1 /*

     2 * Copyright (c) 2006 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:   Bitmap provider interface.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef C_ALFBITMAPPROVIDER_H

    21 #define C_ALFBITMAPPROVIDER_H

    22 

    23 class CFbsBitmap;

    24 

    25 /** 

    26  * MAlfBitmapProvider is an interface that provides a bitmap and its alpha 

    27  * mask when requested.

    28  * 

    29  * By storing MAlfBitmapProviders in the CAlfTextureManager we can delete and 

    30  * regenerate the textures used by the toolkit as needed - enabling improved 

    31  * use of memory resource, such as when the application goes to background.

    32  * In this case, when we want to restore all the textures, we may just recall 

    33  * the providers to reload the textures. 

    34  *

    35  * Typically, control classes would implement the ProvideBitmapL method of this

    36  * class, which would handle all the loading or generation needed to produce the

    37  * bitmaps stored by the TextureManager.

    38  * 

    39  * A provider should exist as long as the associated texture is stored within

    40  * the texture manager.

    41  */

    42 class MAlfBitmapProvider 

    43     {

    44 public:

    45 

    46     virtual ~MAlfBitmapProvider()

    47         {

    48         }

    49             

    50     /**

    51      * Provide a bitmap and mask from the given UID.

    52      * This method should create a bitmap and its mask, usually by loading it from disk.

    53      *

    54      * @param aId      TextureManager id of this bitmap, may be used for extracting

    55      *                 an icon resource.

    56      * @param aBitmap  Output parameter for the provider: On return, has to store 

    57      *                 a pointer to the generated bitmap. Ownership transferred to caller.

    58      *                 The support for input CFbsBitmap formats varies between 

    59      *                 different renderers. See \ref cfbsbitmapsupport 

    60      *                 Table describing renderer bitmap support.      

    61      * @param aMaskBitmap  

    62      *                 Output parameter for the provider: On return, has to store 

    63      *                 a pointer to the generated alpha mask or <code>NULL</code> 

    64      * 				   if there is no mask. Ownership of the bitmap is transferred 

    65      *                 to the caller.

    66      * 

    67      * @see CAlfTextureManager::CreateTextureL()

    68      */

    69      virtual void ProvideBitmapL(TInt aId, CFbsBitmap*& aBitmap, CFbsBitmap*& aMaskBitmap) = 0;

    70     

    71     };

    72 

    73 

    74 #endif // C_ALFBITMAPPROVIDER_H