diff options
| -rw-r--r-- | docs/api_reference.rst | 4 | ||||
| -rw-r--r-- | docs/changelog.rst | 36 | ||||
| -rw-r--r-- | docs/common_use_cases.rst | 7 | ||||
| -rwxr-xr-x | pydyf/__init__.py | 210 |
4 files changed, 178 insertions, 79 deletions
diff --git a/docs/api_reference.rst b/docs/api_reference.rst index 80bf16c..0ceb6c5 100644 --- a/docs/api_reference.rst +++ b/docs/api_reference.rst @@ -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: diff --git a/docs/changelog.rst b/docs/changelog.rst index 3eb90e6..f652602 100644 --- a/docs/changelog.rst +++ b/docs/changelog.rst @@ -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: diff --git a/docs/common_use_cases.rst b/docs/common_use_cases.rst index 45e2d3d..b045fa6 100644 --- a/docs/common_use_cases.rst +++ b/docs/common_use_cases.rst @@ -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) - diff --git a/pydyf/__init__.py b/pydyf/__init__.py index 85811f4..2e589fe 100755 --- a/pydyf/__init__.py +++ b/pydyf/__init__.py @@ -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`. - """ +class Dictionary(Object, 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) - - # 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) + 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 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) + self.write_line(b'startxref', output) self.write_line(f'{self.xref_position}'.encode(), output) self.write_line(b'%%EOF', output) |