/*

* 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:  DTMF handler interface for DTMF states and media 

*                handler to use.

*

*/

#ifndef MVTENGDTMFHANDLER_H

#define MVTENGDTMFHANDLER_H

//  INCLUDES

#include <e32std.h>

// DATA TYPES

// FORWARD DECLARATIONS

class CVtEngOperation;

class TVtEngDtmfTone;

class MVTUserInput;

class CVtEngDtmfState;

// CLASS DECLARATION

/**

*  Base class for data types

*

*  @lib videoteleng

*  @since 2.6

*/

class MVtEngDtmfHandler

    {

    public: // 

        /**

        * Dtmf states

        */

        enum TVtEngDtmfState 

            {

            // Not sending DTMF

            EVtDtmfStateIdle = 0,

            // Sending DTMF

            EVtDtmfStateSending,

            // Sending DTMF, another waiting in buffer

            EVtDtmfStateBuffered

            };

    public:

        /**

        * Handles a DTMF command.

        * @param 

        */

        virtual void HandleL( CVtEngOperation& aOp ) = 0;

        /**

        * Activates a DTMF state.

        * @param aNewState state index

        * @return activated state

        */

        virtual CVtEngDtmfState& ActivateState( 

            MVtEngDtmfHandler::TVtEngDtmfState aNewState ) = 0;

        /**

        * Handles completion of DTMF sending, non-leavable method.

        * @param aError Symbian OS error code

        */

        virtual void SendComplete( TInt aError ) = 0;

        /**

        * Returns new instance used for sending DTMF tone to protocol 

        * @param aTone tone to send

        * @return protocol DTMF tone.

        */

        virtual MVTUserInput& ReserveProtoDtmfL(

            const TVtEngDtmfTone& aTone  ) = 0;

        /**

        * Releses protocol DTMF instance.

        */

        virtual void ReleaseProtoDtmf() = 0;

		/**

        * Compares last issued DTMF command ID to given command ID.

        * @param aCheckCommandId command ID to be compared against

        * @return ETrue if IDs are same, otherwise EFalse

        */

		virtual TBool CheckCommandId( TInt aCheckCommandId ) const = 0 ;

		/**

        * Stores command ID, used in CheckCommandID.

        * @param aStoreCommandId command ID to be stored.        

        */

		virtual void StoreCommandId( TInt aStoreCommandId ) = 0;

    };

#endif      MVTENGDTMFHANDLER_H

// End of File