Gui.java

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

public class Gui {
   // Connect status constants
   final static int DISCONNECTED = 0;
   final static int BEGIN_CONNECT = 1;
   final static int CONNECTED = 2;

   // Various GUI components and info
   public static JFrame mainFrame = null;
   public static JTextArea chatText = null;
   public static JTextField chatLine = null;
   public static JLabel statusBar = null;
   public static JTextField ipField = null;
   public static JTextField portField = null;
   public static JRadioButton hostOption = null;
   public static JRadioButton guestOption = null;
   public static JButton connectButton = null;
   public static JButton disconnectButton = null;

   // Connection info
   public static String hostIP = "localhost";
   public static int port = 1234;
   public static int connectionStatus = DISCONNECTED;
   public static boolean isHost = true;

   private static JPanel initOptionsPane() {
      JPanel pane = null;
      ActionAdapter buttonListener = null;

      // Create an options pane
      JPanel optionsPane = new JPanel(new GridLayout(4, 1));

      // IP address input
      pane = new JPanel(new FlowLayout(FlowLayout.RIGHT));
      pane.add(new JLabel("Host IP:"));
      ipField = new JTextField(10); ipField.setText(hostIP);
      ipField.setEditable(true);
      pane.add(ipField);
      optionsPane.add(pane);

      // Port input
      pane = new JPanel(new FlowLayout(FlowLayout.RIGHT));
      pane.add(new JLabel("Port:"));
      portField = new JTextField(10); portField.setEditable(true);
      portField.setText((new Integer(port)).toString());
      pane.add(portField);
      optionsPane.add(pane);

      // Host/guest option
      ButtonGroup bg = new ButtonGroup();
      hostOption = new JRadioButton("Host", true);
      hostOption.setMnemonic(KeyEvent.VK_H);
      guestOption = new JRadioButton("Guest", false);
      guestOption.setMnemonic(KeyEvent.VK_G);
      bg.add(hostOption);
      bg.add(guestOption);
      pane = new JPanel(new GridLayout(1, 2));
      pane.add(hostOption);
      pane.add(guestOption);
      optionsPane.add(pane);

      // Connect/disconnect buttons
      JPanel buttonPane = new JPanel(new GridLayout(1, 2));
      buttonListener = new ActionAdapter() {
            public void actionPerformed(ActionEvent e) {
               // Request a connection initiation
               if (e.getActionCommand().equals("connect")) {
                  connectButton.setEnabled(false);
                  disconnectButton.setEnabled(true);
                  connectionStatus = BEGIN_CONNECT;
                  ipField.setEnabled(false);
                  portField.setEnabled(false);
                  hostOption.setEnabled(false);
                  guestOption.setEnabled(false);
                  chatLine.setEnabled(true);
                  statusBar.setText("Online");
                  mainFrame.repaint();
               }
               // Disconnect
               else {
                  connectButton.setEnabled(true);
                  disconnectButton.setEnabled(false);
                  connectionStatus = DISCONNECTED;
                  ipField.setEnabled(true);
                  portField.setEnabled(true);
                  hostOption.setEnabled(true);
                  guestOption.setEnabled(true);
                  chatLine.setText(""); chatLine.setEnabled(false);
                  statusBar.setText("Offline");
                  mainFrame.repaint();
               }
            }
         };
      connectButton = new JButton("Connect");
      connectButton.setMnemonic(KeyEvent.VK_C);
      connectButton.setActionCommand("connect");
      connectButton.addActionListener(buttonListener);
      connectButton.setEnabled(true);
      disconnectButton = new JButton("Disconnect");
      disconnectButton.setMnemonic(KeyEvent.VK_D);
      disconnectButton.setActionCommand("disconnect");
      disconnectButton.addActionListener(buttonListener);
      disconnectButton.setEnabled(false);
      buttonPane.add(connectButton);
      buttonPane.add(disconnectButton);
      optionsPane.add(buttonPane);

      return optionsPane;
   }

   private static void initGUI() {
      // Set up the status bar
      statusBar = new JLabel();
      statusBar.setText("Offline");

      // Set up the options pane
      JPanel optionsPane = initOptionsPane();

      // Set up the chat pane
      JPanel chatPane = new JPanel(new BorderLayout());
      chatText = new JTextArea(10, 20);
      chatText.setLineWrap(true);
      chatText.setEditable(false);
      chatText.setForeground(Color.blue);
      JScrollPane chatTextPane = new JScrollPane(chatText,
         JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
         JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
      chatLine = new JTextField();
      chatLine.setEnabled(false);
      chatPane.add(chatLine, BorderLayout.SOUTH);
      chatPane.add(chatTextPane, BorderLayout.CENTER);
      chatPane.setPreferredSize(new Dimension(200, 200));

      // Set up the main pane
      JPanel mainPane = new JPanel(new BorderLayout());
      mainPane.add(statusBar, BorderLayout.SOUTH);
      mainPane.add(optionsPane, BorderLayout.WEST);
      mainPane.add(chatPane, BorderLayout.CENTER);

      // Set up the main frame
      mainFrame = new JFrame("Simple TCP Chat");
      mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      mainFrame.setContentPane(mainPane);
      mainFrame.setSize(mainFrame.getPreferredSize());
      mainFrame.setLocation(200, 200);
      mainFrame.pack();
      mainFrame.setVisible(true);
   }

   public static void main(String args[]) {
      initGUI();
   }
}

// Action adapter for easy event-listener coding
class ActionAdapter implements ActionListener {
   public void actionPerformed(ActionEvent e) {}
}