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.
27 #ifndef MAUDIOGAINCONTROLOBSERVER_H
28 #define MAUDIOGAINCONTROLOBSERVER_H
31 #include <a3f/a3fbase.h>
32 #include <a3f/maudiogaincontrol.h>
35 * An interface to a set of AudioGainControl callback functions.
37 * this serves as the method of communication between the client and the
40 * The class is a mixin and is intended to be inherited by the client class
41 * that is interested in observing the Gain operations. The functions
42 * encapsulated by this class are called when specific events occur while
46 class MAudioGainControlObserver
51 * Notifies the observer that the max ramp time supported by the gain
52 * control has changed.
54 * @param aGain a reference to GainControl whose max ramp time changed.
56 virtual void MaxRampTimeChanged(MAudioGainControl& aGain)=0;
59 * Notifies the observer that the maximum gain value supported by the
60 * gain control has changed.
62 * @param aGain a reference to GainControl whose max gain changed.
64 virtual void MaxGainChanged(MAudioGainControl& aGain)=0;
67 * Notifies the observer that the gain has changed,
68 * due to request from the client or otherwise.
69 * If gain change by the client cannot be fulfilled,
70 * a gain change with an error code other than KErrNone will be issued.
71 * @param aGain a reference to the gain control whose gain has changed.
72 * @return aError an error code.
73 * KErrNone if the gain change was requested by the client and was completed successfully.
74 * KErrNotSupported if the SetGain() call referred to non-existent channels.
75 * KErrArgument if aGain of less than 0 or larger than max gain,
76 * the same channel is specified multiple times,
77 * or aRampDuration is less than 0 or greater than max ramp duration.
78 * KErrA3fUnsupportedRamp if the ramp operation requested is not supported,
79 * or the Uid value supplies is unknown.
80 * Other system-wide errors are also possible. They will indicate that the gain change failed.
81 * Note that these errors could alternatively be returned by the associated SetGain() call.
83 virtual void GainChanged(MAudioGainControl& aGain, TInt aError)=0;
87 #endif // MAUDIOGAINCONTROLOBSERVER_H