1 /*

     2 * Copyright (c) 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 #ifndef HGSCROLLBUFFERMANAGER_H_

    20 #define HGSCROLLBUFFERMANAGER_H_

    21 

    22 #include <e32base.h>

    23 class MHgScrollBufferObserver;

    24 class MHgBufferOwner;

    25 

    26 NONSHARABLE_CLASS( CHgScrollBufferManager ) : public CActive

    27     {

    28 public:

    29 

    30     static CHgScrollBufferManager* NewL( 

    31             MHgScrollBufferObserver& aObserver, 

    32             TInt aBufferSize,

    33             TInt aBufferTreshold,

    34             TInt aInitialPosition,

    35             TInt aTotalCount );

    36     

    37     virtual ~CHgScrollBufferManager();

    38     

    39 protected: // From CActive

    40 

    41     void RunL();

    42     void DoCancel();

    43     TInt RunError( TInt aError );

    44 

    45 public:

    46     void SetPosition( TInt aIndex );

    47 

    48     void ItemCountChanged( TInt aIndex, TBool aRemoved, TInt aNewTotalCount );

    49     

    50     void SetTotalCount( TInt aTotalCount );

    51     

    52     void SetBufferOwner( MHgBufferOwner& aOwner );

    53     

    54     void ResetBuffer( TInt aPosition, TInt aTotalCount);

    55 

    56 protected:

    57     CHgScrollBufferManager(

    58             MHgScrollBufferObserver& aObserver, 

    59             TInt aBufferSize,

    60             TInt aBufferTreshold,

    61             TInt aInitialPosition,

    62             TInt aTotalCount );

    63     

    64     void ConstructL();

    65 

    66 private:

    67     void NotifyObserver();

    68     

    69 private:

    70     MHgScrollBufferObserver& iObserver; 

    71     MHgBufferOwner* iOwner;

    72     

    73     TInt iBufferSize;

    74     TInt iBufferTreshold;

    75     TInt iBufferPosition;

    76     TInt iDiff;

    77     TInt iTotalCount;

    78     

    79     TBool iResetOrdered;

    80     

    81     TInt iRequestStart;

    82     TInt iRequestCount;

    83     TInt iReleaseStart;

    84     TInt iReleaseCount;

    85     };

    86 

    87 #endif /*HGSCROLLBUFFERMANAGER_H_*/