1 /*

     2 * Copyright (c) 2007-2007 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:  CCFScriptSubscription class declaration.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef C_CFSCRIPTSUBSCRIPTION_H

    21 #define C_CFSCRIPTSUBSCRIPTION_H

    22 

    23 // INCLUDES

    24 #include <e32base.h>

    25 

    26 // FORWARD DECLARATIONS

    27 class MCFContextInterface;

    28 class MCFContextSubscriptionListener;

    29 class MCFScriptListener;

    30 class CCFContextSubscriptionImpl;

    31 class CCFContextObject;

    32 

    33 // CLASS DECLARATION

    34 

    35 /**

    36 *  Script subscription class provides a centralized context subscription for

    37 *  operations on Context Framework Scripts. Script subscription stores all

    38 *  operation subscriptions for a context and manages one real context

    39 *  subscription on Context Framework.

    40 *

    41 *  @lib CFScriptEngine

    42 *  @since S60 v5.0

    43 */

    44 NONSHARABLE_CLASS( CCFScriptSubscription ): public CBase

    45     {

    46 public: // Constructors and destructor

    47 

    48     /**

    49     * Creates a CCFScriptSubscription instance.

    50     * @param aCF is a reference to context interface.

    51     * @param aCFListener is a reference to context subscription listener.

    52     * @param aListener is a pointer to script listener, i.e. context operation.

    53     * @return a pointer to the created instance of CCFScriptSubscription.

    54     */

    55     static CCFScriptSubscription* NewL( MCFContextInterface& aCF,

    56             MCFContextSubscriptionListener& aCFListener,

    57             MCFScriptListener* aListener );

    58 

    59     /**

    60     * Creates a CCFScriptSubscription instance.

    61     * @param aCF is a reference to context interface.

    62     * @param aCFListener is a reference to context subscription listener.

    63     * @param aListener is a pointer to script listener, i.e. context operation.

    64     * @return a pointer to the created instance of CCFScriptSubscription.

    65     */

    66     static CCFScriptSubscription* NewLC( MCFContextInterface& aCF,

    67             MCFContextSubscriptionListener& aCFListener,

    68             MCFScriptListener* aListener );

    69 

    70     /**

    71     * Destructor.

    72     */

    73     virtual ~CCFScriptSubscription();

    74 

    75 public: // New functions

    76 

    77     /**

    78     * Adds a script listener to this context subscription. Notifies the listener

    79     * about the current value of subscribed context.

    80     * @param aListener is a pointer to script listener, i.e. context operation.

    81     * @return None.

    82     */

    83     void AddListenerL( MCFScriptListener* aListener );

    84 

    85     /**

    86     * Removes a script listener from this context subscription. Removing the

    87     * last listener also removes the context subscription.

    88     * @param aListener is a pointer to script listener, i.e. context operation.

    89     * @return ETrue if there are no more listeners and the instance could be

    90     *   deleted, EFalse otherwise.

    91     */

    92     TBool RemoveListener( MCFScriptListener* aListener );

    93 

    94     /**

    95     * Checks whether the context subscription is a match with a script listener.

    96     * @param aListener is a pointer to script listener, i.e. context operation.

    97     * @return ETrue if the subscription is a match with the listener, EFalse

    98     *   otherwise.

    99     */

   100     TBool Match( const MCFScriptListener& aListener ) const;

   101 

   102     /**

   103     * Checks whether the context subscription is a match with a context.

   104     * @param aContext is a reference to a context.

   105     * @return ETrue if the subscription is a match with the context, EFalse

   106     *   otherwise.

   107     */

   108     TBool Match( const CCFContextObject& aContext ) const;

   109 

   110     /**

   111     * Notifies listeners about a context, i.e. evaluates context operations with

   112     * the context.

   113     * @param aContext is a reference to the context to be notified.

   114     * @param aContextLevelDelay is storage for context level delay requirement

   115     *   from the context operation evaluation.

   116     * @return ETrue if any listener executed actual evaluation, EFalse

   117     *   otherwise.

   118     */

   119     TBool NotifyListeners( const CCFContextObject& aContext,

   120             TInt& aContextLevelDelay ) const;

   121 

   122 protected:

   123 

   124     /**

   125     * C++ default constructor.

   126     */

   127     CCFScriptSubscription( MCFContextInterface& aCF,

   128             MCFContextSubscriptionListener& aCFListener );

   129 

   130     /**

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

   132     */

   133     void ConstructL( MCFScriptListener* aListener );

   134 

   135 private: // New functions

   136 

   137     /**

   138     * Subscribes context requested by a listener and notifies the listener about

   139     * the current value of the context.

   140     * @param aListener is a pointer to script listener, i.e. context operation.

   141     * @return KErrNone if successful, otherwise any system wide error code.

   142     */

   143     TInt DoSubscribeL( MCFScriptListener* aListener );

   144 

   145     /**

   146     * Notifies a listener about the current value of a context it is interested.

   147     * @param aListener is a pointer to script listener, i.e. context operation.

   148     * @return None.

   149     */

   150     void NotifyListenerOfCurrentContextValueL(

   151             MCFScriptListener* aListener ) const;

   152 

   153 private: // Data

   154 

   155     // Context interface for managing subscriptions.

   156     MCFContextInterface& iCF;

   157 

   158     // Context subscription listener interface for managing subscriptions.

   159     MCFContextSubscriptionListener& iCFListener;

   160 

   161     // Flag telling whether subscription has been made (ownership transferred).

   162     TBool iSubscribed;

   163 

   164     // Context subscription for script listeners; when subscription has been

   165     // activated (SubscribeContext() called) the ownership has been transferred.

   166     CCFContextSubscriptionImpl* iSubscription;

   167 

   168     // Script listeners for the context subscription. Not owned.

   169     RPointerArray< MCFScriptListener > iListeners;

   170     };

   171 

   172 

   173 #endif // C_CFSCRIPTSUBSCRIPTION_H