source: OGRE/trunk/ogrenew/Dependencies/include/CEGUI/CEGUIProperty.h @ 657

/************************************************************************
        filename:       CEGUIProperty.h
        created:        21/2/2004
        author:         Paul D Turner
        
        purpose:        Defines the Property class which forms part of a
                                PropertySet
*************************************************************************/
/*************************************************************************
    Crazy Eddie's GUI System (http://www.cegui.org.uk)
    Copyright (C)2004 - 2005 Paul D Turner (paul@cegui.org.uk)

    This library 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 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*************************************************************************/
#ifndef _CEGUIProperty_h_
#define _CEGUIProperty_h_

#include "CEGUIBase.h"
#include "CEGUIString.h"


// Start of CEGUI namespace section
namespace CEGUI
{

/*!
\brief
        Dummy base class to ensure correct casting of receivers.
*/
class CEGUIEXPORT PropertyReceiver
{
public:
        PropertyReceiver() {}
        virtual ~PropertyReceiver() {}
};


/*!
\brief
        An abstract class that defines the interface to access object properties by name.

        Property objects allow (via a PropertySet) access to certain properties of objects
        by using simple get/set functions and the name of the property to be accessed.
*/
class CEGUIEXPORT Property
{
public:
        /*!
        \brief
                Creates a new Property object.

        \param name
                String containing the name of the new Property.

        \param help
                String containing a description of the Property and it's usage.
                
        \param defaultValue
                String holding the textual representation of the default value for this Property
        */
        Property(const String& name, const String& help, const String& defaultValue = "") : 
          d_name(name),
          d_help(help),
          d_default(defaultValue)
        {
        }


        /*!
        \brief
                Destructor for Property objects
        */
        virtual ~Property(void) {}


        /*!
        \brief
                Return a String that describes the purpose and usage of this Property.

        \return
                String that contains the help text
        */
        const String& getHelp(void) const               {return d_help;}


        /*!
        \brief
                Return a the name of this Property

        \return
                String containing the name of the Property
        */
        const String& getName(void) const               {return d_name;}


        /*!
        \brief
                Return the current value of the Property as a String

        \param receiver
                Pointer to the target object.

        \return
                String object containing a textual representation of the current value of the Property
        */
        virtual String  get(const PropertyReceiver* receiver) const = 0;


        /*!
        \brief
                Sets the value of the property

        \param receiver
                Pointer to the target object.

        \param value
                A String object that contains a textual representation of the new value to assign to the Property.

        \return
                Nothing.

        \exception InvalidRequestException      Thrown when the Property was unable to interpret the content of \a value.
        */
        virtual void    set(PropertyReceiver* receiver, const String& value) = 0;


        /*!
        \brief
                Returns whether the property is at it's default value.

        \param receiver
                Pointer to the target object.

        \return
                - true if the property has it's default value.
                - false if the property has been modified from it's default value.
        */
        virtual bool    isDefault(const PropertyReceiver* receiver) const;


        /*!
        \brief
                Returns the default value of the Property as a String.

        \param receiver
                Pointer to the target object.

        \return
                String object containing a textual representation of the default value for this property.
        */
        virtual String  getDefault(const PropertyReceiver* receiver) const;

protected:
        String  d_name;         //!< String that stores the Property name.
        String  d_help;         //!< String that stores the Property help text.
        String  d_default;      //!< String that stores the Property default value string.
};

} // End of  CEGUI namespace section

#endif  // end of guard _CEGUIProperty_h_