widget/nsTransferable.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsTransferable_h__
   7 #define nsTransferable_h__
   8
   9 #include "nsIFormatConverter.h"
  10 #include "nsITransferable.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsString.h"
  13 #include "nsTArray.h"
  14 #include "nsWeakPtr.h"
  15
  16 class nsString;
  17 class nsDataObj;
  18
  19 //
  20 // DataStruct
  21 //
  22 // Holds a flavor (a mime type) that describes the data and the associated data.
  23 //
  24 struct DataStruct
  25 {
  26   explicit DataStruct ( const char* aFlavor )
  27     : mDataLen(0), mFlavor(aFlavor), mCacheFileName(nullptr) { }
  28   ~DataStruct();
  29
  30   const nsCString& GetFlavor() const { return mFlavor; }
  31   void SetData( nsISupports* inData, uint32_t inDataLen );
  32   void GetData( nsISupports** outData, uint32_t *outDataLen );
  33   already_AddRefed<nsIFile> GetFileSpec(const char* aFileName);
  34   bool IsDataAvailable() const { return (mData && mDataLen > 0) || (!mData && mCacheFileName); }
  35
  36 protected:
  37
  38   enum {
  39     // The size of data over which we write the data to disk rather than
  40     // keep it around in memory.
  41     kLargeDatasetSize = 1000000        // 1 million bytes
  42   };
  43
  44   nsresult WriteCache(nsISupports* aData, uint32_t aDataLen );
  45   nsresult ReadCache(nsISupports** aData, uint32_t* aDataLen );
  46
  47   nsCOMPtr<nsISupports> mData;   // OWNER - some varient of primitive wrapper
  48   uint32_t mDataLen;
  49   const nsCString mFlavor;
  50   char *   mCacheFileName;
  51
  52 };
  53
  54 /**
  55  * XP Transferable wrapper
  56  */
  57
  58 class nsTransferable : public nsITransferable
  59 {
  60 public:
  61
  62   nsTransferable();
  63
  64     // nsISupports
  65   NS_DECL_ISUPPORTS
  66   NS_DECL_NSITRANSFERABLE
  67
  68 protected:
  69   virtual ~nsTransferable();
  70
  71     // get flavors w/out converter
  72   nsresult GetTransferDataFlavors(nsISupportsArray** aDataFlavorList);
  73
  74   nsTArray<DataStruct> mDataArray;
  75   nsCOMPtr<nsIFormatConverter> mFormatConv;
  76   bool mPrivateData;
  77   nsWeakPtr mRequestingNode;
  78 #if DEBUG
  79   bool mInitialized;
  80 #endif
  81
  82 };
  83
  84 #endif // nsTransferable_h__