general_exception.hpp

// general_exception.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/detail/include.hpp>


/* 
The exception-hierarchy presented here is serveral layers:
     - To catch all exceptions of background_wnd and the painters catch background_wnd_exception
     - To catch all exceptions of a specific class catch general_exception_of_type<class_name>
     - To catch a specific exception of a class catch general_exception<class_name, exception_number> 
       (most likely this will be typedef'ed in the class)
*/

namespace win32 { namespace gui {
namespace bg_wnd {

     struct background_wnd_exception : std::exception
     {
          background_wnd_exception() : std::exception("Exception caused by background_wnd or a painter")
          {}
     };


     template<class T>
     class general_exception_of_type : public background_wnd_exception
     {
          const T& obj_;
     public:
          typedef T class_type;

          general_exception_of_type(const T& obj) : obj_(obj)
          {}
          
          const T& get_object() const
          {
               return obj_;
          }
     };

     template <class T, int num>
     struct general_exception : general_exception_of_type<T>
     {                   
          general_exception(const T& obj) : general_exception_of_type<T> (obj)
          {}   
     };

}    // namespace bg_wnd
} }  // namespace win32::gui