// ssyreferencechanneldataprovider.h

/*

* Copyright (c) 2006-2009 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:

*

*/

/**

 @file

 @internalComponent

*/

#ifndef SSYREFERENCECHANNELDATAPROVIDER_H

#define SSYREFERENCECHANNELDATAPROVIDER_H

#include <sensors/spi/ssychanneldataprovider.h>

class CSsyReferenceChannel;

class TSsyReferenceMsg;

/**

 *  Channel data provider implementation.

 */

class CSsyReferenceChannelDataProvider : public CBase, public MSsyChannelDataProvider

    {

public:

    /**

     * Two-phase constructor

     *

     * @param[in] aChannel Reference to channel this provider belongs to

     * @return Pointer to created CSsyReferenceControl object

     */

    static CSsyReferenceChannelDataProvider* NewL( CSsyReferenceChannel& aChannel );

    /**

     * Virtual destructor

     */

    virtual ~CSsyReferenceChannelDataProvider();

// from base class MSsyChannelDataProvider

    /**

     * From MSsyChannelDataProvider

     * Starts asynchronous data listening. Multiple OpenChannel()-requests

     * can be active for different channels at the same time.

     *

     * @param[in] aBuffer Pointer to a data buffer 

     * @param[in] aCount Indicates data buffer size as a count of the data objects.

     */

    void StartChannelDataL( const TSensrvChannelId aChannelId, TUint8* aBuffer, TInt aCount );

    /**

     * From MSsyChannelDataProvider

     * Stops asynchronous data listening. The data buffer is not valid after call of 

     * this function.

     */

    void StopChannelDataL( const TSensrvChannelId aChannelId );

    /**

     * From MSsyChannelDataProvider

     * Forces SSY to call BufferFilled() regardless of how many data items have been

     * written to buffer. Even if no data items have yet been written, BufferFilled()

     * must be called.

     */

    void ForceBufferFilledL( const TSensrvChannelId aChannelId );

    /** 

    * Returns a pointer to a specified interface - to allow future extension

    * of this class without breaking binary compatibility

    *

    * @param aInterfaceUid Identifier of the interface to be retrieved

    * @param aInterface A reference to a pointer that retrieves the specified interface.

    */

    void GetChannelDataProviderInterfaceL( TUid aInterfaceUid, TAny*& aInterface );

    /**

     * Channel data item received

     *

     * @param[in] aMessage Contains channel item

     */

    void ChannelDataReceivedL( TSsyReferenceMsg* aMessage );

private:

    /**

     * C++ constructor.

     * @param[in] aChannel Reference to channel this provider belongs to

     */

    CSsyReferenceChannelDataProvider( CSsyReferenceChannel& aChannel );

    /**

     * Symbian 2nd phase constructor.

     */

    void ConstructL();

    /**

     * Adds data into buffer. 

     *

     *@param[in] aData Data to add to buffer

     *@param[in] aSize Size of data

     */

    void AddDataToBuffer( TUint8* aData, const TInt aSize );

    /**

     * Sends BufferFilled notification to MSsyCallback

     */

    void SendBufferFilled();

private: // data

    /**

     * Reference to channel for which this provider belongs to

     */

    CSsyReferenceChannel& iChannel;

    /**

     * Pointer to data buffer in Sensor Server side

     */

    TUint8* iDataBuffer;

    /**

     * Maximum requested data items

     */

    TInt iMaxCount;

    /**

     * Number of items in buffer

     */

    TInt iDataCount;

    };

#endif // SSYREFERENCECHANNELDATAPROVIDER_H