import java.applet.*;
import java.awt.*;
import java.lang.*;
import javax.swing.*;
import java.awt.event.*;

    public class MyApplet extends JApplet
    {
    int i=0;
    JButton b1;
    JComboBox cb1,cb2;
    JLabel l1,l2,l3;
    String st="Air",st1="Water";
    String st3="BLACK";
    public void init()
    {
    b1=new JButton("Start");
    cb1=new JComboBox();
    cb2=new JComboBox();
    l1=new JLabel("Medium 1");
    l2=new JLabel("Medium 2");
    l3=new JLabel(" ");
    cb1.addItem("Air");
    cb1.addItem("Water");
    cb1.addItem("Glass");
    cb1.addItem("Diamond");
    cb2.addItem("Air");
    cb2.addItem("Water");
    cb2.addItem("Glass");
    cb2.addItem("Diamond");
    setLayout(new FlowLayout());
    add(l1);
    add(cb1);
    cb1.addActionListener(new ChoiceClicked());
    add(l3);
    add(l2);
    add(cb2);
    cb2.addActionListener(new ChoiceClicked1());
    add(b1);
       b1.addActionListener(new ButtonClicked());
    setVisible(true);
    }
    class ChoiceClicked implements ActionListener
    {
    public void actionPerformed(ActionEvent ev)
    {
    st=(String)cb1.getSelectedItem();
    repaint();
    }
    }
    class ChoiceClicked1 implements ActionListener
    {
    public void actionPerformed(ActionEvent ev)
    {
    st1=(String)cb2.getSelectedItem();
    repaint();
    }
    }     

        class ButtonClicked implements ActionListener
    {
    public void actionPerformed(ActionEvent ev)
    {
    public void paint(Graphics g1)
        {
    Graphics2D g = (Graphics2D) g1;
    Color c=new Color(239, 0, 0, 50);
    g.setBackground(c);
    g.setColor(Color.black);
    g.drawString("REFLECTION",220,45);
    g.drawString("REFRACTION",220,365);
    g.setColor(Color.pink);
    g.fillRect(100,50,300,150);
    g.setColor(Color.black);
    g.drawString(st,125,125);
    g.setColor(Color.cyan);
    g.fillRect(100,200,300,150);
    g.setColor(Color.black);
    g.drawString(st1,125,275);
    g.setColor(Color.black);
    g.drawLine(100,200,400,200);
    g.drawLine(250,50,250,350);
    g.setColor(Color.blue);
    try
    {
    for(i=0;i<150;i++)
    {
    g.drawLine(100,50,100+i,50+i);
    Thread.sleep(20);
    }
    for(i=0;i<150;i++)
    {
    g.drawLine(250,200,250+i,200-i);
    Thread.sleep(20);
    }
    for(i=0;i<75;i++)
    {
    g.drawLine(250,200,250+i,200+2*i);
    Thread.sleep(50);
    }
    }
    catch(InterruptedException e)
    {
    }
}
}
}