import java.awt.event.KeyListener;

import java.awt.event.KeyEvent;

import java.awt.Graphics;



class Avatar implements KeyListener

{

	private int x;

	private int y;

	private int xs = 0;

	private int ys = 0;

	

	public Avatar(int _x, int _y)

	{

		x = _x;

		y = _y;

	}

	

	public void doStep()

	{

		x += xs;

		y += ys;

	}

	

	public String getUpdate()

	{

		return intToString(x) + intToString(y) + intToString(xs) + intToString(ys);

	}

	

	public void setUpdate(String update)

	{

		x = stringToInt(update.substring(0,4));

		y = stringToInt(update.substring(4,8));

		xs = stringToInt(update.substring(8,12));

		ys = stringToInt(update.substring(12,16));

	}

	

	private static String intToString(int num)

	{

		String result = "" + num;

		while(result.length() < 4)

		{

			result = " " + result;

		}

		return result;

	}

	

	private static int stringToInt(String str)

	{

		while(str.substring(0,1).equals(" "))

		{

			str = str.substring(1);

		}

		return Integer.parseInt(str);

	}

	

	public void draw(Graphics g)

	{

		g.fillRect(x, y, 4, 4);

	}

	

	public void keyPressed(KeyEvent e)

	{

		switch(e.getKeyCode())

		{

			case KeyEvent.VK_RIGHT: xs = 1;  break;

			case KeyEvent.VK_UP:    ys = -1; break;

			case KeyEvent.VK_LEFT:  xs = -1; break;

			case KeyEvent.VK_DOWN:  ys = 1;  break;

		}

	}

	

	public void keyReleased(KeyEvent e)

	{

		switch(e.getKeyCode())

		{

			case KeyEvent.VK_RIGHT: if (xs > 0) xs = 0; break;

			case KeyEvent.VK_UP:    if (ys < 0) ys = 0; break;

			case KeyEvent.VK_LEFT:  if (xs < 0) xs = 0; break;

			case KeyEvent.VK_DOWN:  if (ys > 0) ys = 0; break;

		}

	}

	

	public void keyTyped(KeyEvent e) {}

	

	public static void main(String[] args)

	{

		//Test run, just tests update logic

		String temp = intToString(1) + intToString(-1);

		System.out.println(temp);

		System.out.println(stringToInt(temp.substring(0,4)));

		System.out.println(stringToInt(temp.substring(4,8)));

	}

}

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.net.Socket;

import java.io.PrintWriter;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import javax.swing.JPanel;

import javax.swing.Timer;

import java.awt.Graphics;

import java.awt.Dimension;

import java.io.IOException;



class LearnNetwork extends JPanel implements ActionListener

{

	public static final int PORT_NUM = 6112;

	

	private Socket socket;

	private PrintWriter out;

	private BufferedReader in;

	

	private Avatar us = new Avatar(0, 0);

	private Avatar them = new Avatar(0, 0);

	private Timer t = new Timer(15, this);

	private boolean updaterStarted = false;

	

	public LearnNetwork(Socket _socket)

	{

		socket = _socket;

		try

		{

			out  = new PrintWriter(socket.getOutputStream(), true);

			in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

		}

		catch(IOException e)

		{

			System.out.println("Error connecting: " + e.getMessage());

			System.exit(-1);

		}

		

		setPreferredSize(new Dimension(512, 512));

		setFocusable(true);

		addKeyListener(us);

		t.start();

	}

	

	public void actionPerformed(ActionEvent eve)

	{

		us.doStep();

		them.doStep();

		out.println(us.getUpdate());

		repaint();

		

		//Abuse a boolean and the automatic threading of timers to get this fork

		if(!updaterStarted)

		{

			updaterStarted = true;

			while(updaterStarted)

			{

				//Closed from outside by setting updaterStarted back to false

				try

				{

					them.setUpdate(in.readLine());

				}

				catch(IOException e)

				{

					System.out.println("Error reading data from connection: " +

						e.getMessage());

					System.exit(-1);

				}

			}

		}

	}

	

	public void paintComponent(Graphics g)

	{

		super.paintComponent(g);

		us.draw(g);

		them.draw(g);

	}

	//TODO -- close all input and output streams, close connections

}