gameoflifemodel.cpp Example File | Qt Quick 5.12.6

Qt 5.12 | Qt Quick | Qt Quick TableView examples - Conway’s Game of Life | gameoflifemodel.cpp Example File

Qt 5.12.6 Reference Documentation

# gameoflifemodel.cpp Example File

tableview/gameoflife/gameoflifemodel.cpp

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      #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());
      }