import codecs
from typing import Dict, List, Tuple, Union
from .._codecs import _pdfdoc_encoding
from .._utils import StreamType, b_, logger_warning, read_non_whitespace
from ..errors import STREAM_TRUNCATED_PREMATURELY, PdfStreamError
from ._base import ByteStringObject, TextStringObject
[docs]def hex_to_rgb(value: str) -> Tuple[float, float, float]:
return tuple(int(value.lstrip("#")[i : i + 2], 16) / 255.0 for i in (0, 2, 4)) # type: ignore
[docs]def read_hex_string_from_stream(
stream: StreamType,
forced_encoding: Union[None, str, List[str], Dict[int, str]] = None,
) -> Union["TextStringObject", "ByteStringObject"]:
stream.read(1)
txt = ""
x = b""
while True:
tok = read_non_whitespace(stream)
if not tok:
raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
if tok == b">":
break
x += tok
if len(x) == 2:
txt += chr(int(x, base=16))
x = b""
if len(x) == 1:
x += b"0"
if len(x) == 2:
txt += chr(int(x, base=16))
return create_string_object(b_(txt), forced_encoding)
[docs]def read_string_from_stream(
stream: StreamType,
forced_encoding: Union[None, str, List[str], Dict[int, str]] = None,
) -> Union["TextStringObject", "ByteStringObject"]:
tok = stream.read(1)
parens = 1
txt = []
while True:
tok = stream.read(1)
if not tok:
raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
if tok == b"(":
parens += 1
elif tok == b")":
parens -= 1
if parens == 0:
break
elif tok == b"\\":
tok = stream.read(1)
escape_dict = {
b"n": b"\n",
b"r": b"\r",
b"t": b"\t",
b"b": b"\b",
b"f": b"\f",
b"c": rb"\c",
b"(": b"(",
b")": b")",
b"/": b"/",
b"\\": b"\\",
b" ": b" ",
b"%": b"%",
b"<": b"<",
b">": b">",
b"[": b"[",
b"]": b"]",
b"#": b"#",
b"_": b"_",
b"&": b"&",
b"$": b"$",
}
try:
tok = escape_dict[tok]
except KeyError:
if b"0" <= tok <= b"7":
# "The number ddd may consist of one, two, or three
# octal digits; high-order overflow shall be ignored.
# Three octal digits shall be used, with leading zeros
# as needed, if the next character of the string is also
# a digit." (PDF reference 7.3.4.2, p 16)
for _ in range(2):
ntok = stream.read(1)
if b"0" <= ntok <= b"7":
tok += ntok
else:
stream.seek(-1, 1) # ntok has to be analyzed
break
tok = b_(chr(int(tok, base=8)))
elif tok in b"\n\r":
# This case is hit when a backslash followed by a line
# break occurs. If it's a multi-char EOL, consume the
# second character:
tok = stream.read(1)
if tok not in b"\n\r":
stream.seek(-1, 1)
# Then don't add anything to the actual string, since this
# line break was escaped:
tok = b""
else:
msg = f"Unexpected escaped string: {tok.decode('utf-8','ignore')}"
logger_warning(msg, __name__)
txt.append(tok)
return create_string_object(b"".join(txt), forced_encoding)
[docs]def create_string_object(
string: Union[str, bytes],
forced_encoding: Union[None, str, List[str], Dict[int, str]] = None,
) -> Union[TextStringObject, ByteStringObject]:
"""
Create a ByteStringObject or a TextStringObject from a string to represent the string.
Args:
string: The data being used
forced_encoding: Typically None, or an encoding string
Returns:
A ByteStringObject
Raises:
TypeError: If string is not of type str or bytes.
"""
if isinstance(string, str):
return TextStringObject(string)
elif isinstance(string, bytes):
if isinstance(forced_encoding, (list, dict)):
out = ""
for x in string:
try:
out += forced_encoding[x]
except Exception:
out += bytes((x,)).decode("charmap")
return TextStringObject(out)
elif isinstance(forced_encoding, str):
if forced_encoding == "bytes":
return ByteStringObject(string)
return TextStringObject(string.decode(forced_encoding))
else:
try:
if string.startswith((codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE)):
retval = TextStringObject(string.decode("utf-16"))
retval.autodetect_utf16 = True
return retval
else:
# This is probably a big performance hit here, but we need
# to convert string objects into the text/unicode-aware
# version if possible... and the only way to check if that's
# possible is to try.
# Some strings are strings, some are just byte arrays.
retval = TextStringObject(decode_pdfdocencoding(string))
retval.autodetect_pdfdocencoding = True
return retval
except UnicodeDecodeError:
return ByteStringObject(string)
else:
raise TypeError("create_string_object should have str or unicode arg")
[docs]def decode_pdfdocencoding(byte_array: bytes) -> str:
retval = ""
for b in byte_array:
c = _pdfdoc_encoding[b]
if c == "\u0000":
raise UnicodeDecodeError(
"pdfdocencoding",
bytearray(b),
-1,
-1,
"does not exist in translation table",
)
retval += c
return retval