/*

* 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:   Bitmap provider interface.

*

*/

#ifndef C_ALFBITMAPPROVIDER_H

#define C_ALFBITMAPPROVIDER_H

class CFbsBitmap;

/** 

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

 * mask when requested.

 * 

 * By storing MAlfBitmapProviders in the CAlfTextureManager we can delete and 

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

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

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

 * the providers to reload the textures. 

 *

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

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

 * bitmaps stored by the TextureManager.

 * 

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

 * the texture manager.

 */

class MAlfBitmapProvider 

    {

public:

    virtual ~MAlfBitmapProvider()

        {

        }

    /**

     * Provide a bitmap and mask from the given UID.

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

     *

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

     *                 an icon resource.

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

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

     *                 The support for input CFbsBitmap formats varies between 

     *                 different renderers. See \ref cfbsbitmapsupport 

     *                 Table describing renderer bitmap support.      

     * @param aMaskBitmap  

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

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

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

     *                 to the caller.

     * 

     * @see CAlfTextureManager::CreateTextureL()

     */

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

    };

#endif // C_ALFBITMAPPROVIDER_H