usModuleActivator.h

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/*============================================================================
 
The Medical Imaging Interaction Toolkit (MITK)
 
Copyright (c) German Cancer Research Center (DKFZ)
All rights reserved.
 
Use of this source code is governed by a 3-clause BSD license that can be
found in the LICENSE file.
 
============================================================================*/
 
#ifndef USMODULEACTIVATOR_H_
#define USMODULEACTIVATOR_H_
 
#ifndef US_MODULE_NAME
#error Missing US_MODULE_NAME preprocessor define
#endif
 
#include <usGlobalConfig.h>
#include <usModuleUtils_p.h>
 
namespace us {
 
class ModuleContext;
 
struct ModuleActivator
{
 
  virtual ~ModuleActivator() {}
 
  virtual void Load(ModuleContext* context) = 0;
 
  virtual void Unload(ModuleContext* context) = 0;
 
};
 
}
 
 
#define US_EXPORT_MODULE_ACTIVATOR(_activator_type)                                       \
  extern "C" US_ABI_EXPORT us::ModuleActivator* US_CONCAT(_us_module_activator_instance_, US_MODULE_NAME) () \
  {                                                                                       \
    struct ScopedPointer                                                                  \
    {                                                                                     \
      ScopedPointer(us::ModuleActivator* activator = 0) : m_Activator(activator) {} \
      ~ScopedPointer() { delete m_Activator; }                                            \
      us::ModuleActivator* m_Activator;                                 \
    };                                                                                    \
                                                                                          \
    static ScopedPointer activatorPtr;                                                    \
    if (activatorPtr.m_Activator == 0) activatorPtr.m_Activator = new _activator_type;    \
    return activatorPtr.m_Activator;                                                      \
  }
 
#endif /* USMODULEACTIVATOR_H_ */