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

Pascal/Delphi Source File | 1997-08-20 | 5KB | 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.