Add conversion to ObservableBuffer

src/main/scala/org/gerweck/scalafx/util/observable.scala

@@ -6,6 +6,7 @@ import scalaz._
 
 import scalafx.beans.property._
 import scalafx.beans.value._
+import scalafx.collections._
 
 trait ObservableImplicits {
   /* NOTE: (Sarah) I believe that the synchronization in these helpers is not
@@ -163,6 +164,14 @@ class RichObservable[A, C](val self: ObservableValue[A, C]) extends AnyVal {
   final def ⊛[B, B1](fb: ObservableValue[B, B1]) = |@|(fb)
 }
 
+class ObservableOfIterable[A](val self: ObservableValue[Iterable[A], Iterable[A]]) extends AnyVal {
+  def toBuffer: ObservableBuffer[A] = {
+    val buff = ObservableBuffer(self.value.toSeq)
+    self onChange { (_, oldV, newV) => fillCollection(buff.delegate, newV) }
+    buff
+  }
+}
+
 class RichProperty[A, B](val inner: Property[A, B]) extends AnyVal {
   def biMap[B <: AnyRef](push: A => B, pull: B => A): ObjectProperty[B] = {
     val original = push(inner.value)