/*

* Copyright (c) 2007 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:  Class for monitoring changes in P&S keys.

* Part of:      Tactile Feedback.

*

*/

#ifndef TACTILEPROPERTYWATCHER_H

#define TACTILEPROPERTYWATCHER_H

#include <e32base.h> 

#include <e32std.h>

#include <e32property.h>

#include "tactilepropertyobserver.h"

/** 

 *  Observer class for accessing to P&S property values, and listening

 *  to changes.

 *

 *  @lib tactilefeedbackresolver.lib

 *  @since S60 v5.0

 */

NONSHARABLE_CLASS( CTactilePropertyWatcher ): public CActive

    {

public:

    /**

     * Intantiation method. 

     * 

     * This will create a property wather active

     * object with given active object priority. 

     *

     * @param aObserver - Reference to observer interface.

     * @param aCategory - P&S category, where the observed key is.

     * @param aKey      - Observed P&S key.

     * @param aPriority - Active object priority, which is given to

     *                    this wather instance.

     * @return New property watcher instance.

     */

    static CTactilePropertyWatcher* NewL( 

        MTactilePropertyObserver& aObserver, 

        const TUid aCategory, 

        const TInt aKey,

        CActive::TPriority aPriority );

    ~CTactilePropertyWatcher();

    /**

     * Retrieves an integer value associated with this property.

     *

     * Leaves with Standard Symbian OS error codes in case 

     * retreving of the value fails. 

     *

     * @param aValue - The property value is returned here

     */

    void GetL( TInt& aValue );

    /**

     * Fills aValue with the buffer associated with this property.

     *

     * Leaves with Standard Symbian OS error codes in case 

     * retreving of the value fails. 

     *

     * @param aValue - The property value is returned here

     */

    void GetL( TDes8& aValue );

    /**

     * Retrieves an integer value associated with this property.

     *

     * Does not leave in case reading of the property fails, but

     * instead returns Standard Symbian OS error code.

     *

     * @param aValue the property value is returned here

     * @return standard Symbian OS error code

     */

    TInt Get( TInt& aValue );

    /**

     * Fills aValue with the buffer associated with this property.

     *

     * Does not leave in case reading of the property fails, but

     * instead returns Standard Symbian OS error code.

     *

     * @param aValue the property value is returned here

     * @return standard Symbian OS error code

     */

    TInt Get( TDes8& aValue );

    /**

     * Sets a P&S property to an integer value. The property must be

     * already defined.

     *

     * @param aValue - The integer value to set to the property

     */

    void SetL( const TInt aValue );

    /**

     * Sets a P&S property to a (large) bytearray value. The property

     * must be already defined.

     *

     * @param aValue - The integer value to set to the property

     */

    void SetL( const TDesC8& aValue );

private:

    CTactilePropertyWatcher( 

        MTactilePropertyObserver& aObserver, 

        const TUid aCategory, 

        const TInt aKey,

        CActive::TPriority aPriority );

    void ConstructL();

    void Subscribe();

 // from base class CActive

    /**

     * Standard DoCancel of an active object.

     */

    void DoCancel();

    /**

     * Standard RunL of an active object.

     */

    void RunL();

private: // data

    /**

     * Access to observer interface

     * Not own.

     */

    MTactilePropertyObserver& iObserver;

    /**

     * The UID of this property

     */

    TUid iCategory;

    /**

     * The key of this property

     */

    TUint iKey;

    /**

     * Handle to the attached property

     * Own.

     */

    RProperty iProperty;

    };

#endif // TACTILEPROPERTYWATCHER_H

// End of File