pluginloader.h

/*
    This file is part of libtdepim.
 
    Copyright (c) 2002,2004 Marc Mutz <mutz@kde.org>
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/
 
#ifndef __KPIM_SHARED_PLUGINLOADER_H__
#define __KPIM_SHARED_PLUGINLOADER_H__
 
#include <pluginloaderbase.h>
 
namespace KPIM {
 
  template< typename T, typename T_config >
  class TDE_EXPORT PluginLoader : public PluginLoaderBase {
  protected:
    PluginLoader() : PluginLoaderBase() {}
 
  private:
    static PluginLoader<T,T_config> * mSelf;
 
  public:
    virtual ~PluginLoader() { mSelf = 0; }
 
    static PluginLoader<T,T_config> * instance() {
      if ( !mSelf ) {
    mSelf = new PluginLoader<T,T_config>();
    mSelf->scan();
      }
      return mSelf;
    }
 
    virtual void scan() {
      doScan( T_config::path );
    }
 
    virtual T * createForName( const TQString & type ) const {
      void * main_func = mainFunc( type, T_config::mainfunc );
      if ( !main_func ) return 0;
 
      // cast to a pointer to a function returning T*, call it and
      // return the result; don't you love C? ;-)
      return ((T* (*)())( main_func ))();
    }
  };
 
  template< typename T, typename T_config >
  PluginLoader<T,T_config> * PluginLoader<T,T_config>::mSelf = 0;
 
}
 
#define KPIM_DEFINE_PLUGIN_LOADER( pl, t, mf, p ) \
  namespace { /* don't pollute namespaces */ \
    struct TDE_EXPORT pl##Config { \
      static const char * const mainfunc; \
      static const char * const path; \
    }; \
    const char * const pl##Config::mainfunc = mf; \
    const char * const pl##Config::path = p; \
  } \
  typedef KPIM::PluginLoader< t, pl##Config > pl; \
 
 
#endif // __KPIM_SHARED_PLUGINLOADER_H__