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: Abstract interface for handling property change events.

    15 *

    16 */

    17 

    18 

    19 #ifndef CFMRADIOPROPERTYOBSERVER_H

    20 #define CFMRADIOPROPERTYOBSERVER_H

    21 

    22 #include <e32base.h>

    23 #include <e32property.h>

    24 

    25 /**

    26  * MFMRadioPropertyChangeObserver

    27  *

    28  * Abstract interface for handling property change events.

    29  */

    30 class MFMRadioPropertyChangeObserver

    31 {

    32 

    33 public:

    34  

    35     /**

    36     * This is a callback function which is called when a property value of 

    37     * type int is changed.

    38     *

    39     * @param aCategory UID of Publish And Subscribe category

    40     * @param aKey subkey to specify the category event; to be used with 

    41     * Publish And Subscribe

    42     *

    43     * @param aValue the new value

    44     */

    45     virtual void HandlePropertyChangeL(

    46         const TUid& aCategory, 

    47         const TUint aKey, 

    48         const TInt aValue ) = 0;

    49         

    50 	/**

    51     * This is a callback function which is called when a property value of 

    52     * type text is changed.

    53     *

    54     * @param aCategory UID of Publish And Subscribe category

    55     * @param aKey subkey to specify the category event; to be used with 

    56     * Publish And Subscribe

    57     * @param aValue the new value

    58     **/

    59     virtual void HandlePropertyChangeL( 

    60         const TUid& aCategory, 

    61         const TUint aKey, 

    62         const TDesC& aValue ) = 0;        

    63         

    64 	/**

    65     * This is a callback function which is called when a property value of 

    66     * type byte array is changed.

    67     *

    68     * @param aCategory UID of Publish And Subscribe category

    69     * @param aKey subkey to specify the category event; to be used with 

    70     * Publish And Subscribe

    71     * @param aValue the new value

    72     **/

    73     virtual void HandlePropertyChangeL( 

    74         const TUid& aCategory, 

    75         const TUint aKey, 

    76         const TDesC8& aValue ) = 0;        

    77                 

    78     /**

    79     * This is a callback function which is called when a P&S components 

    80     * returns an error

    81     *

    82     * @param aCategory UID of Publish And Subscribe category

    83     * @param aKey subkey to specify the category event

    84     * @param aError an error code

    85     */

    86     virtual void HandlePropertyChangeErrorL(

    87         const TUid& aCategory, 

    88         const TUint aKey, 

    89         TInt aError) = 0;    

    90 };

    91 

    92 

    93 

    94 /**

    95  * Observer class that observes changes of Property values and propogates 

    96  * them further.

    97  * The class defines a handle to a property, a single data value representing

    98  * an item of state information.

    99  *

   100  */

   101  class CFMRadioPropertyObserver : public CActive

   102 	{  

   103 	

   104  public:

   105 

   106     /**

   107      * Property type. Cannot use RProperty::TType because EByteArray == EText.

   108      */

   109     enum TFMRadioPropertyType

   110     	{

   111     	EFMRadioPropertyInt, // Integral property type.

   112     	EFMRadioPropertyByteArray, // Byte-array (8 bit), max size 512 bytes

   113     	EFMRadioPropertyText // Text (16 bit), max size 512 bytes

   114     	};

   115     	

   116     /**

   117      * Two-phased constructor.

   118      *

   119      * @param aObserver a reference to the observer interface implementer

   120      * @param aCategory UID of Publish And Subscribe category

   121      * @param aKey subkey to specify the category event; to be used with 

   122      * Publish And Subscribe

   123      * @param aPropertyType property type to observe

   124      */

   125     static CFMRadioPropertyObserver* NewL(

   126         MFMRadioPropertyChangeObserver& aObserver, 

   127         const TUid& aCategory, 

   128         const TUint aKey, 

   129         const TFMRadioPropertyType aPropertyType);

   130         

   131     /**

   132      * Two-phased constructor.

