Ch 16. Case Study A Card Game

1
Ch 16. Case Study A Card Game

• Timothy Budd
• Oregon State University

2
Introduction

• Simple card game Solitaire
• Microsoft Foundation Classes (MFC) is used for
  the graphical interface

3
The Class Card

• Use the preprocessor to ensure that including a
  header file more than once will not cause error.
• Names defined within a class declaration must
  always be qualified when they are used outside
  the class.
• include "card.h"CardColors Cardcolor ()
  if (suit() Heart suit()
  Diamond) return Red return Black

4

• ifndef CARDH // ensure only included once
• define CARDH
• // Playing Card Abstraction
• class Card public enum Suits Heart, Spade,
  Diamond, Club enum Colors Red, Black //
  constructors Card (Suits sv, int rv) s(sv),
  r(rv) fup false // return attributes int
  rank () return r Suits suit() return s
  bool faceup () return fup Colors color
  () // change attributes void flip () fup !
  fup private const Suits s const int
  r bool fup
• endif

5
Data and View Classes

• A view class provides the tools used to view data
  values held by another class.
• To isolate the library-specific aspects of the
  card view, the actual display methods are
  declared as pure virtual methods.

6

• ifndef CardViewH define CardViewH include
  "card.h"// CardView -- Display a graphical
  representation of a card
• class CardView public static const int
  Width 40 static const int Height
  70 virtual void display (Card aCard, int,
  int) 0 virtual void halfDisplay (Card
  aCard, int, int) 0 endif

7
The Game

• Klondike
• The cards that are not part of the tableau are
  initially all in the deck.
• Cards in the deck are face down, and are drawn
  one by one from the deck and placed, face up, on
  the discard pile.
• Can be moved onto either a tableau pile or a
  foundation.
• Cards are drawn from the deck until the pile is
  empty then the game is over if no further moves
  can be made.

8
Figure 16.2 Layout for the Solitaire Game
Shit piles
Discard pile
Deck
Table piles
9
Card Piles Inheritance in Action

• Use inheritance to factor out common behavior
  from similar behavior in similar classes.
• Top method
• Card CardPiletop() throw (CardPilePopError)
  if (cards.empty()) throw new
  PopError() return cards.front()

10

• class CardPile //CardPile -- representation
  of a Pile of Cards public CardPile (int
  xl, int yl) x(xl), y(yl) class PopError
  // exception on pop from empty stack
• // drawing cards from pile bool empty ()
  return cards.empty() Card top () throw
  (PopError) Card pop () throw (PopError)
  Card result top() cards.pop_front() return
  result
• // virtual methods that can be
  overridden virtual bool includes (int,
  int) virtual void addCard (Card ) virtual
  void display (CardView ) virtual bool canTake
  (Card ) virtual void select ()
  protected list cards const int x //
  location of display const int y ... //
  definitions of subclasses

11
Card Piles

• To catch the potential stack underflow, the main
  program will at some point be surrounded by a try
  clause
• Card CardPiletop() throw (CardPilePopError)
  if (cards.empty()) throw new
  PopError() return cards.front()

12
Card Piles

• includes Determines if the coordinates given as
  arguments are contained within the boundaries of
  the pile.
• canTake Tells whether a pile can take a specific
  card.
• addCard Adds a card to the card list. It is
  redefined in the discard pile class to ensure
  that the card is face up.

13
Card Piles

• display Displays the card deck. The default
  method merely displays the topmost card of the
  pile, but is overridden in the tableau class to
  display a column of cards. Only the topmostand
  bottommost face-up cards are displayed.
• select Performs an action in response to a mouse
  click. It is invoked when the user selects a pile
  by clicking the mouse in the portion of the
  playing field covered by the pile.

