/*

* 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:    

*

*/

#ifndef C_TURNASYNCCALLBACK_H

#define C_TURNASYNCCALLBACK_H

// INCLUDES

#include <e32base.h>

#include "tturnplugincallbackinfo.h"

// FORWARD DECLARATIONS

class MNATFWPluginObserver;

// CLASS DECLARATION

/**

 * CTurnAsyncCallback is an active object used to guarantee that when the

 * function calls to the MNATFWPluginObserver are made, the upper layer

 * can delete any TURN Plug-in related object it owns.

 */

class CTurnAsyncCallback : public CActive

    {

    friend class UT_CNATFWTurnConnectionHandler;

public: // Constructor and destructor

    /**

     * Two-phased constructor.

     * @param aTurnPlugin The TURN Plug-in instance

     * @param aObserver Observer implementing the callback functions

     */

    static CTurnAsyncCallback* NewL(

        const CNATFWPluginApi& aTurnPlugin,

        MNATFWPluginObserver& aObserver );

    /**

     * Frees the resources of CTurnAsyncCallback. Any issued callback

     * request that have not yet been executed, are discarded.

     *

     * @since   S60 3.2

     */

    ~CTurnAsyncCallback();

public: // New functions

    /**

     * Orders a specified callback function to be called, and provides all

     * necessary parameters.

     *

     * @since   S60 3.2

     * @param   aFunction Identifies the function of MNATFWPluginObserver

     *          to use

     * @param   aStreamId   Stream ID

     * @param   aErrorCode  Error reason

     * @param   aEventData  Event data

     */

    void MakeCallbackL( TTurnPluginCallbackInfo::TFunction aFunction,

                        TUint aStreamId,

                        TInt aErrorCode,

                        TAny* aEventData );

    /**

     * Removes all pending callbacks, which have the specified stream ID

     * as a parameter.

     *

     * @since   S60 3.2

     * @param   aStreamId   Stream ID

     */

    void CancelCallback( TUint aStreamId );

protected: // From CActive

    /**

     * from CActive

     */

    void DoCancel();

    /**

     * from CActive

     */

    void RunL();

    /**

     * from CActive

     */

    TInt RunError( TInt aError );

private: // Constructors

    CTurnAsyncCallback();

    CTurnAsyncCallback( const CNATFWPluginApi& aTurnPlugin,

        MNATFWPluginObserver& aObserver );

    CTurnAsyncCallback( const CTurnAsyncCallback& aAsyncCallback );

private: // New functions, for internal use

    /**

     * Starts waiting for MakeCallbackL events.

     *

     * @since   S60 3.2

     */

    void WaitForRequestsL();

    /**

     * Wakes system up.

     *

     * @since   S60 3.2

     */

    void Wakeup();

    /**

     * Calls the oldest callback entry, if any.

     *

     * @since   S60 3.2

     */

    void ExecuteFirstCallback();

private: // Data

    /**

     * TURN Plug-in instance

     */

    const CNATFWPluginApi& iTurnPlugin;

    /**

     * Implements the callback functions

     */

    MNATFWPluginObserver& iObserver;

    /**

     * Callback requests that have not yet been executed

     */

    TSglQue<TTurnPluginCallbackInfo> iPendingCallbacks;

    };

#endif // C_TURNASYNCCALLBACK_H