1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/mm/devsound/a3facf/inc/maudiogaincontrolobserver.h	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,87 @@
     1.4 +/*
     1.5 +* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.6 +* All rights reserved.
     1.7 +* This component and the accompanying materials are made available
     1.8 +* under the terms of "Eclipse Public License v1.0"
     1.9 +* which accompanies this distribution, and is available
    1.10 +* at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.11 +*
    1.12 +* Initial Contributors:
    1.13 +* Nokia Corporation - initial contribution.
    1.14 +*
    1.15 +* Contributors:
    1.16 +*
    1.17 +* Description:
    1.18 +*
    1.19 +*/
    1.20 +
    1.21 +
    1.22 +
    1.23 +
    1.24 +/**
    1.25 + @file
    1.26 + @publishedPartner
    1.27 + @released
    1.28 +*/
    1.29 +
    1.30 +#ifndef MAUDIOGAINCONTROLOBSERVER_H
    1.31 +#define MAUDIOGAINCONTROLOBSERVER_H
    1.32 +
    1.33 +#include <e32base.h>
    1.34 +#include <a3f/a3fbase.h>
    1.35 +#include <a3f/maudiogaincontrol.h>
    1.36 +
    1.37 +/**
    1.38 + *  An interface to a set of AudioGainControl callback functions.
    1.39 + *
    1.40 + *  this serves as the method of communication between the client and the
    1.41 + *  AudioGainControl.
    1.42 + *
    1.43 + *  The class is a mixin and is intended to be inherited by the client class
    1.44 + *  that is interested in observing the Gain operations. The functions
    1.45 + *  encapsulated by this class are called when specific events occur while
    1.46 + *  processing audio.
    1.47 + *
    1.48 + */
    1.49 +class MAudioGainControlObserver
    1.50 +	{
    1.51 +public:
    1.52 +
    1.53 +	/**
    1.54 +	* Notifies the observer that the max ramp time supported by the gain
    1.55 +	* control has changed.
    1.56 +	*
    1.57 +	* @param aGain a reference to GainControl whose max ramp time changed.
    1.58 +	*/
    1.59 +	virtual void MaxRampTimeChanged(MAudioGainControl& aGain)=0;
    1.60 +
    1.61 +	/**
    1.62 +	* Notifies the observer that the maximum gain value supported by the
    1.63 +	* gain control has changed.
    1.64 +	*
    1.65 +	* @param aGain a reference to GainControl whose max gain changed.
    1.66 +	*/
    1.67 +	virtual void MaxGainChanged(MAudioGainControl& aGain)=0;
    1.68 +
    1.69 +	/**
    1.70 +	* Notifies the observer that the gain has changed, 
    1.71 +	* due to request from the client or otherwise.  
    1.72 +	* If gain change by the client cannot be fulfilled, 
    1.73 +	* a gain change with an error code other than KErrNone will be issued.
    1.74 +	* @param aGain	a reference to the gain control whose gain has changed.
    1.75 +	* @return aError		an error code. 
    1.76 +	* KErrNone if the gain change was requested by the client and was completed successfully.
    1.77 +	* KErrNotSupported if the SetGain() call referred to non-existent channels.
    1.78 +	* KErrArgument if aGain of less than 0 or larger than max gain, 
    1.79 +	* the same channel is specified multiple times, 
    1.80 +	* or aRampDuration is less than 0 or greater than max ramp duration.
    1.81 +	* KErrA3fUnsupportedRamp if the ramp operation requested is not supported, 
    1.82 +	* or the Uid value supplies is unknown.
    1.83 +	* Other system-wide errors are also possible. They will indicate that the gain change failed.
    1.84 +	* Note that these errors could alternatively be returned by the associated SetGain() call.
    1.85 +	*/
    1.86 +	virtual void GainChanged(MAudioGainControl& aGain, TInt aError)=0;
    1.87 +
    1.88 +	};
    1.89 +
    1.90 +#endif // MAUDIOGAINCONTROLOBSERVER_H