1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/mm/devsound/a3facf/inc/maudiostreamobserver.h	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,103 @@
     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 +
    1.31 +#ifndef MAUDIOSTREAMOBSERVER_H
    1.32 +#define MAUDIOSTREAMOBSERVER_H
    1.33 +
    1.34 +#include <e32base.h>
    1.35 +#include <a3f/a3fbase.h>
    1.36 +#include <a3f/maudiostream.h>
    1.37 +
    1.38 +/**
    1.39 + * An interface to a set of AudioStream callback functions.
    1.40 + *
    1.41 + * this serves as the method of communication between the client and the
    1.42 + * AudioStream.
    1.43 + *
    1.44 + * The class is a mixin and is intended to be inherited by the client class
    1.45 + * that is interested in observing the AudioStream operation. The functions
    1.46 + * encapsulated by this class are called when specific events occur while
    1.47 + * processing audio.
    1.48 + */
    1.49 +class MAudioStreamObserver
    1.50 +	{
    1.51 +public:
    1.52 +	/**
    1.53 +	 * Handles audio stream state change event.
    1.54 +	 *
    1.55 +	 * @param aStream A reference to the stream whose state changed.
    1.56 +	 * @param aReason A set of values describing why the state change occurred 
    1.57 +	 * corresponding to the system-wide error codes. The value will be KErrNone on successful calls.
    1.58 +	 * @param aNewState indicating the state in which the audio stream has changed.
    1.59 +	 */
    1.60 +	virtual void StateEvent(MAudioStream& aStream , TInt aReason, TAudioState aNewState)=0;
    1.61 +
    1.62 +	/**
    1.63 +	 * Notifies that adding of processing unit to the stream has been completed successfully or otherwise.
    1.64 +	 *
    1.65 +	 * if the processing unit is added succesfully, then it must be removed from the
    1.66 +	 * stream before the processing unit is removed from the context or before the stream is removed.
    1.67 +	 *
    1.68 +	 * @param aStream A reference to the stream to which the processing unit was added.
    1.69 +	 * @param aInstance a pointer to the processing unit instance.
    1.70 +	 * @param aError an error code. KErrNone on success. Otherwise one of the system wide error codes.
    1.71 +	 */
    1.72 +	virtual void AddProcessingUnitComplete(MAudioStream& aStream, MAudioProcessingUnit* aInstance, TInt aError)=0;
    1.73 +
    1.74 +	/**
    1.75 +	 * Notifies that removing of processing unit from the stream has been completed
    1.76 +	 * successfully or otherwise.
    1.77 +	 * 
    1.78 +	 * if the processing unit has been added succesfully, then it must be removed
    1.79 +	 * from the stream, before the processing unit is removed from the
    1.80 +	 * context or before the stream is removed.
    1.81 +	 * 
    1.82 +	 * @param aStream A reference to the stream from which the processing unit has been removed.
    1.83 +	 * @param aType the processing unit type.
    1.84 +	 * @param aInstance a pointer to the processing unit instance.
    1.85 +	 * @param aError an error code. KErrNone on success. Otherwise one of the system wide error codes.
    1.86 +	 */
    1.87 +	virtual void RemoveProcessingUnitComplete(MAudioStream& aStream, MAudioProcessingUnit* aInstance, TInt aError)=0;
    1.88 +
    1.89 +	/**
    1.90 +	 * Call-back indicating that is the last buffer has been processed by the sink.
    1.91 +	 *
    1.92 +	 * @param aStream A reference to the stream.
    1.93 +	 */
    1.94 +	virtual void ProcessingFinished (MAudioStream& aStream)=0;
    1.95 +
    1.96 +	/**
    1.97 +	 * Signals completion of a Flush() operation.
    1.98 +	 *
    1.99 +	 * @param aStream A reference to the stream on which Flush() was called.  
   1.100 +	 * @param aError an error code. KErrAbort if the associated stream has been unloaded, and the buffers cease to exist.
   1.101 +	 */
   1.102 +	virtual void FlushComplete (MAudioStream& aStream, TInt aError) = 0;
   1.103 +
   1.104 +	};
   1.105 +
   1.106 +#endif // MAUDIOSTREAMOBSERVER_H