"""
weasyprint.document
-------------------
:copyright: Copyright 2011-2019 Simon Sapin and contributors, see AUTHORS.
:license: BSD, see LICENSE for details.
"""
import collections
import functools
import io
import math
import shutil
import warnings
import cairocffi as cairo
from . import CSS
from .css import get_all_computed_styles
from .css.targets import TargetCollector
from .draw import draw_page, stacked
from .fonts import FontConfiguration
from .formatting_structure import boxes
from .formatting_structure.build import build_formatting_structure
from .html import W3C_DATE_RE
from .images import get_image_from_uri as original_get_image_from_uri
from .layout import layout_document
from .layout.percentages import percentage
from .logger import LOGGER, PROGRESS_LOGGER
from .pdf import write_pdf_metadata
if cairo.cairo_version() < 11504:
warnings.warn(
'There are known rendering problems and missing features with '
'cairo < 1.15.4. WeasyPrint may work with older versions, but please '
'read the note about the needed cairo version on the "Install" page '
'of the documentation before reporting bugs. '
'http://weasyprint.readthedocs.io/en/latest/install.html')
def _get_matrix(box):
"""Return the matrix for the CSS transforms on this box.
:returns: a :class:`cairocffi.Matrix` object or :obj:`None`.
"""
# "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 = cairo.Matrix()
matrix.translate(origin_x, origin_y)
for name, args in box.style['transform']:
if name == 'scale':
matrix.scale(*args)
elif name == 'rotate':
matrix.rotate(args)
elif name == 'translate':
translate_x, translate_y = args
matrix.translate(
percentage(translate_x, border_width),
percentage(translate_y, border_height),
)
else:
if name == 'skewx':
args = (1, 0, math.tan(args), 1, 0, 0)
elif name == 'skewy':
args = (1, math.tan(args), 0, 1, 0, 0)
else:
assert name == 'matrix'
matrix = cairo.Matrix(*args) * matrix
matrix.translate(-origin_x, -origin_y)
box.transformation_matrix = matrix
return matrix
def rectangle_aabb(matrix, pos_x, pos_y, width, height):
"""Apply a transformation matrix to an axis-aligned rectangle
and return its axis-aligned bounding box as ``(x, y, width, height)``
"""
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_x1, box_y2 - box_y1
def _gather_links_and_bookmarks(box, bookmarks, links, anchors, matrix):
transform = _get_matrix(box)
if transform:
matrix = transform * matrix if matrix else transform
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)
# In case of duplicate IDs, only the first is an anchor.
has_anchor = anchor_name and anchor_name not in anchors
is_attachment = hasattr(box, 'is_attachment') and box.is_attachment
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 is_attachment:
link_type = 'attachment'
if matrix:
link = (
link_type, target, rectangle_aabb(
matrix, pos_x, pos_y, width, height))
else:
link = (link_type, target, (pos_x, pos_y, width, height))
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:
bookmarks.append(
(bookmark_level, bookmark_label, (pos_x, pos_y), state))
if has_anchor:
anchors[anchor_name] = pos_x, pos_y
for child in box.all_children():
_gather_links_and_bookmarks(child, bookmarks, links, anchors, matrix)
def _w3c_date_to_iso(string, attr_name):
"""Tranform W3C date to ISO-8601 format."""
if string is None:
return None
match = W3C_DATE_RE.match(string)
if match is None:
LOGGER.warning('Invalid %s date: %r', attr_name, string)
return None
groups = match.groupdict()
iso_date = '%04i-%02i-%02iT%02i:%02i:%02i' % (
int(groups['year']),
int(groups['month'] or 1),
int(groups['day'] or 1),
int(groups['hour'] or 0),
int(groups['minute'] or 0),
int(groups['second'] or 0))
if groups['hour']:
assert groups['minute']
if groups['tz_hour']:
assert groups['tz_hour'].startswith(('+', '-'))
assert groups['tz_minute']
iso_date += '%+03i:%02i' % (
int(groups['tz_hour']), int(groups['tz_minute']))
else:
iso_date += '+00:00'
return iso_date
class Page(object):
"""Represents a single rendered page.
.. versionadded:: 0.15
Should be obtained from :attr:`Document.pages` but not
instantiated directly.
