diff -r 000000000000 -r 05e9090e2422 uiresources_pub/skins_api/inc/AknsDataContext.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/uiresources_pub/skins_api/inc/AknsDataContext.h Thu Dec 17 09:14:12 2009 +0200 @@ -0,0 +1,138 @@ +/* +* Copyright (c) 2002 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: Defines a public interface class MAknsDataContext. +* +*/ + + +#ifndef AKNSDATACONTEXT_H +#define AKNSDATACONTEXT_H + +// INCLUDES +#include +#include +#include + +// CLASS DECLARATION + +/** +* Interface that provides context sensitive control over data allocation. +* MAknsDataContext can be used to indicate need for specific skin items +* and thus to ensure that they are allocated before first use. +* +* This is a public class with exported functions. +* The class is not usually intended for user derivation - concrete classes +* implementing the interface are provided by the library. +* See @c AknsUtils::CreateDataContextForContainerL() for further +* details. +* +* @lib AknSkins.lib +* +* @since 2.0 +*/ +class MAknsDataContext + { + public: // Type UID + /** + * Type ID declaration. + * Type ID is used to make it possible to retrieve data context + * through @c MObjectProvider::MopSupplyObject interface. + */ + DECLARE_TYPE_ID(0x10005a28) + + public: // Constructors and destructor + + /** + * Destructor. + * Destructor is only provided to enable deletion using base class + * pointer. Caller should never delete context retrieved using + * @c MObjectProvider interface. + */ + inline virtual ~MAknsDataContext() {} + + public: // New functions + + /** + * Reserves and allocates specified item. + * Instructs the data context that the specified item will be used + * by caller and should be allocated and cached by skin instance. + * Any control using cached skin items should reserve them, preferably + * in @c ConstructL(), by calling this method. + * Note that reservation does not guarantee that the item will be + * available in cache - it's only a tentative request for allocation. + * + * @since 2.0 + * + * @param aID Item ID of the item to be reserved. + * + * @par Exceptions: + * If item data allocation fails, function leaves with error code. + */ + virtual void ReserveItemL( const TAknsItemID& aID ) =0; + + /** + * Indicates that specified item will no longer be used. + * Instructs the data context that the specified item will not + * be used by caller anymore. Exact behavior (e.g. whether cached + * instance is deallocated) depends on the cache policy of data + * context and skin instance. Controls should not usually call this + * method, but instead allow data context (in most cases implemented + * by a container) go out of scope. + * + * @since 2.0 + * + * @param aID Item ID of the item to be released. + */ + virtual void ReleaseItem( const TAknsItemID& aID ) =0; + + protected: // Reserved virtual functions + + /** + * Reserved for future use. + * + * @since 2.0 + */ + virtual TInt Reserved1(); + + /** + * Reserved for future use. + * + * @since 2.0 + */ + virtual TInt Reserved2(); + + public: // New functions + + /** + * Returns type UID pointer that can be used in MopSupplyObject. + * + * @since 2.0 + * + * @param aId Type UID, should be the same that was given as aId + * parameter of MopSupplyObject. + * + * @param aContext Pointer to an MAknsDataContext instance. + * + * @return Type UID pointer containing aContext, or @c NULL type UID + * pointer if given type UID does not match MAknsDataContext or + * aContext is @c NULL. + */ + IMPORT_C static TTypeUid::Ptr SupplyMopObject( TTypeUid aId, + MAknsDataContext* aContext ); + + }; + +#endif // AKNSDATACONTEXT_H + +// End of File