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: Telephony Multimedia Service

    15  *

    16  */

    17 

    18 #ifndef TMS_STREAM_OBSRVR_H

    19 #define TMS_STREAM_OBSRVR_H

    20 

    21 // Include files

    22 #include <tms.h>

    23 

    24 namespace TMS {

    25 

    26 // Forward declarations

    27 class TMSStream;

    28 

    29 /**

    30  * TMSStreamObserver class

    31  *

    32  * This class provides callback mechanism for TMSStream listeners.

    33  *

    34  * Client class that is interested in observing stream notifications has to

    35  * inherit from TMSStreamObserver class and register itself with the TMSStream.

    36  * Functions declared in this class are called when events occur in TMSStream.

    37  *

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

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

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

    41  * the event in asynchronous way.

    42  *

    43  * Usage:

    44  * <code>

    45  * // Register as an observer to the uplink stream

    46  * iUplinkStream->AddObserver(*this, NULL);

    47  * ...

    48  * // Unregister (optional)

    49  * iUplinkStream->RemoveObserver(*this);

    50  * ...

    51  * </code>

    52  *

    53  * @lib tmsapi.lib

    54  *

    55  */

    56 class TMSStreamObserver

    57     {

    58 public:

    59     /**

    60      * Signal stream event.

    61      *

    62      * This function is called when a stream event occurs.

    63      *      (1) TMS_EVENT_TYPE_STATE_CHANGED.

    64      *

    65      *

    66      * @param  stream

    67      *      Pointer to the object that is being signaled.

    68      *

    69      * @param  event

    70      *      Event descriptor.

    71      *

    72      */

    73     virtual void TMSStreamEvent(TMSStream* stream, TMSSignalEvent event) = 0;

    74     };

    75 

    76 } //namespace TMS

    77 

    78 #endif // TMS_STREAM_OBSRVR_H

    79 

    80 // End of file