michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_dom_encodingutils_h_
michael@0: #define mozilla_dom_encodingutils_h_
michael@0: 
michael@0: #include "nsDataHashtable.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: class nsIUnicodeDecoder;
michael@0: class nsIUnicodeEncoder;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: class EncodingUtils
michael@0: {
michael@0: public:
michael@0: 
michael@0:   /**
michael@0:    * Implements get an encoding algorithm from Encoding spec.
michael@0:    * http://encoding.spec.whatwg.org/#concept-encoding-get
michael@0:    * Given a label, this function returns the corresponding encoding or a
michael@0:    * false.
michael@0:    * The returned name may not be lowercased due to compatibility with
michael@0:    * our internal implementations.
michael@0:    *
michael@0:    * @param      aLabel, incoming label describing charset to be decoded.
michael@0:    * @param      aRetEncoding, returning corresponding encoding for label.
michael@0:    * @return     false if no encoding was found for label.
michael@0:    *             true if valid encoding found.
michael@0:    */
michael@0:   static bool FindEncodingForLabel(const nsACString& aLabel,
michael@0:                                    nsACString& aOutEncoding);
michael@0: 
michael@0:   static bool FindEncodingForLabel(const nsAString& aLabel,
michael@0:                                    nsACString& aOutEncoding)
michael@0:   {
michael@0:     return FindEncodingForLabel(NS_ConvertUTF16toUTF8(aLabel), aOutEncoding);
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Remove any leading and trailing space characters, following the
michael@0:    * definition of space characters from Encoding spec.
michael@0:    * http://encoding.spec.whatwg.org/#terminology
michael@0:    * Note that nsAString::StripWhitespace() doesn't exactly match the
michael@0:    * definition. It also removes all matching chars in the string,
michael@0:    * not just leading and trailing.
michael@0:    *
michael@0:    * @param      aString, string to be trimmed.
michael@0:    */
michael@0:   template<class T>
michael@0:   static void TrimSpaceCharacters(T& aString)
michael@0:   {
michael@0:     aString.Trim(" \t\n\f\r");
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Check is the encoding is ASCII-compatible in the sense that Basic Latin
michael@0:    * encodes to ASCII bytes. (The reverse may not be true!)
michael@0:    *
michael@0:    * @param aPreferredName a preferred encoding label
michael@0:    * @return whether the encoding is ASCII-compatible
michael@0:    */
michael@0:   static bool IsAsciiCompatible(const nsACString& aPreferredName);
michael@0: 
michael@0:   /**
michael@0:    * Instantiates a decoder for an encoding. The input must be a
michael@0:    * Gecko-canonical encoding name.
michael@0:    * @param aEncoding a Gecko-canonical encoding name
michael@0:    * @return a decoder
michael@0:    */
michael@0:   static already_AddRefed<nsIUnicodeDecoder>
michael@0:   DecoderForEncoding(const char* aEncoding)
michael@0:   {
michael@0:     nsDependentCString encoding(aEncoding);
michael@0:     return DecoderForEncoding(encoding);
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Instantiates a decoder for an encoding. The input must be a
michael@0:    * Gecko-canonical encoding name
michael@0:    * @param aEncoding a Gecko-canonical encoding name
michael@0:    * @return a decoder
michael@0:    */
michael@0:   static already_AddRefed<nsIUnicodeDecoder>
michael@0:   DecoderForEncoding(const nsACString& aEncoding);
michael@0: 
michael@0:   /**
michael@0:    * Instantiates an encoder for an encoding. The input must be a
michael@0:    * Gecko-canonical encoding name.
michael@0:    * @param aEncoding a Gecko-canonical encoding name
michael@0:    * @return an encoder
michael@0:    */
michael@0:   static already_AddRefed<nsIUnicodeEncoder>
michael@0:   EncoderForEncoding(const char* aEncoding)
michael@0:   {
michael@0:     nsDependentCString encoding(aEncoding);
michael@0:     return EncoderForEncoding(encoding);
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Instantiates an encoder for an encoding. The input must be a
michael@0:    * Gecko-canonical encoding name.
michael@0:    * @param aEncoding a Gecko-canonical encoding name
michael@0:    * @return an encoder
michael@0:    */
michael@0:   static already_AddRefed<nsIUnicodeEncoder>
michael@0:   EncoderForEncoding(const nsACString& aEncoding);
michael@0: 
michael@0: private:
michael@0:   EncodingUtils() MOZ_DELETE;
michael@0: };
michael@0: 
michael@0: } // dom
michael@0: } // mozilla
michael@0: 
michael@0: #endif // mozilla_dom_encodingutils_h_