如何将新的Graphic元素添加到JPanel并使用其链接更改其在循环中的位置？

Question

我只需要在MyPanel（扩展JPanel）初始化时创建一个响铃。然后我需要在MyPanel上更改（在循环iterate()）环的位置。如何以及添加到此代码中的内容？

import javax.swing.SwingUtilities;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.BorderFactory;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;

public class mull {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JPanel p = createAndShowGUI();
                iterate(p);
                // "The method iterate(MyPanel) in the type mull is not applicable for the arguments (JPanel)"
            }
        });
    }

    private static JPanel createAndShowGUI() {
        System.out.println("Created GUI on EDT? "+
        SwingUtilities.isEventDispatchThread());
        JFrame f = new JFrame("Swing Paint Demo");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        // how to grab link to this panel - in order to use it in iteration loop ?
        MyPanel p = new MyPanel();
        f.add(p);
//        f.add(new MyPanel());
        f.pack();
        f.setVisible(true);
        return p;
    } 
    private static void iterate(JPanel p){
        // the loop should change square position on each iteration
        // how to implement ?

        for (int i  = 0; i < 999; i++){
            ((MyPanel) p).moveSquare(100 + i*10, 200 + i*10); // here is problem: 
            //"Cannot make a static reference to the non-static method moveSquare(int, int) from the type MyPanel"
        }


    }
}

class MyPanel extends JPanel {

    private int squareX = 50;
    private int squareY = 50;
    private int squareW = 200;
    private int squareH = 200;

    public MyPanel() {

        setBorder(BorderFactory.createLineBorder(Color.black));

        addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                moveSquare(e.getX(),e.getY());
            }
        });

        addMouseMotionListener(new MouseAdapter() {
            public void mouseDragged(MouseEvent e) {
                moveSquare(e.getX(),e.getY());
            }
        });

    }
    // originally this method was private - in orger to access it within mull, it vas changed to public
    public void moveSquare(int x, int y) {
        int OFFSET = 1;
        if ((squareX!=x) || (squareY!=y)) {
            repaint(squareX,squareY,squareW+OFFSET,squareH+OFFSET);
            squareX=x;
            squareY=y;
            repaint(squareX,squareY,squareW+OFFSET,squareH+OFFSET);
        } 
    }


    public Dimension getPreferredSize() {
        return new Dimension(900,700);
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);       
        g.drawString("This is my custom Panel!",10,20);
        g.setColor(Color.RED);
        g.fillRect(squareX,squareY,squareW,squareH);
        g.setColor(Color.BLACK);
        g.drawRect(squareX,squareY,squareW,squareH);
    }  
}