PMFlavorStream.h

//========================================================================================
// 
// $File$
// 
// Owner: Dave Burnard
// 
// $Author$
// 
// $DateTime$
// 
// $Revision$
// 
// $Change$
// 
// Copyright 1997-2010 Adobe Systems Incorporated. All rights reserved.
// 
// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance 
// with the terms of the Adobe license agreement accompanying it. If you have received
// this file from a source other than Adobe, then your use, modification, or 
// distribution of it requires the prior written permission of Adobe.
// 
// 
// Provides an accessor class for obtaining and automatically releasing
// Read or Write streams from data exchange data objects.
// 
//========================================================================================

#ifndef __PMFlavorStream__
#define __PMFlavorStream__

#include "IPMDataObject.h"
#include "PMFlavorTypes.h"

class IPMStream;

// -------------------------------------------------------------
// Class PMFlavorStream
// -------------------------------------------------------------
enum eFlavorStreamType {kReadFlavorStream = 0, kWriteFlavorStream = 1};

class PMFlavorStream
{
 public: 
 PMFlavorStream(IPMDataObject* dataObject, ExternalPMFlavor flavor, 
 eFlavorStreamType type = kReadFlavorStream)
 : fDataObject(dataObject), fStream(nil)
 {
 if (type == kReadFlavorStream)
 fStream = fDataObject->GetStreamForReading(flavor);
 else if (type == kWriteFlavorStream)
 fStream = fDataObject->GetStreamForWriting(flavor);
 }
 
 ~PMFlavorStream()
 {
 if (fStream != nil)
 fDataObject->FinishedWithStream(fStream);
 fDataObject = nil;
 fStream = nil;
 }
 
 operator IPMStream*() { return fStream; }
 // We allow the cast operator to return a nil pointer
 // since it is valid to test against nil and may be valid
 // to pass a nil pointer to some methods.
 
 IPMStream* operator ->()
 {
 #ifdef DEBUG
 ASSERT_MSG(fStream != nil,"About to use nil PMFlavorStream!");
 #endif
 return fStream;
 }

 private:
 IPMDataObject* fDataObject;
 IPMStream * fStream;
};

#endif