ScalaでSwing

ScalaSwing1.scala

// ScalaでSwing

import scala.swing._
import scala.swing.event.{ WindowClosing, ButtonClicked }
import java.awt.Color
import java.io.File
import java.util.Date
import java.text.SimpleDateFormat

object ScalaSwing1 extends SimpleGUIApplication {
  def top = new MainFrame {
    val fileLabel = new Label {
      text = "Label"
      opaque = true
      background = Color.BLACK
      foreground = Color.WHITE
    }
    val timeButton = new Button {
      text = "時刻"
      reactions += {
        case ButtonClicked(_) => {
          text = new SimpleDateFormat("yyyy'年'M'月'd'日'H'時'm'分's'秒'").format(new Date)
        }
      }
    }
    val mainPanel = new GridPanel(2, 1) {
      contents += fileLabel
      contents += timeButton
    }

    val openFileChooser =
      new FileChooser(new File(System.getProperty("user.dir"))) {
        title = "ファイルを開く"
        def openFile(): Unit = {
          showOpenDialog(mainPanel) match {
            case FileChooser.Result.Approve =>
              fileLabel.text = "開く " + selectedFile.getAbsolutePath
            case _ =>
              fileLabel.text = "取消し";
          }
        }
      }

    title = "SimpleGUIApplication"
    menuBar = new MenuBar {
      contents += (
        new Menu("ファイル") {
          contents += new MenuItem(Action("ファイルを開く") {
            openFileChooser.openFile
          })
          contents += new MenuItem(Action("終了") {
            top.publish(new WindowClosing(top))
          })
        }
      )
      contents += (new Menu("ヘルプ"))
    }
    contents = mainPanel
    size = (300, 300)
  }
}