Chat Client

1
Chat Client

• ACM
• 15 October 2003

2
Goals

• Connect to custom chat server
• Send and receive simple text messages
• Inform user of connection and disconnection

3
Implementation

• .NET Application written in C
• Swing Application written in Java
• Sockets for network interface
• Multi-threaded application for asynchronously
  receiving messages
• Chat style interface

4
Overview of Sockets

• End-point of a two-way communication link between
  networked applications
• Used to send and receive data
• Available in many languages
• C, Perl, C, Java, etc.

• Two types of socket operations
• Blocking
• Non-blocking
• We will use blocking operations in conjunction
  with multi-threading

5
Overview of Multi-threading

• Multiple concurrent paths of execution in a
  single process
• Much more difficult than single threaded
  programming
• No guarantee on thread execution order
• No guarantee on time slice size
• We will use one extra thread to perform blocking
  operations

6
Chat Style Interface

• Chat window must scroll with incoming text
• C
• Win32 API messages must be sent to and received
  from a RichTextBox control
• Message swapping functions must be imported
  (DllImport)
• Java
• JTextPane.setCaretPosition(DocumentLength)

7
Improvements

• Server
• Use multiple ports to communicate efficiently
  with clients
• Pass XML instead of simple text
• Add ability to login
• Send text colors and fonts
• Enforce advanced chat rules
• Encrypt messages
• Client
• Interpret incoming message as XML and process
  accordingly
• Gracefully deal with failed connections
• Allow for custom colors and fonts