1
1
mirror of https://github.com/Kozea/WeasyPrint.git synced 2024-10-05 00:21:15 +03:00
WeasyPrint/weasyprint/document.py
2021-03-19 15:58:22 +01:00

1331 lines
53 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

"""
weasyprint.document
-------------------
"""
import collections
import functools
import hashlib
import io
import math
import shutil
import zlib
from os.path import basename
from urllib.parse import unquote, urlsplit
import pydyf
from fontTools import subset
from fontTools.ttLib import TTFont, TTLibError
from . import CSS, Attachment, __version__
from .css import get_all_computed_styles
from .css.counters import CounterStyle
from .css.targets import TargetCollector
from .draw import draw_page, stacked
from .formatting_structure import boxes
from .formatting_structure.build import build_formatting_structure
from .html import W3C_DATE_RE, get_html_metadata
from .images import get_image_from_uri as original_get_image_from_uri
from .layout import LayoutContext, layout_document
from .layout.percentages import percentage
from .logger import LOGGER, PROGRESS_LOGGER
from .text.ffi import ffi, pango
from .text.fonts import FontConfiguration
from .urls import URLFetchingError
def _w3c_date_to_pdf(string, attr_name):
"""Tranform W3C date to PDF format."""
if string is None:
return None
match = W3C_DATE_RE.match(string)
if match is None:
LOGGER.warning(f'Invalid {attr_name} date: {string!r}')
return None
groups = match.groupdict()
pdf_date = ''
found = groups['hour']
for key in ('second', 'minute', 'hour', 'day', 'month', 'year'):
if groups[key]:
found = True
pdf_date = groups[key] + pdf_date
elif found:
pdf_date = f'{(key in ("day", "month")):02d}{pdf_date}'
if groups['hour']:
assert groups['minute']
if groups['tz_hour']:
assert groups['tz_hour'].startswith(('+', '-'))
assert groups['tz_minute']
tz_hour = int(groups['tz_hour'])
tz_minute = int(groups['tz_minute'])
pdf_date += f"{tz_hour:+03d}'{tz_minute:02d}"
else:
pdf_date += 'Z'
return pdf_date
class Font:
def __init__(self, file_content, pango_font):
pango_metrics = pango.pango_font_get_metrics(pango_font, ffi.NULL)
self._font_description = pango.pango_font_describe(pango_font)
self.family = ffi.string(pango.pango_font_description_get_family(
self._font_description))
font_size = pango.pango_font_description_get_size(
self._font_description)
description_string = ffi.string(
pango.pango_font_description_to_string(self._font_description))
sha = hashlib.sha256()
sha.update(description_string)
self.file_content = file_content
self.file_hash = hash(file_content)
self.hash = ''.join(
chr(65 + letter % 26) for letter in sha.digest()[:6])
self.name = (
b'/' + self.hash.encode('ascii') + b'+' +
self.family.replace(b' ', b''))
self.italic_angle = 0 # TODO: this should be different
self.ascent = int(
pango.pango_font_metrics_get_ascent(pango_metrics) /
font_size * 1000)
self.descent = -int(
pango.pango_font_metrics_get_descent(pango_metrics) /
font_size * 1000)
self.stemv = 80
self.stemh = 80
self.bbox = [0, 0, 0, 0]
self.widths = {}
self.cmap = {}
@property
def flags(self):
flags = 2 ** 3 # Symbolic, custom character set
if pango.pango_font_description_get_style(self._font_description):
flags += 2 ** 7 # Italic
if b'Serif' in self.family.split():
flags += 2 ** 2 # Serif
widths = self.widths.values()
if len(widths) > 1 and len(set(widths)) == 1:
flags += 2 ** 1 # FixedPitch
return flags
class Context(pydyf.Stream):
"""PDF stream object with context storing alpha states."""
def __init__(self, document, page_rectangle, alpha_states, x_objects,
patterns, shadings, *args, **kwargs):
super().__init__(*args, **kwargs)
self.compress = True
self.page_rectangle = page_rectangle
self._document = document
self._alpha_states = alpha_states
self._x_objects = x_objects
self._patterns = patterns
self._shadings = shadings
self._current_color = self._current_color_stroke = None
self._current_alpha = self._current_alpha_stroke = None
self._current_font = self._current_font_size = None
self._old_font = self._old_font_size = None
self._ctm_stack = [Matrix()]
# These objects are used in text.show_first_line
self.length = ffi.new('unsigned int *')
self.ink_rect = ffi.new('PangoRectangle *')
self.logical_rect = ffi.new('PangoRectangle *')
@property
def ctm(self):
return self._ctm_stack[-1]
def push_state(self):
super().push_state()
self._ctm_stack.append(self.ctm)
def pop_state(self):
super().pop_state()
self._current_color = self._current_color_stroke = None
self._current_alpha = self._current_alpha_stroke = None
self._current_font = None
self._ctm_stack.pop()
assert self._ctm_stack
def transform(self, a=1, b=0, c=0, d=1, e=0, f=0):
super().transform(a, b, c, d, e, f)
self._ctm_stack[-1] = Matrix(a, b, c, d, e, f) @ self.ctm
def begin_text(self):
if self.stream[-1] == b'ET':
self._current_font = self._old_font
self.stream.pop()
else:
super().begin_text()
def end_text(self):
self._old_font, self._current_font = self._current_font, None
super().end_text()
