/*

* Copyright (c) 2002-2006 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  ?Description

*

*/

#ifndef C_CFCONTEXTSUBSCRIPTIONIMPL_H

#define C_CFCONTEXTSUBSCRIPTIONIMPL_H

#include "cfcontextsubscription.h"

// FORWARD DECLARATIONS

class MCFContextSubscriptionListener;

class CCFContextQueryImpl;

class CCFContextObject;

class CCFContextDataObject;

class RWriteStream;

/**

* Subscription for observing context value changes for certain

* context type or a subtree of context types coming from certain

* source or all sources.

* 

* Information about context changes will be sent to object implementing

* <code>MCFListener</code>-interface.

*

* @since S60 5.0

* @lib cfservices.lib

*/

NONSHARABLE_CLASS( CCFContextSubscriptionImpl ): public CCFContextSubscription

    {

    public:

        /**

        * Two phased construction.

        *

        * @since S60 5.0

        * @param None.

        * @return CCFContextSubscriptionImpl*

        */

        IMPORT_C static CCFContextSubscriptionImpl* NewL();

        IMPORT_C static CCFContextSubscriptionImpl* NewLC();

        /**

        * Two phased construction with parameters.

        *

        * @since S60 5.0

        * @param aStream Stream where to initialize.

        * @return CCFContextSubscriptionImpl*

        */

        IMPORT_C static CCFContextSubscriptionImpl* NewL (

        	RReadStream& aStream);

        IMPORT_C static CCFContextSubscriptionImpl* NewLC (

        	RReadStream& aStream);

        // Destructor.

        ~CCFContextSubscriptionImpl();

    public: // From base classes

        // @see CCFContextSubscription

        void SetContextTypeL( const TDesC& aContextType );

        // @see CCFContextSubscription

        const TDesC& ContextType() const;

        // @see CCFContextSubscription

        void SetContextSourceL( const TDesC& aSource );

        // @see CCFContextSubscription

        const TDesC& ContextSource() const;

        // @see CCFContextSubscription

		TBool SubTypeMatch() const;

        // @see CCFContextSubscription

		void SetSubTypeMatch( TBool aMatchSubTypes );

        // @see CCFContextSubscription

		TBool OnlyChangesIndicated() const;

        // @see CCFContextSubscription

		void SetOnlyChangesIndicated( TBool aIndicateChangesOnly );

        // @see CCFContextSubscription

		void SetDataObjectEnabled( TBool aEnabled );

        // @see CCFContextSubscription

		TBool DataObjectEnabled() const;

    public: // New methods

        /**

        * Internalizes object.

        *

        * @since S60 5.0

        * @param aStream Stream from which to internalize.

        * @return None.

        */

        IMPORT_C void InternalizeL( RReadStream& aStream );

        /**

        * Externalizes object.

        * 

        * @since S60 5.0

        * @param aStream Stream where to externalize.

        * @return None

        */

        IMPORT_C void ExternalizeL( RWriteStream& aStream );

        /**

        * Gets object size in bytes.

        *

        * @since S60 5.0

        * @param None

        * @return TInt

        */

        IMPORT_C TInt Size() const;

        /**

        * Returns subscriber of this subscription.

        *

        * @since S60 5.0

        * @param None.

        * @return MCFContextSubscriptionListener&

        */

        IMPORT_C MCFContextSubscriptionListener& SubscriptionListener() const;

        /**

        * Sets a subscriber for this subscription.

        *

        * @since S60 5.0

        * @param aListener Call back to subscriber.

        * @return None.

        */

        IMPORT_C void SetSubscriptionListener(

            MCFContextSubscriptionListener& aListener );

        /**

        * Evaluates context change event coming from data manager and sends

        * indication to the subscriber if it matches this subscription.

        *

        * @since S60 5.0

        * @param aOldContext Previous context.

        * @param aNewContext Current context.

        * @return

        */

        IMPORT_C void EvaluateContextChangeL(

            const CCFContextObject& aNewContext,

            const CCFContextObject& aOldContext, TBool aValueChanged ) const;

        /**

        * Tells whether this instance is the same as the argument.

        * Comparison is made based on client session, subscribed context source

        * and type.

        *

        * @return ETrue if this instance equals the argument. Otherwise, EFalse.

        */

        IMPORT_C TBool IsSame(

            const CCFContextSubscriptionImpl& aSubscription) const;

        /**

        * Checks if a context type matches with this subscription.

        * 

        * @since S60 5.0

        * @param aContextType Context type to match.

        * @return ETrue if a match.

        */

        IMPORT_C TBool Matches( const TDesC& aContextType ) const;

        /**

        * Checks if a context source and a context type matches

        * this subscription.

        *

        * @since S60 5.0

        * @param aContextType Context type to match.

        * @param aContextSource Context source to match.

        * @return ETrue if a match.

        */

		IMPORT_C TBool Matches( const TDesC& aContextType,

			const TDesC& aContextSource ) const;

        /**

        * Evaluates context change event coming from data manager and sends

        * indication to the subscriber if it matches this subscription.

        *

        * @since S60 5.0

        * @param aNewContext Current context.

        * @param aData Data object associated with the context.

        * @param aValueChanged Value changed.

        * @return

        */

        IMPORT_C void EvaluateContextChangeL(

            const CCFContextObject& aNewContext,

            CCFContextDataObject& aData,

            TBool aValueChanged ) const;

    private:

        // Check if a context notification is needed.

        TBool NotificationNeeded( const CCFContextObject& aNewContext,

            TBool aValueChanged ) const;

    private:

        // C++ constructor

        CCFContextSubscriptionImpl();

        // 2nd phase constructors

        void ConstructL();

        void ConstructL( RReadStream& aStream );

    private:

        /** Context query related to subscription */

        CCFContextQueryImpl* iContextQuery;

        /** A call back interface to the subscriber */

        MCFContextSubscriptionListener* iSubscriptionListener;

        /** Flag indicating whether only changes in context value are indicated */

        TBool iOnlyChangesIndicated;

        /** Flag indicating that subscriber wants also data objects */

        TBool iDataObjectEnabled;

    };

#endif