gameoflifemodel.cpp Example File

tableview/gameoflife/gameoflifemodel.cpp

  /****************************************************************************
  **
  ** Copyright (C) 2018 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, 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
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #include "gameoflifemodel.h"
  #include <QFile>
  #include <QTextStream>
  #include <QRect>

  GameOfLifeModel::GameOfLifeModel(QObject *parent)
      : QAbstractTableModel(parent)
  {
      clear();
  }

  int GameOfLifeModel::rowCount(const QModelIndex &parent) const
  {
      if (parent.isValid())
          return 0;

      return height;
  }

  int GameOfLifeModel::columnCount(const QModelIndex &parent) const
  {
      if (parent.isValid())
          return 0;

      return width;
  }

  QVariant GameOfLifeModel::data(const QModelIndex &index, int role) const
  {
      if (!index.isValid() || role != CellRole)
          return QVariant();

      return QVariant(m_currentState[cellIndex({index.column(), index.row()})]);
  }

  bool GameOfLifeModel::setData(const QModelIndex &index, const QVariant &value, int role)
  {
      if (role != CellRole || data(index, role) == value)
          return false;

      m_currentState[cellIndex({index.column(), index.row()})] = value.toBool();
      emit dataChanged(index, index, {role});

      return true;
  }

  Qt::ItemFlags GameOfLifeModel::flags(const QModelIndex &index) const
  {
      if (!index.isValid())
          return Qt::NoItemFlags;

      return Qt::ItemIsEditable;
  }

  void GameOfLifeModel::nextStep()
  {
      StateContainer newValues;

      for (std::size_t i = 0; i < size; ++i) {
          bool currentState = m_currentState[i];

          int cellNeighborsCount = this->cellNeighborsCount(cellCoordinatesFromIndex(static_cast<int>(i)));

          newValues[i] = currentState == true
                  ? cellNeighborsCount == 2 || cellNeighborsCount == 3
                  : cellNeighborsCount == 3;
      }

      m_currentState = std::move(newValues);

      emit dataChanged(index(0, 0), index(height - 1, width - 1), {CellRole});
  }

  bool GameOfLifeModel::loadFile(const QString &fileName)
  {
      QFile file(fileName);
      if (!file.open(QIODevice::ReadOnly))
          return false;

      QTextStream in(&file);
      loadPattern(in.readAll());

      return true;
  }

  void GameOfLifeModel::loadPattern(const QString &plainText)
  {
      clear();

      QStringList rows = plainText.split("\n");
      QSize patternSize(0, rows.count());
      for (QString row : rows) {
          if (row.size() > patternSize.width())
              patternSize.setWidth(row.size());
      }

      QPoint patternLocation((width - patternSize.width()) / 2, (height - patternSize.height()) / 2);

      for (int y = 0; y < patternSize.height(); ++y) {
          const QString line = rows[y];

          for (int x = 0; x < line.length(); ++x) {
              QPoint cellPosition(x + patternLocation.x(), y + patternLocation.y());
              m_currentState[cellIndex(cellPosition)] = line[x] == 'O';
          }
      }

      emit dataChanged(index(0, 0), index(height - 1, width - 1), {CellRole});
  }

  void GameOfLifeModel::clear()
  {
      m_currentState.fill(false);
      emit dataChanged(index(0, 0), index(height - 1, width - 1), {CellRole});
  }

  int GameOfLifeModel::cellNeighborsCount(const QPoint &cellCoordinates) const
  {
      int count = 0;

      for (int x = -1; x <= 1; ++x) {
          for (int y = -1; y <= 1; ++y) {
              if (x == 0 && y == 0)
                  continue;

              const QPoint neighborPosition { cellCoordinates.x() + x, cellCoordinates.y() + y };
              if (!areCellCoordinatesValid(neighborPosition))
                  continue;

              if (m_currentState[cellIndex(neighborPosition)])
                  ++count;

              if (count > 3)
                  return count;
          }
      }

      return count;
  }

  bool GameOfLifeModel::areCellCoordinatesValid(const QPoint &coordinates)
  {
      return QRect(0, 0, width, height).contains(coordinates);
  }

  QPoint GameOfLifeModel::cellCoordinatesFromIndex(int cellIndex)
  {
      return {cellIndex % width, cellIndex / width};
  }

  std::size_t GameOfLifeModel::cellIndex(const QPoint &coordinates)
  {
      return std::size_t(coordinates.y() * width + coordinates.x());
  }