WidgetHandler.h

Go to the documentation of this file.

/*********************************************************\
 *  File: WidgetHandler.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 __PLGUI_WIDGETHANDLER_H__
#define __PLGUI_WIDGETHANDLER_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include <PLCore/Base/Event/EventHandler.h>
#include "PLGui/PLGui.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLGui {


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
class Widget;


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Widget handler class
*
*  @remarks
*    A widget handler is a smart pointer to widgets. Use it whenever you want to store a pointer
*    to a widget for a longer time, this way you can be sure that the pointer will be reset to a null pointer
*    if the widget has been destroyed in the meantime.
*/
class WidgetHandler {


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        */
        PLGUI_API WidgetHandler();

        /**
        *  @brief
        *    Copy constructor
        *
        *  @param[in] cOther
        *    Widget handler
        */
        PLGUI_API WidgetHandler(const WidgetHandler &cOther);

        /**
        *  @brief
        *    Destructor
        */
        PLGUI_API ~WidgetHandler();

        /**
        *  @brief
        *    Get widget pointer
        *
        *  @return
        *    Pointer to widget, can be a null pointer
        */
        PLGUI_API Widget *GetWidget() const;

        /**
        *  @brief
        *    Set widget pointer
        *
        *  @param[in] pWidget
        *    Pointer to widget, can be a null pointer
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        PLGUI_API bool SetWidget(Widget *pWidget);

        /**
        *  @brief
        *    Clear widget pointer
        */
        PLGUI_API void Clear();

        /**
        *  @brief
        *    Check if the widget pointer is valid
        *
        *  @return
        *    'true' if the handler points to a valid widget, else 'false'
        */
        PLGUI_API bool IsValid() const;

        /**
        *  @brief
        *    Compare operator
        *
        *  @param[in] cOther
        *    Widget handler
        *
        *  @return
        *    'true' if equal, else 'false'
        */
        PLGUI_API bool operator ==(const WidgetHandler &cOther) const;

        /**
        *  @brief
        *    Assignment operator
        *
        *  @param[in] cOther
        *    Widget handler
        *
        *  @return
        *    Reference to this object
        */
        PLGUI_API WidgetHandler &operator =(const WidgetHandler &cOther);


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        void OnWidgetDestroy();


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        // Event handlers
        PLCore::EventHandler<>  EventHandlerDestroy;    /**< Widget is going to be destroyed */

        // Data
        Widget *m_pWidget; /**< Pointer to widget, can be a null pointer */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLGui


#endif // __PLGUI_WIDGETHANDLER_H__