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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is Mozilla Communicator client code.
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 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 1998
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 * Contributor(s):
 *
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#ifndef nsUCS2BEToUnicode_h___
#define nsUCS2BEToUnicode_h___

#include "nsISupports.h"
#include "nsUCSupport.h"

// internal base class
class nsUTF16ToUnicodeBase : public nsBasicDecoderSupport
{
protected:
  // ctor accessible only by child classes
  nsUTF16ToUnicodeBase() { Reset();}

public: 
  //--------------------------------------------------------------------
  // Subclassing of nsDecoderSupport class [declaration]

  NS_IMETHOD GetMaxLength(const char * aSrc, PRInt32 aSrcLength, 
      PRInt32 * aDestLength);
  NS_IMETHOD Reset();

protected:
  PRUint8 mState;
  // to store an odd byte left over between runs
  PRUint8 mOddByte;
  // to store an odd high surrogate left over between runs
  PRUnichar mOddHighSurrogate;
  // to store an odd low surrogate left over between runs
  PRUnichar mOddLowSurrogate;
};

// UTF-16 big endian
class nsUTF16BEToUnicode : public nsUTF16ToUnicodeBase
{
public:

  NS_IMETHOD Convert(const char * aSrc, PRInt32 * aSrcLength,
      PRUnichar * aDest, PRInt32 * aDestLength); 
};

// UTF-16 little endian
class nsUTF16LEToUnicode : public nsUTF16ToUnicodeBase
{
public:

  NS_IMETHOD Convert(const char * aSrc, PRInt32 * aSrcLength,
      PRUnichar * aDest, PRInt32 * aDestLength); 
};

// UTF-16 with BOM
class nsUTF16ToUnicode : public nsUTF16ToUnicodeBase
{
public:

  nsUTF16ToUnicode() { Reset();}
  NS_IMETHOD Convert(const char * aSrc, PRInt32 * aSrcLength,
      PRUnichar * aDest, PRInt32 * aDestLength); 

  NS_IMETHOD Reset();

private:

  enum Endian {kUnknown, kBigEndian, kLittleEndian};
  Endian  mEndian; 
  PRBool  mFoundBOM;
};

#endif /* nsUCS2BEToUnicode_h___ */
