/*

* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Generic observer array.

*

*/

#ifndef __RGENERICOBSERVERARRAYBASE_H__

#define __RGENERICOBSERVERARRAYBASE_H__

//  INCLUDES

#include <E32Base.h>

// CLASS DECLARATION

/**

 * Observer notify mediator base.

 *

 * Base interface to manage observer notifications

 * and notify errors. Typical implementation will

 * forward notifications to actual type specific

 * mediator.

 *

 * Main idea behind the notify mediator is encapsulate

 * the observer array management from actual observer

 * type specific details. (Type specific details will

 * be implemented by the concrete mediator.) Usage

 * of mediator base interface allows generic

 * observer array implementation.

 *

 * @since 3.0

 */

class MGenObserverNotifyMediatorBase

    {

    public:

        /**

         * Observer notification.

         * This member is internal and not intended for use.

         */

        virtual void MediateNotifyL( TAny* aObserverToNotify ) = 0;

        /**

         * Observer notification from error.

         * This member is internal and not intended for use.

         */

        virtual void MediateNotifyError( TAny* aObserverToNotify, TInt aLeaveError ) = 0;

    protected:

        /**

         * Protected destructor.

         */

        virtual ~MGenObserverNotifyMediatorBase() {}

    };

// CLASS DECLARATION

/**

 * Generic observer array.

 *

 * Generic observer array to manage observers

 * and notify them. Observers are managed as

 * typeless TAny pointers. Notification is done

 * trough generic MGenObserverNotifyMediatorBase

 * notify mediator.

 *

 * @since 3.0

 */

NONSHARABLE_CLASS( RGenericObserverArrayBase ) :

        private RPointerArrayBase   // CSI: 70 #

    {

protected: //protected members for derived classes

    /**

     * C++ constructor.

     * This member is internal and not intended for use.

     */

    RGenericObserverArrayBase();

    /**

     * Closes the array and frees all memory allocated to it.

     * This member is internal and not intended for use.

     */

    void Close();

    /**

     * Adds observer.

     * This member is internal and not intended for use.

     */

    TInt AddObserver( const TAny* aObserver );

    /**

     * Removes observer.

     * This member is internal and not intended for use.

     */

    TInt RemoveObserver( const TAny* aObserver );

    /**

     * Gets observer count.

     * This member is internal and not intended for use.

     */

    TInt Count();

    /**

     * Observer notify implementation.

     * This member is internal and not intended for use.

     */

    void NotifyObservers( MGenObserverNotifyMediatorBase& aNotifyMediator );

    /**

     * Observer notify implementation.

     * This member is internal and not intended for use.

     */

    void NotifyErrorObservers( MGenObserverNotifyMediatorBase& aNotifyMediator,

                               TInt aError );

    /**

     * Observer notify implementation.

     * This member is internal and not intended for use.

     */

    TBool IsNotifyLoopRunning() const;

private: //private helpers

    /**

     * Private helper.

     * This member is internal and not intended for use.

     */

    void FinalizeObsArrayAfterNotifyLoop();

private: //Data

    //OWN: Flag describing the observer array state

    TBool iNotifyLoopRunning;

    };

#endif      //__RGenericObserverArrayBase_H__

//  End of File