   133      *

   134      * @param aObserver a reference to the observer interface implementer

   135      * @param aCategory UID of Publish And Subscribe category

   136      * @param aKey subkey to specify the category event; to be used with 

   137      * Publish And Subscribe

   138      * @param aPropertyType property type to observe

   139      */

   140     static CFMRadioPropertyObserver* NewLC(

   141         MFMRadioPropertyChangeObserver& aObserver, 

   142         const TUid& aCategory, 

   143         const TUint aKey, 

   144         const TFMRadioPropertyType aPropertyType);

   145 

   146     /**

   147      * Destructor.

   148      */

   149     ~CFMRadioPropertyObserver();

   150         

   151     /**

   152      * Subscribes the object to listen to the specified key. Does nothing if already active.

   153      * Must be called after construction, or after calling Cancel().

   154      */

   155     void ActivateL();

   156     

   157     /**

   158      * Returns current integer property value

   159      * @param aUpdate ETrue if the cache value should be updated

   160      * 

   161      * @return int value

   162      */	

   163 	TInt ValueInt( TBool aUpdate = EFalse );

   164 	

   165 	/**

   166      * Returns current byte array property value

   167      ** @param aUpdate ETrue if the cache value should be updated

   168      * 

   169      * @return byte array value

   170      */	

   171 	const TDesC8& ValueDes8( TBool aUpdate = EFalse );

   172 	

   173 	/**

   174      * Returns current text property value

   175      * * @param aUpdate ETrue if the cache value should be updated

   176      *

   177      * @return text value

   178      */	

   179 	const TDesC& ValueDes( TBool aUpdate = EFalse );

   180 		

   181 private:

   182 

   183     /**

   184      * C++ default constructor overload.

   185      * Two-phased constructor.

   186      *

   187      * @param aObserver a reference to the observer interface implementer

   188      * @param aCategory UID of Publish And Subscribe category

   189      * @param aKey subkey to specify the category event; to be used with 

   190      * Publish And Subscribe

   191      * @param aPropertyType property type to observe

   192      */

   193 	CFMRadioPropertyObserver(

   194 	    MFMRadioPropertyChangeObserver& aObserver, 

   195 	    const TUid& aCategory, 

   196 	    const TUint aKey, 

   197 	    const TFMRadioPropertyType aPropertyType);

   198 

   199     /**

   200      * By default Symbian 2nd phase constructor is private.

   201      **/

   202     void ConstructL(); 

   203     

   204     // from base class Cactive

   205     /**

   206      * From CActive

   207      *

   208      * @see CActive::RunL()

   209      */

   210     void RunL();

   211 

   212     /**

   213      * From CActive, 

   214      * 

   215      * @see CActive::DoCancel()

   216      */

   217     void DoCancel();

   218 

   219 private: // data

   220 

   221  	/** 

   222  	 * Value of a subscribed category property of type int. 

   223  	 */

   224  	TInt iValueInt;

   225  	

   226  	/** 

   227  	 * Value of a subscribed category property of type byte array. 

   228  	 */

   229  	HBufC8* iValueByteArray;

   230  	

   231  	/** 

   232  	 * Value of a subscribed category property of type text. 

   233  	 */

   234  	HBufC* iValueText;

   235  	

   236     /** 

   237      * Handle to Publish And Subscribe component

   238      */ 

   239     RProperty iProperty;

   240     

   241     /**

   242      * Observer to be notified when particular Property value has changed

   243      */

   244     MFMRadioPropertyChangeObserver& iObserver;

   245     

   246     /** 

   247      * UID of Publish And Subscribe category

   248      */

   249     TUid iCategory;

   250     

   251     /**

   252      * Subkey to be used with Publish And Subscribe

   253      */

   254     TUint iKey;

   255     

   256     /** 

   257      * Type of the observed property. 

   258      */

   259     TFMRadioPropertyType iPropertyType;

   260     

   261 	};

   262 

   263 #endif  // CFMRADIOPROPERTYOBSERVER_H

   264