How can I change size rect in JPanel from another JPanel?

Question

I have code:
import java.awt.*;
import javax.swing.*;
public class ProgramD {
public static void main(String[] arg) {
JFrame f=new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(840,440);
f.setLayout(null);
PanelLeft p1=new PanelLeft();
p1.setSize(400,400);
p1.setLocation(0,0);
f.add(p1);
PanelRight p2=new PanelRight();
p2.setSize(400,400);
p2.setLocation(400,0);
f.add(p2);
f.setVisible(true);
class PanelLeft extends JPanel {
Shape shape1;
PanelLeft() {
shape1=new Rectangle(30,30,100,50);
public void paintComponent(Graphics g) {
Graphics2D g2=(Graphics2D) g;
g2.setColor(Color.red);
g2.fill(shape1);
class PanelRight extends JPanel {
PanelRight() {
setBackground(Color.green);
JTextField field1=new JTextField(4);
JTextField field2=new JTextField(4);
JButton b=new JButton("resize");
add(field1);
add(field2);
add(b);
}I would like to wrote width and height size of rect and click resize button, rect must change its size. I may add ActionListener, but I don't know what I may get size from PanelLeft and set size to PanelLeft. How may I solve this problem?

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ProgramDada{
  public static void main(String[] arg) {
    JFrame f=new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container con = f.getContentPane();
    con.setLayout(new GridBagLayout());
    GridBagConstraints gbc = new GridBagConstraints();
    PanelLeft p1 = new PanelLeft();
    p1.setPreferredSize(new Dimension(400, 400));
    gbc.gridx = 0;
    gbc.gridy = 0;
    con.add(p1, gbc);
    PanelRight p2 = new PanelRight(p1);
    p2.setPreferredSize(new Dimension(400,400));
    gbc.gridx = 1;
    con.add(p2, gbc);
    f.pack();
    f.setVisible(true);
class PanelLeft extends JPanel {
  int x, y, w, h;
  Shape shape1;
  PanelLeft() {
    x = 30;
    y = 30;
    w = 100;
    h = 50;
  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2=(Graphics2D) g;
    shape1 = new Rectangle(x, y, w, h);
    g2.setColor(Color.red);
    g2.fill(shape1);
class PanelRight extends JPanel implements ActionListener{
  PanelLeft pt;
  JTextField field1, field2;
  JButton b;
  PanelRight(PanelLeft p) {
    pt = p;
    setBackground(Color.green);
    field1 = new JTextField(4);
    field2 = new JTextField(4);
    b = new JButton("resize");
    add(field1);
    add(field2);
    add(b);
    b.addActionListener(this);
  public void actionPerformed(ActionEvent e){
    pt.w = Integer.parseInt(field1.getText());
    pt.h = Integer.parseInt(field2.getText());
    pt.repaint();
}