1 /*

     2 * Copyright (c) 2006-2007 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:  Active class notifying metada and channel name changes to SongHistoryDb engine

    15 *

    16 */

    17 

    18 #ifndef CIRSONGHISTORYENGPUBSUB_H

    19 #define CIRSONGHISTORYENGPUBSUB_H

    20 

    21 #define KMAXLENGTH 250

    22 #include <e32base.h>

    23 #include <e32property.h>

    24 

    25 class MIRSongHistoryEngPubSubNotifyHandler;

    26 

    27 

    28 

    29 /**

    30 * Listens to one specified Publish & Subscribe key, notifying the observer whenever that key is changed.

    31 */

    32 NONSHARABLE_CLASS(CIRSongHistoryEngPubSub) : public CActive

    33     {

    34     public:

    35 

    36         /**

    37         * Static constructor.

    38         * @param    aObserver   The observer to be notified of the changes in the listened key.

    39         * @param    aCategory   The category of the key.

    40         * @param    aKey        The key to listen to.

    41         */

    42     static CIRSongHistoryEngPubSub* NewL( MIRSongHistoryEngPubSubNotifyHandler&

    43     		aPubSubObserver, const TUid& aCategory, TUint aKey ,

    44     		const RProperty::TType aPropertyType  );

    45         /**

    46         * Static constructor.

    47         * @param    aObserver   The observer to be notified of the changes in the listened key.

    48         * @param    aCategory   The category of the key.

    49         * @param    aKey        The key to listen to.

    50         */

    51     static CIRSongHistoryEngPubSub* NewLC( MIRSongHistoryEngPubSubNotifyHandler&

    52     		aPubSubObserver, const TUid& aCategory, TUint aKey ,

    53     		const RProperty::TType aPropertyType  );

    54         /**

    55         * Destructor.

    56         */

    57         ~CIRSongHistoryEngPubSub();

    58 

    59 

    60     protected: // From CActive

    61 

    62         /**

    63     *void RunL()

    64     *The function is called by the active scheduler

    65     *when a request completion event occurs,

    66         */

    67         void RunL();

    68 

    69         /**

    70     *void DoCancel()

    71     *Invoked when the active object is cancelled.

    72         */

    73         void DoCancel();

    74 

    75     private:

    76 

    77         /**

    78         * Constructor.

    79         * @param    aObserver   The observer to be notified of the changes in the listened key.

    80         * @param    aCategory   The category of the key.

    81         * @param    aKey        The key to listen to.

    82         */

    83     CIRSongHistoryEngPubSub( MIRSongHistoryEngPubSubNotifyHandler& aPubSubObserver,

    84     	const TUid& aCategory, TUint aKey, const RProperty::TType aPropertyType );

    85 

    86         /**

    87         * Second-phase constructor.

    88         */

    89         void ConstructL();

    90 

    91     protected:

    92 

    93         /** Handle to the property. */

    94         RProperty iProperty;

    95         RProperty::TType iPropertyType;

    96 

    97         /** The observer to be notified of the changes in the listened key. */

    98         MIRSongHistoryEngPubSubNotifyHandler& iPubSubObserver;

    99 

   100         /** The category of the key to listen to. */

   101         TUid iCategory;

   102 

   103         /** The key to listen to. */

   104         TUint iKey;

   105 

   106         /** The cached value of the key. */

   107         mutable TBuf8<KMAXLENGTH> iText;

   108 

   109 

   110     };

   111 

   112 #endif//IR_SONGHISTORYENGPUBSUB