diff -r deec7e509f66 -r ca9a0fc2f082 contentmgmt/contentaccessfwfordrm/engineering/dox/NavigatingArchiveFiles.dox --- a/contentmgmt/contentaccessfwfordrm/engineering/dox/NavigatingArchiveFiles.dox Wed Oct 06 11:09:48 2010 +0530 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,102 +0,0 @@ -// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). -// All rights reserved. -// This component and the accompanying materials are made available -// under the terms of the License "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: -// An application can explore the content objects inside a file using the ContentAccess::CContent class. -//
-// The Content Access Framework provides a generic mechanism for exploring files that contain multiple -// content objects. These files are often referred to as archive files. This could -// be anything from a .ZIP compression archive to a DRM protected archive such as an OMA .DCF file. -// Inside an archive file, and in addition to the content objects, there will be meta-data or information -// associated with the content. This meta-data could include information such as the MIME type of the content, -// encryption algorithm, compressed size of the content etc.. This information can be retrieved from the attributes -// The content and meta-data may also be arranged in a heirachy with container objects grouping -// content objects together. A typical archive could have a complex structure like the example shown below: -// In this situation the file itself can be considered as the top level container. All other content, containers and -// meta-data are nested inside. -// In an archive file applications can quickly search for the content objects they are interested in by using -// ContentAccess::CContent::Search(). -//
-// Archive files containing several content objects cannot be referred to using just the URI of the file. The Content Access -// Framework uses a concept of virtual paths to identify content objects within a file. The virtual path is a combination -// of the file URI and a unique identifier supplied by the agent: -// A content file is only ever handled by the agent that recognises it. The unique identifier will never need to be -// decoded by anyone other that the agent that generated it, so the format is left for the agent to implement as it sees -// fit. For instance an OMA DRM agent may put the Content ID (CID) in the \c UniqueId field. -// The only constraint is that the \c UniqueId must be unique within the file. An application must be able to directly -// reference a content object just using the UniqueId. -//
-// Virtual Path pointer objects on the Stack -// The ContentAccess::TVirtualPathPtr is used to point to two descriptors holding the URI -// of a file and the UniqueId of a content object within the file. It can also be used to -// point to another TVirtualPathPtr. Since it is only a pointer, the original descriptors -// used to initalise the TVirtualPathPtr should not be destroyed or modified while the -// TVirtualPathPtr is still in use. -// Virtual Path objects on the heap -// The ContentAccess::CVirtualPath class stores the file URI and content object UniqueId in its own -// descriptors. There is a cast operator that allows the CVirtualPath to be used as -// if it were a TVirtualPathPtr. -// Examples -// // Open a CContent object to browse the objects inside a file -// CContent *c = CContent::NewL(_L("C:\file.dcf")); -// CleanupStack::PushL(c); -// // Create an array to store the embedded objects -// RStreamablePtrArray myArray; -// CleanupClosePushL(myArray); -// // Get an array of the embedded objects within the current container in the file -// c->GetEmbeddedObjectsL(myArray); -// // If necessary we can get a "mangled" version of the URI that -// // references the particular object within the file -// // ie. "C:\file.dcf\\OBJECT1" -// TPtrC aURI = *myArray[0]; -// // Now we can use our TPtrC later to create a TVirtualPath object from a URI -// TVirtualPathPtr aPtr = aURI; -// // print the file URI "C:\file.dcf" -// printf(aPtr.URI()); -// // print the content object's UniqueId "OBJECT1" -// printf(aPtr.UniqueId()); -// // Create a copy of aVirtualPath on the heap so we don't have any ownership problems -// CVirtualPath *myVirtualpath = CVirtualPath::NewL(aPtr); -// // Can now delete the CContent object without loosing our VirtualPath -// CleanupStack::PopAndDestroy(2); // c, myArray -//
-// KNullDesC16() - "" -// A zero length \c UniqueId is used to refer to the entire file. If a file is opened this way no translation of the contents will be -// performed. The ability to open the file with no translation is required for example to attach the file to an outgoing message. -// As with any other function in CAF access to the file is at the agents discretion. -// KDefaultContentObject() - "DEFAULT" -// Allows an application to refer to the default content object within a file. In the case of an unprotected file handled -// by the \c F32Agent this will be the entire file, the same as if the UniqueId "" was used. Other agents, particularly those -// with a single content object embedded within the file, use "DEFAULT" to refer to their only content object. -// Even though the DEFAULT content object is supported, it is recommended that agents always use \c CContent to enumerate the -// objects within the file. -//
-// -// - -/** - @page FileOverview Files containing multiple content objects - - @ref FileOverviewDescription - - @ref VirtualPaths - - @ref VirtualPathObjects - - @ref SpecialUniqueIds - @section FileOverviewDescription Structure of a file containing multiple content objects - related to a content object, see @ref ContentAttributes "Content Object Attributes". - @image html "multiple DRM file2.gif" - @section VirtualPaths Identifying a content object within a File - @li \c URI - The location of the file - @li \c UniqueId - The content object inside the file. - @section VirtualPathObjects Objects used to identify a content object within a File - @code - @endcode - @section SpecialUniqueIds Special Cases for the UniqueId field -*/