/*

* 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 the License "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:  Class for requesting notifications to Publish & Subscribe

*                properties.

*

*/

#ifndef WLMPLATFORMSUBSCRIBER_H

#define WLMPLATFORMSUBSCRIBER_H

#include <e32base.h>

#include <e32property.h>

enum TWlmSubscribeType

    {

    EWlmSubscribeTypeCenRep,

    EWlmSubscribeTypePubSub,

    };

class CRepository;

/**

* Callback interface to client

*/

class MWlmPlatformResponder

    {

    public: // New functions

        /**

        * From The subscribed property has changed.

        * @since Series 60 3.0

        * @param aCategory Category of the changed property.

        * @param aKey Key of the changed property.

        */

        virtual void HandlePropertyChangedL( const TUid& aCategory, const TUint aKey ) = 0;

    };

// CLASS DECLARATION

/**

* Class for requesting notifications about changed PubSub/CenRep properties/keys.

* @lib wlmplatform.dll

* @since Series 60 3.0

*/

NONSHARABLE_CLASS( CWlmPlatformSubscriber ) : public CActive

    {

    public:  // Constructors and destructor

        /**

        * Two-phased constructor.

        * @since Series 60 3.0

        * @param aType specifies whether observed key is in CenRep or PubSub

        * @param aCallback specifies the callback object

        * @param aCategory specifies the key's category (PubSub)

        *        or repository file (CenRep)

        * @param aKey specifies the key to be watched

        */

        static CWlmPlatformSubscriber* NewL(

            TWlmSubscribeType aType,

            MWlmPlatformResponder& aCallback,

            const TUid& aCategory,

            const TUint aKey );

        /**

        * Destructor.

        */

        virtual ~CWlmPlatformSubscriber();

    public: // New functions

        /**

        * IssueRequest subscribes to changes of a property

        * @since Series 60 3.0

        */

        void IssueRequest();

        /**

        * Get requests the value of the property under subscription

        * (callback only tells the client that the value has changed)

        * @since Series 60 3.0

        */

        TInt Get( TInt& aValue );

    protected:  // Functions from base classes

        /**

        * From CActive

        */

        virtual void DoCancel();

        /**

        * From CActive

        */        

        virtual TInt RunError( TInt aError );

        /**

        * From CActive

        */

        virtual void RunL();

    private:

        /**

        * C++ default constructor.

        */

        CWlmPlatformSubscriber(

            TWlmSubscribeType aType,

            MWlmPlatformResponder& aCallback,

            const TUid& aCategory,

            const TUint aKey );

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

    private:    // Data

        /** Type of the property to watch (PubSub or CenRep). */

        TWlmSubscribeType iType;

        /** Callback to call when the property changes. */

        MWlmPlatformResponder &iCallback;

        /** The category/repository to watch. */

        const TUid iCategory;

        /** The key to watch. */

        const TUint iKey;

        /** The property to watch in PubSub. */

        RProperty iProperty;

        /** The handle to CenRep. */

        CRepository* iCenRep;

    };

#endif // WLMPLATFORMSUBSCRIBER_H