Nada

Lab assignment 3 - Rock, paper, scissors

This program is run against a server. Here is the server program. If the server is down, start it on the computer you're working on.

In lecture 4 a server program was written which plays "rock, paper, scissors" with its clients. The code is available here. Your task is to write a graphical client program using only Swing components, namely JFrame, JTextField, JLabel, JButton, ImageIcon and Box. The game is widely known, and you can find useful material at Rock, paper, scissors, e.g. three gif images.

Note: the server speaks Swedish, so either change the server code (and run the server locally), or translate the replies from the server inside the client program ("sten"->rock, "sax"->scissors, "påse"->paper).

A simple client

Start off by making a client without the graphics, using the following code to open a connection to the server.

  try                                                          {
     Socket socket=new Socket("my.nada.kth.se",4712)           ;
     BufferedReader in=new BufferedReader(new InputStreamReader(
                           socket.getInputStream()))           ;
     PrintWriter ut=new PrintWriter(socket.getOutputStream())  ;
     ut.println("Charlotta"); ut.flush()                       ;
     System.out.println(in.readLine())                         ;}

If the server is down, try the one at rungner by replacing "my.nada.kth.se" with "rungner.nada.kth.se". The client should send your name to the server listening on port 4712 and display the answer you receive. Remember to do ut.flush(), or the name won't be sent. Once the client works you can focus completely on the graphical interface.

The Swing components

Your program should be a

public class Client extends JFrame implements ActionListener{

where the left half is your game area and the right half is that of the computer. Use BoxLayout since this often gives the best results. Each game area is a vertical Box which contains, in order from top to bottom,

Header, a JLabel with either Me: or Computer:.
Message, a JTextField where whatever is being sent from you or from the server is shown (first the greeting, then "ROCK", "PAPER" or "SCISSORS").
A button showing "rock" (created using new JButton(rockimg)...)
A button showing "paper" (...where the image is an ImageIcon...)
A button showing "scissors" (... the constructor of which takes a gif image as a parameter)
Result, a JLabel which after one click displays ONE..., after a second click TWO... and after a third click WINS, DRAW or LOSES.
Score, a JTextField which displays Score: 7

Let GameArea be an inner class, to make it easy to create two instances of it beside each other in a horizontal box. The advantage of a box is the ability to put fixed spaces between the components inside. With the declaration Box box=Box.createHorizontalBox(); one can do this:

   box.add(me);  //GameArea me=new GameArea("Me:"); has already been declared
   box.add(Box.createHorizontalStrut(20)); //Spacer
   box.add(you); //GameArea you=new GameArea("Computer:"); has already been declared

Extra assignment: Add sound effects! (May require headphones on some computers).

Hints and advice

If GameArea inherits from Box you can start the constructor with
super(BoxLayout.Y_AXIS) to make it vertical.
The images can be created in the declaration ImageIcon rock=new ImageIcon("rock.gif") and collected in an array Icon[] imgs={rock,scissors,paper}.
Feel free to make a corresponding text array String[]text={"ROCK","PAPER","SCISSORS"}.
And in the GameArea class there could be a button array. Although there is no text on the buttons, one can associate them with a text by using button[i].setActionCommand(text[i]). This can then be retrieved in actionPerformed by e.getActionCommand().
If you want the outer Client class to be a listener on the inner class GameArea, write button[i].addActionListener(Client.this).
It's nice if the button turns yellow when clicked. Therefore a method public void select(String text) is suitable for the GameArea class. It might go through the buttons and set a grey background for all buttons except the one with the specified text, which instead is turned yellow. At the same time, write a new message to the message field.
For each click, receive a server message which is sent to the select method in the computer area.
You need a global variable which counts to three, and then returns to zero. And every player needs a score counter. Where should that be placed?
The idea is that the first two clicks don't count. They are just preparations for the third and final click.
You are not forced to use the Model-View-Controller pattern (like in the last assignment) or make a text-based client, but it might be a good idea.

A beautiful client by (student)................................................................
admired by (teacher)........................................... on (date) .....................
Sidansvarig: <karlm@nada.kth.se>
Senast ändrad 13 april 2008
Tekniskt stöd: <webmaster@nada.kth.se>