/*

* Copyright (c) 2002-2005 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:  This is encapsulation of a background task,

*                part of CCARequestMapper

*

*/

#ifndef CCABACKGROUNDTASK_H

#define CCABACKGROUNDTASK_H

// INCLUDES

#include "MCABackgroundInterface.h"

#include <e32base.h>

// FORWARD DECLARATIONS

// CLASS DECLARATION

class MCABackgroundCallback;

/**

*  Encapsulates a background task. This is a part of CCARequestMapper.

*

*

*  @lib CAEngine.lib

*  @since 1.2

*/

class CCABackgroundTask : public CBase

    {

    public:  // Constructors and destructor

        /**

        * Static constructor.

        * @param aParent instance to call back with CIdle

        * @param aBackgroundTask background task to encapsulate

        * @param aTask id of the background task

        * @param aSubTasks number of iterations - greater than zero

        *	it leaves with KErrArgument if aSubTasks <= 0

        * @see MCABackgroundInterface::TCABackgroundTasks

        */

        static CCABackgroundTask* NewL(

            MCABackgroundCallback* aParent

            , MCABackgroundTask* aBackgroundTask

            , MCABackgroundInterface::TCABackgroundTasks aTask

            , TInt aSubTasks

        );

        /**

        * Static constructor.

        * @param aParent instance to call back with CIdle

        * @param aBackgroundTask background task to encapsulate

        * @param aTask id of the background task

        * @param aSubTasks number of iterations - greater than zero

        *	it leaves with KErrArgument if aSubTasks <= 0

        * @see MCABackgroundInterface::TCABackgroundTasks

        */

        static CCABackgroundTask* NewLC(

            MCABackgroundCallback* aParent

            , MCABackgroundTask* aBackgroundTask

            , MCABackgroundInterface::TCABackgroundTasks aTask

            , TInt aSubTasks

        );

        /**

        * Destructor.

        */

        virtual ~CCABackgroundTask();

    public: // New functions

        /**

        * Starts background execution ( CIdle ).

        */

        void Start();

        /**

        * Cancels background execution ( CIdle ).

        */

        void Cancel();

        /**

        * Identity relation for RArray Find(...)

        * @param aA for comparison

        * @param aB for comparison

        * @return ETrue if task ids are the same, EFalse otherwise

        */

        static TBool Identity( const CCABackgroundTask& aA

                               , const CCABackgroundTask& aB

                             );

        /**

        * @return the number of subtask/iteration left

        */

        TInt SubTasks();

        /**

        * @return the last execution state

        * @see MCABackgroundInterface::TCABackgroundStatus

        */

        MCABackgroundInterface::TCABackgroundStatus TaskState();

        /**

        * Sets State of this background task

        * @param aTaskState new state to set

        * @see MCABackgroundInterface::TCABackgroundStatus

        */

        void SetTaskState(

            MCABackgroundInterface::TCABackgroundStatus aTaskState );

        /**

        * Is more iteration left.

        * It detracts number of iterations by 1

        * @return ETrue if there is any after detraction( SubTasks() >0 ),

        */

        TBool More();

        /**

        * @return id of the background task

        * @see MCABackgroundInterface::TCABackgroundTasks

        */

        MCABackgroundInterface::TCABackgroundTasks TaskId();

        /**

        * @return pointer to the background task

        * no ownership transfer

        */

        MCABackgroundTask* BackgroundTask();

        /**

        * Executes background task.

        */

        void ExecuteTaskL();

        /**

        * @return ETrue if this task is active.

        */

        TBool Pending();

    private:

        /**

        * C++ default constructor.

        * @param aParent instance to call back with CIdle

        * @param aBackgroundTask background task to encapsulate

        * @param aTask id if the background task

        * @param aSubTasks number of iterations - greater than zero

        *	it leaves with KErrArgument if aSubTasks <= 0

        * @see MCABackgroundInterface::TCABackgroundTasks

        */

        CCABackgroundTask(

            MCABackgroundCallback* aParent

            , MCABackgroundTask* aBackgroundTask

            , MCABackgroundInterface::TCABackgroundTasks aTask

            , TInt aSubTasks

        );

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        /**

        * CIdle-kind of function for background task implementation

        * @param aInstance Instance of this class

        * @return Need for recall

        */

        static TInt BackgroundTask( TAny *aInstance );

        /**

        * Called by BackgroundTask().

        * Its calling instace given as aParent with aTask on construction.

        */

        TInt DoBackgroundTask();

    private:    // Data

        // Doesn't own

        MCABackgroundCallback* iParent;

        MCABackgroundTask* iBackgroundTask;

        //do own

        MCABackgroundInterface::TCABackgroundTasks iTask;

        TInt iSubTasks;

        MCABackgroundInterface::TCABackgroundStatus iTaskState;

        //Owns

        CIdle* iIdle;

    };

#endif      // CCABACKGROUNDTASK_H

// End of File