/*

* Copyright (c) 2005-2007 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:  Group for distance attenuation controls

*

*/

#ifndef CAMMSDISTANCEATTENUATIONCONTROLGROUP_H

#define CAMMSDISTANCEATTENUATIONCONTROLGROUP_H

//  INCLUDES

#include <e32base.h>

#include "cammsaudio3dcontrolgroup.h"

// CONSTANTS

_LIT(KAMMSDistanceAttenuationClassName,

     ".amms.control.audio3d.DistanceAttenuationControl");

// FORWARD DECLARATIONS

class CAMMSBaseDistanceAttenuationControl;

// CLASS DECLARATION

/**

 *  Group for distance attenuation controls

 *

 *  @since 3.0

 */

NONSHARABLE_CLASS(CAMMSDistanceAttenuationControlGroup): public CAMMSAudio3DControlGroup

{

public:  // Constructors and destructor

    /**

     * Two-phased constructor.

     */

    static CAMMSDistanceAttenuationControlGroup* NewLC();

    /**

     * Destructor.

     */

    ~CAMMSDistanceAttenuationControlGroup();

public: // New functions

    /**

     * Returns the maximum distance. At the maximum distance, the gain does

     * not decrease any more. The exact behavior of the gain at distances

     * beyond the maximum distance depends on the value of muteAfterMax

     *

     * @return the maximum distance

     */

    TInt32 MaxDistance() const;

    /**

     * Returns the distance where the source is loudest.

     *

     * @return the minimum distance

     */

    TInt32 MinDistance() const;

    /**

     * Returns how the distance gain behaves for distances beyond the

     * maximum distance.

     *

     * @return true if beyond the maximum distance the source is silent,

     * or false if beyond the maximum distance the source's gain is held

     * constant at the level at the maximum distance

     */

    TBool MuteAfterMax() const;

    /**

     * Returns the rolloff factor for the distance gain.

     *

     * @return the rolloff factor as an exponent specified in thousandths

     */

    TUint32 RolloffFactor() const;

    /**

     * Sets all the 3D audio distance attenuation parameters simultaneously

     *

     * @param aMinDistance      the minimum distance, below which the

     *                          distance gain is clipped to its maximum

     *                          value of 1.0

     * @param aMaxDistance      the maximum distance, beyond which the

     *                          distance gain does not decrease any more

     * @param aMuteAfterMax     a boolean determining how the distance

     *                          gain behaves at distances greater than

     *                          maxDistance

     * @param aRolloffFactor    the rolloff factor

     */

    void SetParametersL(TInt32 aMinDistance, TInt32 aMaxDistance,

                        TBool aMuteAfterMax, TUint32 aRolloffFactor);

private: // New functions

    /**

     * Gets and casts a control. Ownership is not tranferred.

     *

     * @param aIndex Control index.

     */

    CAMMSBaseDistanceAttenuationControl* TypeSafeControl(TInt aIndex) const;

public: // Functions from base classes

    /**

     * Returns class name that identifies this control group.

     *

     * @return Control group name.

     */

    const TDesC16& ClassName();

protected:

    /**

     * Transfers all the pending parameters to the audio processing system.

     *

     * @param aCommit   variable id that need to be commited

     */

    virtual void CommitL(TInt aCommit);

    /**

     * Called by when a new player is added

     *

     * @param aPlayer   The player being added

     * @param aControl  The player's control relevant to this group

     */

    void NotifyPlayerAddedL(CMMAPlayer* aPlayer, CMMAControl* aControl);

private:

    /**

     * C++ default constructor.

     */

    CAMMSDistanceAttenuationControlGroup();

private: // Data

    class TVariables

    {

    public:

        TInt32 iMinDistance;

        TInt32 iMaxDistance;

        TBool iMuteAfterMax;

        TUint32 iRolloffFactor;

    };

    TVariables iCommited; // holder for variables after commit

    TVariables iUncommited; // holder for variables before commit

    enum TCommit { EDistance = 1 };

};

#endif // CAMMSDISTANCEATTENUATIONCONTROLGROUP_H