1 /**

     2 * Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef CACTIVELOOP_H

    21 #define CACTIVELOOP_H

    22 

    23 #include <e32base.h>

    24 

    25 class MActiveLoopCallBack 

    26 	{

    27 public:

    28 	virtual TBool DoStepL() = 0;

    29 	virtual void  DoError(TInt aError) = 0;

    30 	};

    31 

    32 

    33 /**

    34 CActiveLoop class should be used in the server for all long-running operations.

    35 Since the server is single threaded any long running operation will effectively

    36 block the server for all other clients. In order to avoid it, the long running

    37 operations should be done with incremental steps. Each step should be called

    38 from the active object and controll should be passed to the active scheduler

    39 afterwards. 

    40 CActiveLoop is based on CTimer in order to give the Server active object

    41 priority on the loop operations. It is particularly necessary for Cancel of

    42 asynchronous operation use case, where ServiceL must be called between the

    43 steps of an incremental operation.

    44 */

    45 class CActiveLoop : public CTimer

    46 	{

    47 public:

    48 	void 	Register(MActiveLoopCallBack & aCallBack, TBool aUseTimer = EFalse);

    49 	void 	RunL();

    50 	static 	CActiveLoop* NewL();

    51 	void 	DoCancel();

    52 		   ~CActiveLoop();

    53 	TInt 	RunError(TInt aError);	  

    54 	

    55 private:

    56 	CActiveLoop();

    57 	

    58 private:	

    59 	MActiveLoopCallBack* iCallBack;

    60 	}; 

    61 

    62 

    63 #endif