"""
def __init__(self, page_box, enable_hinting=False):
#: 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['bleed_%s' % 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 = {}
_gather_links_and_bookmarks(
page_box, self.bookmarks, self.links, self.anchors, matrix=None)
self._page_box = page_box
self._enable_hinting = enable_hinting
def paint(self, cairo_context, left_x=0, top_y=0, scale=1, clip=False):
"""Paint the page in cairo, on any type of surface.
:type cairo_context: :class:`cairocffi.Context`
:param cairo_context:
Any cairo context object.
:type left_x: float
:param left_x:
X coordinate of the left of the page, in cairo user units.
:type top_y: float
:param top_y:
Y coordinate of the top of the page, in cairo user units.
:type scale: float
:param scale:
Zoom scale in cairo user units per CSS pixel.
:type clip: bool
:param clip:
Whether to clip/cut content outside the page. If false or
not provided, content can overflow.
"""
with stacked(cairo_context):
if self._enable_hinting:
left_x, top_y = cairo_context.user_to_device(left_x, top_y)
# Hint in device space
left_x = int(left_x)
top_y = int(top_y)
left_x, top_y = cairo_context.device_to_user(left_x, top_y)
# Make (0, 0) the top-left corner:
cairo_context.translate(left_x, top_y)
# Make user units CSS pixels:
cairo_context.scale(scale, scale)
if clip:
width = self.width
height = self.height
if self._enable_hinting:
width, height = (
cairo_context.user_to_device_distance(width, height))
# Hint in device space
width = int(math.ceil(width))
height = int(math.ceil(height))
width, height = (
cairo_context.device_to_user_distance(width, height))
cairo_context.rectangle(0, 0, width, height)
cairo_context.clip()
draw_page(self._page_box, cairo_context, self._enable_hinting)
class DocumentMetadata(object):
"""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
#: `W3C’s 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
#: `W3C’s 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 []
BookmarkSubtree = collections.namedtuple(
'BookmarkSubtree', ('label', 'destination', 'children', 'state'))
class Document(object):
"""A rendered document ready to be painted on a cairo surface.
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.fonts.FontConfiguration>`.
"""
@classmethod
def _render(cls, html, stylesheets, enable_hinting,
presentational_hints=False, font_config=None):
if font_config is None:
font_config = FontConfiguration()
target_collector = TargetCollector()
page_rules = []
user_stylesheets = []
for css in stylesheets or []:
if not hasattr(css, 'matcher'):
css = CSS(
guess=css, media_type=html.media_type,
font_config=font_config)
user_stylesheets.append(css)
style_for = get_all_computed_styles(
html, user_stylesheets, presentational_hints, font_config,
page_rules, target_collector)
get_image_from_uri = functools.partial(
original_get_image_from_uri, {}, html.url_fetcher)
PROGRESS_LOGGER.info('Step 4 - Creating formatting structure')
root_box = build_formatting_structure(
html.etree_element, style_for, get_image_from_uri,
html.base_url, target_collector)
page_boxes = layout_document(
enable_hinting, style_for, get_image_from_uri, root_box,
font_config, html, target_collector)
rendering = cls(
[Page(page_box, enable_hinting) for page_box in page_boxes],
DocumentMetadata(**html._get_metadata()),
html.url_fetcher, font_config)
return rendering
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:`default_url_fetcher` called to fetch external resources such
#: as stylesheets and images. (See :ref:`url-fetchers`.)
self.url_fetcher = url_fetcher
# 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')
Write each page to a numbred PNG file::
for i, page in enumerate(document.pages):
document.copy(page).write_png('page_%s.png' % i)
Combine multiple documents into one PDF file,
using metadata from the first::
all_pages = [p for p in doc.pages for doc in documents]
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 resolve_links(self):
"""Resolve internal hyperlinks.
.. versionadded:: 0.15
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(self.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 self.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))
else:
# External link
page_links.append(link)
yield page_links, paged_anchors.pop(0)
def make_bookmark_tree(self):
"""Make a tree of all bookmarks in the document.
.. versionadded:: 0.15
:return: A list of bookmark subtrees.
