text: #pragma once
  
  #include "Point.h"
  #include "Window.h"
  #include "Graph.h"
  
  #include <string>
  
  namespace Graph_lib {
  
  	typedef void* Address;
  	typedef void (*Callback)(Address, Address);	// FLTK's required function type for all callbacks
  
  	template<class W> W& reference_to(Address pw)
  		// treat an address as a reference to a W
  	{
  		return *static_cast<W*>(pw);
  	}
  
  	class Widget {
  		// Widget is a handle to a Fl_widget - it is *not* a Fl_widget
  		// We try to keep our interface classes at arm's length from FLTK
  	public:
  		Widget(Point xy, int w, int h, const std::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;	// each Widgit define at least one action for a window
  
  		Point loc;
  		int width;
  		int height;
  		std::string label;
  		Callback do_it;
  
  		virtual ~Widget() { }
  
  		/*
  		Widget(const Widget& a) :loc(a.loc) { error("attempt to copy Widget by constructor"); }
  		Widget& operator=(const Widget& a)
  		{
  				error("attempt to copy Widget by cassignment");
  				return *this;
  		}
  		*/
  
  	protected:
  		Window* own;	// every Widget belongs to a Window
  		Fl_Widget* pw;
  	private:
  		Widget& operator=(const Widget&);	// don't copy Widgets
  		Widget(const Widget&);
  	};
  
  	class Button : public Widget {
  	public:
  		Button(Point xy, int ww, int hh, const std::string& s, Callback cb)
  			:Widget(xy, ww, hh, s, cb)
  		{
  		}
  		void attach(Window& win);
  	};
  
  	struct In_box : Widget {
  		In_box(Point xy, int w, int h, const std::string& s)
  			:Widget(xy, w, h, s, 0)
  		{
  		}
  		int get_int();
  		std::string get_string();
  
  		void attach(Window& win);
  	};
  
  	struct Out_box : Widget {
  		Out_box(Point xy, int w, int h, const std::string& s/*, Window& win*/)
  			:Widget(xy, w, h, s, 0)
  		{
  		}
  		void put(int);
  		void put(const std::string&);
  
  		void attach(Window& win);
  	};
  
  	struct Menu : Widget {
  		enum Kind { horizontal, vertical };
  		Menu(Point xy, int w, int h, Kind kk, const std::string& s);
  		Vector_ref<Button> selection;
  		Kind k;
  		int offset;
  		int attach(Button& b);	// attach button; Menu does not delete &b
  		int attach(Button* p);	// attach new button; Menu deletes p
  		void show() { for (int i = 0; i < selection.size(); ++i) selection[i].show(); }
  		void hide() { for (int i = 0; i < selection.size(); ++i) selection[i].hide(); }
  		void move(int dx, int dy)
  		{
  			for (int i = 0; i < selection.size(); ++i) selection[i].move(dx, dy);
  		}
  		//	int insert(int i, const Button& b);	// not implemented
  
  		void attach(Window& win)
  		{
  			for (int i = 0; i < selection.size(); ++i) win.attach(selection[i]);
  		}
  
  	};
  
  }
  