/*

* 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:  Base class for disk watchers.

*

*/

#ifndef C_DISK_WATCHER_BASE_H

#define C_DISK_WATCHER_BASE_H

//  INCLUDES

#include <e32base.h>

// FORWARD DECLARATIONS

class MDiskNotifyHandlerCallback;

class RFs;

// CLASS DECLARATION

/**

* Class provides base functionality of disk watcher.

*

* @since S60 5.0

*/

NONSHARABLE_CLASS(CDiskWatcherBase) : public CActive

    {

protected:

    /**

    * C++ constructor.

    *

    * @since S60 5.0

    * @param aCallback Reference to callback

    * @param aFs Reference to open file server session

    */

    CDiskWatcherBase(

        MDiskNotifyHandlerCallback& aCallback,

        RFs& aFs );

    /**

    * Destructor.

    */

    ~CDiskWatcherBase();

private: // From CActive

    void RunL();

    TInt RunError( TInt aError );

    void DoCancel();

private:

    /**

    * Notifies watcher error

    *

    * @since S60 5.0

    * @param aError A system wide error code

    * @param aKilled A reference to indicate if watcher has been killed by callback

    */

    virtual void WatcherError( TInt aError, const TBool& aKilled ) = 0;

    /**

    * Reactivites watcher to catch notifications

    *

    * @since S60 5.0

    */

    virtual void ReactivateWatcher() = 0;

    /**

    * Runs watcher action on notification

    *

    * @since S60 5.0

    * @param aKilled A reference to indicate if watcher has been killed by callback

    */

    virtual void RunWatcher( const TBool& aKilled ) = 0;

    /**

    * Cancels watcher

    *

    * @since S60 5.0

    */

    virtual void CancelWatcher() = 0;

protected:

    /**

    * Returns open file server session. 

    *

    * @since S60 5.0

    * @return A reference to open file server session.

    */

    inline RFs& Fs();

    /**

    * Returns callback. 

    *

    * @since S60 5.0

    * @return A reference to callback.

    */

    inline MDiskNotifyHandlerCallback& Callback();

    /**

    * Compares two items

    *

    * @since S60 5.0

    * @param aItem1 Refefence to first item

    * @param aItem1 Refefence to second item

    * @return Comparison result

    */

    template < class T >

    inline static TInt Compare( const T& aItem1, const T& aItem2 );

private:

    /**

     * Callback instance. Not owned.

     */

    MDiskNotifyHandlerCallback& iCallback;

    /**

     * Open file server session. Not owned.

     */

    RFs& iFs;

    /**

     * Indicates if instance is killed from callback. Not owned.

     */

    TBool* iKilled;

    };

// Include inline method implementations

#include "diskwatcherbase.inl"

#endif // C_DISK_WATCHER_BASE_H   

// End of File