/*

* Copyright (c) 2008 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:  Interface for channel listener

*

*/

#ifndef SENSRVCHANNELLISTENER_H

#define SENSRVCHANNELLISTENER_H

#include <e32base.h>

#include <sensrvchannelfinder.h>

#include <sensrvtypes.h>

#include <sensrvchannelinfo.h>

/**

* Channel listener callback interface to indicate when channels have been added or removed.

* 

* This class is for use with the CSensrvChannelFinder::SetChannelListenerL() method. Clients wishing

* to find channels must inherit from this class and provide a reference to an instance of it in

* CSensrvChannelFinder::SetChannelListenerL().

* 

* @see CSensrvChannelFinder::SetChannelListenerL()

* @lib sensrvclient.lib

* @since S60 5.0

*/

class MSensrvChannelListener

    {

    public:

    /**

    * Callback implemented by a client so that they can be notified when channels are added

    * or removed from the system when new software is installed or uninstalled.

    * 

    * Clients providing an implementation for this callback must ensure that the operation does

    * not leave. If a leave does occur then the behaviour is undefined.

    * 

    * @since S60 5.0

    * @param aDetectedChannel Information for the channel that has been added or removed

    * @param  aChangeType If ESensrvChannelAdded, channel is a newly available channel.

    * If ESensrvChannelRemoved, channel has been removed and is no longer available.

    */

    virtual void ChannelChangeDetected( const TSensrvChannelInfo& aDetectedChannel,

                                        TSensrvChannelChangeType aChangeType ) = 0;

    /**

    * Callback implemented by a client so that they can be notified when channel listening

    * has failed. If the error is fatal the sensor server session has been terminated and

    * the channel finder is no longer useable. If the error is minor some notifications have

    * potentially been lost, however listening is still active.

    * 

    * Clients providing an implementation for this callback must ensure that the operation does

    * not leave. If a leave does occur then the behaviour is undefined.

    * 

    * @since S60 5.0

    * @param  aChannelFinder Reference to the related channelfinder object

    * @param  aError The error severity

    */

    virtual void ChannelDetectionError( CSensrvChannelFinder& aChannelFinder,

                                        TSensrvErrorSeverity aError ) = 0;

    /** 

    * Callback to future proof this API so that additional callbacks can be added in the future 

    * without breaking binary compatibility.

    * 

    * @since S60 5.0

    * @param  aInterfaceUid Identifier for the interface to be retrieved

    * @param  aInterface A reference to a pointer for the specified interface. Implementation sets

    * aInterface to a valid pointer if the M-class identified by aInterfaceUid is supported, otherwise

    * it is set to NULL on exit.

    * @leave  One of the system-wide error codes

    */

	virtual void GetChannelListenerInterfaceL( TUid aInterfaceUid, TAny*& aInterface ) = 0;

    };

#endif //SENSRVCHANNELLISTENER_H

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