qpdf/libqpdf/QPDF_String.cc

#include <qpdf/QPDF_String.hh>

#include <qpdf/QUtil.hh>
#include <qpdf/QTC.hh>

// DO NOT USE ctype -- it is locale dependent for some things, and
// it's not worth the risk of including it in case it may accidentally
// be used.
#include <string.h>

// See above about ctype.
static bool is_ascii_printable(char ch)
{
    return ((ch >= 32) && (ch <= 126));
}
static bool is_iso_latin1_printable(char ch)
{
    return (((ch >= 32) && (ch <= 126)) ||
            (static_cast<unsigned char>(ch) >= 160));
}

QPDF_String::QPDF_String(std::string const& val) :
    val(val)
{
}

QPDF_String::~QPDF_String()
{
}

QPDF_String*
QPDF_String::new_utf16(std::string const& utf8_val)
{
    std::string result;
    if (! (QUtil::utf8_to_ascii(utf8_val, result, '?') ||
           QUtil::utf8_to_pdf_doc(utf8_val, result, '?')))
    {
        result = QUtil::utf8_to_utf16(utf8_val);
    }
    return new QPDF_String(result);
}

std::string
QPDF_String::unparse()
{
    return unparse(false);
}

JSON
QPDF_String::getJSON()
{
    return JSON::makeString(getUTF8Val());
}

QPDFObject::object_type_e
QPDF_String::getTypeCode() const
{
    return QPDFObject::ot_string;
}

char const*
QPDF_String::getTypeName() const
{
    return "string";
}

std::string
QPDF_String::unparse(bool force_binary)
{
    bool use_hexstring = force_binary;
    if (! use_hexstring)
    {
	unsigned int nonprintable = 0;
	int consecutive_printable = 0;
	for (unsigned int i = 0; i < this->val.length(); ++i)
	{
	    char ch = this->val.at(i);
	    // Note: do not use locale to determine printability.  The
	    // PDF specification accepts arbitrary binary data.  Some
	    // locales imply multibyte characters.  We'll consider
	    // something printable if it is printable in 7-bit ASCII.
	    // We'll code this manually rather than being rude and
	    // setting locale.
	    if ((ch == 0) || (! (is_ascii_printable(ch) ||
				 strchr("\n\r\t\b\f", ch))))
	    {
		++nonprintable;
		consecutive_printable = 0;
	    }
	    else
	    {
		if (++consecutive_printable > 5)
		{
		    // If there are more than 5 consecutive printable
		    // characters, I want to see them as such.
		    nonprintable = 0;
		    break;
		}
	    }
	}

	// Use hex notation if more than 20% of the characters are not
	// printable in plain ASCII.
	if (5 * nonprintable > val.length())
	{
	    use_hexstring = true;
	}
    }
    std::string result;
    if (use_hexstring)
    {
	result += "<" + QUtil::hex_encode(this->val) + ">";
    }
    else
    {
	result += "(";
	for (unsigned int i = 0; i < this->val.length(); ++i)
	{
	    char ch = this->val.at(i);
	    switch (ch)
	    {
	      case '\n':
		result += "\\n";
		break;

	      case '\r':
		result += "\\r";
		break;

	      case '\t':
		result += "\\t";
		break;

	      case '\b':
		result += "\\b";
		break;

	      case '\f':
		result += "\\f";
		break;

	      case '(':
		result += "\\(";
		break;

	      case ')':
		result += "\\)";
		break;

	      case '\\':
		result += "\\\\";
		break;

	      default:
		if (is_iso_latin1_printable(ch))
		{
		    result += this->val.at(i);
		}
		else
		{
		    result += "\\" + QUtil::int_to_string_base(
                        static_cast<int>(static_cast<unsigned char>(ch)),
                        8, 3);
		}
		break;
	    }
	}
	result += ")";
    }

    return result;
}

std::string
QPDF_String::getVal() const
{
    return this->val;
}

std::string
QPDF_String::getUTF8Val() const
{
    if (QUtil::is_utf16(this->val))
    {
        return QUtil::utf16_to_utf8(this->val);
    }
    else
    {
        return QUtil::pdf_doc_to_utf8(this->val);
    }
}