/*

* Copyright (c) 2003 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:  This file contains the header file of the RCbsTopicCollection class.

*                This is the client-side subsession which handles requests regarding

*                topic identities stored on CBS Server.

*

*

*/

#ifndef     RCBSTOPICCOLLECTION_H

#define     RCBSTOPICCOLLECTION_H

//  INCLUDES

#include <e32base.h>

#include "CbsCommon.h"

//  FORWARD DECLARATIONS

class RCbs;

//  CLASS DECLARATION 

/**

*   This represents the client-side subsession to retrieve information 

*   from topic collections.

*/

class RCbsTopicCollection 

        : public RSubSessionBase

    {

    public:     // New functions

        /**

        *   Constructor.

        */

        RCbsTopicCollection();

        /**

        *   Creates a subsession to the server.

        *

        *   Note that the method must be called before any other method 

        *   can be used.

        *

        *   @param  aServer             The base session.

        *   @return                     Error code.

        */

        TInt Open( RCbs& aServer );

        /**

        *   Closes the subsession.

        *

        *   @return                     Error code.

        */

        TInt Close();

        /**

        *   Returns the total amount of topic information the topic collection

        *   contains.

        *

        *   @param  aCount              It will contain the amount.

        */

        void GetTopicCount( TInt& aCount );

        /**

        *   Returns a topic information structure.

        *

        *   @param  aIndex              It is index to the topic info.

        *   @param  aInfo               It will contain the information.

        *   @return                     Error code.

        */

        TInt GetTopicInfo( TInt aIndex, TCbsTopicInfo& aInfo );

        /**

        *   Notifies the client next time when topic collection changes.

        *   

        *   @param  aStatus             It will be changed when topic collection

        *                               changes.

        */

        void NotifyOnChange( TRequestStatus& aStatus );

        /**

        *   Cancels the pending request to notify.

        */

        void NotifyOnChangeCancel();

        /**

        *   Resets the iterator. Must be called prior any call to HasNextTopic() 

        *   or NextTopic()!

        */

        void Start();

        /**

        *   Returns ETrue, if there is a topic not accessed with NextTopic()

        *   

        *   @return     ETrue, if there is a topic. EFalse if the end of the

        *               collection has been reached.

        */

        TBool HasNextTopic();                          

        /**

        *   Returns the next topic in the topic collection skipping all topics with 

        *   a topic number matching a topic already listed in the current topic list.

        *   This function will return KErrNotFound if the collection is tried to 

        *   access beyond the end of the list. Otherwise the error code will be 

        *   the same returned by GetTopicInfo().

        *

        *   @param aInfo        The topic information will be stored here.

        *   @return             The error code. KErrNotFound if there are no topics

        *                       left.

        */

        TInt NextTopic( TCbsTopicInfo& aInfo );

    private:

        /**

        *   Returns information whether the topic was in topic list.

        *   

        *   @param 	aIndex      Topic index

        *   @param  aInList     Was the topic in the list

        *   @return             Error code. KErrNotFound, if topic

        *                       didn't exist.

        */

        TInt TopicInList( TInt aIndex, TBool& aInList );

    private:// prohibited functions

        // Prohibited copy constructor

        RCbsTopicCollection( const RCbsTopicCollection& );

        // Prohibited assignment operator

        RCbsTopicCollection& operator=( const RCbsTopicCollection& );

    private:    // Data

        //Iterator is used to point to the next unlisted topic in topic collection. 

        //Unlisted topic is a topic which is not listed in the current topic list but 

        //is awailable in the topic collection

        TInt iIterator;     

    };

#endif      //  RCBSTOPICCOLLECTION_H

// End of File