A subtree is ``(label, target, children)``. ``label`` is
a string, ``target`` is ``(page_number, x, y)`` like in
:meth:`resolve_links`, and ``children`` is a
list of child subtrees.
"""
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 in enumerate(self.pages):
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> we’re
# 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 = []
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)
return root
def add_hyperlinks(self, links, anchors, context, scale):
"""Include hyperlinks in current PDF page.
.. versionadded:: 43
"""
if cairo.cairo_version() < 11504:
return
# We round floats to avoid locale problems, see
# https://github.com/Kozea/WeasyPrint/issues/742
# TODO: Instead of using rects, we could use the drawing rectangles
# defined by cairo when drawing targets. This would give a feeling
# similiar to what browsers do with links that span multiple lines.
for link in links:
link_type, link_target, rectangle = link
if link_type == 'external':
attributes = "rect=[{} {} {} {}] uri='{}'".format(*(
[int(round(i * scale)) for i in rectangle] +
[link_target.replace("'", '%27')]))
elif link_type == 'internal':
attributes = "rect=[{} {} {} {}] dest='{}'".format(*(
[int(round(i * scale)) for i in rectangle] +
[link_target.replace("'", '%27')]))
elif link_type == 'attachment':
# Attachments are handled in write_pdf_metadata
continue
context.tag_begin(cairo.TAG_LINK, attributes)
context.tag_end(cairo.TAG_LINK)
for anchor in anchors:
anchor_name, x, y = anchor
attributes = "name='{}' x={} y={}".format(
anchor_name.replace("'", '%27'), int(round(x * scale)),
int(round(y * scale)))
context.tag_begin(cairo.TAG_DEST, attributes)
context.tag_end(cairo.TAG_DEST)
def write_pdf(self, target=None, zoom=1, attachments=None):
"""Paint the pages in a PDF file, with meta-data.
PDF files written directly by cairo do not have meta-data such as
bookmarks/outlines and hyperlinks.
:type target: str, pathlib.Path or file object
:param target:
A filename where the PDF file is generated, a file object, or
:obj:`None`.
:type zoom: float
:param 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".
:type attachments: list
:param attachments: A list of additional file attachments for the
generated PDF document or :obj:`None`. The list's elements are
:class:`Attachment` objects, filenames, URLs or file-like objects.
: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 (cairo units) per inch / 96 CSS pixel per inch
scale = zoom * 0.75
# Use an in-memory buffer. We will need to seek for metadata
# TODO: avoid this if target can seek? Benchmark first.
file_obj = io.BytesIO()
# (1, 1) is overridden by .set_size() below.
surface = cairo.PDFSurface(file_obj, 1, 1)
context = cairo.Context(surface)
PROGRESS_LOGGER.info('Step 6 - Drawing')
paged_links_and_anchors = list(self.resolve_links())
for page, links_and_anchors in zip(
self.pages, paged_links_and_anchors):
links, anchors = links_and_anchors
surface.set_size(
math.floor(scale * (
page.width + page.bleed['left'] + page.bleed['right'])),
math.floor(scale * (
page.height + page.bleed['top'] + page.bleed['bottom'])))
with stacked(context):
context.translate(
page.bleed['left'] * scale, page.bleed['top'] * scale)
page.paint(context, scale=scale)
self.add_hyperlinks(links, anchors, context, scale)
surface.show_page()
PROGRESS_LOGGER.info('Step 7 - Adding PDF metadata')
# TODO: overwrite producer when possible in cairo
if cairo.cairo_version() >= 11504:
# Set document information
for attr, key in (
('title', cairo.PDF_METADATA_TITLE),
('description', cairo.PDF_METADATA_SUBJECT),
('generator', cairo.PDF_METADATA_CREATOR)):
value = getattr(self.metadata, attr)
if value is not None:
surface.set_metadata(key, value)
for attr, key in (
('authors', cairo.PDF_METADATA_AUTHOR),
('keywords', cairo.PDF_METADATA_KEYWORDS)):
value = getattr(self.metadata, attr)
if value is not None:
surface.set_metadata(key, ', '.join(value))
for attr, key in (
('created', cairo.PDF_METADATA_CREATE_DATE),
('modified', cairo.PDF_METADATA_MOD_DATE)):
