8.3. An Extended Example: Tic-Tac-Toe

Tic-tac-toe is a game ordinarily played on paper by two people sitting near each other. The board is a three-by-three grid and usually one player marks squares using X’s and the other using O’s. The players alternate marking the squares, trying to end up with three of their marked squares in a line (i.e., across, down, or diagonally).

In the Zeroconf version, players register service instances of type _tic-tac-toe-ex._tcp and browse for other players. The game program has two main classes, TicTacToe and GameBoard.