1
1
mirror of https://github.com/Kozea/WeasyPrint.git synced 2024-08-17 16:40:45 +03:00
WeasyPrint/weasyprint/svg/__init__.py
2024-04-26 18:40:44 +02:00

820 lines
29 KiB
Python
Raw Permalink 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.

"""Render SVG images."""
import re
from contextlib import suppress
from math import cos, hypot, pi, radians, sin, sqrt
from xml.etree import ElementTree
from cssselect2 import ElementWrapper
from ..urls import get_url_attribute
from .css import parse_declarations, parse_stylesheets
from .defs import apply_filters, clip_path, draw_gradient_or_pattern, paint_mask, use
from .images import image, svg
from .path import path
from .shapes import circle, ellipse, line, polygon, polyline, rect
from .text import text
from .bounding_box import ( # isort:skip
EMPTY_BOUNDING_BOX, bounding_box, extend_bounding_box, is_valid_bounding_box)
from .utils import ( # isort:skip
PointError, alpha_value, color, normalize, parse_url, preserve_ratio, size,
transform)
TAGS = {
'a': text,
'circle': circle,
'clipPath': clip_path,
'ellipse': ellipse,
'image': image,
'line': line,
'path': path,
'polyline': polyline,
'polygon': polygon,
'rect': rect,
'svg': svg,
'text': text,
'textPath': text,
'tspan': text,
'use': use,
}
NOT_INHERITED_ATTRIBUTES = frozenset((
'clip',
'clip-path',
'filter',
'height',
'id',
'mask',
'opacity',
'overflow',
'rotate',
'stop-color',
'stop-opacity',
'style',
'transform',
'transform-origin',
'viewBox',
'width',
'x',
'y',
'dx',
'dy',
'{http://www.w3.org/1999/xlink}href',
'href',
))
COLOR_ATTRIBUTES = frozenset((
'fill',
'flood-color',
'lighting-color',
'stop-color',
'stroke',
))
DEF_TYPES = frozenset((
'clipPath',
'filter',
'gradient',
'image',
'marker',
'mask',
'path',
'pattern',
))
class Node:
"""An SVG document node."""
def __init__(self, wrapper, style):
self._wrapper = wrapper
self._etree_node = wrapper.etree_element
self._style = style
self.attrib = wrapper.etree_element.attrib.copy()
self.vertices = []
self.bounding_box = None
def copy(self):
"""Create a deep copy of the node as it was when first created."""
return Node(self._wrapper, self._style)
def get(self, key, default=None):
"""Get attribute."""
return self.attrib.get(key, default)
@property
def tag(self):
"""XML tag name with no namespace."""
return self._etree_node.tag.split('}', 1)[-1]
@property
def text(self):
"""XML node text."""
return self._etree_node.text
@property
def tail(self):
"""Text after the XML node."""
return self._etree_node.tail
@property
def display(self):
"""Whether node should be displayed."""
return self.get('display') != 'none'
@property
def visible(self):
"""Whether node is visible."""
return self.display and self.get('visibility') != 'hidden'
def __iter__(self):
"""Yield node children, handling cascade."""
for wrapper in self._wrapper:
child = Node(wrapper, self._style)
# Cascade
for key, value in self.attrib.items():
if key not in NOT_INHERITED_ATTRIBUTES:
if key not in child.attrib:
child.attrib[key] = value
# Apply style attribute
style_attr = child.get('style')
if style_attr:
normal_attr, important_attr = parse_declarations(style_attr)
else:
normal_attr, important_attr = [], []
normal_matcher, important_matcher = self._style
normal = [rule[-1] for rule in normal_matcher.match(wrapper)]
important = [rule[-1] for rule in important_matcher.match(wrapper)]
declarations_lists = (
normal, [normal_attr], important, [important_attr])
for declarations_list in declarations_lists:
for declarations in declarations_list:
for name, value in declarations:
child.attrib[name] = value.strip()
# Replace 'currentColor' value
for key in COLOR_ATTRIBUTES:
if child.get(key) == 'currentColor':
child.attrib[key] = child.get('color', 'black')
# Handle 'inherit' values
for key, value in child.attrib.copy().items():
if value == 'inherit':
value = self.get(key)
if value is None:
del child.attrib[key]
else:
child.attrib[key] = value
# Fix text in text tags
if child.tag in ('text', 'textPath', 'a'):
children, _ = child.text_children(
wrapper, trailing_space=True, text_root=True)
child._wrapper.etree_children = [
child._etree_node for child in children]
yield child
def get_viewbox(self):
"""Get node viewBox as a tuple of floats."""
viewbox = self.get('viewBox')
if viewbox:
return tuple(
float(number) for number in normalize(viewbox).split())
def get_href(self, base_url):
"""Get the href attribute, with or without a namespace."""
for attr_name in ('{http://www.w3.org/1999/xlink}href', 'href'):
url = get_url_attribute(
self, attr_name, base_url, allow_relative=True)
if url:
return url
def del_href(self):
"""Remove the href attributes, with or without a namespace."""
for attr_name in ('{http://www.w3.org/1999/xlink}href', 'href'):
self.attrib.pop(attr_name, None)
@staticmethod
def process_whitespace(string, preserve):
"""Replace newlines by spaces, and merge spaces if not preserved."""
