How can I externally update a JavaFX scene?

Question

I am trying to learn JavaFX and convert a swing application to JavaFX. What I want to do is use JavaFX to display the progress of a program.

What I was previously do

Answer 1

This code does what I think you're looking to do:

package javafxtest;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

/**
 * @author ericjbruno
 */
public class ShowJFXWindow {
    {
        // Clever way to init JavaFX once
        JFXPanel fxPanel = new JFXPanel();
    }

    public static void main(String[] args) {
        ShowJFXWindow dfx = new ShowJFXWindow();
        dfx.showWindow();
    }

    public void showWindow() {
        // JavaFX stuff needs to be done on JavaFX thread
        Platform.runLater(new Runnable() {
            @Override
            public void run() {
                openJFXWindow();
            }
        });
    }

    public void openJFXWindow() {
        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler() {

            @Override
            public void handle(ActionEvent event) {
                System.out.println("Hello World!");
            }
        });

        StackPane root = new StackPane();
        root.getChildren().add(btn);

        Scene scene = new Scene(root, 300, 250);
        Stage stage = new Stage();
        stage.setTitle("Hello World!");
        stage.setScene(scene);
        stage.show();
    }
}