dom/encoding/TextDecoder.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 file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_dom_textdecoder_h_
   7 #define mozilla_dom_textdecoder_h_
   8
   9 #include "mozilla/dom/NonRefcountedDOMObject.h"
  10 #include "mozilla/dom/TextDecoderBinding.h"
  11 #include "mozilla/dom/TypedArray.h"
  12 #include "nsIUnicodeDecoder.h"
  13
  14 namespace mozilla {
  15
  16 class ErrorResult;
  17
  18 namespace dom {
  19
  20 class ArrayBufferViewOrArrayBuffer;
  21
  22 class TextDecoder MOZ_FINAL
  23   : public NonRefcountedDOMObject
  24 {
  25 public:
  26   // The WebIDL constructor.
  27   static TextDecoder*
  28   Constructor(const GlobalObject& aGlobal,
  29               const nsAString& aEncoding,
  30               const TextDecoderOptions& aOptions,
  31               ErrorResult& aRv)
  32   {
  33     nsAutoPtr<TextDecoder> txtDecoder(new TextDecoder());
  34     txtDecoder->Init(aEncoding, aOptions.mFatal, aRv);
  35     if (aRv.Failed()) {
  36       return nullptr;
  37     }
  38     return txtDecoder.forget();
  39   }
  40
  41   TextDecoder()
  42     : mFatal(false)
  43   {
  44     MOZ_COUNT_CTOR(TextDecoder);
  45   }
  46
  47   ~TextDecoder()
  48   {
  49     MOZ_COUNT_DTOR(TextDecoder);
  50   }
  51
  52   JSObject* WrapObject(JSContext* aCx, bool* aTookOwnership)
  53   {
  54     return TextDecoderBinding::Wrap(aCx, this, aTookOwnership);
  55   }
  56
  57   /**
  58    * Validates provided label and throws an exception if invalid label.
  59    *
  60    * @param aLabel       The encoding label (case insensitive) provided.
  61    * @param aFatal       indicates whether to throw an 'EncodingError'
  62    *                     exception or not when decoding.
  63    * @return aRv         EncodingError exception else null.
  64    */
  65   void Init(const nsAString& aLabel, const bool aFatal, ErrorResult& aRv);
  66
  67   /**
  68    * Performs initialization with a Gecko-canonical encoding name (as opposed
  69    * to a label.)
  70    *
  71    * @param aEncoding    A Gecko-canonical encoding name
  72    * @param aFatal       indicates whether to throw an 'EncodingError'
  73    *                     exception or not when decoding.
  74    */
  75   void InitWithEncoding(const nsACString& aEncoding, const bool aFatal);
  76
  77   /**
  78    * Return the encoding name.
  79    *
  80    * @param aEncoding, current encoding.
  81    */
  82   void GetEncoding(nsAString& aEncoding);
  83
  84   /**
  85    * Decodes incoming byte stream of characters in charset indicated by
  86    * encoding.
  87    *
  88    * The encoding algorithm state is reset if aOptions.mStream is not set.
  89    *
  90    * If the fatal flag is set then a decoding error will throw EncodingError.
  91    * Else the decoder will return a decoded string with replacement
  92    * character(s) for unidentified character(s).
  93    *
  94    * @param      aView, incoming byte stream of characters to be decoded to
  95    *                    to UTF-16 code points.
  96    * @param      aOptions, indicates if streaming or not.
  97    * @param      aOutDecodedString, decoded string of UTF-16 code points.
  98    * @param      aRv, error result.
  99    */
 100   void Decode(const char* aInput, const int32_t aLength,
 101               const bool aStream, nsAString& aOutDecodedString,
 102               ErrorResult& aRv);
 103
 104   void Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
 105               const TextDecodeOptions& aOptions,
 106               nsAString& aOutDecodedString,
 107               ErrorResult& aRv);
 108
 109   bool Fatal() const {
 110     return mFatal;
 111   }
 112
 113 private:
 114   nsCString mEncoding;
 115   nsCOMPtr<nsIUnicodeDecoder> mDecoder;
 116   bool mFatal;
 117 };
 118
 119 } // dom
 120 } // mozilla
 121
 122 #endif // mozilla_dom_textdecoder_h_