/*

* Copyright (c) 2008-2009 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:  Monitors USB activity

 *

*/

#ifndef C_USBBUSACTIVITYOBSERVER_H

#define C_USBBUSACTIVITYOBSERVER_H

#include <e32base.h>

#include <e32property.h>

/**

 *  This interface has to be implemented by observer

 *  to receive notifications from USB bus activity property

 */

NONSHARABLE_CLASS(MUsbBusActivityObserver)

    {

public:

    /**

     * Called when bus turn to idle

     */

    virtual void BusIdleL() = 0;

    /**

     * Called when when bus is in Idle, and some activity appears on the bus

     */

    virtual void BusActiveL() = 0;

    /**

      * Called when when error happened

      * @param aError errorcode

      */

     virtual void BusActivityErrorL(TInt aError) = 0;   

    };

/**

 *  Class observes USB OTG State property

 *

 */

NONSHARABLE_CLASS(CUsbBusActivityObserver) : public CActive

    {

public:

    enum TBusActivity

        {

        EBusIdle = 0, EBusActive = 1

        };

    /**

     * Two-phased constructor.

     */

    static CUsbBusActivityObserver* NewL();

    /**

     * Destructor.

     */

    virtual ~CUsbBusActivityObserver();

    /**

     * Returns bus activity state

     * @return bus activity

     */

    TBusActivity BusActivity();

    /**

     * Adds subscriber for the notification

     * @param aObserver Observer

     */

    /**

     * Removes observer

     * @param aObserver Observer

     */

private:

    // From CActive

    /**

     * Called when request on bus activity completed

     */

    void RunL();

    /**

     * Called by framwork, when canceling outstanding request

     */

    void DoCancel();

    /**

     * Called when RunL leaves

     * @param aError error code

     */

    TInt RunError(TInt aError);

private:

    /**

     * Default constructor

     */

    CUsbBusActivityObserver();

    /**

     * 2nd phase construction

     */

    void ConstructL();

private:

    // data

    /**

     * The observer reports state changes to own observers

     * Owns

     */

    RPointerArray<MUsbBusActivityObserver> iObservers;

    /**

     * The observer observes property change

     */

    RProperty iBusActivity;

    };

#endif //  C_USBOTGSTATEOBSERVER_H