#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/fl_draw.H>
#include <FL/Fl_Value_Output.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Scroll.H>
#include <FL/Fl_Group.H>




class Drawing : public Fl_Widget {
  void draw() {
    fl_color(FL_WHITE);
    fl_arc(140,140,70,0,-360);
    fl_end_line();
  }
public:
  Drawing(int X,int Y,int W,int H) : Fl_Widget(X,Y,W,H) {}
};


class MyClass : public Fl_Scroll {
 
  
 public:
  MyClass(int X,int Y,int W,int H) : Fl_Scroll(X,Y,W,H) {
  Drawing *d=new Drawing(X,Y,W,500);
  }
  
  

 };

int main(int argc, char** argv) {
  Fl_Window window(300,300);
  MyClass *o= new MyClass(10,10,280,280);
  
  

  window.end();
  window.show(argc,argv);


  return Fl::run();
}

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/fl_draw.H>
#include <FL/Fl_Value_Output.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Scroll.H>
#include <FL/Fl_Group.H>
#include <FL/Fl_Box.H>
#include<stdio.h>
#include<math.h>
#define M_PI 3.14159

Fl_Scroll* thescroll;
class Drawing :public Fl_Widget
{

	
	void draw() 
	{
	  draw_box();	
          fl_begin_line();
          fl_color(FL_BLACK);
	  fl_arc(140-thescroll->xposition(),140-thescroll->yposition(),70,0,-360);
	  fl_end_line();
	}


public:
  Drawing(int X,int Y,int W,int H) :Fl_Widget(X,Y,W,H) 
  {
   align(FL_ALIGN_TOP);
   box(FL_FLAT_BOX);
   color(FL_WHITE);
  }
};


int main(int argc, char** argv) {
 Fl_Window window(600,500);
  Fl_Scroll *o= new Fl_Scroll(10,10,280,300);
  Drawing drawin(	o->x(),o->y(),800,800);
  o->end(); 
  o->end();
  thescroll=o;
  window.resizable(o);
  window.end();
  window.show();


  return Fl::run();
}