def set_color_rgb(self, r, g, b, stroke=False):
if stroke:
if (r, g, b) == self._current_color_stroke:
return
else:
self._current_color_stroke = (r, g, b)
else:
if (r, g, b) == self._current_color:
return
else:
self._current_color = (r, g, b)
super().set_color_rgb(r, g, b, stroke)
def set_font_size(self, font, size):
if (font, size) == self._current_font:
return
self._current_font = (font, size)
super().set_font_size(font, size)
def set_alpha(self, alpha, stroke=False):
if stroke:
if alpha == self._current_alpha_stroke:
return
else:
self._current_alpha_stroke = alpha
else:
if alpha == self._current_alpha:
return
else:
self._current_alpha = alpha
if alpha not in self._alpha_states:
self._alpha_states[alpha] = pydyf.Dictionary()
if stroke in (None, False):
self._alpha_states[alpha]['ca'] = alpha
if stroke in (None, True):
self._alpha_states[alpha]['CA'] = alpha
self.set_state(alpha)
def add_font(self, font_hash, font_content, pango_font):
self._document.fonts[font_hash] = Font(font_content, pango_font)
return self._document.fonts[font_hash]
def get_fonts(self):
return self._document.fonts
def add_transparency_group(self, bounding_box):
alpha_states = pydyf.Dictionary()
x_objects = pydyf.Dictionary()
patterns = pydyf.Dictionary()
shadings = pydyf.Dictionary()
resources = pydyf.Dictionary({
'ExtGState': alpha_states,
'XObject': x_objects,
'Pattern': patterns,
'Shading': shadings,
'Font': None, # Will be set by _use_references
})
extra = pydyf.Dictionary({
'Type': '/XObject',
'Subtype': '/Form',
'BBox': pydyf.Array(bounding_box),
'Resources': resources,
'Group': pydyf.Dictionary({
'Type': '/Group',
'S': '/Transparency',
'I': 'true',
'CS': '/DeviceRGB',
}),
})
group = Context(
self._document, self.page_rectangle, alpha_states, x_objects,
patterns, shadings, extra=extra)
group.id = f'x{len(self._x_objects)}'
self._x_objects[group.id] = group
return group
def add_image(self, pillow_image, image_rendering, optimize_image):
if 'transparency' in pillow_image.info:
pillow_image = pillow_image.convert('RGBA')
elif pillow_image.mode in ('1', 'P'):
pillow_image = pillow_image.convert('RGB')
if pillow_image.mode in ('RGB', 'RGBA'):
color_space = '/DeviceRGB'
elif pillow_image.mode == 'L':
color_space = '/DeviceGray'
elif pillow_image.mode == 'CMYK':
color_space = '/DeviceCMYK'
else:
LOGGER.warning('Unknown image mode: %s', pillow_image.mode)
color_space = '/DeviceRGB'
interpolate = 'true' if image_rendering == 'auto' else 'false'
extra = pydyf.Dictionary({
'Type': '/XObject',
'Subtype': '/Image',
'Width': pillow_image.width,
'Height': pillow_image.height,
'ColorSpace': color_space,
'BitsPerComponent': 8,
'Interpolate': interpolate,
})
image_file = io.BytesIO()
if pillow_image.format == 'JPEG':
extra['Filter'] = '/DCTDecode'
pillow_image.save(
image_file, format='JPEG', optimize=optimize_image)
else:
extra['Filter'] = '/JPXDecode'
if pillow_image.mode == 'RGBA':
alpha = pillow_image.getchannel('A')
pillow_image = pillow_image.convert('RGB')
alpha_file = io.BytesIO()
alpha.save(
alpha_file, format='JPEG2000', optimize=optimize_image,
num_resolutions=1)
extra['SMask'] = pydyf.Stream([alpha_file.getvalue()], extra={
'Filter': '/JPXDecode',
'Type': '/XObject',
'Subtype': '/Image',
'Width': pillow_image.width,
'Height': pillow_image.height,
'ColorSpace': '/DeviceGray',
'BitsPerComponent': 8,
'Interpolate': interpolate,
})
# Set number of resolutions to 1 because of
# https://github.com/uclouvain/openjpeg/issues/215
pillow_image.save(
image_file, format='JPEG2000', optimize=optimize_image,
num_resolutions=1)
stream = [image_file.getvalue()]
xobject = pydyf.Stream(stream, extra=extra)
image_name = f'Im{len(self._x_objects)}'
self._x_objects[image_name] = xobject
return image_name
def add_pattern(self, x, y, width, height, repeat_width, repeat_height,
matrix):
alpha_states = pydyf.Dictionary()
x_objects = pydyf.Dictionary()
patterns = pydyf.Dictionary()
shadings = pydyf.Dictionary()
resources = pydyf.Dictionary({
'ExtGState': alpha_states,
'XObject': x_objects,
'Pattern': patterns,
'Shading': shadings,
'Font': None, # Will be set by _use_references
})
matrix = Matrix(1, 0, 0, 1, x, y) @ matrix
extra = pydyf.Dictionary({
'Type': '/Pattern',
'PatternType': 1,
'BBox': pydyf.Array([0, 0, width, height]),
'XStep': repeat_width,
'YStep': repeat_height,
'TilingType': 1,
'PaintType': 1,
'Matrix': pydyf.Array(matrix.values),
'Resources': resources,
})
pattern = Context(
self._document, self.page_rectangle, alpha_states, x_objects,
patterns, shadings, extra=extra)
pattern.id = f'p{len(self._patterns)}'
self._patterns[pattern.id] = pattern
return pattern
def add_shading(self):
shading = pydyf.Dictionary()
shading.id = f's{len(self._shadings)}'
self._shadings[shading.id] = shading
return shading
BookmarkSubtree = collections.namedtuple(
'BookmarkSubtree', ('label', 'destination', 'children', 'state'))
def _write_pdf_attachment(pdf, attachment, url_fetcher):
"""Write an attachment to the PDF stream.
:return:
the attachment PDF dictionary.
