usModuleActivator.h

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/*=============================================================================

  Library: CppMicroServices

  Copyright (c) German Cancer Research Center,
    Division of Medical and Biological Informatics

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

=============================================================================*/

#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>

US_BEGIN_NAMESPACE

class ModuleContext;

struct ModuleActivator
{

  virtual ~ModuleActivator() {}

  virtual void Load(ModuleContext* context) = 0;

  virtual void Unload(ModuleContext* context) = 0;

};

US_END_NAMESPACE


#define US_EXPORT_MODULE_ACTIVATOR(_activator_type)                                       \
  extern "C" US_ABI_EXPORT US_PREPEND_NAMESPACE(ModuleActivator)* US_CONCAT(_us_module_activator_instance_, US_MODULE_NAME) () \
  {                                                                                       \
    struct ScopedPointer                                                                  \
    {                                                                                     \
      ScopedPointer(US_PREPEND_NAMESPACE(ModuleActivator)* activator = 0) : m_Activator(activator) {} \
      ~ScopedPointer() { delete m_Activator; }                                            \
      US_PREPEND_NAMESPACE(ModuleActivator)* m_Activator;                                 \
    };                                                                                    \
                                                                                          \
    static ScopedPointer activatorPtr;                                                    \
    if (activatorPtr.m_Activator == 0) activatorPtr.m_Activator = new _activator_type;    \
    return activatorPtr.m_Activator;                                                      \
  }

#endif /* USMODULEACTIVATOR_H_ */