/*

* Copyright (c) 2005-2006 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:  Header file for CIRControlEventObserver

*

*/

#ifndef CIRCONTROLEVENTOBSERVER_H

#define CIRCONTROLEVENTOBSERVER_H

#include <e32base.h>

#include <e32property.h>

#include "irui.h"

#define KMAXLENGTH 256

NONSHARABLE_CLASS( CIRControlEventObserver ) : public CActive

	{  

 public:

    /**

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

     */

    enum TVRPropertyType

    	{

    	EVRPropertyInt, // Integral property type.

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

    	EVRPropertyText // Text (16 bit), max size 512 bytes

    	};

    /**

     * Two-phased constructor.

     *

     * @param aObserver a reference to the observer interface implementer

     * @param aCategory UID of Publish And Subscribe category

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

     * Publish And Subscribe

     * @param aPropertyType property type to observe

     */

    IMPORT_C static CIRControlEventObserver* NewL(

        CIRUi& aObserver, 

        const TUid& aCategory, 

        const TUint aKey, 

        const RProperty::TType aPropertyType);

    /**

     * Destructor.

     */

    ~CIRControlEventObserver();

    /**

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

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

     */

    IMPORT_C void SecondConstructL();

private:

    /**

     * C++ default constructor overload.

     * Two-phased constructor.

     *

     * @param aObserver a reference to the observer interface implementer

     * @param aCategory UID of Publish And Subscribe category

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

     * Publish And Subscribe

     * @param aPropertyType property type to observe

     */

	CIRControlEventObserver(

	    CIRUi& aObserver, 

	    const TUid& aCategory, 

	    const TUint aKey, 

	    const RProperty::TType aPropertyType);

    /**

     * By default Symbian 2nd phase constructor is private.

     **/

    void ConstructL();

protected:  

    // from base class Cactive

    /**

     * From CActive

     *

     * @see CActive::RunL()

     */

    void RunL();

    /**

     * From CActive, 

     * 

     * @see CActive::DoCancel()

     */

    void DoCancel();

private: // data

    /**

     * Observer to be notified when particular Property value has changed

     */

    CIRUi& iObserver;

    /** 

     * UID of Publish And Subscribe category

     */

    TUid iCategory;

    /**

     * Subkey to be used with Publish And Subscribe

     */

    TUint iKey;

    RProperty iProperty;

    RProperty::TType iPropertyType;

 	/** The cached value of the key. */

        mutable TBuf8<KMAXLENGTH> iText;

        TInt iValue;

	};

#endif  // CIRCONTROLEVENTOBSERVER_H