Ejemplo Animacion en JavaFX

Aqui un pequeño ejemplo de animacion en javaFX, se trata de un circulo que recorre la ventana.

package mov1;

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.shape.Circle;
import javafx.scene.paint.Color;
import javafx.animation.Timeline;
import javafx.animation.KeyFrame;
import javafx.animation.Interpolator;
import javafx.ext.swing.SwingSlider;
import javafx.scene.transform.Translate;

class bola extends CustomNode {
  public var CX:Number;
  public var CY:Number;
  public var V:Number=100;
  public override function create(): Node {
    return Group {
      content: [
        Circle {
          centerX: bind CX,
          centerY: bind CY
          radius: 50
          fill: Color.BLACK
        }
      ]
    };
  }

  init{
    var timeline=Timeline {
      repeatCount: Timeline.INDEFINITE
      keyFrames : [
        KeyFrame {time: 0s values:[CX => 50 CY => 50]}
        KeyFrame {time: 2s values:[CX => 50 CY => 450 tween Interpolator.LINEAR]}
        KeyFrame {time: 4s values:[CX => 450 CY => 450 tween Interpolator.LINEAR]}
        KeyFrame {time: 6s values:[CX => 450 CY => 50 tween Interpolator.LINEAR]}
        KeyFrame {time: 8s values:[CX => 50 CY => 50 tween Interpolator.LINEAR]}
      ]
    }
    timeline.play();
  }
}

Stage {
  title: "MyApp"
  onClose: function(){
    java.lang.System.exit(0);
  }
  scene: Scene {
  width: 500
  height: 500
  content: [bola{}]
  }
}