PC World 1998 October/PCWorld_1998-10_cd.bin/software/prehled/komix/DATA.Z/TicTacToe_ComputerUnit.pas

Pascal/Delphi Source File | 1997-08-20 | 5.0 KB | 252 lines

//

// File          : TicTacToe_ComputerUnit.pas

//

// Project       : PCProject

// Configuration : PCConfig 1

// Phase         : Implementation 1

// System        : TicTacToe 1

//

unit TicTacToe_ComputerUnit;



interface



uses

  // Start user include section

  // End user include section

  TicTacToe_GameUnit;



type

  // The computer opponent.

  TicTacToe_Computer = class



  private

    // User defined attributes

    id: String   (* = '' *);



    // Association attributes

    guiRef: Pointer;



    // User defined methods



    // Properties



  protected

    // User defined attributes



    // User defined methods



    // Properties



  public

    // User defined attributes



    // Association attributes

    gameRef: TicTacToe_Game;



    // Default constructor/destructor

    constructor Create(newgame: TicTacToe_Game);

    destructor Destroy; override;



    // User defined methods

    function getMaxValue(x: Integer): Integer;

    procedure checkTurn;

    procedure selectCell;



    // Access methods

    procedure setId(newId: String);

    function getId: String;



    // Association methods

    function getGui: Pointer;

    procedure removeGui;

    procedure setGame(newTicTacToe_Game: TicTacToe_Game);

    function getGame: TicTacToe_Game;

    procedure setGui(newTTicTacToe_GUI: Pointer);



    // Properties



  published

    // User defined attributes



    // User defined methods



    // Properties

  end;





implementation



uses

  // Start user include section

  TicTacToe_CellUnit,

  // End user include section

  TTicTacToe_GUIUnit,

  SysUtils;



constructor TicTacToe_Computer.Create(newgame: TicTacToe_Game);

  // Start user section

  // End user section

begin

  id := '';



  if (newgame <> NIL) then

  begin

    gameRef := newgame;

  end

  else

    raise EInvalidOp.Create('Object newgame has mandatory relation. NIL object reference not allowed.');

  inherited Create;

  // Start user section

  // End user section

end;





destructor TicTacToe_Computer.Destroy;

  // Start user section

  // End user section

begin

  // Start user section

  // End user section

  removeGui;



  inherited Destroy;

end;





// Determines the strategic value of the specified empty cell.

function TicTacToe_Computer.getMaxValue(x: Integer): Integer;

var

  i, retValue, temp: Integer;

  game: TicTacToe_Game;

  cell: TicTacToe_Cell;



begin

  game := getGame();

  retValue := -1;



  cell := game.getBoard(x);

  for i := 1 to Length(game.getPlayers()) do

  begin

    cell.setContents(game.getPlayers()[i]);

    temp := cell.getMaxLine();

    if (retValue < temp) or (retValue = -1) then

      retValue := temp;

  end;

  cell.setContents(' ');

  getMaxValue := retValue;

end;





// Checks if it's its turn.

procedure TicTacToe_Computer.checkTurn;

begin

  if getId() = TicTacToe_Game (getGame()).getActivePlayer then selectCell;

end;





// Chooses a good empty cell.

procedure TicTacToe_Computer.selectCell;

var

  i, maxi, temp: Integer;

  selection: Integer;

  game: TicTacToe_Game;

  gui: TTicTacToe_GUI;

  cell: TicTacToe_Cell;



begin

  game := getGame();

  gui := getGUI();

  maxi := 0;

  selection := -1;



  for i:= 1 to 9 do

  begin

    cell := game.getBoard(i);

    if cell.getContents() = ' ' then

    begin

      temp := getMaxValue(i);

      if (maxi < temp) or (selection = -1) then

      begin

        maxi := temp;

        selection := i;

      end;

    end;

  end;

  if selection <> -1 then

    gui.cellButtonClick(selection);

end;





// Do not delete this line -- regeneration marker



procedure TicTacToe_Computer.setId(newId: String);

begin

  id := newId;

end;





function TicTacToe_Computer.getId: String;

begin

  getId := id;

end;





function TicTacToe_Computer.getGui: Pointer;

begin

  getGui := guiRef;

end;





procedure TicTacToe_Computer.removeGui;

var

  oldTTicTacToe_GUI: TTicTacToe_GUI;



begin

  if (guiRef <> NIL) then

  begin

    oldTTicTacToe_GUI := guiRef;

    guiRef := NIL;

    oldTTicTacToe_GUI.removeComputer();

  end;

end;





procedure TicTacToe_Computer.setGame(newTicTacToe_Game: TicTacToe_Game);

begin

  if (newTicTacToe_Game <> NIL) then

  begin

    gameRef := newTicTacToe_Game;

  end;

end;





function TicTacToe_Computer.getGame: TicTacToe_Game;

begin

  getGame := gameRef;

end;





procedure TicTacToe_Computer.setGui(newTTicTacToe_GUI: Pointer);

begin

  if (newTTicTacToe_GUI <> NIL) then

  begin

    if (newTTicTacToe_GUI <> guiRef) then

    begin

      if (guiRef <> NIL) then

      begin

        TTicTacToe_GUI(guiRef).removeComputer;

      end;

      guiRef := newTTicTacToe_GUI;

      TTicTacToe_GUI(newTTicTacToe_GUI).setComputer(SELF);

    end;

  end

  else

  begin

    removeGui;

  end;

end;







end.