2 * Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
4 * This component and the accompanying materials are made available
5 * under the terms of "Eclipse Public License v1.0"
6 * which accompanies this distribution, and is available
7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".
9 * Initial Contributors:
10 * Nokia Corporation - initial contribution.
28 #ifndef MAUDIOSTREAMOBSERVER_H
29 #define MAUDIOSTREAMOBSERVER_H
32 #include <a3f/a3fbase.h>
33 #include <a3f/maudiostream.h>
36 * An interface to a set of AudioStream callback functions.
38 * this serves as the method of communication between the client and the
41 * The class is a mixin and is intended to be inherited by the client class
42 * that is interested in observing the AudioStream operation. The functions
43 * encapsulated by this class are called when specific events occur while
46 class MAudioStreamObserver
50 * Handles audio stream state change event.
52 * @param aStream A reference to the stream whose state changed.
53 * @param aReason A set of values describing why the state change occurred
54 * corresponding to the system-wide error codes. The value will be KErrNone on successful calls.
55 * @param aNewState indicating the state in which the audio stream has changed.
57 virtual void StateEvent(MAudioStream& aStream , TInt aReason, TAudioState aNewState)=0;
60 * Notifies that adding of processing unit to the stream has been completed successfully or otherwise.
62 * if the processing unit is added succesfully, then it must be removed from the
63 * stream before the processing unit is removed from the context or before the stream is removed.
65 * @param aStream A reference to the stream to which the processing unit was added.
66 * @param aInstance a pointer to the processing unit instance.
67 * @param aError an error code. KErrNone on success. Otherwise one of the system wide error codes.
69 virtual void AddProcessingUnitComplete(MAudioStream& aStream, MAudioProcessingUnit* aInstance, TInt aError)=0;
72 * Notifies that removing of processing unit from the stream has been completed
73 * successfully or otherwise.
75 * if the processing unit has been added succesfully, then it must be removed
76 * from the stream, before the processing unit is removed from the
77 * context or before the stream is removed.
79 * @param aStream A reference to the stream from which the processing unit has been removed.
80 * @param aType the processing unit type.
81 * @param aInstance a pointer to the processing unit instance.
82 * @param aError an error code. KErrNone on success. Otherwise one of the system wide error codes.
84 virtual void RemoveProcessingUnitComplete(MAudioStream& aStream, MAudioProcessingUnit* aInstance, TInt aError)=0;
87 * Call-back indicating that is the last buffer has been processed by the sink.
89 * @param aStream A reference to the stream.
91 virtual void ProcessingFinished (MAudioStream& aStream)=0;
94 * Signals completion of a Flush() operation.
96 * @param aStream A reference to the stream on which Flush() was called.
97 * @param aError an error code. KErrAbort if the associated stream has been unloaded, and the buffers cease to exist.
99 virtual void FlushComplete (MAudioStream& aStream, TInt aError) = 0;
103 #endif // MAUDIOSTREAMOBSERVER_H