--- /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 <e32cmn.h>
+
+#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