A sample Scala/JavaFX application

By Alvin Alexander. Last updated: August 29, 2022

As a brief note to self, here’s an example JavaFX application written using Scala 2:

package pizzastore

import javafx.application.Application
import javafx.event.ActionEvent
import javafx.event.EventHandler
import javafx.geometry.{Insets, Pos}
import javafx.scene.Scene
import javafx.scene.control.{Button, Label, Separator}
import javafx.scene.layout._
import javafx.scene.paint.Color
import javafx.scene.text.Font
import javafx.stage.Stage

object MainWindow {
    def main(args: Array[String]) {
        Application.launch(classOf[MainWindow], args: _*)
    }
}

class MainWindow extends Application  {
    override def start(stage: Stage) {
        val borderPane = new MainBorderPane
        val scene = new Scene(borderPane, 600, 400)
        scene.getStylesheets.add(getClass.getResource("pizza.css").toExternalForm)
        stage.setScene(scene)
        stage.setTitle("Al’s Pizza")
        stage.show
    }
}

class MainBorderPane extends BorderPane {

    // others need to be able to get this to add an action to it
    val placeOrderButton = new Button

    val alsPizzaLabel = new Label("Al’s Pizza")
    //label.setId("fancytext")   //css approach
    alsPizzaLabel.setFont(new Font("Arial", 50))
    alsPizzaLabel.setTextFill(Color.TOMATO)

    placeOrderButton.setText("Start An Order")
    placeOrderButton.setOnAction((e: ActionEvent) => {
        println("Hello World!")
    })
    placeOrderButton.setFont(new Font("Arial", 24))

    // a spacer to push the visible elements up a little
    val spacer = new Region
    spacer.setPrefHeight(40)

    val vbox = new VBox
    vbox.setSpacing(40)
    vbox.setAlignment(Pos.CENTER)
    vbox.getChildren.addAll(alsPizzaLabel, placeOrderButton, spacer)

    this.setCenter(vbox)

}

A few redeeming features of this example:

It shows the magic recipe to launch a JavaFX application in Scala
It shows how to add a stylesheet to a JavaFX Scene in Scala

Scala, JavaFX, and SBT

Note that when you’re working with Scala and JavaFX in SBT (formerly known as the Simple Build Tool), you’ll want to add this setting to your build.sbt file:

fork in run := true

As Monk would say, you’ll thank me later. :)

Other Scala/JavaFX code snippets

While I’m in the neighborhood, here are a couple of other Scala/JavaFX source code snippets.

Scala + JavaFX Button (handling a button action)

val placeOrderButton = new Button

placeOrderButton.setText("Start An Order")
placeOrderButton.setOnAction((e: ActionEvent) => {
    println("Hello World!")
})

placeOrderButton.setFont(new Font("Arial", 24))

Spacer

val spacer = new Region
spacer.setPrefHeight(40)

TextField

val searchField = new TextField
searchField.setPromptText("<search>")

VBox

val vbox = new VBox
vbox.setSpacing(40)
vbox.setAlignment(Pos.CENTER)
vbox.getChildren.addAll(alsPizzaLabel, placeOrderButton, spacer)

MenuItem

Some code to work with a MenuItem, Alert, Buttons, and ButtonType:

addNoteMenuItem.setOnAction(e => {
    val alert = new Alert(AlertType.CONFIRMATION)
    val okButton = new ButtonType("OK")
    val cancelButton = new ButtonType("Cancel", ButtonData.CANCEL_CLOSE)

    alert.setTitle("Add Note")
    val editNotePane = new EditNotePane
    alert.getDialogPane().setExpandableContent(editNotePane)
    alert.showAndWait()
})