"""
# Attachments from document links like <link> or <a> can only be URLs.
# They're passed in as tuples
url = ''
if isinstance(attachment, tuple):
url, description = attachment
attachment = Attachment(
url=url, url_fetcher=url_fetcher, description=description)
elif not isinstance(attachment, Attachment):
attachment = Attachment(guess=attachment, url_fetcher=url_fetcher)
try:
with attachment.source as (source_type, source, url, _):
if isinstance(source, bytes):
source = io.BytesIO(source)
uncompressed_length = 0
stream = b''
md5 = hashlib.md5()
compress = zlib.compressobj()
for data in iter(lambda: source.read(4096), b''):
uncompressed_length += len(data)
md5.update(data)
compressed = compress.compress(data)
stream += compressed
compressed = compress.flush(zlib.Z_FINISH)
stream += compressed
file_extra = pydyf.Dictionary({
'Type': '/EmbeddedFile',
'Filter': '/FlateDecode',
'Params': pydyf.Dictionary({
'CheckSum': f'<{md5.hexdigest()}>',
'Size': uncompressed_length,
})
})
file_stream = pydyf.Stream([stream], file_extra)
pdf.add_object(file_stream)
except URLFetchingError as exception:
LOGGER.error('Failed to load attachment: %s', exception)
return
# TODO: Use the result object from a URL fetch operation to provide more
# details on the possible filename.
if url and urlsplit(url).path:
filename = basename(unquote(urlsplit(url).path))
else:
filename = 'attachment.bin'
attachment = pydyf.Dictionary({
'Type': '/Filespec',
'F': pydyf.String(),
'UF': pydyf.String(filename),
'EF': pydyf.Dictionary({'F': file_stream.reference}),
'Desc': pydyf.String(attachment.description or ''),
})
pdf.add_object(attachment)
return attachment
def create_bookmarks(bookmarks, pdf, parent=None):
count = len(bookmarks)
outlines = []
for title, (page, x, y), children, state in bookmarks:
destination = pydyf.Array((
pdf.objects[pdf.pages['Kids'][page * 3]].reference,
'/XYZ', x, y, 0))
outline = pydyf.Dictionary({
'Title': pydyf.String(title), 'Dest': destination})
pdf.add_object(outline)
children_outlines, children_count = create_bookmarks(
children, pdf, parent=outline)
outline['Count'] = children_count
if state == 'closed':
outline['Count'] *= -1
else:
count += children_count
if outlines:
outline['Prev'] = outlines[-1].reference
outlines[-1]['Next'] = outline.reference
if children_outlines:
outline['First'] = children_outlines[0].reference
outline['Last'] = children_outlines[-1].reference
if parent is not None:
outline['Parent'] = parent.reference
outlines.append(outline)
return outlines, count
def add_hyperlinks(links, anchors, matrix, pdf, page, names):
"""Include hyperlinks in current PDF page."""
for link in links:
link_type, link_target, rectangle, _ = link
x1, y1 = matrix.transform_point(*rectangle[:2])
x2, y2 = matrix.transform_point(*rectangle[2:])
if link_type in ('internal', 'external'):
annot = pydyf.Dictionary({
'Type': '/Annot',
'Subtype': '/Link',
'Rect': pydyf.Array([x1, y1, x2, y2]),
'BS': pydyf.Dictionary({'W': 0}),
})
if link_type == 'internal':
annot['Dest'] = pydyf.String(link_target)
else:
annot['A'] = pydyf.Dictionary({
'Type': '/Action',
'S': '/URI',
'URI': pydyf.String(link_target),
})
pdf.add_object(annot)
if 'Annots' not in page:
page['Annots'] = pydyf.Array()
page['Annots'].append(annot.reference)
for anchor in anchors:
anchor_name, x, y = anchor
x, y = matrix.transform_point(x, y)
names.append(pydyf.String(anchor_name))
names.append(pydyf.Array([page.reference, '/XYZ', x, y, 0]))
def rectangle_aabb(matrix, pos_x, pos_y, width, height):
"""Apply a transformation matrix to an axis-aligned rectangle.
Return its axis-aligned bounding box as ``(x1, y1, x2, y2)``.
"""
transform_point = matrix.transform_point
x1, y1 = transform_point(pos_x, pos_y)
x2, y2 = transform_point(pos_x + width, pos_y)
x3, y3 = transform_point(pos_x, pos_y + height)
x4, y4 = transform_point(pos_x + width, pos_y + height)
box_x1 = min(x1, x2, x3, x4)
box_y1 = min(y1, y2, y3, y4)
box_x2 = max(x1, x2, x3, x4)
box_y2 = max(y1, y2, y3, y4)
return box_x1, box_y1, box_x2, box_y2
def resolve_links(pages):
"""Resolve internal hyperlinks.
Links to a missing anchor are removed with a warning.
If multiple anchors have the same name, the first one is used.
:returns:
A generator yielding lists (one per page) like :attr:`Page.links`,
except that ``target`` for internal hyperlinks is
``(page_number, x, y)`` instead of an anchor name.
The page number is a 0-based index into the :attr:`pages` list,
and ``x, y`` are in CSS pixels from the top-left of the page.
