Desktop.java

import java.awt.*;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.*;

@SuppressWarnings("serial")
class Desktop extends JFrame // create frame for canvas
{

  GCanvas canvas;

  public Desktop() // constructor
  {
    super("Airscribe Demo");
    setBounds(0, 0, 1000, 1000);// set frame
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container con = this.getContentPane(); // inherit main frame
    con.setBackground(Color.white); // paint background
    canvas = new GCanvas(); // create drawing canvas
    con.add(canvas);
    setVisible(true);// add to frame and show
  }

  public static void main(String args[]) {
    Desktop as = new Desktop();
    int port;
    ServerSocket server_socket;
    BufferedReader input;
    BufferedWriter output;
    try {
      port = Integer.parseInt(args[0]);
    } catch (Exception e) {
      System.out.println("port = 1500 (default)");
      port = 1500;
    }

    try {

      server_socket = new ServerSocket(port);
      System.out.println("Server waiting for client on port "
          + server_socket.getLocalPort());

      // server infinite loop
      while (true) {
        Socket socket = server_socket.accept();
        System.out.println("New connection accepted "
            + socket.getInetAddress() + ":" + socket.getPort());
        input = new BufferedReader(new InputStreamReader(
            socket.getInputStream()));
        output = new BufferedWriter(new OutputStreamWriter(
            socket.getOutputStream()));
        // print received data
        Enum wd = new Enum();
        boolean print = false;
        try {
          while (true) {
            char[] buf = new char[12];
            input.read(buf, 0, buf.length);
            if (buf == null) {
              return;
            }
            String str = new String(buf);
            str = str.substring(0, str.indexOf("\n"));
            String type = str.substring(0, 2);

            if (type.equals("AX")) {
              print = false;
              wd.accel_x1 = Float.parseFloat(str.substring(2));
            } else if (type.equals("AY")) {
              wd.accel_y1= Float.parseFloat(str.substring(2));
            } else if (type.equals("AZ")) {
              wd.accel_z1= Float.parseFloat(str.substring(2));
            } else if (type.equals("GX")) {
              wd.accel_x2 = Integer.parseInt(str.substring(2));
            } else if (type.equals("GY")) {
              wd.accel_y2 = Integer.parseInt(str.substring(2));
            } else if (type.equals("GZ")) {
              wd.accel_z2 = Integer.parseInt(str.substring(2));
              print = true;
            } else if (type.equals("CL")){
              System.out.println("DETECTED CLEAR");
              as.canvas.clearCanvas();              
            }

            if (print) {
              // data ready to process
              System.out.println(wd);
              as.canvas.newPoint(wd.accel_x1, wd.accel_y1);
            }
            // System.out.println(str);

            // Flushing the output after the write will immediatly
            // intimate the client
            // output.write(buf,0,buf.length);
            output.flush();
          }

        } catch (IOException e) {
          System.out.println(e);
        }
        input.close();
        output.close();

        // connection closed by client
        socket.close();
        System.out.println("Connection closed by client");

      }
    } catch (IOException e) {
      System.out.println(e);
    }
  }
}