exercise7_32.h

#ifndef CP5_ex7_32_h
#define CP5_ex7_32_h

#include <vector>
#include <iostream>
#include <string>

class Screen;

class Window_mgr
{
public:
	using ScreenIndex = std::vector<Screen>::size_type;
	inline void clear(ScreenIndex);

private:
	std::vector<Screen> screens;
};

class Screen
{
	friend void Window_mgr::clear(ScreenIndex);

public:
	using pos = std::string::size_type;

	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]; }
	char get(pos r, pos c) const { return contents[r*width + c]; }
	inline Screen& move(pos r, pos c);
	inline Screen& set(char c);
	inline Screen& set(pos r, pos c, char ch);

	const Screen& display(std::ostream& os) const { do_display(os); return *this; }
	Screen& display(std::ostream& os) { do_display(os); return *this; }
	
private:
	void do_display(std::ostream &os) const { os << contents; }

private:
	pos cursor = 0;
	pos width = 0, height = 0;
	std::string contents;
};


inline void Window_mgr::clear(ScreenIndex i)
{
	Screen& s = screens[i];
	s.contents = std::string(s.height*s.width,' ');
}

inline Screen& Screen::move(pos r, pos c)
{
	cursor = r*width + c;
	return *this;
}

inline Screen& Screen::set(char c)
{
	contents[cursor] = c;
	return *this;
}

inline Screen& Screen::set(pos r, pos c, char ch)
{
	contents[r*width + c] = ch;
	return *this;
}


#endif