1 /*

     2  * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3  * All rights reserved.

     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".

     8  *

     9  * Initial Contributors:

    10  * Nokia Corporation - initial contribution.

    11  *

    12  * Contributors:

    13  *

    14  * Description:This class provides callback mechanism for TMSEffect listeners.

    15  *

    16  */

    17 

    18 #ifndef TMS_EFFECT_OBSRVR_H

    19 #define TMS_EFFECT_OBSRVR_H

    20 

    21 // Include files

    22 #include <tms.h>

    23 

    24 namespace TMS {

    25 

    26 // FORWARD DECLARATIONS

    27 class TMSEffect;

    28 

    29 /**

    30  * TMSEffectObserver class

    31  *

    32  * This class provides callback mechanism for TMSEffect listeners.

    33  *

    34  * Client class that wants to receive events from TMSEffect concrete class

    35  * objects must inherit from TMSEffectObserver class and register itself with

    36  * the TMSEffect object.

    37  *

    38  * Functions declared in this class are called when effect events occur.

    39  *

    40  * The client must not do any blocking, or perform any CPU-intensive operations

    41  * in the callback methods. It is recommended that the client saves event data,

    42  * returns from this function immediately and if necessary, responds to

    43  * the event in asynchronous way.

    44  *

    45  * Usage:

    46  * <code>

    47  * // Register as observer to TMSVolumeEffect

    48  * iClient->AddObserver(*this);

    49  * ...

    50  * // Unregister (optional)

    51  * iClient->RemoveObserver(*this);

    52  * ...

    53  * </code>

    54  *

    55  * @lib tmsapi.lib

    56  *

    57  */

    58 class TMSEffectObserver

    59     {

    60 public:

    61     /**

    62      * Signal Effects event.

    63      *

    64      * This method is called when an Effects event occurs.

    65      *

    66      * Effect types:

    67      *  TMS_EFFECT_GLOBAL_VOL

    68      *  TMS_EFFECT_GLOBAL_GAIN

    69      *  TMS_EFFECT_VOLUME

    70      *  TMS_EFFECT_GAIN

    71      *

    72      * Notified events:

    73      *  TMS_EVENT_EFFECT_VOL_CHANGED

    74      *  TMS_EVENT_EFFECT_GAIN_CHANGED

    75      *

    76      * @param  tmseffect

    77      *      Pointer to the object that is being signaled.

    78      *

    79      * @param  event

    80      *      Event descriptor.

    81      *

    82      */

    83     virtual void EffectsEvent(TMSEffect* tmseffect, TMSSignalEvent event) = 0;

    84     };

    85 

    86 } //namespace TMS

    87 

    88 #endif // TMS_EFFECT_OBSRVR_H

    89 

    90 // End of file