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Merging upstream version 0.6.0.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-02-08 07:47:42 +01:00
parent 72fc7a26f9
commit 60b3c4718d
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
4 changed files with 176 additions and 77 deletions
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4
docs/api_reference.rst
View file

@ -7,13 +7,17 @@ API Reference
:members:
.. autoclass:: Dictionary
:show-inheritance:
.. autoclass:: Stream
:members:
:show-inheritance:
.. autoclass:: String
:show-inheritance:
.. autoclass:: Array
:show-inheritance:
.. autoclass:: PDF
:members:

36
docs/changelog.rst
View file

@ -2,6 +2,40 @@ Changelog
=========
Version 0.6.0
-------------
Released on 2023-03-29.
New features:
* Add an option to use compressed object streams for PDF 1.5+, with financial support from Code & Co.
* Add new text operators
* Clean and fix documentation
Backers and sponsors:
* Kobalt
* Grip Angebotssoftware
* Spacinov
* Crisp BV
* Castedo Ellerman
* Manuel Barkhau
* SimonSoft
* Menutech
* KontextWork
* NCC Group
* René Fritz
* Moritz Mahringer
* Yanal-Yvez Fargialla
* Piotr Horzycki
* Healthchecks.io
* Hammerbacher
* TrainingSparkle
* Synapsium
Version 0.5.0
-------------
@ -10,7 +44,7 @@ Released on 2022-10-11.
New features:
* Add the PDF.page_references property
* Revert the PDF.pages['Kids'] behavior to be retro-compatible with version 0.3.0
* Revert the PDF.pages['Kids'] behavior to be backwards compatible with version 0.3.0
Backers and sponsors:

7
docs/common_use_cases.rst
View file

@ -97,7 +97,7 @@ Display image
document = pydyf.PDF()
extra = Dictionary({
extra = pydyf.Dictionary({
'Type': '/XObject',
'Subtype': '/Image',
'Width': 197,
@ -158,9 +158,9 @@ Display text
# And display it
text = pydyf.Stream()
text.begin_text()
text.set_font_size('F1', 24)
text.set_font_size('F1', 20)
text.text_matrix(1, 0, 0, 1, 10, 90)
text.show_text(pydyf.String('Hello World'))
text.show_text(pydyf.String('Bœuf grillé & café'.encode('macroman')))
text.end_text()
document.add_object(text)
@ -179,4 +179,3 @@ Display text
with open('document.pdf', 'wb') as f:
document.write(f)

