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# tictactoe.cpp Example File

designer/taskmenuextension/tictactoe.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
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     **     the documentation and/or other materials provided with the
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     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     #include <QtGui>

     #include "tictactoe.h"

     TicTacToe::TicTacToe(QWidget *parent)
         : QWidget(parent)
     {
     }

     QSize TicTacToe::minimumSizeHint() const
     {
         return QSize(200, 200);
     }

     QSize TicTacToe::sizeHint() const
     {
         return QSize(200, 200);
     }

     void TicTacToe::setState(const QString &newState)
     {
         turnNumber = 0;
         myState = "---------";
         int position = 0;
         while (position < 9 && position < newState.length()) {
             QChar mark = newState.at(position);
             if (mark == Cross || mark == Nought) {
                 ++turnNumber;
                 myState.replace(position, 1, mark);
             }
             position++;
         }
         update();
     }

     QString TicTacToe::state() const
     {
         return myState;
     }

     void TicTacToe::clearBoard()
     {
         myState = "---------";
         turnNumber = 0;
         update();
     }

     void TicTacToe::mousePressEvent(QMouseEvent *event)
     {
         if (turnNumber == 9) {
             clearBoard();
             update();
         } else {
             for (int position = 0; position < 9; ++position) {
                 QRect cell = cellRect(position / 3, position % 3);
                 if (cell.contains(event->pos())) {
                     if (myState.at(position) == Empty) {
                         if (turnNumber % 2 == 0)
                             myState.replace(position, 1, Cross);
                         else
                             myState.replace(position, 1, Nought);
                         ++turnNumber;
                         update();
                     }
                 }
             }
         }
     }

     void TicTacToe::paintEvent(QPaintEvent * /* event */)
     {
         QPainter painter(this);
         painter.setRenderHint(QPainter::Antialiasing);

         painter.setPen(QPen(Qt::darkGreen, 1));
         painter.drawLine(cellWidth(), 0, cellWidth(), height());
         painter.drawLine(2 * cellWidth(), 0, 2 * cellWidth(), height());
         painter.drawLine(0, cellHeight(), width(), cellHeight());
         painter.drawLine(0, 2 * cellHeight(), width(), 2 * cellHeight());

         painter.setPen(QPen(Qt::darkBlue, 2));

         for (int position = 0; position < 9; ++position) {
             QRect cell = cellRect(position / 3, position % 3);

             if (myState.at(position) == Cross) {
                 painter.drawLine(cell.topLeft(), cell.bottomRight());
                 painter.drawLine(cell.topRight(), cell.bottomLeft());
             } else if (myState.at(position) == Nought) {
                 painter.drawEllipse(cell);
             }
         }

         painter.setPen(QPen(Qt::yellow, 3));

         for (int position = 0; position < 9; position = position + 3) {
             if (myState.at(position) != Empty
                     && myState.at(position + 1) == myState.at(position)
                     && myState.at(position + 2) == myState.at(position)) {
                 int y = cellRect((position / 3), 0).center().y();
                 painter.drawLine(0, y, width(), y);
                 turnNumber = 9;
             }
         }

         for (int position = 0; position < 3; ++position) {
             if (myState.at(position) != Empty
                     && myState.at(position + 3) == myState.at(position)
                     && myState.at(position + 6) == myState.at(position)) {
                 int x = cellRect(0, position).center().x();
                 painter.drawLine(x, 0, x, height());
                 turnNumber = 9;
             }
         }
         if (myState.at(0) != Empty && myState.at(4) == myState.at(0)
                 && myState.at(8) == myState.at(0)) {
             painter.drawLine(0, 0, width(), height());
             turnNumber = 9;
         }
         if (myState.at(2) != Empty && myState.at(4) == myState.at(2)
                 && myState.at(6) == myState.at(2)) {
             painter.drawLine(0, height(), width(), 0);
             turnNumber = 9;
         }
     }

     QRect TicTacToe::cellRect(int row, int column) const
     {
         const int HMargin = width() / 30;
         const int VMargin = height() / 30;
         return QRect(column * cellWidth() + HMargin,
                      row * cellHeight() + VMargin,
                      cellWidth() - 2 * HMargin,
                      cellHeight() - 2 * VMargin);
     }