Temperature2.scala

object Temperature {
  implicit def unboxText2Double(t: Text) = java.lang.Double.parseDouble(t.getText())
  implicit def convertDouble2String(d: Double) = d.toString

  var fahrenheit: Text = null
  var celsius: Text = null

  def main(args: Array[String]): Unit = {
    val window = shell("Demo!",
      composite(
        _.setLayout(new GridLayout(2, true)),

        label("Fahrenheit"),
        label("Celsius"),

        text(fahrenheit = _,
          layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false)),
        text(celsius = _,
          layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false)),

        button(
          "Fahrenheit => Celsius",
          { e: SelectionEvent => celsius.setText((5.0 / 9.0) * (fahrenheit - 32)) }),
        button(
          "Celsius -> Fahrenheit",
          layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false),
          { e: SelectionEvent => fahrenheit.setText((9.0 / 5.0) * celsius + 32) })))
    runEventLoop(window)
  }
}