Merge pull request #561 from samuelgruetter/scala-constructors

Creating Observables in Scala: Approach04

Author: benjchristensen

language-adaptors/rxjava-scala/src/examples/java/rx/lang/scala/examples/MovieLibUsage.java

@@ -19,7 +19,7 @@
 import rx.lang.scala.examples.Movie;
 import rx.lang.scala.examples.MovieLib;
 import rx.util.functions.Action1;
-import static rx.lang.scala.ImplicitFunctionConversions.toScalaObservable;
+import static rx.lang.scala.JavaConversions.toScalaObservable;
 
 public class MovieLibUsage {
 

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

@@ -21,15 +21,15 @@ import scala.concurrent.duration.Duration
 import scala.concurrent.duration.DurationInt
 import scala.concurrent.duration.DurationLong
 import scala.language.postfixOps
+import scala.language.implicitConversions
 
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Ignore
 import org.junit.Test
 import org.scalatest.junit.JUnitSuite
 
-import rx.lang.scala.Notification
-import rx.lang.scala.Observable
+import rx.lang.scala._
 import rx.lang.scala.concurrency._
 
 @Ignore // Since this doesn't do automatic testing, don't increase build time unnecessarily
@@ -132,15 +132,14 @@ class RxScalaDemo extends JUnitSuite {
   }
 
   @Test def rangeAndBufferExample() {
-    val o = Observable(1 to 18)
+    val o = Observable.from(1 to 18)
     o.buffer(5).subscribe((l: Seq[Int]) => println(l.mkString("[", ", ", "]")))
   }
 
   @Test def windowExample() {
-    // this will be nicer once we have zipWithIndex
-    (for ((o, i) <- Observable(1 to 18).window(5) zip Observable(0 until 4); n <- o)
-    yield s"Observable#$i emits $n")
-      .subscribe(output(_))
+    (for ((o, i) <- Observable.from(1 to 18).window(5).zipWithIndex; n <- o)
+      yield s"Observable#$i emits $n"
+    ).subscribe(output(_))
   }
 
   @Test def testReduce() {
@@ -217,6 +216,7 @@ class RxScalaDemo extends JUnitSuite {
     }).flatten.toBlockingObservable.foreach(println(_))
   }
 
+  @Ignore // TODO something's bad here
   @Test def timingTest1() {
     val numbersByModulo3 = Observable.interval(1000 millis).take(9).groupBy(_ % 3)
 
@@ -368,13 +368,13 @@ class RxScalaDemo extends JUnitSuite {
 
   @Test def parallelExample() {
     val t0 = System.currentTimeMillis()
-    Observable(1 to 10).parallel(work(_)).toBlockingObservable.foreach(println(_))
+    Observable.from(1 to 10).parallel(work(_)).toBlockingObservable.foreach(println(_))
     println(s"Work took ${System.currentTimeMillis()-t0} ms")
   }
 
   @Test def exampleWithoutParallel() {
     val t0 = System.currentTimeMillis()
-    work(Observable(1 to 10)).toBlockingObservable.foreach(println(_))
+    work(Observable.from(1 to 10)).toBlockingObservable.foreach(println(_))
     println(s"Work took ${System.currentTimeMillis()-t0} ms")
   }
 
@@ -402,11 +402,10 @@ class RxScalaDemo extends JUnitSuite {
     }
 
     val o1 = Observable.interval(100 millis).take(3)
-    val o2 = Observable(new IOException("Oops"))
+    val o2 = Observable.error(new IOException("Oops"))
     printObservable(o1)
-    //waitFor(o1)
     printObservable(o2)
-    //waitFor(o2)
+    Thread.sleep(500)
   }
 
   @Test def materializeExample2() {
@@ -431,6 +430,17 @@ class RxScalaDemo extends JUnitSuite {
     val condition = true
     Observable("a", "b").zipWithIndex.takeWhile{case (elem, index) => condition}.map(_._1)
   }
+  
+  @Test def createExample() {
+    val o = Observable.create[String](observer => {
+      // this is bad because you cannot unsubscribe!
+      observer.onNext("a")
+      observer.onNext("b")
+      observer.onCompleted()
+      Subscription {}
+    })
+    o.subscribe(println(_))
+  }
 
   def output(s: String): Unit = println(s)
 

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

@@ -18,19 +18,22 @@ package rx.lang.scala
 import java.lang.Exception
 import java.{ lang => jlang }
 
-import scala.collection.Seq
 import scala.language.implicitConversions
+import scala.collection.Seq
 
 import rx.util.functions._
+import rx.lang.scala.JavaConversions._
+
 
 /**
  * These function conversions convert between Scala functions and Rx `Func`s and `Action`s.
  * Most RxScala users won't need them, but they might be useful if one wants to use
  * the `rx.Observable` directly instead of using `rx.lang.scala.Observable` or if one wants
  * to use a Java library taking/returning `Func`s and `Action`s.
+ * This object only contains conversions between functions. For conversions between types,
+ * use [[rx.lang.scala.JavaConversions]].
  */
 object ImplicitFunctionConversions {
-  import language.implicitConversions
 
