/*

* Copyright (c) 2006-2007 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 thumbnail server tasks

 *

*/

#ifndef THUMBNAILTASK_H

#define THUMBNAILTASK_H

#include "thumbnailmanager.h"    // TThumbnailRequestId

#include "thumbnailmanagerconstants.h" // TThumbnailServerRequestId

class CThumbnailTaskProcessor;

class CThumbnailServerSession;

/**

 *  Base class for thumbnail server tasks.

 *

 *  @since S60 v5.0

 */

class CThumbnailTask: public CActive

    {

public:

    /**

     * Task state.

     * @since S60 v5.0

     */

    enum TTaskState

        {

        /**

         * This task is waiting to be run.

         */

        EIdle, 

        /**

         * This task is currently running.

         */

        ERunning, 

        /**

         * This task has completed and can be destroyed.

         */

        EComplete

    };

public:

    /**

     * C++ default constructor

     *

     * @since S60 v5.0

     * @param aProcessor Processor object for running tasks.

     * @param aPriority Priority of the task.

     * @return New CThumbnailTask instance.

     */

    CThumbnailTask( CThumbnailTaskProcessor& aProcessor, TInt aPriority );

    /**

     * Destructor

     *

     * @since S60 v5.0

     */

    virtual ~CThumbnailTask();

public:

    /**

     * Returns priority of task.

     *

     * @since S60 v5.0

     * @return Priority of the task.

     */

    TInt Priority()const;

    /**

     * Returns state of task.

     *

     * @since S60 v5.0

     * @return State.

     */

    TTaskState State()const;

    /**

     * SetMessageData

     *

     * @since S60 v5.0

     * @param aRequestId Request ID.

     * @param aMessage Message.

     * @param aClientThread Client thread.

     */

    virtual void SetMessageData( const TThumbnailServerRequestId& aRequestId,

        const RMessage2& aMessage, const RThread& aClientThread );

    /**

     * SetMessageData if message is not needed to complete

     *

     * @since S60 v5.0

     * @param aRequestId Request ID.

     */

     virtual void SetMessageData( const TThumbnailServerRequestId& aRequestId );

    /**

     * Resets message data.

     *

     * @since S60 v5.0

     */

    virtual void ResetMessageData();

    /**

     * Cancels message.

     *

     * @since S60 v5.0

     */

    virtual void CancelMessage();

    /**

     * Returns ID of specific task.

     *

     * @since S60 v5.0

     * @return Request ID.

     */

    virtual TThumbnailServerRequestId RequestId()const;

    /**

     * Changes priority of the task.

     *

     * @since S60 v5.0

     * @param aNewPriority New priority.

     */

    virtual void ChangeTaskPriority( TInt aNewPriority );

    /**

     * StartL

     *

     * @since S60 v5.0

     */

    virtual void StartL();

    /**

     * Implements cancellation of an outstanding request.

     *

     * @since S60 v5.0

     */

    virtual void DoCancel();    

    /**

     * StartError

     *

     * @since S60 v5.0

     * @param aError Error code.

     */

    virtual void StartError( TInt aError );

    /**

     * Complete

     *

     * @since S60 v5.0

     * @param aReason Status code.

     */

    virtual void Complete( TInt aReason );

    /**

     * Continue without deleting task

     *

     * @since S60 v5.0

     */

    virtual void Continue();

    /**

     * Checks if client thread is still alive and RMessage2 handle valid.

     *

     * @since S60 v5.0

     * @param aGetThread Need to get thread first.

     */

    TBool ClientThreadAlive(const TBool aGetThread = EFalse);    

    inline RMessage2& GetMessageData()

        {

        return iMessage;

        }

protected:

    // data

    /**

     * Processor.

     */

    CThumbnailTaskProcessor& iProcessor;

    /**

     * Priority of the task.

     */

    TInt iPriority;

    /**

     * State of the task.

     */

    TTaskState iState;

    /**

     * Id of the request.

     */

    TThumbnailServerRequestId iRequestId;

    /**

     * Message.

     */

    RMessage2 iMessage;

    // client thread from RMessage2

    RThread iClientThread;

};

#endif // THUMBNAILTASK_H