JavaFX Rectangle create

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

public class Main extends Application {

  public void start(Stage primaryStage) {

    GridPane pane = new GridPane();
    boolean isBlack = false;
    for (int i = 0; i < 8; i++) {
      for (int j = 0; j < 8; j++) {
        Rectangle rec = new Rectangle(50, 50, (isBlack) ? Color.BLACK : Color.WHITE);
        pane.add(rec, j, i);/*  w ww .  j a  va  2s .c o m*/
        isBlack = !isBlack;
      }
      isBlack = !isBlack;
    }

    Scene scene = new Scene(pane, 400, 400);
    primaryStage.setScene(scene);
    primaryStage.setTitle("Checkerboard");
    primaryStage.setMinHeight(400);
    primaryStage.setMinWidth(400);
    primaryStage.show();
  }

  public static void main(String[] args) {
    Application.launch(args);
  }
}