Design Patterns em Scala: Facade

Facade: Facade.scala package scala.structural // Facilita o uso de um sistema unificando o comportamento de diversos objetos // Concrete Implementation trait SubSystemA {  def methodA1()  def methodA2() } trait SubSystemB {  def methodB() } class ConcreteSubSystemA extends SubSystemA {  override def methodA1() {   println("System A")  }  override def methodA2() {   println("System A")  } } class ConcreteSubSystemB extends SubSystemB {  override def methodB() {   println("System B")  } } class Facade extends SubSystemA with SubSystemB {  val subsystemA = new ConcreteSubSystemA()  val subsystemB = new ConcreteSubSystemB()  override def methodA1() {   subsystemA.methodA1()  }  override def methodA2() {   subsystemA.methodA2()  }  override def methodB() {   subsystemB.methodB()  } } // Client object FacadeClient extends Application {  var facade = new Facade()  facade.methodA1()  facade.methodA2()  facade.methodB() }