gecko/dom/encoding/TextDecoderBase.h

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_textdecoderbase_h_
#define mozilla_dom_textdecoderbase_h_

#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/TypedArray.h"
#include "nsIUnicodeDecoder.h"

namespace mozilla {
class ErrorResult;

namespace dom {

class TextDecoderBase
{
protected:
  TextDecoderBase()
    : mFatal(false)
  {}

  virtual
  ~TextDecoderBase()
  {}

  /**
   * Validates provided encoding and throws an exception if invalid encoding.
   * If no encoding is provided then mEncoding is default initialised to "utf-8".
   *
   * @param aEncoding    Optional encoding (case insensitive) provided.
   *                     Default value is "utf-8" if no encoding is provided.
   * @param aFatal       aFatal, indicates whether to throw an 'EncodingError'
   *                     exception or not.
   * @return aRv         EncodingError exception else null.
   */
  void Init(const nsAString& aEncoding, const bool aFatal, ErrorResult& aRv);

public:
  /**
   * Return the encoding name.
   *
   * @param aEncoding, current encoding.
   */
  void GetEncoding(nsAString& aEncoding);

  /**
   * Decodes incoming byte stream of characters in charset indicated by
   * encoding.
   *
   * The encoding algorithm state is reset if aOptions.mStream is not set.
   *
   * If the fatal flag is set then a decoding error will throw EncodingError.
   * Else the decoder will return a decoded string with replacement
   * character(s) for unidentified character(s).
   *
   * @param      aView, incoming byte stream of characters to be decoded to
   *                    to UTF-16 code points.
   * @param      aOptions, indicates if streaming or not.
   * @param      aOutDecodedString, decoded string of UTF-16 code points.
   * @param      aRv, error result.
   */
  void Decode(const char* aInput, const int32_t aLength,
              const bool aStream, nsAString& aOutDecodedString,
              ErrorResult& aRv);

private:
  nsCString mEncoding;
  nsCOMPtr<nsIUnicodeDecoder> mDecoder;
  bool mFatal;
};

} // dom
} // mozilla

#endif // mozilla_dom_textdecoderbase_h_