Question

4 Derived class JPG 4.1 Class declaration • The class JPG inherits from File and is a non-abstract class. 1. Hence objects of the class JPG can be instantiated. 2. To do so, we must override the pure virtual function clone() in the base class. • The class declaration is given below. class JPG : public File { public: JPG(const std::string& n, int n, int w, const double rgb()) : File(...) { // ... } *JPG() { // ... } JPG(const JPG &orig) : File (orig) { // } JPG& operator= (const JPG &rhs) { // ... } virtual File* clone () const { return new JPG(*this); ها virtual void print () const { // ... } protected: int height, width; double *p-pixels; }; See next page(s).
please write in c++.

Answer 1

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

class File
{
public:
virtual ~File() {} // virtual destructor

const string& getName() { return name;}
const string& getType() { return type;}
int getSize() {return size;}

virtual void print() const {} // virtual
virtual File* clone() const = 0; // pure virtual

protected:
File(const string& n, const string& t, int x){ // protected constructor
name = n;
type = t;
size = x;
}

string name;
string type;
int size;
};

//end of File class

class PDF: public File
{
public:
PDF(const string& n, const string& text) : File(n, "pdf", text.length())
{
p_text = new string(); // allocate memory for p_text
(*p_text) = text; // copy the text contents
}

~PDF()
{
delete p_text; // delete the dynamically allocated
}

PDF(const PDF& orig) : File(orig) // call File's copy constructor // copy constructor
{
p_text = new string; // allocate memory for p_text
(*p_text) = *(orig.p_text); // copy the text in p_text of orig
}

PDF& operator=(const PDF& orig) // assignment operator
{
*this = orig; // call File's assignment operator
(*p_text) = *(orig.p_text); // copy the text of p_text from orig

return *this;
}

virtual File* clone() const // override pure virtual function
{
return new PDF(*this); // return a new PDF object created using copy constructor by passing this object
}

virtual void print() const{ // override virtual function
// display name, type, size and p_text
cout<<name<<", "<<type<<", "<<size<<endl<<(*p_text)<<endl;
}

protected:
string *p_text; // data (allocated dynamically)
};

//end of PDF class

class JPG : public File
{
public:
JPG(const string& n, int h, int w, const double rgb[]) : File(n, "jpg",h*w)
{
// set height and width
height = h;
width = w;
// allocate memory for p_pixels
p_pixels = new double[size];
// loop to copy p_pixels form rgb
for(int i=0;i<size;i++)
{
p_pixels[i] = rgb[i];
}
}

~JPG() // destructor
{
delete[] p_pixels; // delete the dynamically allocated array
}

JPG(const JPG& orig) : File(orig) // copy constructor
{
// copy height and width
height = orig.height;
width = orig.width;
// allocate memory for p_pixels
p_pixels = new double[size];
// loop to copy p_pixels form orig's p_pixels
for(int i=0;i<size;i++)
p_pixels[i] = orig.p_pixels[i];
}

JPG& operator=(const JPG& orig) // assignment operator
{
*this = orig; // call File's assignment operator
// copy height and width
height = orig.height;
width = orig.width;
// delete the existing array
delete [] p_pixels;
// allocate memory for the new array
p_pixels = new double[size];
// loop to copy values from orig's p_pixels
for(int i=0;i<size;i++)
p_pixels[i] = orig.p_pixels[i];

return *this;
}

virtual File* clone() const // pure virtual function
{
return new JPG(*this);
}

virtual void print() const{ // virtual function
// display the name, type, size
cout<<name<<", "<<type<<", "<<size<<endl;
// display height and width
cout<<height<<", "<<width<<endl;
// loop to display the pixel values
for(int i=0;i<height;i++)
{
for(int j=0;j<width;j++)
{
cout<<p_pixels[i*width+j]<<" ";
}
cout<<endl;
}
}

protected:
int height, width;
double *p_pixels;
};

//end of JPG class