/*

* Copyright (c) 2006-2007 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:  ?Description

*

*/

#ifndef IRCTRLCMDOBSERVER_H

#define IRCTRLCMDOBSERVER_H

#include <e32base.h>

#include "ircontrolparams.h"

class MIRCtrlCmdObserver;

class MIRStreamFill;

/**

 * This is the class is implemented to provide completed independence to 

 * mediaengine from client as well as network.It is through this class media 

 * engine interacts with client and network. This also provides additional 

 * features like audio fade in, audio fade out effect. This design is has to 

 * provide flexiblilty to irmediaengine by avoiding any other dll interaction

 * other than ircommandchannel.dll

 *

 * @code

 *

 * Observer* observer; //Observer class should be derived from MIRCtrlCmdObserver

 * StreamFill* stream; //Streamfill class should be derived from MIRStreamFill

 * CIRCtrlCmdObserver* channel = CIRCtrlCmdObserver::NewL(observer,stream);   

 * //creates instance of ircommandchannel

 * TIRControlCommmand command = EError;

 * //senting an error value and is defined in IRControlParams.h

 * TInt some_integer_value;

 * TPtr ptrbuffer;

 * TUint8* ptr = new (ELeave) TUint8[100];

 * ptrbuffer.Set(ptr,100,100);

 * channel->SentRequest(command,some_integer_value); 

 * //sending a command to channel

 * channel->FilltheBuffer(ptrbuffer); //call for filling the buffer

 * TInt volume = channel->FetchVolume(); 

 * //gets current volume (which can stored in database)

 * command = EBufferFadeIn; //calling for a fade in effect

 * channel->AudioFadeInOut(command,5);

 * channel->DoAudioFadeOut(); //function for fade out effect

 * delete channel;

 *

 * @endcode

 * 

 * @lib ircommandchannel.lib

 * @since S_60 3.0

 *

 */

NONSHARABLE_CLASS(CIRCtrlCmdObserver) :  public CBase

    {

public:                                //member function

    /**

     * Function : NewL

     * Function returns an instance of CIRCtrlCmdObserver

     * Two phase constructor

     * @param MIRCtrlCmdObserver observers instance,pointer to MIRStreamFill

     * @return instance of CIRCtrlCmdObserver

     */

    IMPORT_C static CIRCtrlCmdObserver* NewL(MIRCtrlCmdObserver* aObserver,

		MIRStreamFill* aStream);    

    /**

     * Function : NewLC

     * Function returns an instance of CIRCtrlCmdObserver

     * Two phase constructor

     * @param MIRCtrlCmdObserver observers instance,pointer to MIRStreamFill

     * @return instance of CIRCtrlCmdObserver

     */

    IMPORT_C static CIRCtrlCmdObserver* NewLC(MIRCtrlCmdObserver* aObserver,

		MIRStreamFill* aStream);

    /**

     * Function : ~CIRCtrlCmdObserver

     * Default destructor calls Cancel function which cancel the active request 

     */

    ~CIRCtrlCmdObserver();

   /**

     * Function : SentRequest

     * Function sends request to handle events represented by 

     * TIRControlCommmand

     * @param TIRControlCommmand represents what action to be taken

     * @param aValue represents any integer value if any, like buffering 

     * percentage

     */

    IMPORT_C void SentRequest(TIRControlCommmand aCommand,TInt aValue);

    /**

     * Function : FilltheBuffer

     * Function sends request to fill the buffer

     * @param buffer to be filled with data

     */

    IMPORT_C void FilltheBuffer(TDes8& aInputBuffer);

    /**

     * Function : FetchVolume

     * Function sends request to get the current volume index

     * @return volume index

     */

    IMPORT_C TInt FetchVolume();

        /**

     * Function : AudioFadeInOut

     * Function is called for audio Fade In Fade Out Effects

     * @param TIRControlCommmand represents what action to be taken Fade 

     * In or Fade Out

     * @param aValue represents any integer value of cuurent volume level

     */

    IMPORT_C void AudioFadeInOut(TIRControlCommmand& aCommand,TInt aValue);

    /**

     * Function : DoAudioFadeOut

     * Function is used to sent request start audio Fade Out

     */

    IMPORT_C void DoAudioFadeOut();

private:

    /**

     * Function : ConstructL

     * Function does all the initializations

     * Two phase constructor

     * @param MIRCtrlCmdObserver observers instance,pointer to MIRStreamFill

     */

    void ConstructL(MIRCtrlCmdObserver* aObserver,MIRStreamFill* aStream);

    /**

     * Function : CIRCtrlCmdObserver

     * Function is the default constructor, sets the CActive priority, 

     * Line status

     */

    CIRCtrlCmdObserver();

    /**

     * Function : StartAudioFadeIn

     * Function Starts audio Fade In effects

     * @param take a parameter of CIRCtrlCmdObserver into a TAny pointer

     * @return KErrNone upon completion

     */

    static TInt StartAudioFadeIn(TAny* aPtr);

    /**

     * Function : StartAudioFadeOut

     * Function Starts audio Fade Out effects

     * @param take a parameter of CIRCtrlCmdObserver into a TAny pointer

     * @return KErrNone upon completion

     */

    static TInt StartAudioFadeOut(TAny* aPtr);

    /**

     * Function : UpdateVolumeInc

     * Function does the Fade In effect

     */

    void UpdateVolumeInc();

    /**

     * Function : UpdateVolumeDec

     * Function does the Fade In effect 

     */

    void UpdateVolumeDec();

private:                                //data members

    //This is instance of MIRCtrlCmdObserver 

    MIRCtrlCmdObserver* iObserver;

    //Access to fill data

    MIRStreamFill* iStream;

    //Volume timer

    CPeriodic* iVolumeTimer;

    //current volume level

    TInt iVolumeLevel;

    //actual volume level

    TInt iPersistentVolume;

    //instance of the command

    TIRControlCommmand iCommand;

    };

#endif//IRCTRLCMDOBSERVER_H