coherence/lang/SmartMember.hpp

/*
* SmartMember.hpp
*
* Copyright 2001-2008 by Oracle. All rights reserved.
*
* Oracle is a registered trademarks of Oracle Corporation and/or its
* affiliates.
*
* This software is the confidential and proprietary information of Oracle
* Corporation. You shall not disclose such confidential and proprietary
* information and shall use it only in accordance with the terms of the
* license agreement you entered into with Oracle.
*
* This notice may not be removed or altered.
*/
#ifndef COH_SMART_MEMBER_HPP
#define COH_SMART_MEMBER_HPP

#include "coherence/lang/compatibility.hpp"

#include "coherence/lang/Object.hpp"

COH_OPEN_NAMESPACE2(coherence,lang)


/**
* Base class for smart data-members of managed Objects.
*
* Smart data-members include additional information regarding their
* life-cycle, including a reference to their enclosing Object (parent). The
* smart member is initalized with a reference to its parent, and has the same
* life-cycle as the parent. Creating a SmartMember which is not a data-member
* of the parent used during initialization will result in unsafe/undefined
* behavior.
*
* @author mf 2008.01.30
*/
class COH_EXPORT SmartMember
    {
    // ----- constructor ----------------------------------------------------

    public:
        /**
        * Construct a new SmartMember
        *
        * @param oParent  the data-member's parent Object.
        */
        SmartMember(Object& oParent);

        /**
        * Destruct the SmartMember.
        */
        virtual ~SmartMember();

    protected:
        /**
        * Construct an orphaned SmartMember.
        *
        * The smart-member will not be usable until a parent is assigned.
        *
        * @see #setParent()
        */
        SmartMember();

    private:
        /**
        * Blocked copy constructor.
        */
        SmartMember(const SmartMember&);


    // ----- operators ------------------------------------------------------

    public:
        SmartMember& operator=(const SmartMember& that);


    // ----- SmartMember interface ------------------------------------------

    public:
        /**
        * Return the parent Object for this data member.
        *
        * @return the parent Object for this data member.
        */
        Object& getParent();

        /**
        * Return the parent Object for this data member.
        *
        * @return the parent Object for this data member.
        */
        const Object& getParent() const;

    protected:
        /**
        * Set the parent for this member.
        *
        * @throws IllegalStateException if a parent has already been
        *                               specified
        */
        void setParent(Object& oParent);


    // ----- life cycle events ----------------------------------------------

    protected:
        /**
        * Event called once the parent Object has finished being constructed.
        * Specifically when the first attachment is made.
        *
        * As with all event methods any derived implementation should
        * include a call to the super class's implementation.
        *
        * The default implmenetation calls the onInit() method of each of the
        * Object's SmartMembers.
        */
        virtual void onInit();

        /**
        * Event called when the parent Object becomes only referenced via
        * const pointers (Views). As the SmartMember is a data-member
        * of this Object, the data-member infer that only const methods will
        * be called from now on.
        *
        * Derived implementations of this method should include a delegation
        * call to their super class onConst() method, after they've done
        * their own processing of the event.
        */
        virtual void onConst();


    // ----- data members ---------------------------------------------------

    private:
        /**
        * The Membe's parent.
        */
        Object* m_pParent;

        /**
        * The next SmartMember in the parent's SmartMember stack.
        */
        SmartMember* m_pNext;


    // ----- friends --------------------------------------------------------

    friend class Object;
    friend class SynchronizedMemberBlock;
    };

COH_CLOSE_NAMESPACE2

#endif // COH_SMART_MEMBER_HPP

Copyright (c) 2000-2008 Oracle. All rights reserved.