dom/encoding/TextDecoder.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_textdecoder_h_
   8 #define mozilla_dom_textdecoder_h_
   9
  10 #include "mozilla/dom/NonRefcountedDOMObject.h"
  11 #include "mozilla/dom/TextDecoderBinding.h"
  12 #include "mozilla/dom/TypedArray.h"
  13 #include "mozilla/Encoding.h"
  14 #include "mozilla/ErrorResult.h"
  15 #include "mozilla/UniquePtr.h"
  16
  17 namespace mozilla {
  18 namespace dom {
  19
  20 class ArrayBufferViewOrArrayBuffer;
  21
  22 class TextDecoder final : public NonRefcountedDOMObject {
  23  public:
  24   // The WebIDL constructor.
  25   static TextDecoder* Constructor(const GlobalObject& aGlobal,
  26                                   const nsAString& aEncoding,
  27                                   const TextDecoderOptions& aOptions,
  28                                   ErrorResult& aRv) {
  29     auto txtDecoder = MakeUnique<TextDecoder>();
  30     txtDecoder->Init(aEncoding, aOptions, aRv);
  31     if (aRv.Failed()) {
  32       return nullptr;
  33     }
  34     return txtDecoder.release();
  35   }
  36
  37   TextDecoder() : mFatal(false), mIgnoreBOM(false) {
  38     MOZ_COUNT_CTOR(TextDecoder);
  39   }
  40
  41   MOZ_COUNTED_DTOR(TextDecoder)
  42
  43   bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
  44                   JS::MutableHandle<JSObject*> aReflector) {
  45     return TextDecoder_Binding::Wrap(aCx, this, aGivenProto, aReflector);
  46   }
  47
  48   /**
  49    * Validates provided label and throws an exception if invalid label.
  50    *
  51    * @param aLabel       The encoding label (case insensitive) provided.
  52    * @param aOptions     The TextDecoderOptions to use.
  53    * @return aRv         EncodingError exception else null.
  54    */
  55   void Init(const nsAString& aLabel, const TextDecoderOptions& aOptions,
  56             ErrorResult& aRv);
  57
  58   /**
  59    * Performs initialization with a Gecko-canonical encoding name (as opposed
  60    * to a label.)
  61    *
  62    * @param aEncoding    An Encoding object
  63    * @param aOptions     The TextDecoderOptions to use.
  64    */
  65   void InitWithEncoding(NotNull<const Encoding*> aEncoding,
  66                         const TextDecoderOptions& aOptions);
  67
  68   /**
  69    * Return the encoding name.
  70    *
  71    * @param aEncoding, current encoding.
  72    */
  73   void GetEncoding(nsAString& aEncoding);
  74
  75   /**
  76    * Decodes incoming byte stream of characters in charset indicated by
  77    * encoding.
  78    *
  79    * The encoding algorithm state is reset if aOptions.mStream is not set.
  80    *
  81    * If the fatal flag is set then a decoding error will throw EncodingError.
  82    * Else the decoder will return a decoded string with replacement
  83    * character(s) for unidentified character(s).
  84    *
  85    * @param      aView, incoming byte stream of characters to be decoded to
  86    *                    to UTF-16 code points.
  87    * @param      aOptions, indicates if streaming or not.
  88    * @param      aOutDecodedString, decoded string of UTF-16 code points.
  89    * @param      aRv, error result.
  90    */
  91   void Decode(mozilla::Span<const uint8_t> aInput, const bool aStream,
  92               nsAString& aOutDecodedString, ErrorResult& aRv);
  93
  94   void Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
  95               const TextDecodeOptions& aOptions, nsAString& aOutDecodedString,
  96               ErrorResult& aRv);
  97
  98   bool Fatal() const { return mFatal; }
  99
 100   bool IgnoreBOM() const { return mIgnoreBOM; }
 101
 102  private:
 103   nsCString mEncoding;
 104   mozilla::UniquePtr<mozilla::Decoder> mDecoder;
 105   bool mFatal;
 106   bool mIgnoreBOM;
 107 };
 108
 109 }  // namespace dom
 110 }  // namespace mozilla
 111
 112 #endif  // mozilla_dom_textdecoder_h_