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#include <iostream>
/*
*
* 7.29
*
*
*/
class Screen {
public:
typedef std::string::size_type Pos;
Screen() = default;
Screen(Pos ht, Pos wd): Height(ht), Width(wd), Contents(ht * wd, ' ') { }
Screen(Pos ht, Pos wd, char c): Height(ht), Width(wd), Contents(ht * wd, c) { }
char get() const { return Contents[Cursor]; }
inline char get(Pos ht, Pos wd) const;
Screen move(Pos r, Pos c);
inline Screen set(char c);
inline Screen set(Pos r, Pos col, char ch);
Screen display(std::ostream &os) { do_display(os); return *this; }
const Screen display(std::ostream &os) const { do_display(os); return *this; }
void printheight(Pos Height);
private:
void do_display(std::ostream &os) const {os << Contents;}
Pos Cursor = 0;
Pos Height = 0;
Pos Width = 0;
std::string Contents;
};
inline Screen Screen::set(char c)
{
Contents[Cursor] = c; // set the new value at the current cursor location
return *this;
// return this object as an lvalue
}
inline Screen Screen::set(Pos r, Pos col, char ch)
{
Contents[r*Width + col] = ch; // set specified location to given value
return *this;
// return this object as an lvalue
}
inline Screen Screen::move(Pos r, Pos c)
{
Pos row = r * Width; // compute the row location
Cursor = row + c;
// move cursor to the column within that row
return *this;
// return this object as an lvalue
}
char Screen::get(Pos r, Pos c) const // declared as inline in the class
{
Pos row = r * Width;
// compute row location
return Contents[row + c]; // return character at the given column
}
void printheight(Screen::Pos Height) {
std::cout << Height;
}
int main () {
Screen myScreen(5, 5, 'X');
myScreen.move(4,0).set('#').display(std::cout);
std::cout << "\n";
myScreen.display(std::cout);
std::cout << "\n";
return 0;
}
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