user_interface

• Overview
  • user_interface is a data structure which encapsulates the user interface for chess/antichess. It handles only the *interface* for displaying the board, making moves, etcetera and doesn't make any decisions of its own...it is called by the arbiter.
  • written by stevenj, twm, pepellet
  • $Log: user_interface.spec.html,v $
  • Revision 1.1 2001/01/12 02:23:24 twm
  • Revision as of January 11, 2001.
  • Revision 1.2 95/04/16 15:55:16 pepellet fixed await_command to send waiting_for_long_process signal
  • Revision 1.1 95/04/15 20:24:17 pepellet Initial revision
• create = proc() returns(cvt)
  • effects: returns a new ui data structure, doing any required initializations (opening windows, etc.)
• destroy = proc(ui: cvt)
  • requires: destroy has not been called on ui yet.
  • effects: destroys the user interface ui, closing windows, etc.
• display_board = proc(ui: cvt, board: chess_board)
  • requires: destroy has not been called on ui yet.
  • effects: displays the contents of board to the user
• display_message = proc(ui: cvt, message: string)
  • requires: destroy has not been called on ui yet.
  • effects: displays the string, message, to the user in some way
• await_command = proc(ui: cvt, board: chess_board, cur_color: pieceColor, gs: game_state) returns(ui_command) signals(waiting_for_long_process)
  • requires: destroy has not been called on ui yet.
  • effects: Waits for a command from the user, and returns the information necessary to execute the command. Does *not* execute the command itself. board is provided in case ui needs to refresh the board display. cur_color is the color the current player's pieces. gs is the current game state. Must support the text-based input described in the problem set handout, in addition to any other input methods. If the current player's time elapses without anything happening, should return a timeout command. If a long process is currently waiting, signals waiting_for_long_process.
• command_waiting = proc(ui: cvt) returns(bool)
  • requires: destroy has not been called on ui yet
  • effects: returns true if there is currently a command waiting to be read by await_command. returns false otherwise.
• display_move = proc(ui: cvt, board: chess_board, move: moveData, the_player: string) signals(no_piece, illegal_location)
  • requires: destroy has not been called on ui yet
  • effects: Displays the effect of the move described in move; board is the chess_board *before* the move occurs. the_player is the name of the player making the move. If there is no piece at the starting point of the move, signals no_piece. If the coordinates in move are not locations on the board, signals illegal_location. (Does *not* check if the move itself is legal).
• wait_long_process = proc(ui: cvt, message: string)
  • requires: destroy has not been called on ui yet
  • effects: displays the message string in preparation for a long process to start. If await_command is called before finish_long_process is called, the user interface will *not* allow or return any user commands. wait_long_process may be called more than once before finish_long_process is called, with different message strings.
• finish_long_process = proc(ui: cvt) signals(not_waiting)
  • requires: destroy has not been called on ui yet
  • effects: after call(s) to wait_long_process, stops displaying message string(s) and resumes normal operation of the interface. Signals not_waiting if there was no call to wait_long_process since the last call to finish_long_process.