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 "nsIPrincipal.h"
  15 #include "prio.h"
  16 #include "mozilla/Maybe.h"
  17
  18 class nsIMutableArray;
  19
  20 //
  21 // DataStruct
  22 //
  23 // Holds a flavor (a mime type) that describes the data and the associated data.
  24 //
  25 struct DataStruct {
  26   explicit DataStruct(const char* aFlavor)
  27       : mCacheFD(nullptr), mFlavor(aFlavor) {}
  28   DataStruct(DataStruct&& aRHS);
  29   ~DataStruct();
  30
  31   const nsCString& GetFlavor() const { return mFlavor; }
  32   void SetData(nsISupports* aData, bool aIsPrivateData);
  33   void GetData(nsISupports** aData);
  34   bool IsDataAvailable() const { return mData || mCacheFD; }
  35
  36  protected:
  37   enum {
  38     // The size of data over which we write the data to disk rather than
  39     // keep it around in memory.
  40     kLargeDatasetSize = 1000000  // 1 million bytes
  41   };
  42
  43   nsresult WriteCache(void* aData, uint32_t aDataLen);
  44   nsresult ReadCache(nsISupports** aData);
  45
  46   // mData OR mCacheFD should be used, not both.
  47   nsCOMPtr<nsISupports> mData;  // OWNER - some varient of primitive wrapper
  48   PRFileDesc* mCacheFD;
  49   const nsCString mFlavor;
  50
  51  private:
  52   DataStruct(const DataStruct&) = delete;
  53   DataStruct& operator=(const DataStruct&) = delete;
  54 };
  55
  56 /**
  57  * XP Transferable wrapper
  58  */
  59
  60 class nsTransferable : public nsITransferable {
  61  public:
  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   void GetTransferDataFlavors(nsTArray<nsCString>& aFlavors);
  73
  74   // Find index for data with the matching flavor in mDataArray.
  75   mozilla::Maybe<size_t> FindDataFlavor(const char* aFlavor);
  76
  77   nsTArray<DataStruct> mDataArray;
  78   nsCOMPtr<nsIFormatConverter> mFormatConv;
  79   bool mPrivateData;
  80   nsCOMPtr<nsIPrincipal> mRequestingPrincipal;
  81   nsContentPolicyType mContentPolicyType;
  82 #if DEBUG
  83   bool mInitialized;
  84 #endif
  85 };
  86
  87 #endif  // nsTransferable_h__