/*

* Copyright (c) 2006 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:  Active Idle Content Observer optimizer

*

*/

#ifndef C_AIMULTICONTENTOBSERVEROPTIMIZER_H

#define C_AIMULTICONTENTOBSERVEROPTIMIZER_H

#include <e32base.h>

#include "aicontentobserver.h"

/**

 *  @ingroup group_devicestatusplugin

 *

 * Active Idle Content Observer optimizer. 

 * 

 * Optimizes the Commit calls to different UI controllers. In 

 * case nothing is published nothing is committed.

 *

 * @see MAiContentObserver

 * @since S60 3.2

 */

class CAiContentObserverOptimizer : public CBase      

    {

private:

    struct TAiPublishBlackList

        {

        TInt iContentId;

        TInt iIndex;              

        };

public:

    static CAiContentObserverOptimizer* NewL(MAiContentObserver& aObserver);

    ~CAiContentObserverOptimizer();

    /**

     * Starts a transaction

     * 

     * @return KErrAlreadyExists in case transaction already ongoing. 

     *         KErrNotSupported in case transaction not supported

     *         KErrNone in case transaction succesfuly started

     */

    TInt StartTransaction( TInt aTxId );

    /**

     * Commits a started transaction. In case no committing is needed

     * (no publish calls has been made) the transaction is cancelled.

     * 

     * @return KErrNotReady in case no transaction is ongoing.

     *         KErrNotSupported in case transaction not supported

     *         KErrNone in case succesfully committed.

     */         

    TInt Commit( TInt aTxId );

    /**

     * Cancels a transactions in case a transaction was started.

     * 

     * @return KErrNotReady in case no transaction is ongoing.

     *         KErrNotSupported in case transactions are not supported

     *         KErrNone in case transaction succesfully cancelled     

     */

    TInt CancelTransaction( TInt aTxId );

    /*

     * @see MAiContentObserver

     */

    TBool CanPublish( MAiPropertyExtension& aPlugin, TInt aContent, TInt aIndex );

    /**

     * @see MAiContentObserver

     */

    TInt Publish( MAiPropertyExtension& aPlugin, TInt aContent,

                  TInt aResource, TInt aIndex );

    /**

     * @see MAiContentObserver

     */

    TInt Publish( MAiPropertyExtension& aPlugin, TInt aContent,

                  const TDesC16& aText, TInt aIndex );

    /**

     * @see MAiContentObserver

     */

    TInt Publish( MAiPropertyExtension& aPlugin, TInt aContent,

                  const TDesC8& aBuf, TInt aIndex );

    /**

     * @see MAiContentObserver

     */

    TInt Publish( MAiPropertyExtension& aPlugin, TInt aContent,

                  RFile& aFile, TInt aIndex );

    /**

     * @see MAiContentObserver

     */

    TInt Clean( MAiPropertyExtension& aPlugin, TInt aContent, TInt aIndex );

    /**

     * Returns the actual content observer.

     */

    MAiContentObserver& Observer() const;

private:

    CAiContentObserverOptimizer(MAiContentObserver& aObserver);

    TInt AddToBlackList( TInt aContentId, TInt aIndex );

    TBool IsInBlackList( TInt aContentId, TInt aIndex ) const;

private: // data

    /**

     * Handle to the observer that receives

     * the publish calls.

     */

    MAiContentObserver &iObserver;

    TBool iCommitNeeded;

    TBool iTransactionStarted;

    RArray<TAiPublishBlackList> iBlackList;

    };

#endif // C_AIMULTICONTENTOBSERVEROPTIMIZER_H