14
Methods and Interface
15
The Default Card Pile

• bool CardPileincludes (int tx, int ty) //
  default behavior is point within bounds of
  card? return x CardViewWidth y CardViewHeightvoid CardPileaddCard
  (Card aCard) // default behavior push card
  on front of stack cards.push_front(aCard)

16
The Default Card Pile

• void CardPiledisplay (CardView cv) //
  default behavior print topmost card if
  (empty()) cv.display(0, x, y) else cv.displa
  y(top(), x, y)bool CardPilecanTake (Card
  ) // default behavior just say no return
  falsevoid CardPileselect () // default
  behavior do nothing

17
The Suit Piles

• Class SuitPile represents the pile of cards at
  the top of the playing surface, the pile being
  built up in suit from ace to king.
• The interface for this class
• class SuitPile public CardPile
  public SuitPile (int xl, int yl) CardPile(xl,
  yl) bool canTake (Card )

18
The Suit Piles

• bool SuitPilecanTake (Card aCard) // can
  take ace if empty if (empty()) return
  aCard-rank() 1
• // otherwise must be next card in suit Card
  topCard top() return (aCard-suit()
  topCard-suit()) (aCard-rank() 1
  topCard-rank())

19
The Deck Pile

• The DeckPile maintains the deck from which new
  cards are drawn.
• class DeckPile public CardPile
  public DeckPile (int, int, Card ) void
  select ()

20
The Deck Pile

• DeckPileDeckPile (int xl, int yl, Card orig
  ) CardPile(xl, yl) for (int i 0 i 52 i) Card theCard origi if
  (theCard-faceup()) theCard-flip() addCard(
  theCard)

21
The Deck Pile

• include "Game.h" // include description of
  game manager extern Game gameManagervoid
  DeckPileselect () // move topmost card to
  discard stack if (empty()) return gameManager
  .discardPile()-addCard (top()) pop()

22
Figure 16.4 Definition of Application Class

• include "CardPile.h"class Game // Game --
  Game Manager public // constructor,
  initialization and Destructor void init
  () Game () // access to the piles CardPile
  deckPile () return piles0 CardPile
  discardPile () return piles1 CardPile
  suitPile (int i) return piles2i CardPile
  tableau (int i) return piles6i //
  handling actions void repaint(CardView ) void
  mouseDown (int, int) private CardPile
  piles13

23
The Discard Pile

• class DiscardPile public CardPile
  public DiscardPile (int xl, int yl)
  CardPile(xl, yl) void addCard (Card
  ) void select ()

24
The Discard Pile

• void DiscardPileselect () if
  (empty()) return Card topCard top() for
  (int i 0 i (i)-canTake(topCard)) gameManager.suitPil
  e(i)-addCard(topCard) pop() return
  for (int i 0 i (gameManager.tableau(i)-canTake(topCard))
  gameManager.tableau(i)-addCard(topCard) pop(
  ) return

25
The Discard Pile

• The C does not use the pseudo-code variable
  super, instead, uses qualified name.
• void DiscardPileaddCard (Card aCard) if
  (! aCard-faceup()) aCard-flip() CardPilead
  dCard(aCard)

26
The Table Piles

• The most complex of the subclasses of CardPile is
  that used to hold a tableau, or table pile.
• The interface for this class redefines nearly all
  of the virtual methods defined in ClassPile
• class TablePile public CardPile
  public TablePile (int xl, int yl, int
  p) bool canTake (Card aCard) bool includes
  (int tx, int ty) void display (CardView
  cv) void select ()

27
The Table Piles

• TablePileTablePile(int xv, int yv, int p)
  CardPile(xv, yv) // copy right number of cards
  into deck for (int i 0 i aCard gameManager.deckPile()-top() if
  (aCard-faceup()) aCard-flip() addCard(aCar
  d) gameManager.deckPile()-pop() // flip
  topmost card top()-flip()

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The Table Piles

• bool TablePilecanTake (Card aCard) if
  (empty()) return aCard-rank() 12 Card
  topCard top() return (aCard-color() !
  topCard-color()) (aCard-rank()
  topCard-rank() - 1)
• bool TablePileincludes (int tx, int
  ty) return x CardViewWidth y

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• void TablePileselect () // if empty, do
  nothing if (empty()) return // if face down,
  then flip Card topCard top() if (!
  topCard-faceup()) topCard-flip() return
  // else see if any pile can take card for
  (int i 0 i (i)-canTake(topCard)) gameManager.suitPile(i
  )-addCard(pop()) return for (int i
  0 i canTa
  ke(topCard)) gameManager.tableau(i)-addCard(
  pop()) return

30
The Table Piles

• void TablePiledisplay (CardView cv) if
  (empty()) CardPiledisplay(cv) else int
  lx x int ly y listiterator
  cptr cards.end() listiterator
  front cards.begin() for (--cptr cptr !
  front --cptr) cv.halfDisplay(cptr, lx,
  ly) ly CardViewHeight/2 cv.display
  (front, lx, ly)