"""
anchors = set()
paged_anchors = []
for i, page in enumerate(pages):
paged_anchors.append([])
for anchor_name, (point_x, point_y) in page.anchors.items():
if anchor_name not in anchors:
paged_anchors[-1].append((anchor_name, point_x, point_y))
anchors.add(anchor_name)
for page in pages:
page_links = []
for link in page.links:
link_type, anchor_name, rectangle, _ = link
if link_type == 'internal':
if anchor_name not in anchors:
LOGGER.error(
'No anchor #%s for internal URI reference',
anchor_name)
else:
page_links.append(
(link_type, anchor_name, rectangle, None))
else:
# External link
page_links.append(link)
yield page_links, paged_anchors.pop(0)
class Matrix(list):
def __init__(self, a=1, b=0, c=0, d=1, e=0, f=0, matrix=None):
if matrix is None:
matrix = [[a, b, 0], [c, d, 0], [e, f, 1]]
super().__init__(matrix)
def __matmul__(self, other):
assert len(self[0]) == len(other) == len(other[0]) == 3
return Matrix(matrix=[
[sum(self[i][k] * other[k][j] for k in range(3)) for j in range(3)]
for i in range(len(self))])
@property
def determinant(self):
assert len(self) == len(self[0]) == 3
return (
self[0][0] * (self[1][1] * self[2][2] - self[1][2] * self[2][1]) -
self[1][0] * (self[0][1] * self[2][2] - self[0][2] * self[2][1]) +
self[2][0] * (self[0][1] * self[1][2] - self[0][2] * self[1][1]))
def transform_point(self, x, y):
return (Matrix(matrix=[[x, y, 1]]) @ self)[0][:2]
@property
def values(self):
(a, b), (c, d), (e, f) = [column[:2] for column in self]
return a, b, c, d, e, f
class Page:
"""Represents a single rendered page.
.. versionadded:: 0.15
Should be obtained from :attr:`Document.pages` but not
instantiated directly.
"""
def __init__(self, page_box):
#: The page width, including margins, in CSS pixels.
self.width = page_box.margin_width()
#: The page height, including margins, in CSS pixels.
self.height = page_box.margin_height()
#: The page bleed widths as a :obj:`dict` with ``'top'``, ``'right'``,
#: ``'bottom'`` and ``'left'`` as keys, and values in CSS pixels.
self.bleed = {
side: page_box.style[f'bleed_{side}'].value
for side in ('top', 'right', 'bottom', 'left')}
#: The :obj:`list` of ``(bookmark_level, bookmark_label, target)``
#: :obj:`tuples <tuple>`. ``bookmark_level`` and ``bookmark_label``
#: are respectively an :obj:`int` and a :obj:`string <str>`, based on
#: the CSS properties of the same names. ``target`` is an ``(x, y)``
#: point in CSS pixels from the top-left of the page.
self.bookmarks = []
#: The :obj:`list` of ``(link_type, target, rectangle)`` :obj:`tuples
#: <tuple>`. A ``rectangle`` is ``(x, y, width, height)``, in CSS
#: pixels from the top-left of the page. ``link_type`` is one of three
#: strings:
#:
#: * ``'external'``: ``target`` is an absolute URL
#: * ``'internal'``: ``target`` is an anchor name (see
#: :attr:`Page.anchors`).
#: The anchor might be defined in another page,
#: in multiple pages (in which case the first occurence is used),
#: or not at all.
#: * ``'attachment'``: ``target`` is an absolute URL and points
#: to a resource to attach to the document.
self.links = []
#: The :obj:`dict` mapping each anchor name to its target, an
#: ``(x, y)`` point in CSS pixels from the top-left of the page.
self.anchors = {}
self._gather_links_and_bookmarks(page_box)
self._page_box = page_box
def _gather_links_and_bookmarks(self, box, parent_matrix=None):
# Get box transformation matrix.
# "Transforms apply to block-level and atomic inline-level elements,
# but do not apply to elements which may be split into
# multiple inline-level boxes."
# http://www.w3.org/TR/css3-2d-transforms/#introduction
if box.style['transform'] and not isinstance(box, boxes.InlineBox):
border_width = box.border_width()
border_height = box.border_height()
origin_x, origin_y = box.style['transform_origin']
offset_x = percentage(origin_x, border_width)
offset_y = percentage(origin_y, border_height)
origin_x = box.border_box_x() + offset_x
origin_y = box.border_box_y() + offset_y
matrix = Matrix(e=origin_x, f=origin_y)
for name, args in box.style['transform']:
a, b, c, d, e, f = 1, 0, 0, 1, 0, 0
if name == 'scale':
a, d = args
elif name == 'rotate':
a = d = math.cos(args)
b = math.sin(args)
c = -b
elif name == 'translate':
e = percentage(args[0], border_width)
f = percentage(args[1], border_height)
elif name == 'skew':
b, c = math.tan(args[1]), math.tan(args[0])
else:
assert name == 'matrix'
a, b, c, d, e, f = args
matrix = Matrix(a, b, c, d, e, f) @ matrix
box.transformation_matrix = (
Matrix(e=-origin_x, f=-origin_y) @ matrix)
if parent_matrix:
matrix = box.transformation_matrix @ parent_matrix
else:
matrix = box.transformation_matrix
else:
matrix = parent_matrix
bookmark_label = box.bookmark_label
if box.style['bookmark_level'] == 'none':
bookmark_level = None
else:
bookmark_level = box.style['bookmark_level']
state = box.style['bookmark_state']
link = box.style['link']
anchor_name = box.style['anchor']
has_bookmark = bookmark_label and bookmark_level
# 'link' is inherited but redundant on text boxes
has_link = link and not isinstance(box, (boxes.TextBox, boxes.LineBox))
# In case of duplicate IDs, only the first is an anchor.
has_anchor = anchor_name and anchor_name not in self.anchors
if has_bookmark or has_link or has_anchor:
pos_x, pos_y, width, height = box.hit_area()
if has_link:
token_type, link = link
assert token_type == 'url'
link_type, target = link
assert isinstance(target, str)
if link_type == 'external' and box.is_attachment:
link_type = 'attachment'
if matrix:
link = (
link_type, target,
rectangle_aabb(matrix, pos_x, pos_y, width, height),
box.download_name)
else:
link = (
link_type, target,
(pos_x, pos_y, pos_x + width, pos_y + height),
box.download_name)
self.links.append(link)
if matrix and (has_bookmark or has_anchor):
pos_x, pos_y = matrix.transform_point(pos_x, pos_y)
if has_bookmark:
self.bookmarks.append(
(bookmark_level, bookmark_label, (pos_x, pos_y), state))
if has_anchor:
self.anchors[anchor_name] = pos_x, pos_y
for child in box.all_children():
self._gather_links_and_bookmarks(child, matrix)
def paint(self, context, left_x=0, top_y=0, scale=1, clip=False):
"""Paint the page into the PDF file.
