actor if the factory is an ActorContext.
@@ -56,6 +41,6 @@ object ActorMaterializer {
    * `namePrefix-flowNumber-flowStepNumber-stepName`.
    */
   def create[T](settings: ActorMaterializerSettings, namePrefix: String, actorSystem: ActorSystem[T]): akka.stream.ActorMaterializer =
-    apply(Option(settings), Option(namePrefix))(actorSystem)
+    akka.stream.ActorMaterializer.create(settings, actorSystem.toUntyped, namePrefix)
 
 }

akka-stream-typed/src/main/scala/akka/stream/typed/package.scala

@@ -0,0 +1,9 @@
+/**
+ * Copyright (C) 2018 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package akka.stream.typed
+
+package object scaladsl {
+  type ActorMaterializer = akka.stream.ActorMaterializer
+}

akka-stream-typed/src/main/scala/akka/stream/typed/scaladsl/ActorMaterializer.scala

@@ -0,0 +1,28 @@
+/**
+ * Copyright (C) 2018 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package akka.stream.typed.scaladsl
+
+import akka.actor.typed.ActorSystem
+import akka.stream.ActorMaterializerSettings
+
+object ActorMaterializer {
+  import akka.actor.typed.scaladsl.adapter._
+
+  /**
+   * Creates an `ActorMaterializer` which will execute every step of a transformation
+   * pipeline within its own [[akka.actor.Actor]]. The required [[akka.actor.typed.ActorSystem]]
+   * will be used to create one actor that in turn creates actors for the transformation steps.
+   *
+   * The materializer's [[akka.stream.ActorMaterializerSettings]] will be obtained from the
+   * configuration of the `context`'s underlying [[akka.actor.typed.ActorSystem]].
+   *
+   * The `namePrefix` is used as the first part of the names of the actors running
+   * the processing steps. The default `namePrefix` is `"flow"`. The actor names are built up of
+   * `namePrefix-flowNumber-flowStepNumber-stepName`.
+   */
+  def apply[T](materializerSettings: Option[ActorMaterializerSettings] = None, namePrefix: Option[String] = None)(implicit actorSystem: ActorSystem[T]): ActorMaterializer =
+    akka.stream.ActorMaterializer(materializerSettings, namePrefix)(actorSystem.toUntyped)
+
+}

akka-stream-typed/src/test/java/akka/stream/typed/javadsl/ActorFlowCompileTest.java

@@ -25,7 +25,7 @@ public class ActorFlowCompileTest {
 
   {
     final ActorSystem<String> system = null;
-    final ActorMaterializer mat = akka.stream.typed.ActorMaterializer.create(system);
+    final ActorMaterializer mat = ActorMaterializerFactory.create(system);
   }
 
   static

akka-stream-typed/src/test/java/akka/stream/typed/javadsl/ActorSourceSinkCompileTest.java

@@ -24,7 +24,7 @@ public class ActorSourceSinkCompileTest {
 
   {
     final ActorSystem<String> system = null;
-    final ActorMaterializer mat = akka.stream.typed.ActorMaterializer.create(system);
+    final ActorMaterializer mat = ActorMaterializerFactory.create(system);
   }
 
   {

akka-stream-typed/src/test/scala/akka/stream/typed/scaladsl/ActorFlowSpec.scala

@@ -5,7 +5,7 @@
 package akka.stream.typed.scaladsl
 
 //#imports
-import akka.stream.typed.ActorMaterializer
+import akka.stream.typed.scaladsl.ActorMaterializer
 import akka.stream.scaladsl._
 
 import akka.actor.typed.ActorRef

akka-stream-typed/src/test/scala/akka/stream/typed/scaladsl/ActorSourceSinkSpec.scala

@@ -11,7 +11,6 @@ import akka.stream.OverflowStrategy
 import akka.stream.scaladsl.Keep
 import akka.stream.scaladsl.Sink
 import akka.stream.scaladsl.Source
-import akka.stream.typed.ActorMaterializer
 import akka.actor.testkit.typed.scaladsl.{ ActorTestKit, _ }
 
 object ActorSourceSinkSpec {

akka-stream-typed/src/test/scala/akka/stream/typed/scaladsl/CustomGuardianAndMaterializerSpec.scala

@@ -10,7 +10,6 @@ import akka.actor.typed.TypedAkkaSpecWithShutdown
 import akka.actor.typed.scaladsl.Behaviors
 import akka.stream.scaladsl.Sink
 import akka.stream.scaladsl.Source
-import akka.stream.typed.ActorMaterializer
 import akka.actor.testkit.typed.scaladsl.ActorTestKit
 
 object CustomGuardianAndMaterializerSpec {

akka-stream-typed/src/test/scala/docs/akka/stream/typed/ActorSourceSinkExample.scala

@@ -5,11 +5,14 @@
 package docs.akka.stream.typed
 
 import akka.NotUsed
-import akka.stream.ActorMaterializer
+import akka.actor.typed.ActorSystem
+import akka.stream.typed.scaladsl.ActorMaterializer
 
 object ActorSourceSinkExample {
 
-  implicit val mat: ActorMaterializer = ???
+  val system: ActorSystem[_] = ???
+
+  implicit val mat: ActorMaterializer = ActorMaterializer()(system)
 
   {
     // #actor-source-ref