//
// This is a GUI support code to the chapters 12-16 of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//

#ifndef GUI_GUARD
#define GUI_GUARD

#include "Window.h"
#include "Graph.h"

namespace Graph_lib {

   //----------------------------------------------------------------------

   typedef void* Address;    // Address is a synonym for void*
   // FLTK's required function type for all callbacks
   typedef void(*Callback)(Address, Address);    

   //----------------------------------------------------------------------

   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 an Fl_widget - it is *not* an Fl_widget
      // We try to keep our interface classes at arm's length from FLTK
   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() { }

   protected:
      Window* own;    // every Widget belongs to a Window
      Fl_Widget* pw;  // connection to the FLTK Widget
   private:
      Widget& operator=(const Widget&); // don't copy Widgets
      Widget(const Widget&);
   };

   //----------------------------------------------------------------------

   struct Button : Widget {
   Button(Point xy, int w, int h, const string& label, Callback cb)
      : Widget(xy,w,h,label,cb)
         {}

      void attach(Window&);
   };

   //----------------------------------------------------------------------

   struct In_box : Widget {
   In_box(Point xy, int w, int h, const string& s)
      :Widget(xy,w,h,s,0) { }
      int get_int();
      string get_string();

      void attach(Window& win);
   };

   //----------------------------------------------------------------------

   struct Out_box : Widget {
   Out_box(Point xy, int w, int h, const string& s)
      :Widget(xy,w,h,s,0) { }
      void put(int);
      void put(const string&);

      void attach(Window& win);
   };

   //----------------------------------------------------------------------

   struct Menu : Widget {
      enum Kind { horizontal, vertical };
      Menu(Point xy, int w, int h, Kind kk, const string& label);
      /*
        : Widget(xy,w,h,label,0), k(kk), offset(0)
        {}
      */

      Vector_ref<Button> selection;
      Kind k;
      int offset;
      int attach(Button& b);      // Menu does not delete &b
      int attach(Button* p);      // Menu deletes p

      void show()                 // show all buttons
      {
         for (int i = 0; i<selection.size(); ++i)
            selection[i].show();
      }
      void hide()                 // hide all buttons
      {
         for (int i = 0; i<selection.size(); ++i) 
            selection[i].hide(); 
      }
      void move(int dx, int dy)   // move all buttons
      {
         for (int i = 0; i<selection.size(); ++i) 
            selection[i].move(dx,dy);
      }

      void attach(Window& win)    // attach all buttons
      {
         for (int i=0; i<selection.size(); ++i) win.attach(selection[i]);
         own = &win;
      }

   };

   //----------------------------------------------------------------------

} // of namespace Graph_lib

#endif // GUI_GUARD