diff -r 000000000000 -r ba25891c3a9e ncdengine/inc/ncdnodepreview.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ncdengine/inc/ncdnodepreview.h Thu Dec 17 08:51:10 2009 +0200 @@ -0,0 +1,150 @@ +/* +* 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: Contains MNcdNodePreview +* +*/ + + +#ifndef M_NCD_NODE_PREVIEW_H +#define M_NCD_NODE_PREVIEW_H + + +#include + +#include "catalogsbase.h" +#include "ncdinterfaceids.h" + + +class MNcdDownloadOperation; +class MNcdDownloadOperationObserver; +class RFile; + +/** + * This interface is provided if the node contains preview content. + * One node may contain multiple preview items. + * + * + */ +class MNcdNodePreview : public virtual MCatalogsBase + { + +public: + + /** + * Unique identifier for the interface, required for all MCatalogsBase interfaces. + * + * + */ + enum { KInterfaceUid = ENcdNodePreviewUid }; + + + /** + * Gives the number of previews of the node. + * + * @note This count is given according to the protocol information + * that informs how many previews are available. So, the information + * can be asked before calling LoadPreviewL. But, to get the + * data of the wanted preview, LoadPreviewL has to be called. + * + * @return The number of preview items. + */ + virtual TInt PreviewCount() const = 0; + + + /** + * IsPreviewLoadedL informs if the preview has already been loaded for the + * node. Then, call of LoadPreviewL is not necessary. + * + * @param aIndex tells which one of the previews is wanted. + * @return ETrue if the preview has already been loaded, EFalse otherwise. + * @exception Panic ENcdPanicIndexOutOfRange Array index out of range. + */ + virtual TBool IsPreviewLoadedL( TInt aIndex ) const = 0; + + + /** + * Gives the mime type of the preview data. + * + * This mime type is set according to the information gotten + * from the protocol if any. So, this information is available before + * calling LoadPreviewL for the preview item of the given index. + * + * @note If the mime type is not received in protocol responses, it is + * taken from Content-Type HTTP header after the preview has been downloaded + * successfully + * + * @param aIndex tells which one of the previews is wanted. + * @return The mime type of the preview data. The type is + * given as a text according to the standards that define MIME types. + * Ownership is transferred. If the protocol has not defined + * any value, KNullDesC is returned. + * @exception Panic ENcdPanicIndexOutOfRange Array index out of range. + */ + virtual const TDesC& PreviewMimeType( TInt aIndex ) const = 0; + + + /** + * Loads the preview data from the internet. + * + * @note The reference count of the operation object is increased by one. + * So, Release() function of the operation should be called when operation + * is not needed anymore. + * + * @param aIndex tells which one of the previews is wanted. + * @param aObserver Observer for the operation. + * @return Pointer to an operation object that handles + * the preview data downloading. This operation can be used + * to check the progressing of the preview download. Counted, Release() must + * be called after use. + * @exception Leave System wide error codes. + * KNcdErrorParallelOperationNotAllowed if a parallel client is running + * an operation for the same metadata. See MNcdOperation for full explanation. + * @exception Panic ENcdPanicIndexOutOfRange Array index out of range. + */ + virtual MNcdDownloadOperation* LoadPreviewL( TInt aIndex, + MNcdDownloadOperationObserver* aObserver ) = 0; + + + /** + * Gives the preview data file. + * + * @note RFile handle can be used to get the unifying id for example + * using RFile::FullName. + * @note The MIME type of the preview may be found automatically + * from the preview data by Symbian methods. + * + * @param aIndex tells which one of the previews is wanted. + * @return Handle to a file containing the preview data. Ownership is transferred. + * So, the user has to call Close when the file is not needed anymore. + * @exception KErrNotFound if the corresponding preview data + * has not been downloaded for the specified preview item. + * @exception Leave System wide error codes. + * @exception Panic ENcdPanicIndexOutOfRange Array index out of range. + */ + virtual RFile PreviewFileL( TInt aIndex ) const = 0; + + +protected: + + /** + * Destructor. + * + * @see MCatalogsBase::~MCatalogsBase() + */ + virtual ~MNcdNodePreview() {} + + }; + + +#endif // M_NCD_NODE_PREVIEW_H