//MtFrame.java
import javax.swing.*;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class MyFrame extends JFrame implements ActionListener
{
    private final int DEFAULT_WIDTH = 640;
    private final int DEFAULT_HEIGHT = 480;
    private MyPanel drawingPanel;

    public static void main(String args[])
    {
        JFrame frame = new JFrame();
        frame.setTitle("DrawPoly");
        frame.setSize(350, 250);

        frame.addWindowListener(new WindowAdapter() {
          public void windowClosing(WindowEvent e) {
            System.exit(0);
          }
        });
        Container contentPane = frame.getContentPane();
        contentPane.add(new MyPanel(1));

        //frame.show();
        frame.setVisible(true);


        JFrame frm1 = new MyFrame();
        frm1.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frm1.setVisible(true);

    }

    private void makeButton(JPanel p , String name , ActionListener target)
    {
        JButton b = new JButton(name);
        p.add(b);
        b.addActionListener(target);

    }

    public MyFrame()
    {
        drawingPanel = new MyPanel(3);

        setTitle("my frame");
        setSize(DEFAULT_WIDTH, DEFAULT_WIDTH);

        JPanel panel = new JPanel(new GridLayout(8,1,0,30));

        for (int i =3;i<10;i++)
        {
            makeButton(panel, String.valueOf(i), this);
        }
        makeButton(panel, "Exit", this);
        add(panel,BorderLayout.EAST);
        add(drawingPanel, BorderLayout.CENTER);

    }

    @Override
    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        String buttonPressed =  e.getActionCommand();

        switch (buttonPressed) {
        case "3":
            drawingPanel.setPolyLines(3);
            break;
        case "4":
            drawingPanel.setPolyLines(4);
            break;
        case "5":
            drawingPanel.setPolyLines(5);

            break;
        case "6":
            drawingPanel.setPolyLines(6);
            break;
        case "7":
            drawingPanel.setPolyLines(7);
            break;
        case "8":
            drawingPanel.setPolyLines(8);
            break;
        case "9":
            drawingPanel.setPolyLines(9);
            break;
        case "Exit":
            System.exit(1);
            break;

        default:
            break;
        }

    }



}


//MyPanel.java

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;

import javax.swing.*;

public class MyPanel extends JPanel
{
    private Polygon p = null;
    private Color color = Color.RED;
    private int _number;


    public int get_number() {
        return _number;
    }

    public void set_number(int _number) {
        this._number = _number;
    }

    @Override
    public void paintComponents(Graphics g)
    {
        Graphics2D g2 = (Graphics2D)g;

        g2.setStroke(new BasicStroke(10));
        g2.setPaint(color);

        //setPolyLines(get_number());
        Polygon p = new Polygon();
        for (int i = 0; i < 5; i++)
          p.addPoint((int) (100 + 50 * Math.cos(i * 2 * Math.PI / 5)),
              (int) (100 + 50 * Math.sin(i * 2 * Math.PI / 5)));

        g2.drawPolygon(p);

        /*
        if(p == null)
            return;
        g2.setStroke(new BasicStroke(10));
        g2.setPaint(color);
        g2.draw(p);
        */

    }

    public void setPolyLines(int sides)
    {
        p = new Polygon();
        int radius = 100;
        for(int i=0;i<sides;i++)
        {
            int x =(int) (radius * Math.cos(i * 2 * Math.PI /5 ));
            int y = (int) (radius * Math.sin(i*2*Math.PI/5));
            p.addPoint(x, y);
        }
        repaint();
    }

    public MyPanel(int sides)
    {
        //set_number(sides);



    }

}