UI for Game of Life in Scala

GofLUI.scala

object GofUI extends SimpleSwingApplication {
  val grid = new OnOffGrid(20, 20) {
    onOff = gridCellIsLive
  }
  val tickButton = new Button {
    text = "Tick"
  }
  def top = new MainFrame {
    title = "Game of Life"

    contents = new BorderPanel {
      layout(grid) = BorderPanel.Position.Center
      layout(tickButton) = BorderPanel.Position.West
    }

    listenTo(tickButton)
    listenTo(grid)
    reactions += {
      case ButtonClicked(`tickButton`) =>
        model = model.tick
        grid.repaint

      case CellClicked(`grid`, x, y) =>
        model = model.toggleCell(Cell(x, y))
        grid.repaint
    }
  }

  /**
   * Holds the GoF model for the current generation. The model is changed in response to a 'tick' 
   * or to cells being toggled by the user.
   */
  var model = GofModel(Cell(0, 0), Cell(0, 2), Cell(2, 2))

  /**
   * Function passed to the OnOffGrid to determine whether any particular cell is dead of alive.
   */
  def gridCellIsLive: (Int, Int) => Boolean = { (x, y) => model.getCells contains (Cell(x, y)) }
}