gistfile1.txt

trait Shape {
  
  var x : Int
  var y : Int

  def draw
  def moveTo(newx: Int, newy: Int) = {
    x = newx
    y = newy
  }

  def rMoveTo(dx: Int, dy: Int) = {
    x += dx
    y += dy
  }
}

class Rectangle(var x: Int, var y: Int, var w: Int, var h: Int) extends Shape {
  def draw = {
    println("Drawing a Rectangle at (" + x + "," + y + "), width " + w + ", height " + h)
  }

}

class Circle(var x: Int, var y: Int, var r: Int) extends Shape {
  def draw = { 
    println("Drawing a Circle at (" + x + "," + y + "), radius " + r)
  }
}

object TryShape {
  def doSomethingWithShape(s: Shape) = {
    s.draw
    s.rMoveTo(100, 100)
    s.draw
  }

  def main(args: Array[String]) = {
    val shapes = new Array[Shape](2)
    shapes(0) = new Rectangle(10, 20, 5, 6)
    shapes(1) = new Circle(15, 25, 8)

    for (shape <- shapes) {
      TryShape.doSomethingWithShape(shape)
    }

    val rect = new Rectangle(0, 0, 15, 15)
      rect.w = 30
    rect.draw
  }
}