:type context: ``Context``
:param context:
A context object.
:param float left_x:
X coordinate of the left of the page, in PDF points.
:param float top_y:
Y coordinate of the top of the page, in PDF points.
:param float scale:
Zoom scale.
:param bool clip:
Whether to clip/cut content outside the page. If false or
not provided, content can overflow.
"""
with stacked(context):
# Make (0, 0) the top-left corner, and make user units CSS pixels:
context.transform(scale, 0, 0, scale, left_x, top_y)
if clip:
width = self.width
height = self.height
context.rectangle(0, 0, width, height)
context.clip()
draw_page(self._page_box, context)
class DocumentMetadata:
"""Meta-information belonging to a whole :class:`Document`.
.. versionadded:: 0.20
New attributes may be added in future versions of WeasyPrint.
"""
def __init__(self, title=None, authors=None, description=None,
keywords=None, generator=None, created=None, modified=None,
attachments=None):
#: The title of the document, as a string or :obj:`None`.
#: Extracted from the ``<title>`` element in HTML
#: and written to the ``/Title`` info field in PDF.
self.title = title
#: The authors of the document, as a list of strings.
#: (Defaults to the empty list.)
#: Extracted from the ``<meta name=author>`` elements in HTML
#: and written to the ``/Author`` info field in PDF.
self.authors = authors or []
#: The description of the document, as a string or :obj:`None`.
#: Extracted from the ``<meta name=description>`` element in HTML
#: and written to the ``/Subject`` info field in PDF.
self.description = description
#: Keywords associated with the document, as a list of strings.
#: (Defaults to the empty list.)
#: Extracted from ``<meta name=keywords>`` elements in HTML
#: and written to the ``/Keywords`` info field in PDF.
self.keywords = keywords or []
#: The name of one of the software packages
#: used to generate the document, as a string or :obj:`None`.
#: Extracted from the ``<meta name=generator>`` element in HTML
#: and written to the ``/Creator`` info field in PDF.
self.generator = generator
#: The creation date of the document, as a string or :obj:`None`.
#: Dates are in one of the six formats specified in
#: `W3Cs profile of ISO 8601 <http://www.w3.org/TR/NOTE-datetime>`_.
#: Extracted from the ``<meta name=dcterms.created>`` element in HTML
#: and written to the ``/CreationDate`` info field in PDF.
self.created = created
#: The modification date of the document, as a string or :obj:`None`.
#: Dates are in one of the six formats specified in
#: `W3Cs profile of ISO 8601 <http://www.w3.org/TR/NOTE-datetime>`_.
#: Extracted from the ``<meta name=dcterms.modified>`` element in HTML
#: and written to the ``/ModDate`` info field in PDF.
self.modified = modified
#: File attachments, as a list of tuples of URL and a description or
#: :obj:`None`. (Defaults to the empty list.)
#: Extracted from the ``<link rel=attachment>`` elements in HTML
#: and written to the ``/EmbeddedFiles`` dictionary in PDF.
#:
#: .. versionadded:: 0.22
self.attachments = attachments or []
class Document:
"""A rendered document ready to be painted in a pydyf stream.
Typically obtained from :meth:`HTML.render() <weasyprint.HTML.render>`, but
can also be instantiated directly with a list of :class:`pages <Page>`, a
set of :class:`metadata <DocumentMetadata>`, a :func:`url_fetcher
<weasyprint.default_url_fetcher>` function, and a :class:`font_config
<weasyprint.text.fonts.FontConfiguration>`.
"""
@classmethod
def _build_layout_context(cls, html, stylesheets,
presentational_hints=False,
optimize_images=False, font_config=None,
counter_style=None, image_cache=None):
if font_config is None:
font_config = FontConfiguration()
if counter_style is None:
counter_style = CounterStyle()
target_collector = TargetCollector()
page_rules = []
user_stylesheets = []
image_cache = {} if image_cache is None else image_cache
for css in stylesheets or []:
if not hasattr(css, 'matcher'):
css = CSS(
guess=css, media_type=html.media_type,
font_config=font_config, counter_style=counter_style)
user_stylesheets.append(css)
style_for = get_all_computed_styles(
html, user_stylesheets, presentational_hints, font_config,
counter_style, page_rules, target_collector)
get_image_from_uri = functools.partial(
original_get_image_from_uri, image_cache, html.url_fetcher,
optimize_images)
PROGRESS_LOGGER.info('Step 4 - Creating formatting structure')
context = LayoutContext(
style_for, get_image_from_uri, font_config, counter_style,
target_collector)
return context
@classmethod
def _render(cls, html, stylesheets, presentational_hints=False,
optimize_images=False, font_config=None, counter_style=None,
image_cache=None):
if font_config is None:
font_config = FontConfiguration()
if counter_style is None:
counter_style = CounterStyle()
context = cls._build_layout_context(
html, stylesheets, presentational_hints, optimize_images,
font_config, counter_style, image_cache)
root_box = build_formatting_structure(
html.etree_element, context.style_for, context.get_image_from_uri,
html.base_url, context.target_collector, counter_style)
page_boxes = layout_document(html, root_box, context)
rendering = cls(
[Page(page_box) for page_box in page_boxes],
DocumentMetadata(**get_html_metadata(html)),
html.url_fetcher, font_config)
return rendering
def _use_references(self, pdf, resources):
# XObjects
for key, x_object in resources.get('XObject', {}).items():
pdf.add_object(x_object)
resources['XObject'][key] = x_object.reference
if 'SMask' in x_object.extra:
pdf.add_object(x_object.extra['SMask'])
x_object.extra['SMask'] = x_object.extra['SMask'].reference
if 'Resources' in x_object.extra:
if 'Font' in x_object.extra['Resources']:
x_object.extra['Resources']['Font'] = resources['Font']
self._use_references(pdf, x_object.extra['Resources'])
pdf.add_object(x_object.extra['Resources'])
x_object.extra['Resources'] = (
x_object.extra['Resources'].reference)
# Patterns
for key, pattern in resources.get('Pattern', {}).items():
pdf.add_object(pattern)
resources['Pattern'][key] = pattern.reference
if 'Resources' in pattern.extra:
if 'Font' in pattern.extra['Resources']:
pattern.extra['Resources']['Font'] = resources['Font']
self._use_references(pdf, pattern.extra['Resources'])
pdf.add_object(pattern.extra['Resources'])
pattern.extra['Resources'] = (
pattern.extra['Resources'].reference)
# Shadings
for key, shading in resources.get('Shading', {}).items():
pdf.add_object(shading)
resources['Shading'][key] = shading.reference
# Alpha states
for key, alpha in resources.get('ExtGState', {}).items():
if 'SMask' in alpha and 'G' in alpha['SMask']:
alpha['SMask']['G'] = alpha['SMask']['G'].reference
def __init__(self, pages, metadata, url_fetcher, font_config):
#: A list of :class:`Page` objects.