value = getattr(self.metadata, attr)
if value is not None:
surface.set_metadata(key, _w3c_date_to_iso(value, attr))
# Set bookmarks
bookmarks = self.make_bookmark_tree()
levels = [cairo.PDF_OUTLINE_ROOT] * len(bookmarks)
while bookmarks:
bookmark = bookmarks.pop(0)
title = bookmark.label
destination = bookmark.destination
children = bookmark.children
state = bookmark.state
page, x, y = destination
# We round floats to avoid locale problems, see
# https://github.com/Kozea/WeasyPrint/issues/742
link_attribs = 'page={} pos=[{} {}]'.format(
page + 1, int(round(x * scale)),
int(round(y * scale)))
outline = surface.add_outline(
levels.pop(), title, link_attribs,
cairo.PDF_OUTLINE_FLAG_OPEN if state == 'open' else 0)
levels.extend([outline] * len(children))
bookmarks = children + bookmarks
surface.finish()
# Add extra PDF metadata: attachments, embedded files
attachment_links = [
[link for link in page_links if link[0] == 'attachment']
for page_links, page_anchors in paged_links_and_anchors]
# Write extra PDF metadata only when there is a least one from:
# - attachments in metadata
# - attachments as function parameters
# - attachments as PDF links
# - bleed boxes
condition = (
self.metadata.attachments or
attachments or
any(attachment_links) or
any(any(page.bleed.values()) for page in self.pages))
if condition:
write_pdf_metadata(
file_obj, scale, self.url_fetcher,
self.metadata.attachments + (attachments or []),
attachment_links, self.pages)
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)
def write_image_surface(self, resolution=96):
"""Render pages on a cairo image surface.
.. versionadded:: 0.17
There is no decoration around pages other than those specified in CSS
with ``@page`` rules. The final image is as wide as the widest page.
Each page is below the previous one, centered horizontally.
:type resolution: float
:param resolution:
The output resolution in PNG pixels per CSS inch. At 96 dpi
(the default), PNG pixels match the CSS ``px`` unit.
:returns:
A ``(surface, png_width, png_height)`` tuple. ``surface`` is a
cairo :class:`ImageSurface <cairocffi.ImageSurface>`. ``png_width``
and ``png_height`` are the size of the final image, in PNG pixels.
"""
dppx = resolution / 96
# This duplicates the hinting logic in Page.paint. There is a
# dependency cycle otherwise:
# this → hinting logic → context → surface → this
# But since we do no transform here, cairo_context.user_to_device and
# friends are identity functions.
widths = [int(math.ceil(p.width * dppx)) for p in self.pages]
heights = [int(math.ceil(p.height * dppx)) for p in self.pages]
max_width = max(widths)
sum_heights = sum(heights)
surface = cairo.ImageSurface(
cairo.FORMAT_ARGB32, max_width, sum_heights)
context = cairo.Context(surface)
pos_y = 0
PROGRESS_LOGGER.info('Step 6 - Drawing')
for page, width, height in zip(self.pages, widths, heights):
pos_x = (max_width - width) / 2
page.paint(context, pos_x, pos_y, scale=dppx, clip=True)
pos_y += height
return surface, max_width, sum_heights
def write_png(self, target=None, resolution=96):
"""Paint the pages vertically to a single PNG image.
There is no decoration around pages other than those specified in CSS
with ``@page`` rules. The final image is as wide as the widest page.
Each page is below the previous one, centered horizontally.
:param target:
A filename, file-like object, or :obj:`None`.
:type resolution: float
:param resolution:
The output resolution in PNG pixels per CSS inch. At 96 dpi
(the default), PNG pixels match the CSS ``px`` unit.
:returns:
A ``(png_bytes, png_width, png_height)`` tuple. ``png_bytes`` is a
byte string if ``target`` is :obj:`None`, otherwise :obj:`None`
(the image is written to ``target``). ``png_width`` and
``png_height`` are the size of the final image, in PNG pixels.
"""
surface, max_width, sum_heights = self.write_image_surface(resolution)
if target is None:
target = io.BytesIO()
surface.write_to_png(target)
png_bytes = target.getvalue()
else:
surface.write_to_png(target)
png_bytes = None
return png_bytes, max_width, sum_heights