DynEvent.h

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/*********************************************************\
 *  File: DynEvent.h                                     *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLCORE_DYNEVENT_H__
#define __PLCORE_DYNEVENT_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/Container/SimpleList.h"
#include "PLCore/Base/Func/Signature.h"
#include "PLCore/Base/Func/DynSignature.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLCore {


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
class EventDesc;
class DynParams;
class XmlElement;
class DynEventHandler;


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Virtual base class for events
*
*  @remarks
*    This is the virtual base class to access events dynamically.
*
*  @note
*    - Implementation of the observer design pattern (this class is the subject/observable, the source)
*/
class DynEvent : public DynSignature {


    //[-------------------------------------------------------]
    //[ Public definitions                                    ]
    //[-------------------------------------------------------]
    public:
        typedef Signature<void, DynParams&, void*>::FuncType FUNC;


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        */
        PLCORE_API DynEvent();

        /**
        *  @brief
        *    Destructor
        */
        PLCORE_API virtual ~DynEvent();

        /**
        *  @brief
        *    Connect event handler to the event
        *
        *  @param[in] cHandler
        *    Event handler
        */
        PLCORE_API void Connect(DynEventHandler &cHandler);

        /**
        *  @brief
        *    Disconnect event handler from the event
        *
        *  @param[in] cHandler
        *    Event handler
        */
        PLCORE_API void Disconnect(DynEventHandler &cHandler);

        /**
        *  @brief
        *    Return the number of connections
        *
        *  @return
        *    The number of connections
        *
        *  @note
        *    - Don't use this method within performance critical situations because due internal
        *      implementation, this request has a linear, not constant runtime!
        */
        inline uint32 GetNumOfConnects() const;


    //[-------------------------------------------------------]
    //[ Public virtual DynEvent functions                     ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Get event descriptor
        *
        *  @return
        *    Descriptor (can be a null pointer)
        */
        PLCORE_API virtual const EventDesc *GetDesc() const;

        /**
        *  @brief
        *    Create a generic event handler which is compatible with this dynamic event
        *
        *  @param[in] pFunc
        *    Function to be called by the dynamic event handler
        *  @param[in] pUserData
        *    Optional pointer to user data to pass on to the given generic function when the event was emitted, can be a null pointer
        *
        *  @return
        *    The generic event handler which is compatible with this dynamic event, null pointer on error (delete the created instance if you no longer need it)
        *
        *  @note
        *    - This method just creates an instance of the generic event handler and does not automatically connect it with this dynamic event
        *    - Use typed instead of generic event handlers whenever possible, this method only exists for situations were no type information
        *      is available at compile time
        */
        PLCORE_API virtual DynEventHandler *CreateGenericEventHandler(const FUNC &pFunc, void *pUserData = nullptr) const;

        /**
        *  @brief
        *    Emit event
        *
        *  @param[in] cParams
        *    Parameters
        */
        PLCORE_API virtual void Emit(DynParams &cParams) const;

        /**
        *  @brief
        *    Emit event
        *
        *  @param[in] cParams
        *    Parameters
        */
        PLCORE_API virtual void Emit(const DynParams &cParams) const;

        /**
        *  @brief
        *    Emit event
        *
        *  @param[in] sParams
        *    Parameters as string
        */
        PLCORE_API virtual void Emit(const String &sParams) const;

        /**
        *  @brief
        *    Emit event
        *
        *  @param[in] cElement
        *    Parameters as XML
        */
        PLCORE_API virtual void Emit(const XmlElement &cElement) const;


    //[-------------------------------------------------------]
    //[ Protected data                                        ]
    //[-------------------------------------------------------]
    protected:
        SimpleList<DynEventHandler*> m_lstHandlers; /**< List of event handlers */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLCore


//[-------------------------------------------------------]
//[ Implementation                                        ]
//[-------------------------------------------------------]
#include "PLCore/Base/Event/DynEvent.inl"


#endif // __PLCORE_DYNEVENT_H__