1 /*

     2 * Copyright (c) 2005-2008 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 object that tracks changes on a PS property.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef C_VCCENGPSPROPERTYLISTENER_H

    21 #define C_VCCENGPSPROPERTYLISTENER_H

    22 

    23 #include <e32base.h>

    24 #include <e32property.h>

    25 

    26 #include "mvccengpspropertylistenerobserver.h"

    27 

    28 /*

    29  *  CVccEngPsPropertyListener subsribes to the given property. It is used to 

    30  *  notify its observers about the changed the value of the property.

    31  *  

    32  *   

    33  *  @code

    34  *  void CExampleClass::ConstructL()

    35  * 	{

    36  *   CVccEngPsPropertyListener* iPropListener = 

    37  *				CVccEngPsPropertyListener::NewL( KPSVccPropertyCategory, 

    38                                                  KVccPropKeyHoRequest );

    39  * 	 iPropListener.AddObserver( this );

    40  * 	 iPropListener.Start();

    41  * 	}	

    42  * 

    43  * 	void CExampleClass::PropertyChangedL( 

    44             const TUid aCategoryId,

    45             const TUint aKeyId,

    46             const TInt aValue )

    47  * 	{

    48         

    49  *  	if( aKeyId )

    50  * 			{

    51  * 			switch( aValue )

    52  * 				{				

    53  * 				case EVccManualStartCsToPsHoRequest:

    54  * 					// start CS->PS handover 

    55  * 					break;

    56  * 				default:

    57  * 					break;

    58  * 				}			

    59  * 			}

    60  *  }

    61  *   

    62  *  @endcode

    63  

    64  * 

    65  *  @lib hoengine.lib

    66  *  @since S60 v3.2

    67  */

    68 class CVccEngPsPropertyListener : public CActive

    69     {

    70 public:

    71 

    72 	/**

    73 	 * Symbian two-phased constructor.

    74      *

    75      * @param aCategoryId	category uid 

    76      * @param aKeyId Id of a key of the property.

    77      */

    78     static CVccEngPsPropertyListener* NewL( const TUid aCategoryId, 

    79     										const TUint aKeyId );

    80 

    81     /**

    82      * Destructor.

    83      */

    84     virtual ~CVccEngPsPropertyListener();

    85 

    86     /**

    87      * Adds an observer

    88      * @param aObserver Reference to observer to be added

    89      */

    90     void AddObserverL( MVccEngPsPropertyListenerObserver& aObserver );

    91 

    92     /**

    93      * Removes an observer

    94      * @param aObserver  Reference to observer to be removed

    95      */

    96     void RemoveObserver( MVccEngPsPropertyListenerObserver& aObserver );

    97 

    98     /**

    99      * Get the current value of the property.

   100      * @return Current key value

   101      */

   102     TInt CurrentValue();

   103 

   104     /**

   105      * Starts the listener.

   106      */

   107     void Start();

   108 

   109 private: 

   110 	/**

   111 	 * Constructor.

   112 	 * 

   113 	 * @param aPropertyUid	category uid 

   114 	 * @param aKeyId Id of a key of the property.

   115 	 */

   116 	CVccEngPsPropertyListener( const TUid aCategoryId, const TUint aKeyId );

   117     

   118 	/**

   119 	 * 2nd phase constructor

   120 	 */

   121  	void ConstructL();

   122  	

   123     /**

   124      * Notifies the observers about the property value change.

   125      * @leave Symbian error code in error case

   126      */

   127     void NotifyObserversL();

   128 

   129 // from base class CActive.

   130 

   131     /**

   132      * @see CActive::RunL()

   133      */

   134     void RunL();

   135      

   136     /**

   137      * See CActive::DoCancel()

   138      */

   139     void DoCancel();

   140  

   141 private: //data

   142 

   143 	/**

   144 	 * Uid of the property category to be watched.

   145 	 */

   146  	TUid iCategoryId;

   147  

   148  	/**

   149  	 * The property key uid to be watched.

   150  	 */

   151  	TUint iKeyId;

   152 

   153  	/**

   154  	 * the property category.

   155  	 * Own

   156  	 */

   157  	RProperty iProperty;

   158    

   159  	/**

   160  	 * Obsevers for callback from this.

   161  	 * Own

   162  	 */

   163  	RPointerArray<MVccEngPsPropertyListenerObserver> iObservers;

   164 

   165     };

   166 

   167 #endif // C_VCCENGPSPROPERTYLISTENER_H

   168