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

public class Rps extends JFrame
implements ActionListener
{
private final char moves[] = {'R', 'P', 'S'};
private JRadioButton rock, paper, scissors;
private JTextField display;


public Rps()
{
super("Rock, paper, Scissors");

rock = new JRadioButton(" Rock ", true);
paper = new JRadioButton(" Paper ");
scissors = new JRadioButton(" Scissors ");

ButtonGroup rpsButtons = new ButtonGroup();
rpsButtons.add(rock);
rpsButtons.add(paper);
rpsButtons.add(scissors);

JButton go = new JButton(" Go ");
go.addActionListener(this);

display = new JTextField(25);
display.setEditable(false);
display.setBackground(Color.yellow);

Container c = getContentPane();
c.setLayout(new FlowLayout());
c.add(rock);
c.add(paper);
c.add(scissors);
c.add(go);
c.add(display);
}

/**
* returns -1 if the player wins,
* 0 if it's a tie, and 1 if the computer wins
*/
private int nextPlay(char computerMove, char playerMove)
{
int result = 0;
switch(computerMove)
{
case 'R':
switch (playerMove)
{
case 'R':
result = 0;
break;
case 'P':
result = -1;
break;
case 'S':
result = 1;
break;
}
break;
case 'P':
switch (playerMove)
{
case 'R':
result = 1;
break;
case 'P':
result = 0;
break;
case 'S':
result = -1;
break;
}
break;

case 'S':
switch (playerMove)
{
case 'R':
result = -1;
break;
case 'P':
result = 1;
break;
case 'S':
result = 0;
break;
}
break;
}
return result;
}

public void actionPerformed(ActionEvent e)
{
char playerMove, computerMove;
if (rock.isSelected())
playerMove = 'R';
else if (paper.isSelected())
playerMove = 'P';
else // if (scissors.isSelected())
playerMove = 'S';

int k = (int)(Math.random() * 3);
computerMove = moves[k];
int result = nextPlay(computerMove, playerMove);

String msg = " You said " + makeWord(playerMove) + ", I said " +
makeWord(computerMove);
if (result < 0)
msg += " -- you win.";
else if (result == 0)
msg += " -- tie.";
else // if (result > 0)
msg += " -- I win.";
display.setText(msg);
}

private String makeWord(char move)
{
String word = "";

switch (move)
{
case 'R': word = "ROCK"; break;
case 'P': word = "PAPER"; break;
case 'S': word = "SCISSORS"; break;
}
return word;
}

public static void main(String[] args)
{
Rps window = new Rps();
window.setBounds(300, 300, 300, 140);
window.setDefaultCloseOperation(EXIT_ON_CLOSE);
window.setVisible(true);
}
}