31
Playing the Polymorphic Game

• Initialize card piles and shuffle deck
• void Gameinit () // first, create a deck and
  randomize itint j 0for (int i 1 i i) originalDeckj new
  Card(CardDiamond, i) originalDeckj new
  Card(CardSpade, i) originalDeckj new
  Card(CardHeart, i) originalDeckj new
  Card(CardClub, i)randomInteger swapper //
  declare the random function objectrandom_shuffle(
  originalDeck, originalDeck52, swapper)
• // continue in back

32
Playing the Polymorphic Game

• Variable piles by all card piles used in drawing
  and other operations.
• // then initialize each of the deck
  pilespiles0 new DeckPile(335, 5,
  originalDeck) piles1 new DiscardPile(268,
  5)j 2for (int i 0 i pilesj new SuitPile(15 60 i,
  5)for (int i 0 i new TablePile(5 55 i, 80, i1)

33
Playing the Polymorphic Game

• class randomInteger public unsigned int
  operator () (unsigned int max) unsigned int
  rval rand() return rval max
• GameGame() // free up all the old card
  values for (int i 0 i originalDecki

34
Playing the Polymorphic Game

• void Gamerepaint(CardView cv) // simply
  repaint each of the card decks for (int i 0 i
  display(cv)
• void GamemouseDown(int x, int y) for (int i
  0 i includes(x, y))
  pilesi-select() return

35
The Graphical User Interface

• Isolate the graphical interface from the rest of
  a program.
• class MFCardView public CardView
  public // constructor saves drawing
  context MFCardView (CPaintDC idc) dc(idc)
  // implement the interface void display
  (Card aCard, int, int) void halfDisplay (Card
  aCard, int, int)private CPaintDC dc //
  drawing context void paintCard(Card aCard,
  int, int)

36
The Graphical User Interface

• void MFCardViewdisplay (Card aCard, int x,
  int y) dc.Rectangle (x, y, x Width, y
  Height) paintCard(aCard, x, y)void
  MFCardViewhalfDisplay (Card aCard, int x, int
  y) dc.Rectangle (x, y, x Width, y Height/
  2) paintCard (aCard, x, y)

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• void MFCardViewpaintCard (Card aCard, int x,
  int y) char buffer80if (aCard 0)
  strcpy(buffer,"mt") // mt
  empty dc.SetTextColor(RGB(0,255, 0)) //
  green dc.TextOut(x5, y5, buffer,
  strlen(buffer)) else if (aCard-faceup())
  char suitCard switch (aCard-suit())
  case CardHeart suitCard 'H'
  break switch (aCard-rank())
  case 1 sprintf(buffer,"A c", suitCard)
  break
• default
• sprintf(buffer, "d c", aCard-rank(),
  suitCard) break if (aCard-color()
  CardRed) dc.SetTextColor(RGB(255, 0, 0)) //
  red else dc.SetTextColor(RGB(0, 0, 0)) //
  black dc.TextOut(x5, y5, buffer,
  strlen(buffer)) else strcpy(buffer,
  "back") dc.SetTextColor(RGB(255, 255,
  0)) // yellow dc.TextOut(x5, y5,
  buffer, strlen(buffer))

38
The Graphical User Interface

• class SolitareMainWindow public CFrameWnd
  public SolitareMainWindow() Create(NULL,
  "Solitare Game") afx_msg void
  OnPaint() afx_msg void OnLButtonDown (UINT
  flag, CPoint loc) DECLARE_MESSAGE_MAP()

39
The Graphical User Interface

• void SolitareMainWindowOnPaint() CPaintDC
  dc(this) MFCardView cv(dc) gameManager.repain
  t(cv)void SolitareMainWindowOnLButtonDown(U
  INT flag, CPoint loc) try gameManager.mouse
  Down(loc.x, loc.y) catch (CardPilePopError
  e) // do nothing on error InvalidateRect(N
  ULL)

40
The Graphical User Interface

• class SolitareApplication public CWinApp
  public BOOL InitInstance()SolitareAppli
  cation theAppBOOL SolitareApplicationInitInst
  ance() gameManager.init() m_pMainWnd new
  SolitareMainWindow() m_pMainWnd-ShowWindow
  (m_nCmdShow) m_pMainWnd-UpdateWindow()