Lab 1

Due: Monday, February 28, at the beginning of class

Because of some errors that were noted in my version of the application, I fixed it so that, if not perfect, it is at least better. The most important bug in the program I gave you before is that it didn't appropriately handle the end of a game, which I repaired. I also dealt with the fact that the human could play even if it was the computer's turn.

Following are the two versions I am making available to you, with explanations:

• ~karl/www-docs/394/labs/lab1/tictactoe-fixed/

  The version above is the fixed version of the code. I made the following changes:

  • I fixed the gameOver() method, as you might have already done.

  • I changed the code so that the board stops when the game is over; now you need to click the "Start new game" button to continue.

  • I fixed a lot of the problem with synchronization between the computer players and the user who is clicking the buttons. Now a button click has no effect if it is not the human's turn. Actually, if you click a _lot_, you can generate a race condition bug. However, it's fairly hard to do, so I am going to leave it as is.

• ~karl/www-docs/394/labs/lab1/tictactoe-buggy/

  For your convenience, I leave a link to the buggy version here as well. Not that you should use it

When running the applets, note how I have the applet spill some information in the TextArea at the bottom (called the outputPanel in the applet).

When you want to start programming, you should recursively copy the first directory above to where you want to work. In order to get you going, I give below a short description of the various files you will be working with:

1. The applet itself:
   • TicTacToe.java

2. The Panels, which are the parts of the applet
   • ControlPanel.java
   • BoardPanel.java
   • OutputPanel.java

3. The various Listeners:
   • CellActionListener.java
   • LearningOnItemListener.java
   • PlayModeItemListener.java
   • StartGameActionListener.java

4. The classes corresponding to the final design of the checkers learning program illustrated in Figure 1.1 on page 12 of our textbook:
   • PerformanceSystem.java
   • Critic.java
   • Generalizer.java
   • ExperimentGenerator.java

5. The Computer player thread:
   • ComputerPlayerThread.java

6. And some special-purpose classes:
   • Move.java
   • Board.java
   • JCRowColLayout.java

1. TicTacToe.java is a relatively simple class. It is of course the only Applet which sets up the game. In particular, it sets up its three subpanels (described in the next grouping of classes), and directly or indirectly instantiates all of the applications objects, simultaneously setting up communication links between them.

2. These Panels are, from top to bottom, the immediate, visible subpanels of the TicTacToe applet itself. You should not have to do much with these.

3. These are the ActionListeners and ItemListeners associated with the Buttons (the board cells and the "Start Game" button) and the Checkboxes ("Learning On" and Player mode Checkboxes). You should not have to do much with these, either.

4. This is the heart of the application, and are what you should send most of your time on. I suggest that you check out the instance variables in these classes as well as there public methods.

   There is one major change (actually a simplification) from how I described these files in class on Monday. Namely, the Evaluator class I described has now been coalesced with Critic.java, which keeps track of the feature and weight vectors. In particular, this is where the V function is calculated.

5. There are two instances of this thread in the application, one corresponding to player X, and the other with player O. Since a player will only move if both (1) it is enabled and (2) it is the player's turn, I have used the technology described on pages 625-629 of Concrete Abstractions in the file ComputerPlayerThread.java in order to have the players wait appropriately.

6. Finally, Move.java is a simple data structure giving the row and column of a move; Board.java is a 2-dimensional array of strings that keeps track of the current board; and JCRowColLayout.java is a Layout manager that Mike Hvidsten found which is like a grid, but is more robust and allows for differently-sized components.