/*

* Copyright (c) 2006 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:  CCE extension interface class. 

*

*/

#ifndef MCCEEXTENSIONINTERFACE_H

#define MCCEEXTENSIONINTERFACE_H

//  INCLUDES

#include <e32base.h>

/**

* Plug-in extension feature provider.

* E.g telephony engine might have plugin features specific to call providers 

* functionality. Plug-in specific actions can be requested syncronous or asyncronous via this class. 

* Async message results are returned using MCCEExtensionObserver

* One instance of extension interface is used in CCE. In CCP many (one for every plug-in). One is used 

* in order to avoid using an array in CCE interface and to notify disapearance of that interface in case 

* plug-in goes down.

*

*  @since S60 3.2

*/

class MCCEExtensionInterface

protected:

    /** 

    * Protected destructor. Object cannot be deleted from client.

    * @since S60 3.2

    */

    virtual ~MCCEExtensionInterface() {};

public:

    /**

    * Request a custom command. Results are returned via MCCEExtensionObserver.

    * Many service-ids may map to same plug-in. 

    * Request-id is used for plug-in internal id of the request. 

    * Replies use also a service-id, but if e.g. one plug-in uses two service-ids 10 and 11 

    * then request might use 10 and reply use 11. The request id is the id used to determine 

    * what the request and respone relate to. Service-id is used as routing information in CCE and 

    * its client.

    * @since S60 3.2

    * @param aServiceId To which plug-in the event targeted to. 

    * @param aRequestId Id of request.

    * @param aData Request data.

    * @return KErrNone Request was started successful.

    * @return KErrNotFound No extension interface found for given service-id.

    * @return KErrNotSupported Service-id related plug-in does not support extension interface.

    * @return Other system wide error code.

    */

    virtual TInt RequestCommand( TUint32 iServiceId,

                                 TDesC8& aData ) = 0;

    /**

    * Cancels request. See MCCEExtensionInterface::RequestCommand for explanation of service-id 

    * handling.

    * @since S60 3.2

    * @param aServiceId To which plug-in the event targeted to.

    * @param aRequestId Id of request to cancel. 

    * @return KErrNone Request was started successful.

    * @return KErrNotFound No extension interface found for given service-id.

    * @return KErrNotSupported Service-id related plug-in does not support extension interface.

    * @return Other system wide error code.

    */

    virtual TInt CancelRequest( TUint32 iServiceId,

#endif // MCCEEXTENSIONINTERFACE_H