// Grid.h

include 
using std::ostream;

// Forward declare Grid template.
template 

   class Grid;

// Prototype for templatized operator<<. 
template
ostream& operator<<(ostream& ostr, const Grid& grid);

template 

Grid</h4>

---

  class Grid
  {
   public:
    Grid(int inWidth = kDefaultWidth, int inHeight = kDefaultHeight);
    Grid(const Grid<T>& src);
    ~Grid();
    Grid<T>& operator=(const Grid<T>& rhs);
  
    void setElementAt(int x, int y, const T& inElem);
    T& getElementAt(int x, int y);
    const T& getElementAt(int x, int y) const;
  
    int getHeight() const { return mHeight; }
    int getWidth() const { return mWidth; }
    static const int kDefaultWidth = 10;
    static const int kDefaultHeight = 10;
  
    friend ostream& operator<< <T>(ostream& ostr, const Grid<T>& grid);
  
   protected:
    void copyFrom(const Grid<T>& src);
    T** mCells;
    int mWidth, mHeight;
  };

---

  
  template <typename T>
  Grid<T>::Grid(int inWidth, int inHeight) : mWidth(inWidth), mHeight(inHeight)
  {
    mCells = new T* [mWidth];
    for (int i = 0; i < mWidth; i++) {
      mCells[i] = new T[mHeight];
    }
  }
  
  template <typename T>
  const int Grid<T>::kDefaultWidth;
  
  template <typename T>
  const int Grid<T>::kDefaultHeight;
  
  template <typename T>
  Grid<T>::Grid(const Grid<T>& src)
  {
    copyFrom(src);
  }
  
  template <typename T>
  Grid<T>::~Grid()
  {
    // free the old memory
    for (int i = 0; i < mWidth; i++) {
      delete [] mCells[i];
    }
    delete [] mCells;
  }
  
  template <typename T>
  void Grid<T>::copyFrom(const Grid<T>& src)
  {
    int i, j;
    mWidth = src.mWidth;
    mHeight = src.mHeight;
  
    mCells = new T* [mWidth];
    for (i = 0; i < mWidth; i++) {
      mCells[i] = new T[mHeight];
    }
  
    for (i = 0; i < mWidth; i++) {
      for (j = 0; j < mHeight; j++) {
        mCells[i][j] = src.mCells[i][j];
      }
    }
  }
  
  template <typename T>
  Grid<T>& Grid<T>::operator=(const Grid<T>& rhs)
  {
    // check for self-assignment
    if (this == &rhs) {
      return (*this);
    }
    // free the old memory
    for (int i = 0; i < mWidth; i++) {
      delete [] mCells[i];
    }
    delete [] mCells;
  
    // copy the new memory
    copyFrom(rhs);
  
    return (*this);
  }
  
  template <typename T>
  void Grid<T>::setElementAt(int x, int y, const T& inElem)
  {
    mCells[x][y] = inElem;
  }
  
  template <typename T>
  T& Grid<T>::getElementAt(int x, int y)
  {
    return (mCells[x][y]);
  }
  
  template <typename T>
  const T& Grid<T>::getElementAt(int x, int y) const
  {
    return (mCells[x][y]);
  }
  
  template <typename T>
  ostream& operator<<(ostream& ostr, const Grid<T>& grid)
  {
    for (int i = 0; i < grid.mHeight; i++) {
      for (int j = 0; j < grid.mWidth; j++) {
        // add a tab between each element of a row
        ostr << grid.mCells[j][i] << "\t"; 
      }
      ostr << std::endl; // add a newline between each row
    }
    return (ostr);
  }
  

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[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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(C) Æliens 20/2/2008

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Hush Online Technology hush@cs.vu.nl 10/19/08