mrptEvent.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef  mrptEvent_H
#define  mrptEvent_H

#include <mrpt/system/datetime.h>

namespace mrpt
{
        namespace utils
        {
                class CObservable;

                /**  The basic event type for the observer-observable pattern in MRPT.
                  *   You can sub-class this base class to create custom event types, then
                  *    tell between them in runtime with isOfType<T>(), for example:
                  * \code
                  *   if (e.isOfType<mrptEventOnDestroy>())
                  *   {
                  *     const mrptEventOnDestroy* ev = e.getAs<mrptEventOnDestroy>();
                  *     ev-> ...
                  *   }
                  * \endcode
                  *
                  * \sa CObserver, CObservable
                 * \ingroup mrpt_base_grp
                  */
                class BASE_IMPEXP mrptEvent
                {
                protected:
                        virtual void do_nothing() { } //!< Just to allow this class to be polymorphic
                public:
                        /** Default ctor */
                        inline mrptEvent() : timestamp(mrpt::system::now()) { }

                        template <class EVENTTYPE>
                        inline bool isOfType() const { return dynamic_cast<const EVENTTYPE*>(this)!=NULL; }

                        template <class EVENTTYPE>
                        inline const EVENTTYPE* getAs() const { return dynamic_cast<const EVENTTYPE*>(this); }

                        template <class EVENTTYPE>
                        inline EVENTTYPE* getAsNonConst() const { return const_cast<EVENTTYPE*>(dynamic_cast<const EVENTTYPE*>(this)); }

                        mrpt::system::TTimeStamp  timestamp;

                }; // End of class def.

                /**  An event sent by any CObservable object (automatically) just before being destroyed and telling its observers to unsubscribe.
                 * \ingroup mrpt_base_grp
                  */
                class BASE_IMPEXP mrptEventOnDestroy : public mrptEvent
                {
                protected:
                        void do_nothing()  MRPT_OVERRIDE { } //!< Just to allow this class to be polymorphic
                public:
                        inline mrptEventOnDestroy(const CObservable *obj) : source_object(obj) { }

                        const CObservable *source_object;

                }; // End of class def.

        } // End of namespace
} // end of namespace
#endif