SGI Freeware 2002 November/SGI Freeware 2002 November - Disc 3.iso/dist/fw_qt3.idb/usr/freeware/Qt/examples/tictac/tictac.cpp.z/tictac.cpp

C/C++ Source or Header | 2002-04-08 | 10.7 KB | 377 lines

/****************************************************************************
** $Id:  qt/tictac.cpp   3.0.3   edited Nov 14 18:02 $
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of an example program for Qt.  This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/

#include "tictac.h"
#include <qapplication.h>
#include <qpainter.h>
#include <qdrawutil.h>
#include <qcombobox.h>
#include <qcheckbox.h>
#include <qlabel.h>
#include <qlayout.h>
#include <stdlib.h>                // rand() function
#include <qdatetime.h>                // seed for rand()


//***************************************************************************
//* TicTacButton member functions
//***************************************************************************

// --------------------------------------------------------------------------
// Creates a TicTacButton
//

TicTacButton::TicTacButton( QWidget *parent ) : QPushButton( parent )
{
    t = Blank;                    // initial type
}

// --------------------------------------------------------------------------
// Paints TicTacButton
//

void TicTacButton::drawButtonLabel( QPainter *p )
{
    QRect r = rect();
    p->setPen( QPen( white,2 ) );        // set fat pen
    if ( t == Circle ) {
    p->drawEllipse( r.left()+4, r.top()+4, r.width()-8, r.height()-8 );
    } else if ( t == Cross ) {            // draw cross
    p->drawLine( r.topLeft()   +QPoint(4,4), r.bottomRight()-QPoint(4,4));
    p->drawLine( r.bottomLeft()+QPoint(4,-4),r.topRight()   -QPoint(4,-4));
    }
}


//***************************************************************************
//* TicTacGameBoard member functions
//***************************************************************************

// --------------------------------------------------------------------------
// Creates a game board with N x N buttons and connects the "clicked()"
// signal of all buttons to the "buttonClicked()" slot.
//

TicTacGameBoard::TicTacGameBoard( int n, QWidget *parent, const char *name )
    : QWidget( parent, name )
{
    st = Init;                    // initial state
    nBoard = n;
    n *= n;                    // make square
    comp_starts = FALSE;            // human starts
    buttons = new TicTacButtons(n);        // create real buttons
    btArray = new TicTacArray(n);        // create button model
    QGridLayout * grid = new QGridLayout( this, nBoard, nBoard, 4 );
    QPalette p( blue );
    for ( int i=0; i<n; i++ ) {            // create and connect buttons
    TicTacButton *ttb = new TicTacButton( this );
    ttb->setPalette( p );
    ttb->setEnabled( FALSE );
    connect( ttb, SIGNAL(clicked()), SLOT(buttonClicked()) );
    grid->addWidget( ttb, i%nBoard, i/nBoard );
    buttons->insert( i, ttb );
    btArray->at(i) = TicTacButton::Blank;    // initial button type
    }
    QTime t = QTime::currentTime();        // set random seed
    srand( t.hour()*12+t.minute()*60+t.second()*60 );
}

TicTacGameBoard::~TicTacGameBoard()
{
    delete buttons;
    delete btArray;
}


// --------------------------------------------------------------------------
// TicTacGameBoard::computerStarts( bool v )
//
// Computer starts if v=TRUE. The human starts by default.
//

void TicTacGameBoard::computerStarts( bool v )
{
    comp_starts = v;
}


// --------------------------------------------------------------------------
// TicTacGameBoard::newGame()
//
// Clears the game board and prepares for a new game
//

void TicTacGameBoard::newGame()
{
    st = HumansTurn;
    for ( int i=0; i<nBoard*nBoard; i++ )
    btArray->at(i) = TicTacButton::Blank;
    if ( comp_starts )
    computerMove();
    else
    updateButtons();
}


// --------------------------------------------------------------------------
// TicTacGameBoard::buttonClicked()        - SLOT
//
// This slot is activated when a TicTacButton emits the signal "clicked()",
// i.e. the user has clicked on a TicTacButton.
//

void TicTacGameBoard::buttonClicked()
{
    if ( st != HumansTurn )            // not ready
    return;
    int i = buttons->findRef( (TicTacButton*)sender() );
    TicTacButton *b = buttons->at(i);        // get piece that was pressed
    if ( b->type() == TicTacButton::Blank ) {    // empty piece?
    btArray->at(i) = TicTacButton::Circle;
    updateButtons();
    if ( checkBoard( btArray ) == 0 )    // not a winning move?
        computerMove();
    int s = checkBoard( btArray );
    if ( s ) {                // any winners yet?
        st = s == TicTacButton::Circle ? HumanWon : ComputerWon;
        emit finished();
    }
    }
}


// --------------------------------------------------------------------------
// TicTacGameBoard::updateButtons()
//
// Updates all buttons that have changed state
//

void TicTacGameBoard::updateButtons()
{
    for ( int i=0; i<nBoard*nBoard; i++ ) {
    if ( buttons->at(i)->type() != btArray->at(i) )
        buttons->at(i)->setType( (TicTacButton::Type)btArray->at(i) );
    buttons->at(i)->setEnabled( buttons->at(i)->type() ==
                    TicTacButton::Blank );
    }
}


