gecko/widget/xpwidgets/nsTransferable.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsTransferable_h__
#define nsTransferable_h__

#include "nsIFormatConverter.h"
#include "nsITransferable.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsTArray.h"

class nsString;
class nsDataObj;

//
// DataStruct
//
// Holds a flavor (a mime type) that describes the data and the associated data.
//
struct DataStruct
{
  DataStruct ( const char* aFlavor )
    : mDataLen(0), mFlavor(aFlavor), mCacheFileName(nsnull) { }
  ~DataStruct();
  
  const nsCString& GetFlavor() const { return mFlavor; }
  void SetData( nsISupports* inData, PRUint32 inDataLen );
  void GetData( nsISupports** outData, PRUint32 *outDataLen );
  nsIFile * GetFileSpec(const char * aFileName);
  bool IsDataAvailable() const { return (mData && mDataLen > 0) || (!mData && mCacheFileName); }
  
protected:

  enum {
    // The size of data over which we write the data to disk rather than
    // keep it around in memory.
    kLargeDatasetSize = 1000000        // 1 million bytes
  };
  
  nsresult WriteCache(nsISupports* aData, PRUint32 aDataLen );
  nsresult ReadCache(nsISupports** aData, PRUint32* aDataLen );
  
  nsCOMPtr<nsISupports> mData;   // OWNER - some varient of primitive wrapper
  PRUint32 mDataLen;
  const nsCString mFlavor;
  char *   mCacheFileName;

};

/**
 * XP Transferable wrapper
 */

class nsTransferable : public nsITransferable
{
public:

  nsTransferable();
  virtual ~nsTransferable();

    // nsISupports
  NS_DECL_ISUPPORTS
  NS_DECL_NSITRANSFERABLE

protected:

    // get flavors w/out converter
  nsresult GetTransferDataFlavors(nsISupportsArray** aDataFlavorList);
 
  nsTArray<DataStruct> mDataArray;
  nsCOMPtr<nsIFormatConverter> mFormatConv;

};

#endif // nsTransferable_h__