self.pages = pages
#: A :class:`DocumentMetadata` object.
#: Contains information that does not belong to a specific page
#: but to the whole document.
self.metadata = metadata
#: A function or other callable with the same signature as
#: :func:`weasyprint.default_url_fetcher` called to fetch external
#: resources such as stylesheets and images. (See :ref:`URL Fetchers`.)
self.url_fetcher = url_fetcher
#: A :obj:`dict` of fonts used by the document. Keys are hashes used to
#: identify fonts, values are ``Font`` objects.
self.fonts = {}
# Keep a reference to font_config to avoid its garbage collection until
# rendering is destroyed. This is needed as font_config.__del__ removes
# fonts that may be used when rendering
self._font_config = font_config
def copy(self, pages='all'):
"""Take a subset of the pages.
.. versionadded:: 0.15
:type pages: :term:`iterable`
:param pages:
An iterable of :class:`Page` objects from :attr:`pages`.
:return:
A new :class:`Document` object.
Examples:
Write two PDF files for odd-numbered and even-numbered pages::
# Python lists count from 0 but pages are numbered from 1.
# [::2] is a slice of even list indexes but odd-numbered pages.
document.copy(document.pages[::2]).write_pdf('odd_pages.pdf')
document.copy(document.pages[1::2]).write_pdf('even_pages.pdf')
Combine multiple documents into one PDF file,
using metadata from the first::
all_pages = [p for doc in documents for p in doc.pages]
documents[0].copy(all_pages).write_pdf('combined.pdf')
"""
if pages == 'all':
pages = self.pages
elif not isinstance(pages, list):
pages = list(pages)
return type(self)(
pages, self.metadata, self.url_fetcher, self._font_config)
def write_pdf(self, target=None, zoom=1, attachments=None, finisher=None):
"""Paint the pages in a PDF file, with metadata.
:type target:
:class:`str`, :class:`pathlib.Path` or :term:`file object`
:param target:
A filename where the PDF file is generated, a file object, or
:obj:`None`.
:param float zoom:
The zoom factor in PDF units per CSS units. **Warning**:
All CSS units are affected, including physical units like
``cm`` and named sizes like ``A4``. For values other than
1, the physical CSS units will thus be "wrong".
:param list attachments: A list of additional file attachments for the
generated PDF document or :obj:`None`. The list's elements are
``Attachment`` objects, filenames, URLs or file-like objects.
:param finisher: A finisher function, that accepts the document and a
:class:`pydyf.PDF` object as parameters, can be passed to perform
post-processing on the PDF right before the trailer is written.
:returns:
The PDF as :obj:`bytes` if ``target`` is not provided or
:obj:`None`, otherwise :obj:`None` (the PDF is written to
``target``).
"""
# 0.75 = 72 PDF point per inch / 96 CSS pixel per inch
scale = zoom * 0.75
PROGRESS_LOGGER.info('Step 6 - Creating PDF')
pdf = pydyf.PDF()
alpha_states = pydyf.Dictionary()
x_objects = pydyf.Dictionary()
patterns = pydyf.Dictionary()
shadings = pydyf.Dictionary()
resources = pydyf.Dictionary({
'ExtGState': alpha_states,
'XObject': x_objects,
'Pattern': patterns,
'Shading': shadings,
})
pdf.add_object(resources)
pdf_names = pydyf.Array()
# Links and anchors
page_links_and_anchors = list(resolve_links(self.pages))
attachment_links = [
[link for link in page_links if link[0] == 'attachment']
for page_links, page_anchors in page_links_and_anchors]
# Annotations
annot_files = {}
# A single link can be split in multiple regions. We don't want to
# embed a file multiple times of course, so keep a reference to every
# embedded URL and reuse the object number.
for page_links in attachment_links:
for link_type, annot_target, rectangle, _ in page_links:
if link_type == 'attachment' and target not in annot_files:
# TODO: Use the title attribute as description. The comment
# above about multiple regions won't always be correct,
# because two links might have the same href, but different
# titles.
annot_files[annot_target] = _write_pdf_attachment(
pdf, (annot_target, None), self.url_fetcher)
# Bookmarks
root = []
