CompositePattern.scala

trait Component {
  val childrens = new collection.mutable.ArrayBuffer[Component]()
  //val parent: Component
  
  def operation: Unit
  def add(component: Component) = ()
  def remove(component: Component) = ()
  def getChildrens: Iterator[Component] = collection.Iterator.empty
}

abstract class Leaf extends Component

abstract class Composite extends Component {
  override def add(component: Component) = { childrens += component }
  override def remove(component: Component) = { childrens -= component }
  override def getChildrens = childrens.toIterator
}

class Leaf1 extends Leaf {
	def operation = {
		println("Leaf1")
	}
}

class Composite1 extends Composite {
	def operation = getChildrens.foreach(_.operation)
}

object Main extends App {
	val c = new Composite1()
	c.add(new Leaf1())
	c.add(new Leaf1())
	c.operation
}