gistfile1.kt

import javafx.application.Application
import javafx.event.ActionEvent
import javafx.geometry.Pos
import javafx.scene.Scene
import javafx.scene.control.Button
import javafx.scene.control.Label
import javafx.scene.layout.VBox
import javafx.stage.Stage
import kotlinfx.*

fun main(args: Array<String>) = Application.launch(JavaFxSample.javaClass)

object JavaFxSample : Application() {

    override fun start(stage: Stage?) {
        var count = 0
        val label = Label("$count")
        val button = Button("Count")

        button.setOnAction {
        (event: ActionEvent) ->
            label.text = "${++count}"
        }

        val vBox = VBox(20.0)
        vBox.alignment = Pos.CENTER
        vBox.children.add(label)
        vBox.children.add(button)

        val scene = Scene(vBox)
        val style = JavaFxSample.javaClass.getResource("css/style.css")?.toExternalForm()
        scene.stylesheets.add(style)

        if (stage != null) {
            stage.width = 400.0
            stage.height = 300.0
            stage.scene = scene
            stage.title = "Counter"
            stage.show()
        }
    }
}