# At one point in the document, for each "output" depth, how much
# to add to get the source level (CSS values of bookmark-level).
# E.g. with <h1> then <h3>, level_shifts == [0, 1]
# 1 means that <h3> has depth 3 - 1 = 2 in the output.
skipped_levels = []
last_by_depth = [root]
previous_level = 0
for page_number, (page, links_and_anchors, page_links) in enumerate(
zip(self.pages, page_links_and_anchors, attachment_links)):
# Draw from the top-left corner
matrix = Matrix(scale, 0, 0, -scale, 0, page.height * scale)
# Links and anchors
links, anchors = links_and_anchors
page_width = scale * (
page.width + page.bleed['left'] + page.bleed['right'])
page_height = scale * (
page.height + page.bleed['top'] + page.bleed['bottom'])
left = -scale * page.bleed['left']
top = -scale * page.bleed['top']
right = left + page_width
bottom = top + page_height
page_rectangle = (
left / scale, top / scale, right / scale, bottom / scale)
stream = Context(
self, page_rectangle, alpha_states, x_objects, patterns,
shadings)
stream.transform(1, 0, 0, -1, 0, page.height * scale)
page.paint(stream, scale=scale)
pdf.add_object(stream)
pdf_page = pydyf.Dictionary({
'Type': '/Page',
'Parent': pdf.pages.reference,
'MediaBox': pydyf.Array([left, top, right, bottom]),
'Contents': stream.reference,
'Resources': resources.reference,
})
pdf.add_page(pdf_page)
add_hyperlinks(links, anchors, matrix, pdf, pdf_page, pdf_names)
# Bleed
bleed = {key: value * 0.75 for key, value in page.bleed.items()}
trim_left = left + bleed['left']
trim_top = top + bleed['top']
trim_right = right - bleed['right']
trim_bottom = bottom - bleed['bottom']
# Arbitrarly set PDF BleedBox between CSS bleed box (MediaBox) and
# CSS page box (TrimBox) at most 10 points from the TrimBox.
bleed_left = trim_left - min(10, bleed['left'])
bleed_top = trim_top - min(10, bleed['top'])
bleed_right = trim_right + min(10, bleed['right'])
bleed_bottom = trim_bottom + min(10, bleed['bottom'])
pdf_page['TrimBox'] = pydyf.Array([
trim_left, trim_top, trim_right, trim_bottom])
pdf_page['BleedBox'] = pydyf.Array([
bleed_left, bleed_top, bleed_right, bleed_bottom])
# Annotations
# TODO: splitting a link into multiple independent rectangular
# annotations works well for pure links, but rather mediocre for
# other annotations and fails completely for transformed (CSS) or
# complex link shapes (area). It would be better to use /AP for all
# links and coalesce link shapes that originate from the same HTML
# link. This would give a feeling similiar to what browsers do with
# links that span multiple lines.
for link_type, annot_target, rectangle, _ in page_links:
annot_file = annot_files[annot_target]
if link_type == 'attachment' and annot_file is not None:
rectangle = (
*matrix.transform_point(*rectangle[:2]),
*matrix.transform_point(*rectangle[2:]))
annot = pydyf.Dictionary({
'Type': '/Annot',
'Rect': pydyf.Array(rectangle),
'Subtype': '/FileAttachment',
'T': pydyf.String(),
'FS': annot_file.reference,
'AP': pydyf.Dictionary({'N': pydyf.Stream([], {
'Type': '/XObject',
'Subtype': '/Form',
'BBox': pydyf.Array(rectangle),
'Length': 0,
})})
})
pdf.add_object(annot)
if 'Annots' not in pdf_page:
pdf_page['Annots'] = pydyf.Array()
pdf_page['Annots'].append(annot.reference)
# Bookmarks
for level, label, (point_x, point_y), state in page.bookmarks:
if level > previous_level:
# Example: if the previous bookmark is a <h2>, the next
# depth "should" be for <h3>. If now we get a <h6> were
# skipping two levels: append 6 - 3 - 1 = 2
skipped_levels.append(level - previous_level - 1)
else:
temp = level
while temp < previous_level:
temp += 1 + skipped_levels.pop()
if temp > previous_level:
# We remove too many "skips", add some back:
skipped_levels.append(temp - previous_level - 1)
previous_level = level
depth = level - sum(skipped_levels)
assert depth == len(skipped_levels)
assert depth >= 1
children = []
point_x, point_y = matrix.transform_point(point_x, point_y)
subtree = BookmarkSubtree(
label, (page_number, point_x, point_y), children, state)
last_by_depth[depth - 1].append(subtree)
del last_by_depth[depth:]
last_by_depth.append(children)
# Outlines
outlines, count = create_bookmarks(root, pdf)
if outlines:
outlines_dictionary = pydyf.Dictionary({
'Count': count,
'First': outlines[0].reference,
'Last': outlines[-1].reference,
})
pdf.add_object(outlines_dictionary)
for outline in outlines:
outline['Parent'] = outlines_dictionary.reference
pdf.catalog['Outlines'] = outlines_dictionary.reference
PROGRESS_LOGGER.info('Step 7 - Adding PDF metadata')
# PDF information
if self.metadata.title:
pdf.info['Title'] = pydyf.String(self.metadata.title)
if self.metadata.authors:
pdf.info['Author'] = pydyf.String(
', '.join(self.metadata.authors))
if self.metadata.description:
pdf.info['Subject'] = pydyf.String(self.metadata.description)
if self.metadata.keywords:
pdf.info['Keywords'] = pydyf.String(