 //  implicit def schedulerActionToFunc2[T](action: (Scheduler, T) => Subscription): Func2[rx.Scheduler, T, rx.Subscription] with Object {def call(s: rx.Scheduler, t: T): rx.Subscription} =
 //    new Func2[rx.Scheduler, T, rx.Subscription] {
@@ -46,25 +49,10 @@ object ImplicitFunctionConversions {
       }
     }
 
-  implicit def toJavaNotification[T](s: Notification[T]): rx.Notification[_ <: T] = s.asJava
-  implicit def toScalaNotification[T](s: rx.Notification[_ <: T]): Notification[T] = Notification(s)
-
-  implicit def toJavaSubscription(s: Subscription): rx.Subscription = s.asJavaSubscription
-  implicit def toScalaSubscription(s: rx.Subscription): Subscription = Subscription(s)
-
-  implicit def scalaSchedulerToJavaScheduler(s: Scheduler): rx.Scheduler = s.asJavaScheduler
-  implicit def javaSchedulerToScalaScheduler(s: rx.Scheduler): Scheduler = Scheduler(s)
-
-  implicit def toJavaObserver[T](s: Observer[T]): rx.Observer[_ >: T] = s.asJavaObserver
-  implicit def toScalaObserver[T](s: rx.Observer[_ >: T]): Observer[T] = Observer(s)
-
-  implicit def toJavaObservable[T](s: Observable[T]): rx.Observable[_ <: T] = s.asJavaObservable
-  implicit def toScalaObservable[T](s: rx.Observable[_ <: T]): Observable[T] = Observable(s)
-
   implicit def scalaFunction1ToOnSubscribeFunc[T](f: rx.lang.scala.Observer[T] => Subscription) =
     new rx.Observable.OnSubscribeFunc[T] {
       def onSubscribe(obs: rx.Observer[_ >: T]): rx.Subscription = {
-        f(Observer(obs))
+        f(obs)
       }
     }
 

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

@@ -0,0 +1,36 @@
+package rx.lang.scala
+
+/**
+ * These functions convert between RxScala types RxJava types.
+ * Pure Scala projects won't need them, but they will be useful for polyglot projects.
+ * This object only contains conversions between types. For conversions between functions,
+ * use [[rx.lang.scala.ImplicitFunctionConversions]].
+ */
+object JavaConversions {
+  import language.implicitConversions
+  
+  implicit def toJavaNotification[T](s: Notification[T]): rx.Notification[_ <: T] = s.asJava
+  
+  implicit def toScalaNotification[T](s: rx.Notification[_ <: T]): Notification[T] = Notification(s)
+
+  implicit def toJavaSubscription(s: Subscription): rx.Subscription = s.asJavaSubscription
+  
+  implicit def toScalaSubscription(s: rx.Subscription): Subscription = Subscription(s)
+
+  implicit def scalaSchedulerToJavaScheduler(s: Scheduler): rx.Scheduler = s.asJavaScheduler
+  
+  implicit def javaSchedulerToScalaScheduler(s: rx.Scheduler): Scheduler = Scheduler(s)
+
+  implicit def toJavaObserver[T](s: Observer[T]): rx.Observer[_ >: T] = s.asJavaObserver
+  
+  implicit def toScalaObserver[T](s: rx.Observer[_ >: T]): Observer[T] = Observer(s)
+
+  implicit def toJavaObservable[T](s: Observable[T]): rx.Observable[_ <: T] = s.asJavaObservable
+  
+  implicit def toScalaObservable[T](observable: rx.Observable[_ <: T]): Observable[T] = {
+    new Observable[T]{
+      def asJavaObservable = observable
+    }
+  }
+
+}

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

@@ -20,6 +20,11 @@ package rx.lang.scala
  */
 sealed trait Notification[+T] {
   def asJava: rx.Notification[_ <: T]
+  override def equals(that: Any): Boolean = that match {
+    case other: Notification[_] => asJava.equals(other.asJava)
+    case _ => false
+  }
+  override def hashCode(): Int = asJava.hashCode()
 }
 
 /**
@@ -48,6 +53,7 @@ object Notification {
 
   class OnNext[+T](val asJava: rx.Notification[_ <: T]) extends Notification[T] {
     def value: T = asJava.getValue
+    override def toString = s"OnNext($value)"
   }
 
   object OnNext {
@@ -64,6 +70,7 @@ object Notification {
 
   class OnError[+T](val asJava: rx.Notification[_ <: T]) extends Notification[T] {
     def error: Throwable = asJava.getThrowable
+    override def toString = s"OnError($error)"
   }
 
   object OnError {
@@ -78,7 +85,9 @@ object Notification {
     }
   }
 
-  class OnCompleted[T](val asJava: rx.Notification[_ <: T]) extends Notification[T] {}
+  class OnCompleted[T](val asJava: rx.Notification[_ <: T]) extends Notification[T] {
+    override def toString = "OnCompleted()"
+  }
 
   object OnCompleted {