ShowEllipse.java

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.scene.shape.Ellipse;

public class ShowEllipse extends Application {
  @Override // Override the start method in the Application class
  public void start(Stage primaryStage) {   
    // Create a scene and place it in the stage
    Scene scene = new Scene(new MyEllipse(), 300, 200);
    primaryStage.setTitle("ShowEllipse"); // Set the stage title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage
  }
  
  /**
   * The main method is only needed for the IDE with limited
   * JavaFX support. Not needed for running from the command line.
   */
  public static void main(String[] args) {
    launch(args);
  }
}

class MyEllipse extends Pane {
  private void paint() {
    getChildren().clear();
    for (int i = 0; i < 16; i++) {
      // Create an ellipse and add it to pane
      Ellipse e1 = new Ellipse(getWidth() / 2, getHeight() / 2, 
        getWidth() / 2 - 50, getHeight() / 2 - 50);
      e1.setStroke(Color.color(Math.random(), Math.random(),
        Math.random()));
      e1.setFill(Color.WHITE);
      e1.setRotate(i * 180 / 16);
      getChildren().add(e1);
    }
  }
  
  @Override
  public void setWidth(double width) {
    super.setWidth(width);
    paint();
  }
  
  @Override
  public void setHeight(double height) {
    super.setHeight(height);
    paint();
  }
}