private void CheckforAndHandleBOM()
{
byte[] utf32be = new byte[] { 0x00, 0x00, 0xfe, 0xff };
byte[] utf32le = new byte[] { 0xff, 0xfe, 0x00, 0x00 };
byte[] utf16be = new byte[] { 0xfe, 0xff };
byte[] utf16le = new byte[] { 0xff, 0xfe };
byte[] utf8 = new byte[] { 0xef, 0xbb, 0xbf };
if (IsCurrentData(utf32le) || IsCurrentData(utf32be))
{
m_foundBOM = true;
m_BOMLength = utf32be.Length;
//m_BOMEncoding = System.Text.Encoding.???; // not currently defined for 32
m_position = m_BOMLength;
}
else if (IsCurrentData(utf8))
{
m_foundBOM = true;
m_BOMLength = utf8.Length;
m_BOMEncoding = System.Text.Encoding.UTF8;
m_position = m_BOMLength;
}
else if (IsCurrentData(utf16le))
{
m_foundBOM = true;
m_BOMLength = utf16le.Length;
m_BOMEncoding = System.Text.Encoding.Unicode;
m_position = m_BOMLength;
}
else if (IsCurrentData(utf16be))
{
m_foundBOM = true;
m_BOMLength = utf16be.Length;
m_BOMEncoding = System.Text.Encoding.BigEndianUnicode;
m_position = m_BOMLength;
}
if (m_foundBOM) // has one
{
if (m_BOMEncoding == System.Text.Encoding.UTF8)
{
// no extra processing needed for UTF8 - this is the default format
}
else if (m_BOMEncoding == System.Text.Encoding.Unicode ||
m_BOMEncoding == System.Text.Encoding.BigEndianUnicode)
{
System.Text.UTF8Encoding utf8Encoder = new System.Text.UTF8Encoding(false, true);
try
{
// decode the wide Unicode byte data to wide chars
System.Text.Decoder uniDecoder = m_BOMEncoding.GetDecoder();
int charCount = uniDecoder.GetCharCount(m_FileData, 2, m_FileData.Length-2);
char[] chars = new Char[charCount];
uniDecoder.GetChars(m_FileData, 2, m_FileData.Length-2, chars, 0);
// decode the wide chars to utf8 bytes
int newLength = utf8Encoder.GetByteCount(chars);
m_FileData = new byte[newLength];
utf8Encoder.GetBytes(chars, 0, chars.Length, m_FileData, 0);
// log msg for user to see
if (m_Log != null)
m_Log.AddWarning(String.Format(Sfm2XmlStrings.FileConvertedFrom0To1,
m_BOMEncoding.WebName, utf8Encoder.WebName));
}
catch (System.Exception e)
{
if (m_Log != null)
{
m_Log.AddFatalError(String.Format(Sfm2XmlStrings.CannotConvertFileFrom0To1,
m_BOMEncoding.WebName, utf8Encoder.WebName));
m_Log.AddFatalError(String.Format(Sfm2XmlStrings.Exception0, e.Message));
}
m_position = 0;
m_FileData = new byte[0]; // don't process anything
}
}
else
{
m_position = 0;
m_FileData = new byte[0]; // don't process anything
if (m_Log != null)
m_Log.AddFatalError(Sfm2XmlStrings.CannotProcessUtf32Files);
}
}
}