// --------------------------------------------------------------------------
// TicTacGameBoard::checkBoard()
//
// Checks if one of the players won the game, works for any board size.
//
// Returns:
//  - TicTacButton::Cross  if the player with X buttons won
//  - TicTacButton::Circle if the player with O buttons won
//  - Zero (0) if there is no winner yet
//

int TicTacGameBoard::checkBoard( TicTacArray *a )
{
    int  t = 0;
    int  row, col;
    bool won = FALSE;
    for ( row=0; row<nBoard && !won; row++ ) {    // check horizontal
    t = a->at(row*nBoard);
    if ( t == TicTacButton::Blank )
        continue;
    col = 1;
    while ( col<nBoard && a->at(row*nBoard+col) == t )
        col++;
    if ( col == nBoard )
        won = TRUE;
    }
    for ( col=0; col<nBoard && !won; col++ ) {    // check vertical
    t = a->at(col);
    if ( t == TicTacButton::Blank )
        continue;
    row = 1;
    while ( row<nBoard && a->at(row*nBoard+col) == t )
        row++;
    if ( row == nBoard )
        won = TRUE;
    }
    if ( !won ) {                // check diagonal top left
    t = a->at(0);                //   to bottom right
    if ( t != TicTacButton::Blank ) {
        int i = 1;
        while ( i<nBoard && a->at(i*nBoard+i) == t )
        i++;
        if ( i == nBoard )
        won = TRUE;
    }
    }
    if ( !won ) {                // check diagonal bottom left
    int j = nBoard-1;            //   to top right
    int i = 0;
    t = a->at(i+j*nBoard);
    if ( t != TicTacButton::Blank ) {
        i++; j--;
        while ( i<nBoard && a->at(i+j*nBoard) == t ) {
        i++; j--;
        }
        if ( i == nBoard )
        won = TRUE;
    }
    }
    if ( !won )                    // no winner
    t = 0;
    return t;
}


// --------------------------------------------------------------------------
// TicTacGameBoard::computerMove()
//
// Puts a piece on the game board. Very, very simple.
//

void TicTacGameBoard::computerMove()
{
    int numButtons = nBoard*nBoard;
    int *altv = new int[numButtons];        // buttons alternatives
    int altc = 0;
    int stopHuman = -1;
    TicTacArray a = btArray->copy();
    int i;
    for ( i=0; i<numButtons; i++ ) {        // try all positions
    if ( a[i] != TicTacButton::Blank )    // already a piece there
        continue;
    a[i] = TicTacButton::Cross;        // test if computer wins
    if ( checkBoard(&a) == a[i] ) {        // computer will win
        st = ComputerWon;
        stopHuman = -1;
        break;
    }
    a[i] = TicTacButton::Circle;        // test if human wins
    if ( checkBoard(&a) == a[i] ) {        // oops...
        stopHuman = i;            // remember position
        a[i] = TicTacButton::Blank;        // restore button
        continue;                // computer still might win
    }
    a[i] = TicTacButton::Blank;        // restore button
    altv[altc++] = i;            // remember alternative
    }
    if ( stopHuman >= 0 )            // must stop human from winning
    a[stopHuman] = TicTacButton::Cross;
    else if ( i == numButtons ) {        // tried all alternatives
    if ( altc > 0 )                // set random piece
        a[altv[rand()%(altc--)]] = TicTacButton::Cross;
    if ( altc == 0 ) {            // no more blanks
        st = NobodyWon;
        emit finished();
    }
    }
    *btArray = a;                // update model
    updateButtons();                // update buttons
    delete[] altv;
}


//***************************************************************************
//* TicTacToe member functions
//***************************************************************************

// --------------------------------------------------------------------------
// Creates a game widget with a game board and two push buttons, and connects
// signals of child widgets to slots.
//

TicTacToe::TicTacToe( int boardSize, QWidget *parent, const char *name )
    : QWidget( parent, name )
{
    QVBoxLayout * l = new QVBoxLayout( this, 6 );

    // Create a message label

    message = new QLabel( this );
    message->setFrameStyle( QFrame::WinPanel | QFrame::Sunken );
    message->setAlignment( AlignCenter );
    l->addWidget( message );

    // Create the game board and connect the signal finished() to this
    // gameOver() slot

    board = new TicTacGameBoard( boardSize, this );
    connect( board, SIGNAL(finished()), SLOT(gameOver()) );
    l->addWidget( board );

    // Create a horizontal frame line

    QFrame *line = new QFrame( this );
    line->setFrameStyle( QFrame::HLine | QFrame::Sunken );
    l->addWidget( line );

    // Create the combo box for deciding who should start, and
    // connect its clicked() signals to the buttonClicked() slot

    whoStarts = new QComboBox( this );
    whoStarts->insertItem( "Computer starts" );
    whoStarts->insertItem( "Human starts" );
    l->addWidget( whoStarts );

    // Create the push buttons and connect their clicked() signals
    // to this right slots.

    newGame = new QPushButton( "Play!", this );
    connect( newGame, SIGNAL(clicked()), SLOT(newGameClicked()) );
    quit = new QPushButton( "Quit", this );
    connect( quit, SIGNAL(clicked()), qApp, SLOT(quit()) );
    QHBoxLayout * b = new QHBoxLayout;
    l->addLayout( b );
    b->addWidget( newGame );
    b->addWidget( quit );

    newState();
}


// --------------------------------------------------------------------------
// TicTacToe::newGameClicked()            - SLOT
//
// This slot is activated when the new game button is clicked.
//

void TicTacToe::newGameClicked()
{
    board->computerStarts( whoStarts->currentItem() == 0 );
    board->newGame();
    newState();
}


// --------------------------------------------------------------------------
// TicTacToe::gameOver()            - SLOT
//
// This slot is activated when the TicTacGameBoard emits the signal
// "finished()", i.e. when a player has won or when it is a draw.
//

void TicTacToe::gameOver()
{
    newState();                    // update text box
}


// --------------------------------------------------------------------------
// Updates the message to reflect a new state.
//

void TicTacToe::newState()
{
    static const char *msg[] = {        // TicTacGameBoard::State texts
    "Click Play to start", "Make your move",
    "You won!", "Computer won!", "It's a draw" };
    message->setText( msg[board->state()] );
    return;
}