Temperature5.scala

object Temperature {
  implicit def unboxText2Double(s: String) = if (s != "") java.lang.Double.parseDouble(s) else 0.0
  implicit def convertDouble2String(d: Double) = d.toString

  val fahrenheit = new Var[String]("0")
  val celsius = new Var[String]("0")

  val calcCelsius = Signal {
    ((5.0 / 9.0) * (fahrenheit() - 32)) toString
  }

  val calcFahrenheit = Signal {
    ((9.0 / 5.0) * celsius() + 32) toString
  }

  def main(args: Array[String]): Unit = {
    val window = shell("Temperature converter take 4",
      group("Temperature converter",
        layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false),
        layout = new GridLayout(2, false),

        label("Fahrenheit"),
        textbox(fahrenheit)(_ bind calcFahrenheit, layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false)),

        label("Celsius"),
        textbox(celsius)(_ bind calcCelsius, layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false))))

    window.setMinimumSize(300, 50)
    window.pack
    runEventLoop(window)
  }
}