Programming Assignment #7 Solution

A  GUI for  Distributed Tic-Tac-Toe

 

You may use the code in ~kearns/public/415/tictactoe or your own code from P4 as a starting point for a graphical  user interface for ttt, the tic-tac-toe client.  Specifically, modify ttt.c so that it spawns a subprocess running  wish to provide a GUI for the client.  Of course, ttt and wish will communicate by means  of a pair  of pipes,  and  ttt will communicate with  TTT through  an IPv4 virtual  circuit.

When  the ttt program  is invoked,  it should operate  as before up through  prompting the user for a handle.   After  obtaining  the  handle,  it  should  interact exclusively through  the  GUI  whose minimal properties  are described  below:

 

• A canvas  widget should display  the tic-tac-toe game board.  A standard tic-tac-toe grid will define the nine regions of the board.

 

• Beneath  the board, there should be an area in which the handle of the players and the symbol

(X or O) each is using is displayed.

 

• There  should  also be an area  in which status information  is displayed  in textual form.  The following messages would be appropriate for status information:

 

–  Awaiting  Match

–  Your Move

–  Awaiting  Opponent Move

–  You Win

–  You Lose

–  Draw

–  Opponent Resigned

 

• When  it  is your  move,  the  system  “bell”  should  sound.    See the  bell(n) manual  page.

Mousing left on an empty square registers your move into that square.  An X or O is displayed in that square as appropriate. If not your move, mousing in a square is a no-op.  If you mouse on a square that is already  occupied, an audible  beep should be produced.

 

• When  an opponent moves, an X or O should  appear  in the  appropriate square  to show the move.

 

• When a game does not end in a draw, a line should be drawn through  one sequence of winning moves.

• There should be three buttons associated with your display.  The Exit button does the obvious thing:  it will shut  down the client,  but  only after  the game is over.  Mousing on this button while the game in being played  is a no-op.  This is the mechanism  by which the GUI should be taken  down under  normal  circumstances.

 

Another  button should  be labeled  Silent. If you mouse left on this  button, it will disable the  required  beeps.   It  will also change  its  label to  Sound.  If you mouse left on the  Sound button, it will turn  beeping  back on (and  will change  its label to Silent). Effectively,  this button will allow you to toggle beeps on and off as you choose.

 

A button labeled Resign should be used by a player to resign from the game before the play is complete.  The  resigning player  loses and  the  other  player  wins; the  message area  of each client  should  reflect the  fact.   We expect  that the  Exit  button would then  be used to  take down  the  client.   Note  that resignation  is a new operation  for the  tic-tac-toe system,  and modifications  in the  underlying  client/server will be required.   This  button should  only be active  when it is a player’s move (hence, you can’t resign until  it is your move).

 

 

Tips and Hacks

 

• Lots of what  you want to do in the  GUI can be phrased  as calls to TCL  procedures.   TCL procedures  can  reference  global  TCL  variables  (i.e.,  defined  at  the  outermost level of the script,  not  within  a procedure  body).  In a given procedure,  to access global variable  x, you must  execute the command

 

global x

 

 

 

probably  early in the procedure,  but  certainly  before a reference to x.

 

• Debugging support is weak.  Diagnostic  puts work for me.

 

• I emphasize  that these are minimal specs for the GUI. Feel free to extend  it, but  you should curb any inclination  to extend  until  you have the minimal  GUI working.

 

 

Submission

 

Create  a gzipped tarball of all the C source and TCL files used to build your system.  Also include a Makefile from which the TA can build your binaries. Here’s what  I would have done to create the tarball:

 

% cd my_working_directory

% tar zcvf submit.tgz Makefile TTT.c ttt.c msg.c common.h child.c child.h ttt.tcl

% gpg -r CSCI415 --sign -e submit.tgz

% mv submit.tgz.gpg ~

% chmod 644 ~/submit.tgz.gpg

We will decrypt  and unpack  your files into an empty  directory.   We will then  make that directory current and  invoke the  command  make to build  your  system.   Finally,  we will bring  your  system into  execution  with  an invocation  of ./TTT, and  (in separate  windows) a couple of invocations  of

./ttt. All activity  will take place from the directory  in which the TA builds your system.