/*

* Copyright (c) 2005-2007 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:  Active transaction stack

*

*/

#ifndef C_ACTIVETRANSACTIONSTACK_H

#define C_ACTIVETRANSACTIONSTACK_H

#include <e32base.h>

namespace AiXmlUiController

    {

    class MTransaction;

    class CTransaction;

    }

namespace AiXmlUiController

{

/**

*  @ingroup group_xmluicontroller

* 

*  CActiveTransactionStack is a stack for CTransactions

*

*  @lib AiXmlUiMain

*/

class CActiveTransactionStack : public CBase

    {

public:  // Constructors and destructor

    static CActiveTransactionStack* NewL();

    virtual ~CActiveTransactionStack();

    // New functions

    /**

    * Checks if stack is empty.

    * @return ETrue if stack is empty

    */

    TBool IsEmpty() const;

    /**

    * Pushes a transaction into the stack.

    * @param aTransaction the transaction

    */

    void Push( MTransaction* aTransaction );

    /**

    * Pops the topmost transaction from the stack.

    * @return the topmost transaction from the stack

    */

    MTransaction* Pop();

    /**

    * Returns the topmost transaction from the stack.

    * @return the topmost transaction from the stack

    */

    MTransaction* Top() const;

    /**

    * Lookups a transaction from the stack.

    * @param aTxId the transaction id of the transaction

    * @return the transaction with aTxId from the stack

    */

    MTransaction* Lookup( TInt aTxId ) const;

    /**

    * Removes a transaction from the stack.

    * @param aTxId the transaction id of the transaction

    * @return the transaction with aTxId from the stack

    */

    MTransaction* Remove( TInt aTxId );

private:

    CActiveTransactionStack();

    CTransaction* DoTop() const;

    CTransaction* DoLookup( TInt aTxId ) const;

private:    // Data

    /**

     * Doubly linked list of transactions

     */ 

    TDblQue< CTransaction > iTransactions;

    };

} // namespace AiXmlUiController

#endif      // C_ACTIVETRANSACTIONSTACK_H

//  End of File