206
pydyf/__init__.py
View file

@ -7,8 +7,9 @@ import re
import zlib
from codecs import BOM_UTF16_BE
from hashlib import md5
from math import ceil, log
VERSION = __version__ = '0.5.0'
VERSION = __version__ = '0.6.0'
def _to_bytes(item):
@ -21,7 +22,7 @@ def _to_bytes(item):
if item.is_integer():
return f'{int(item):d}'.encode('ascii')
else:
return f'{item:f}'.encode('ascii')
return f'{item:f}'.rstrip('0').encode('ascii')
elif isinstance(item, int):
return f'{item:d}'.encode('ascii')
return str(item).encode('ascii')
@ -43,51 +44,41 @@ class Object:
@property
def indirect(self):
"""Indirect representation of an object."""
return b'\n'.join((
str(self.number).encode() + b' ' +
str(self.generation).encode() + b' obj',
self.data,
b'endobj',
))
header = f'{self.number} {self.generation} obj\n'.encode()
return header + self.data + b'\nendobj'
@property
def reference(self):
"""Object identifier."""
return (
str(self.number).encode() + b' ' +
str(self.generation).encode() + b' R')
return f'{self.number} {self.generation} R'.encode()
@property
def data(self):
"""Data contained in the object. Shall be defined in each subclass."""
raise NotImplementedError()
@property
def compressible(self):
"""Whether the object can be included in an object stream."""
return not self.generation and not isinstance(self, Stream)
class Dictionary(Object, dict):
"""PDF Dictionary object.
Inherits from :class:`Object` and Python :obj:`dict`.
"""
"""PDF Dictionary object."""
def __init__(self, values=None):
Object.__init__(self)
dict.__init__(self, values or {})
@property
def data(self):
result = [b'<<']
for key, value in self.items():
result.append(b'/' + _to_bytes(key) + b' ' + _to_bytes(value))
result.append(b'>>')
return b'\n'.join(result)
result = [
b'/' + _to_bytes(key) + b' ' + _to_bytes(value)
for key, value in self.items()]
return b'<<' + b''.join(result) + b'>>'
class Stream(Object):
"""PDF Stream object.
Inherits from :class:`Object`.
"""
"""PDF Stream object."""
def __init__(self, stream=None, extra=None, compress=False):
super().__init__()
#: Python array of data composing stream.
@ -221,6 +212,10 @@ class Stream(Object):
"""Begin new subpath by moving current point to ``(x, y)``."""
self.stream.append(b' '.join((_to_bytes(x), _to_bytes(y), b'm')))
def move_text_to(self, x, y):
"""Move text to next line at ``(x, y)`` distance from previous line."""
self.stream.append(b' '.join((_to_bytes(x), _to_bytes(y), b'Td')))
def shading(self, name):
"""Paint shape and color shading using shading dictionary ``name``."""
self.stream.append(b'/' + _to_bytes(name) + b' sh')
@ -310,9 +305,13 @@ class Stream(Object):
self.stream.append(b'/' + _to_bytes(state_name) + b' gs')
def show_text(self, text):
"""Show text."""
"""Show text strings with individual glyph positioning."""
self.stream.append(b'[' + _to_bytes(text) + b'] TJ')
def show_text_string(self, text):
"""Show single text string."""
self.stream.append(String(text).data + b' Tj')
def stroke(self):
"""Stroke path."""
self.stream.append(b'S')
@ -369,7 +368,7 @@ class Stream(Object):
extra = Dictionary(self.extra.copy())
if self.compress:
extra['Filter'] = '/FlateDecode'
compressobj = zlib.compressobj()
compressobj = zlib.compressobj(level=9)
stream = compressobj.compress(stream)
stream += compressobj.flush()
extra['Length'] = len(stream)
@ -377,11 +376,7 @@ class Stream(Object):
class String(Object):
"""PDF String object.
Inherits from :class:`Object`.
"""
"""PDF String object."""
def __init__(self, string=''):
super().__init__()
#: Unicode string.
@ -402,22 +397,14 @@ class String(Object):
class Array(Object, list):
"""PDF Array object.
Inherits from :class:`Object` and Python :obj:`list`.
"""
"""PDF Array object."""
def __init__(self, array=None):
Object.__init__(self)
list.__init__(self, array or [])
@property
def data(self):
result = [b'[']
for child in self:
result.append(_to_bytes(child))
result.append(b']')
return b' '.join(result)
return b'[' + b' '.join(_to_bytes(child) for child in self) + b']'
class PDF:
@ -500,13 +487,14 @@ class PDF:
self.current_position += len(content) + 1
output.write(content + b'\n')
def write(self, output, version=None, identifier=None):
def write(self, output, version=None, identifier=None, compress=False):
"""Write PDF to output.
:param output: Output stream.
:type output: binary :term:`file object`
:param bytes version: PDF version.
:param bytes identifier: PDF file identifier.
:param bool compress: whether the PDF uses a compressed object stream.
