private void displayContentStream(DictionaryToken contentDictionaryToken)
{
var fonts = ((PdfContent)contentDictionaryToken.PdfObject !).Fonts;
var bytes = bytesMemory.Span;
sb.Clear();
var fontSb = new StringBuilder();
if (bytes.Length < 10)
{
for (int bytesIndex = 0; bytesIndex < bytes.Length - 1; bytesIndex++)
{
append(sb, bytes[bytesIndex]);
}
StreamTextBox.Text = sb.ToString();
sb.Clear();
return;
}
var contentState = contentStateEnum.parse;
var startBTIndex = int.MinValue;
char[]? fontEncoding = null;
byte b0;
var b1 = (byte)' ';//"add" space before buffer in case the very first 2 characters are like BI or BT
var b2 = bytes[0];
var b3 = bytes[1];
append(sb, b2);
append(sb, b3);
for (int bytesIndex = 2; bytesIndex < bytes.Length; bytesIndex++)
{
b0 = b1;
b1 = b2;
b2 = b3;
b3 = bytes[bytesIndex];
if (contentState == contentStateEnum.ID)
{
//checking if that ever occurs
if ((b1 == '\n' || b1 == '\r') && (b2 != 'E' || b3 != 'I'))
{
System.Diagnostics.Debugger.Break();
}
}
if (contentState == contentStateEnum.BT)
{
//process T, i.e. strings one byte at a time
if (b3 == '(')
{
//inside a string
sb.Append('(');
var encoding = fontEncoding ?? PdfEncodings.Standard;
while (true)
{
b3 = bytes[++bytesIndex];
if (b3 == ')')
{
//sb.Append(')'); not needed, will b3 will be later added to sb
break;
}
var c = encoding[b3];
if (c == 0xFFFF)
{
sb.Append('\'' + b3.ToString("x") + '\'');
}
else
{
sb.Append(c);
}
}
}
else if (b3 == 'T' && bytes[bytesIndex + 1] == 'f')
{
//font definition found
int searchBackIndex;
var isFontFound = false;
for (searchBackIndex = bytesIndex - 1; searchBackIndex > startBTIndex; searchBackIndex--)
{
if (bytes[searchBackIndex] == '/')
{
fontSb.Clear();
searchBackIndex++;
for (; searchBackIndex < bytesIndex; searchBackIndex++)
{
var b = bytes[searchBackIndex];
if (Tokeniser.IsWhiteSpace(b))
{
var fontString = fontSb.ToString();
fontEncoding = fonts[fontString].Encoding8Bit;
isFontFound = true;
break;
}
fontSb.Append((char)b);
}
if (!isFontFound)
{
System.Diagnostics.Debugger.Break();
}
break;
}
}
if (!isFontFound)
{
System.Diagnostics.Debugger.Break();
}
}
else if (b3 == 'E' && bytes[bytesIndex + 1] == 'T')
{
startBTIndex = int.MinValue;
fontEncoding = null;
contentState = contentStateEnum.parse;
}
}
else
{
//search for BI, DI, EI and BT
if (Tokeniser.IsDelimiterByte(b0) && Tokeniser.IsDelimiterByte(b3))
{
switch (contentState)
{
case contentStateEnum.parse:
if (b1 == 'B' && b2 == 'I')
{
contentState = contentStateEnum.BI;
}
else if (b1 == 'B' && b2 == 'T')
{
contentState = contentStateEnum.BT;
startBTIndex = bytesIndex;
}
break;
case contentStateEnum.BI:
if (b1 == 'I' && b2 == 'D')
{
contentState = contentStateEnum.ID;
}
break;
case contentStateEnum.ID:
if (b1 == 'E' && b2 == 'I')
{
contentState = contentStateEnum.parse;
}
break;
default:
throw new NotSupportedException();
}
}
}
append(sb, b3);
}
StreamTextBox.Text = sb.ToString();
sb.Clear();
}