painter_holder.hpp

// painter_holder.hpp

// Copyright (C) 2004 Steven Weiß (steven11@gmx.de)
//
// Permission to copy, use, sell and distribute this software is granted
// provided this copyright notice appears in all copies.
// Permission to modify the code and to distribute modified code is granted
// provided this copyright notice appears in all copies, and a notice
// that the code was modified is included with the copyright notice.
//
// This software is provided "as is" without express or implied warranty,
// and with no claim as to its suitability for any purpose.


#pragma once
#include <background_wnd/painter_base.hpp>
#include <background_wnd/detail/general_exception.hpp>


namespace win32 { namespace gui {

struct painter_holder
{
private:  
     std::auto_ptr<painter_base> pPainter_;
     void set_raw_painter(painter_base* pPainter);

public:    
     // exceptions  
     typedef bg_wnd::general_exception<painter_holder, 0> no_painter;
     typedef bg_wnd::general_exception<painter_holder, 1> invalid_painter_cast;
          

     // the big 4
     painter_holder(painter_base* pPainter = NULL);
     painter_holder(const painter_holder& holder);
     virtual ~painter_holder();                   
     const painter_holder& operator= (const painter_holder& holder);

     // operations  
     void release_painter();  
     void set_painter(const painter_base& painter);
     void swap(painter_holder& holder);

     // attributes
     painter_base& get_painter() const;    
     bool painter_available() const;

public:
     // template-memberfunctions
     
     template <class Painter> Painter& get_painter() const
     {         
          Painter* p = dynamic_cast<Painter*> (&get_painter());
          if (p == NULL)                                    // dynamic type of p isn't Painter -> throw
               throw invalid_painter_cast(*this);
          return *p;
     }

     template <class Painter> void set_painter()
     {
          set_raw_painter(new Painter());
     }

     template <class Painter> void set_painter(typename Painter::param0 param)
     {
          set_raw_painter(new Painter(param));         
     }

     template <class Painter> void set_painter(typename Painter::param0 param0, typename Painter::param1 param1)
     {
          set_raw_painter(new Painter(param0, param1));        
     }
};    


} }  // namespace win32::gui