/*

* 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:  CCP extension provider class. 

*

*/

#ifndef MCCPEXTENSIONPROVIDER_H

#define MCCPEXTENSIONPROVIDER_H

//  INCLUDES

#include <e32base.h>

class MCCPExtensionObserver;

/**

* 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 via this class. 

* Asyncronous results are are returned using MCCPExtensionObserver

*

*  @since S60 3.2

*/

class MCCPExtensionProvider

protected:

    /** 

    * Protected destructor. Object cannot be deleted from plug-in client (CCE).

    * @since S60 3.2

    */

    virtual inline ~MCCPExtensionProvider() {};

public:

    /**

    * Request a custom command from the plug-in. Result returned via MCCPExtensionObserver.

    * @since S60 3.2

    * @param aRequest Id of request. 

    * @param aData Request data.

    * @return none

    */

    virtual void RequestCommand( TInt aRequest, 

                                 TDesC8& aData ) = 0;

    /**

    * Cancels request. Result returned via MCCPExtensionObserver.

    * @since S60 3.2

    * @param aReqToCancel Id of request to cancel. 

    * @return none

    */

    virtual void CancelRequest( TInt aReqToCancel ) = 0;

    /**

    * Add an observer for extension related events.

    * Currently CCE will set only one observer.

    * @since S60 v3.2

    * @param aObserver Observer to add.

    * @return none

    * @leave system error if observer adding fails

    */

    virtual void AddObserverL( const MCCPExtensionObserver& aObserver ) = 0;

    /**

    * Remove an observer.

    * @since S60 v3.2

    * @param aObserver Observer to remove.

    * @return KErrNone if removed succesfully. 

    * @return KErrNotFound if observer was not found.

    */

    virtual TInt RemoveObserver( const MCCPExtensionObserver& aObserver ) = 0;

#endif // MCCPEXTENSIONPROVIDER_H