--- /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 <AknsConstants.h>
+#include <AknsItemID.h>
+#include <coemop.h>
+
+// 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