"""
version = self.version if version is None else _to_bytes(version)
@ -516,36 +504,110 @@ class PDF:
self.write_line(b'%PDF-' + version, output)
self.write_line(b'%\xf0\x9f\x96\xa4', output)
# Write all non-free PDF objects
for object_ in self.objects:
if object_.free == 'f':
continue
object_.offset = self.current_position
self.write_line(object_.indirect, output)
if version >= b'1.5' and compress:
# Store compressed objects for later and write other ones in PDF
compressed_objects = []
for object_ in self.objects:
if object_.free == 'f':
continue
if object_.compressible:
compressed_objects.append(object_)
else:
object_.offset = self.current_position
self.write_line(object_.indirect, output)
# Write cross reference table
self.xref_position = self.current_position
self.write_line(b'xref', output)
self.write_line(f'0 {len(self.objects)}'.encode(), output)
for object_ in self.objects:
self.write_line(
(f'{object_.offset:010} {object_.generation:05} '
f'{object_.free} ').encode(), output)
# Write compressed objects in object stream
stream = [[]]
position = 0
for i, object_ in enumerate(compressed_objects):
data = object_.data
stream.append(data)
stream[0].append(object_.number)
stream[0].append(position)
position += len(data) + 1
stream[0] = ' '.join(str(i) for i in stream[0])
extra = {
'Type': '/ObjStm',
'N': len(compressed_objects),
'First': len(stream[0]) + 1,
}
object_stream = Stream(stream, extra, compress)
object_stream.offset = self.current_position
self.add_object(object_stream)
self.write_line(object_stream.indirect, output)
# Write cross-reference stream
xref = []
dict_index = 0
for object_ in self.objects:
if object_.compressible:
xref.append((2, object_stream.number, dict_index))
dict_index += 1
else:
xref.append((
bool(object_.number), object_.offset,
object_.generation))
xref.append((1, self.current_position, 0))
field2_size = ceil(log(self.current_position, 8))
max_generation = max(
object_.generation for object_ in self.objects)
field3_size = ceil(log(
max(max_generation, len(compressed_objects)), 8))
xref_lengths = (1, field2_size, field3_size)
xref_stream = b''.join(
value.to_bytes(length, 'big')
for line in xref for length, value in zip(xref_lengths, line))
extra = {
'Type': '/XRef',
'Index': Array((0, len(self.objects) + 1)),
'W': Array(xref_lengths),
'Size': len(self.objects) + 1,
'Root': self.catalog.reference,
'Info': self.info.reference,
}
if identifier is not None:
data = b''.join(
obj.data for obj in self.objects if obj.free != 'f')
data_hash = md5(data).hexdigest().encode()
extra['ID'] = Array((
String(identifier).data, String(data_hash).data))
dict_stream = Stream([xref_stream], extra, compress)
self.xref_position = dict_stream.offset = self.current_position
self.add_object(dict_stream)
self.write_line(dict_stream.indirect, output)
else:
# Write all non-free PDF objects
for object_ in self.objects:
if object_.free == 'f':
continue
object_.offset = self.current_position
self.write_line(object_.indirect, output)
# Write cross-reference table
self.xref_position = self.current_position
self.write_line(b'xref', output)
self.write_line(f'0 {len(self.objects)}'.encode(), output)
for object_ in self.objects:
self.write_line(
(f'{object_.offset:010} {object_.generation:05} '
f'{object_.free} ').encode(), output)
# Write trailer
self.write_line(b'trailer', output)
self.write_line(b'<<', output)
self.write_line(f'/Size {len(self.objects)}'.encode(), output)
self.write_line(b'/Root ' + self.catalog.reference, output)
self.write_line(b'/Info ' + self.info.reference, output)
if identifier is not None:
data = b''.join(
obj.data for obj in self.objects if obj.free != 'f')
data_hash = md5(data).hexdigest().encode()
self.write_line(
b'/ID [' + String(identifier).data + b' ' +
String(data_hash).data + b']', output)
self.write_line(b'>>', output)
# Write trailer
self.write_line(b'trailer', output)
self.write_line(b'<<', output)
self.write_line(f'/Size {len(self.objects)}'.encode(), output)
self.write_line(b'/Root ' + self.catalog.reference, output)
self.write_line(b'/Info ' + self.info.reference, output)
if identifier is not None:
data = b''.join(
obj.data for obj in self.objects if obj.free != 'f')
data_hash = md5(data).hexdigest().encode()
self.write_line(
b'/ID [' + String(identifier).data + b' ' +
String(data_hash).data + b']', output)
self.write_line(b'>>', output)
self.write_line(b'startxref', output)
self.write_line(f'{self.xref_position}'.encode(), output)
self.write_line(b'%%EOF', output)