QPDF_String.cc
3.54 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#include <qpdf/QPDF_String.hh>
#include <qpdf/QUtil.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_iso_latin1_printable(unsigned char ch)
{
return (((ch >= 32) && (ch <= 126)) || (ch >= 160));
}
QPDF_String::QPDF_String(std::string const& val) :
val(val)
{
}
QPDF_String::~QPDF_String()
{
}
std::string
QPDF_String::unparse()
{
return unparse(false);
}
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[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 ISO-Latin-1. We'll code
// this manually rather than being rude and setting locale.
if ((ch == 0) || (! (is_iso_latin1_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 the current locale. Uniformly distributed random
// characters will not pass this test even with ISO-Latin-1 in
// which 76% are either printable or in the set of standard
// escaped characters.
if (5 * nonprintable > val.length())
{
use_hexstring = true;
}
}
std::string result;
if (use_hexstring)
{
result += "<";
char num[3];
for (unsigned int i = 0; i < this->val.length(); ++i)
{
sprintf(num, "%02x", (unsigned char) this->val[i]);
result += num;
}
result += ">";
}
else
{
result += "(";
char num[5];
for (unsigned int i = 0; i < this->val.length(); ++i)
{
char ch = this->val[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[i];
}
else
{
sprintf(num, "\\%03o", (unsigned char)ch);
result += num;
}
break;
}
}
result += ")";
}
return result;
}
std::string
QPDF_String::getVal() const
{
return this->val;
}
std::string
QPDF_String::getUTF8Val() const
{
std::string result;
unsigned int len = this->val.length();
if ((len >= 2) && (len % 2 == 0) &&
(this->val[0] == '\xfe') && (this->val[1] == '\xff'))
{
// This is a Unicode string using big-endian UTF-16. This
// code is not actually correct as it doesn't properly handle
// characters past 0xffff.
for (unsigned int i = 2; i < len; i += 2)
{
result += QUtil::toUTF8(((unsigned char) this->val[i] << 8) +
((unsigned char) this->val[i+1]));
}
}
else
{
for (unsigned int i = 0; i < len; ++i)
{
result += QUtil::toUTF8((unsigned char) this->val[i]);
}
}
return result;
}