topical media & game development
actionscript-book-TelnetSocket-com-example-programmingas3-socket-Telnet.ax
actionscript-book-TelnetSocket-com-example-programmingas3-socket-Telnet.ax
[swf]
flex
package // com.example.programmingas3.socket
{
import flash.events.*;
import flash.net.Socket;
import flash.system.Security;
import flash.utils.ByteArray;
import flash.utils.setTimeout;
import mx.controls.TextArea;
import mx.core.UIComponent;
public class @ax-actionscript-book-TelnetSocket-com-example-programmingas3-socket-Telnet extends UIComponent{
private const CR:int = 13; // Carriage Return (CR)
private const WILL:int = 0xFB; // 251 - WILL (option code)
private const WONT:int = 0xFC; // 252 - WON'T (option code)
private const DO:int = 0xFD; // 253 - DO (option code)
private const DONT:int = 0xFE; // 254 - DON'T (option code)
private const IAC:int = 0xFF; // 255 - Interpret as Command (IAC)
private var serverURL:String;
private var portNumber:int;
private var socket:Socket;
private var ta:TextArea;
private var state:int = 0;
public function @ax-actionscript-book-TelnetSocket-com-example-programmingas3-socket-Telnet(server:String, port:int, output:TextArea) {
// set class variables to the values passed to the constructor.
serverURL = server;
portNumber = port;
ta = output;
// Create a new Socket object and assign event listeners.
socket = new Socket();
socket.addEventListener(Event.CONNECT, connectHandler);
socket.addEventListener(Event.CLOSE, closeHandler);
socket.addEventListener(ErrorEvent.ERROR, errorHandler);
socket.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
socket.addEventListener(ProgressEvent.SOCKET_DATA, dataHandler);
// Load policy file from remote server.
Security.loadPolicyFile("http://" + serverURL + "/crossdomain.xml");
//Security.loadPolicyFile("http://www.cs.vu.nl" + "/~eliens/flex/crossdomain.xml");
// Attempt to connect to remote socket server.
try {
msg("Trying to connect to " + serverURL + ":" + portNumber + "\n");
socket.connect(serverURL, portNumber);
} catch (error:Error) {
/*
Unable to connect to remote server, display error
message and close connection.
*/
msg(error.message + "\n");
socket.close();
}
}
This method is called if the socket encounters an ioError event.
public function ioErrorHandler(event:IOErrorEvent):void {
msg("Unable to connect: socket error.\n");
}
This method is called by our application and is used to send data
to the server.
public function writeBytesToSocket(ba:ByteArray):void {
socket.writeBytes(ba);
socket.flush();
}
private function connectHandler(event:Event):void {
if (socket.connected) {
msg("connected...\n");
} else {
msg("unable to connect\n");
}
}
This method is called when the socket connection is closed by
the server.
private function closeHandler(event:Event):void {
msg("closed...\n");
}
This method is called if the socket throws an error.
private function errorHandler(event:ErrorEvent):void {
msg(event.text + "\n");
}
This method is called when the socket receives data from the server.
private function dataHandler(event:ProgressEvent):void {
var n:int = socket.bytesAvailable;
// Loop through each available byte returned from the socket connection.
while (--n >= 0) {
// Read next available byte.
var b:int = socket.readUnsignedByte();
switch (state) {
case 0:
// If the current byte is the "Interpret as Command" code, set the state to 1.
if (b == IAC) {
state = 1;
// Else, if the byte is not a carriage return, display the character using the msg() method.
} else if (b != CR) {
msg(String.fromCharCode(b));
}
break;
case 1:
// If the current byte is the "DO" code, set the state to 2.
if (b == DO) {
state = 2;
} else {
state = 0;
}
break;
// Blindly reject the option.
case 2:
/*
Write the "Interpret as Command" code, "WONT" code,
and current byte to the socket and send the contents
to the server by calling the flush() method.
*/
socket.writeByte(IAC);
socket.writeByte(WONT);
socket.writeByte(b);
socket.flush();
state = 0;
break;
}
}
}
Append message to the TextArea component on the display list.
After appending text, call the setScroll() method which controls
the scrolling of the TextArea.
private function msg(value:String):void {
ta.text += value;
ta.dispatchEvent(new Event(Event.CHANGE));
setTimeout(setScroll, 100);
}
Scroll the TextArea component to its maximum vertical scroll
position so that the TextArea always shows the last line returned
from the server.
public function setScroll():void {
ta.verticalScrollPosition = ta.maxVerticalScrollPosition;
}
}
}
(C) Æliens
27/08/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