', '.join(self.metadata.keywords))
if self.metadata.generator:
pdf.info['Creator'] = pydyf.String(self.metadata.generator)
pdf.info['Producer'] = pydyf.String(f'WeasyPrint {__version__}')
if self.metadata.created:
pdf.info['CreationDate'] = pydyf.String(
_w3c_date_to_pdf(self.metadata.created, 'created'))
if self.metadata.modified:
pdf.info['ModDate'] = pydyf.String(
_w3c_date_to_pdf(self.metadata.modified, 'modified'))
# Embedded files
attachments = self.metadata.attachments + (attachments or [])
pdf_attachments = []
for attachment in attachments:
pdf_attachment = _write_pdf_attachment(
pdf, attachment, self.url_fetcher)
if pdf_attachment is not None:
pdf_attachments.append(pdf_attachment)
if pdf_attachments:
content = pydyf.Dictionary({'Names': pydyf.Array()})
for i, pdf_attachment in enumerate(pdf_attachments):
content['Names'].append(pydyf.String(f'attachment{i}'))
content['Names'].append(pdf_attachment.reference)
pdf.add_object(content)
if 'Names' not in pdf.catalog:
pdf.catalog['Names'] = pydyf.Dictionary()
pdf.catalog['Names']['EmbeddedFiles'] = content.reference
# Embeded fonts
pdf_fonts = pydyf.Dictionary()
fonts_by_file_hash = {}
for font in self.fonts.values():
if font.file_hash in fonts_by_file_hash:
fonts_by_file_hash[font.file_hash].append(font)
else:
fonts_by_file_hash[font.file_hash] = [font]
font_references_by_file_hash = {}
for file_hash, fonts in fonts_by_file_hash.items():
# Optimize font
cmap = {}
for font in fonts:
cmap = {**cmap, **font.cmap}
full_font = io.BytesIO(fonts[0].file_content)
optimized_font = io.BytesIO()
try:
ttfont = TTFont(full_font)
options = subset.Options(
retain_gids=True, passthrough_tables=True)
subsetter = subset.Subsetter(options)
subsetter.populate(gids=cmap)
subsetter.subset(ttfont)
ttfont.save(optimized_font)
content = optimized_font.getvalue()
except TTLibError:
content = fonts[0].file_content
# Include font
font_type = 'otf' if content[:4] == b'OTTO' else 'ttf'
if font_type == 'otf':
font_extra = pydyf.Dictionary({'Subtype': '/OpenType'})
else:
font_extra = pydyf.Dictionary({'Length1': len(content)})
font_stream = pydyf.Stream([content], font_extra, compress=True)
pdf.add_object(font_stream)
font_references_by_file_hash[file_hash] = font_stream.reference
for font in self.fonts.values():
widths = pydyf.Array()
for i in sorted(font.widths):
if i - 1 not in font.widths:
widths.append(i)
current_widths = pydyf.Array()
widths.append(current_widths)
current_widths.append(font.widths[i])
font_descriptor = pydyf.Dictionary({
'Type': '/FontDescriptor',
'FontName': font.name,
'FontFamily': pydyf.String(font.family),
'Flags': font.flags,
'FontBBox': pydyf.Array(font.bbox),
'ItalicAngle': font.italic_angle,
'Ascent': font.ascent,
'Descent': font.descent,
'CapHeight': font.bbox[3],
'StemV': font.stemv,
'StemH': font.stemh,
(f'FontFile{"3" if font_type == "otf" else "2"}'):
font_references_by_file_hash[font.file_hash],
})
if font_type == 'otf':
font_descriptor['Subtype'] = '/OpenType'
pdf.add_object(font_descriptor)
subfont_dictionary = pydyf.Dictionary({
'Type': '/Font',
'Subtype': f'/CIDFontType{"0" if font_type == "otf" else "2"}',
'BaseFont': font.name,
'CIDSystemInfo': pydyf.Dictionary({
'Registry': pydyf.String('Adobe'),
'Ordering': pydyf.String('Identity'),
'Supplement': 0,
}),
'W': widths,
'FontDescriptor': font_descriptor.reference,
})
pdf.add_object(subfont_dictionary)
to_unicode = pydyf.Stream([
b'/CIDInit /ProcSet findresource begin',
b'12 dict begin',
b'begincmap',
b'/CIDSystemInfo',
b'<< /Registry (Adobe)',
b'/Ordering (UCS)',
b'/Supplement 0',
b'>> def',
b'/CMapName /Adobe-Identity-UCS def',
b'/CMapType 2 def',
b'1 begincodespacerange',
b'<0000> <ffff>',
b'endcodespacerange',
f'{len(font.cmap)} beginbfchar'.encode('ascii')])
for glyph, text in font.cmap.items():
unicode_codepoints = ''.join(
f'{letter.encode("utf-16-be").hex()}' for letter in text)
to_unicode.stream.append(
f'<{glyph:04x}> <{unicode_codepoints}>'.encode('ascii'))
to_unicode.stream.extend([
b'endbfchar',
b'endcmap',
b'CMapName currentdict /CMap defineresource pop',
b'end',
b'end'])
pdf.add_object(to_unicode)
font_dictionary = pydyf.Dictionary({
'Type': '/Font',
'Subtype': '/Type0',
'BaseFont': font.name,
'Encoding': '/Identity-H',
'DescendantFonts': pydyf.Array([subfont_dictionary.reference]),
'ToUnicode': to_unicode.reference,
})
pdf.add_object(font_dictionary)
pdf_fonts[font.hash] = font_dictionary.reference
pdf.add_object(pdf_fonts)
resources['Font'] = pdf_fonts.reference
self._use_references(pdf, resources)
# Anchors
if pdf_names:
pdf.catalog['Names'] = pydyf.Dictionary(
{'Dests': pydyf.Dictionary({'Names': pdf_names})})
if finisher:
finisher(self, pdf)
file_obj = io.BytesIO()
pdf.write(file_obj)
if target is None:
return file_obj.getvalue()
else:
file_obj.seek(0)
if hasattr(target, 'write'):
shutil.copyfileobj(file_obj, target)
else:
with open(target, 'wb') as fd:
shutil.copyfileobj(file_obj, fd)