SwingBot有椭圆和矩形

Question

我目前正在使用swingbot进行作业。我使用用户命令移动了我的矩形，我创建了2个新形状，但它们不会移动。我不确定我是否没有正确宣布它们或者发生了什么。任何帮助表示赞赏。

import javax.swing.JFrame; 
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;

import java.awt.geom.Line2D;
import javax.swing.JComponent;
import java.awt.geom.Ellipse2D;
 import java.awt.geom.Line2D;
 import java.awt.Color;
 import java.awt.Polygon;
 import java.util.Scanner;



 public class SwingBot {

    public static void main(String[] args) {

    // contruction of new JFrame object
    JFrame frame = new JFrame();

    // mutators
    frame.setSize(400,400);
    frame.setTitle("SwingBot");

    // program ends when window closes
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Robot r = new Robot();

    frame.add(r);

    // voila!
    frame.setVisible(true);


    // your Scanner-based command loop goes here
    Scanner input = new Scanner(System.in);
    int noend = 0;
    System.out.println("Do you want to move this square up, down, left or right?:");
    while(noend == 0)
     {

         String command = input.next(); 
         if(command.equals("left"))
             r.moveBot(-10,0);

         if(command.equals("right"))
             r.moveBot(10,0);

         if(command.equals("down"))
             r.moveBot(0,10);

         if(command.equals("up"))
             r.moveBot(0,-10);
    }       
    // call methods on the Robot instance like w.moveBot(10,10) in response to
    // user input



  }


  public static class Robot extends JComponent
  {
    private Rectangle rect = new Rectangle(10,10);
    private Ellipse2D elps = new Ellipse2D.Double(10,10,10,10);
    private Polygon poly = new Polygon();



    public void paintComponent(Graphics g)
    {
        Graphics2D g2 = (Graphics2D) g;

        // set the color
        g2.setColor(Color.RED);

        // draw the shape`
        g2.fill(rect);
        g2.setColor(Color.BLUE);
        g2.fill(poly);
        g2.setColor(Color.YELLOW);
        g2.fill(elps);


        int xPoly[] = {75,125,170,170,200,105,60};
        int yPoly[] = {75,50,88,111,125,180,150};
     poly = new Polygon(xPoly,yPoly,xPoly.length);
    }


    public void moveBot(int x, int y)
    {
        // move the rectangle 
        rect.translate(x,y);
        poly.translate(WIDTH, HEIGHT);
        elps.



        // redraw the window
        repaint();
    }

}


}