[C++] ”プログラミング入門” : GUIソースコード修正 Gui.h, Gui.cpp他

#ifndef GUI_GUARD
#define GUI_GUARD

#include "Point.h"
#include <FL/Fl_Widget.H>
#include "Window.h"

namespace Graph_lib {
	
typedef void* Address;
typedef void (*Callback)(Address,Address);

template<class W> W& reference_to(Address pw)
{
	return *static_cast<W*>(pw);
}


class Widget {
public:
	Widget(Point xy, int w, int h, const string& s, Callback cb)
		:loc(xy), width(w), height(h), label(s), do_it(cb)
	{ }

	virtual void move(int dx,int dy) { hide(); pw->position(loc.x+=dx, loc.y+=dy); show(); }
	virtual void hide() { pw->hide(); }
	virtual void show() { pw->show(); }
	virtual void attach(Window&) = 0;

	Point loc;
	int width;
	int height;
	string label;
	Callback do_it;

	virtual ~Widget() { }