1 /*

     2 * Copyright (c) 2007 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 *  Version     : 2 << Don't touch! Updated by Synergy at check-out.

    16 *

    17 */

    18 

    19 #ifndef MMITEMSDATACACHE_H

    20 #define MMITEMSDATACACHE_H

    21 

    22 #include <e32base.h>

    23 #include <e32cmn.h>

    24 

    25 class CMmCacheForItem;

    26 

    27 /**

    28  * Provides a cache of data needed to draw every item in grid or list view.

    29  * This class is only used by CMmListBoxItemDrawer.

    30  */

    31 NONSHARABLE_CLASS( CMmItemsDataCache ): public CBase

    32     {

    33 public:

    34     /**

    35      * Creates new CMmItemsDataCache object. 

    36      */

    37     static CMmItemsDataCache* NewLC();

    38     

    39     /**

    40      * Creates new CMmItemsDataCache object.

    41      */

    42     static CMmItemsDataCache* NewL();

    43     

    44     /**

    45      * Returns item cache object for an item at specified index.

    46      * 

    47      * @param aItemIndex Item index

    48      * @return Item cache object.

    49      */

    50     CMmCacheForItem* GetItemCacheL( TInt aItemIndex );

    51     

    52     /**

    53      * Gets an integer identifier of a template of given name.

    54      * The identifier is guaranteed to be unique among other

    55      * identifiers obtained from this instance of CMmItemsDataCache

    56      * object.

    57      * Such identifier can be used to perform fast template

    58      * comparisons in the CMmListBoxItemDrawer code.

    59      * @c TMmSubcellsSetupCode code assumes that the template

    60      * identifier will not exceed 255. Assumption will be met unless

    61      * there are more that 256 different templates used in one suite

    62      * which is extremely unlikely.

    63      * 

    64      * @param aTemplateName Name of a template.

    65      * @return Template identifier based on template name.

    66      */

    67     TInt GetTemplateIdentifierL( const TDesC8& aTemplateName );

    68     

    69     /**

    70      * Translates a template identifier obtained from @c GetTemplateIdentifierL

    71      * into a regular string containing template name.

    72      * 

    73      * @param aTemplateIdentifier Template identifier from GetTemplateIdentifierL.

    74      * @return Template name.

    75      */

    76     const TDesC8& GetTemplateNameByIdentifier( TInt aTemplateIdentifier ) const;

    77     

    78     /**

    79      * Marks the whole data in cache as outdated so that

    80      * it cannot possibly be used until it is updated by

    81      * setting up subcells in normal (non-cached) mode.

    82      */

    83     void Invalidate();

    84     

    85     /**

    86      * Reduces the number of cache entries to given number.

    87      * If there are less entries than aItemCount then nothing

    88      * is done.

    89      * 

    90      * @param aItemCount number of items to store cached data for

    91      */

    92     void Trim( TInt aItemCount );

    93     

    94     /**

    95      * Standard C++ virtual destructor. 

    96      */

    97     ~CMmItemsDataCache();

    98 protected:

    99     

   100     /**

   101      * Standard C++ constructor.

   102      */

   103     CMmItemsDataCache();

   104     

   105     /**

   106      * 2nd phase constructor.

   107      */

   108     void ConstructL();

   109 

   110 protected: // data

   111 

   112     /**

   113      * Array of cache objects for individual items.

   114      * Own.

   115      */

   116     RPointerArray<CMmCacheForItem> iItemCacheArr;

   117     

   118     /**

   119      * Array of template names used by @c GetTemplateIdentifierL and

   120      * @c GetTemplateNameByIdentifier methods. Template identifiers

   121      * that @c GetTemplateIdentifierL returns are in fact indices in

   122      * this array.

   123      * Own. Contents of the array owned too.

   124      */

   125     RPointerArray<HBufC8> iTemplateNames;

   126 

   127     };

   128 

   129 #endif // MMITEMSDATACACHE_H