# TODO: should be merged with build.process_whitespace
if not string:
return ''
if preserve:
return re.sub('[\n\r\t]', ' ', string)
else:
string = re.sub('[\n\r]', '', string)
string = re.sub('\t', ' ', string)
return re.sub(' +', ' ', string)
def get_child(self, id_):
"""Get a child with given id in the whole child tree."""
for child in self:
if child.get('id') == id_:
return child
grandchild = child.get_child(id_)
if grandchild:
return grandchild
def text_children(self, element, trailing_space, text_root=False):
"""Handle text node by fixing whitespaces and flattening tails."""
children = []
space = '{http://www.w3.org/XML/1998/namespace}space'
preserve = self.get(space) == 'preserve'
self._etree_node.text = self.process_whitespace(
element.etree_element.text, preserve)
if trailing_space and not preserve:
self._etree_node.text = self.text.lstrip(' ')
original_rotate = [
float(i) for i in
normalize(self.get('rotate')).strip().split(' ') if i]
rotate = original_rotate.copy()
if original_rotate:
self.pop_rotation(original_rotate, rotate)
if self.text:
trailing_space = self.text.endswith(' ')
element_children = tuple(element.iter_children())
for child_element in element_children:
child = child_element.etree_element
if child.tag in ('{http://www.w3.org/2000/svg}tref', 'tref'):
child_node = Node(child_element, self._style)
child_node._etree_node.tag = 'tspan'
# Retrieve the referenced node and get its flattened text
# and remove the node children.
child = child_node._etree_node
child._etree_node.text = child.flatten()
child_element = ElementWrapper.from_xml_root(child)
else:
child_node = Node(child_element, self._style)
child_preserve = child_node.get(space) == 'preserve'
child_node._etree_node.text = self.process_whitespace(
child.text, child_preserve)
child_node.children, trailing_space = child_node.text_children(
child_element, trailing_space)
trailing_space = child_node.text.endswith(' ')
if original_rotate and 'rotate' not in child_node:
child_node.pop_rotation(original_rotate, rotate)
children.append(child_node)
tail = self.process_whitespace(child.tail, preserve)
if text_root and child_element is element_children[-1]:
if not preserve:
tail = tail.rstrip(' ')
if tail:
anonymous_etree = ElementTree.Element(
'{http://www.w3.org/2000/svg}tspan')
anonymous = Node(
ElementWrapper.from_xml_root(anonymous_etree), self._style)
anonymous._etree_node.text = tail
if original_rotate:
anonymous.pop_rotation(original_rotate, rotate)
if trailing_space and not preserve:
anonymous._etree_node.text = anonymous.text.lstrip(' ')
if anonymous.text:
trailing_space = anonymous.text.endswith(' ')
children.append(anonymous)
if text_root and not children and not preserve:
self._etree_node.text = self.text.rstrip(' ')
return children, trailing_space
def flatten(self):
"""Flatten text in node and in its children."""
flattened_text = [self.text or '']
for child in list(self):
flattened_text.append(child.flatten())
flattened_text.append(child.tail or '')
self.remove(child)
return ''.join(flattened_text)
def pop_rotation(self, original_rotate, rotate):
"""Merge nested letter rotations."""
self.attrib['rotate'] = ' '.join(
str(rotate.pop(0) if rotate else original_rotate[-1])
for i in range(len(self.text)))
def override_iter(self, iterator):
"""Override nodes children iterator."""
# As special methods are bound to classes and not instances, we have to
# create and assign a new type.
self.__class__ = type(
'Node', (Node,), {'__iter__': lambda _: iterator})
class SVG:
"""An SVG document."""
def __init__(self, tree, url):
wrapper = ElementWrapper.from_xml_root(tree)
style = parse_stylesheets(wrapper, url)
self.tree = Node(wrapper, style)
self.url = url
# Replace 'currentColor' value
for key in COLOR_ATTRIBUTES:
if self.tree.get(key) == 'currentColor':
self.tree.attrib[key] = self.tree.get('color', 'black')
self.filters = {}
self.gradients = {}
self.images = {}
self.markers = {}
self.masks = {}
self.patterns = {}
self.paths = {}
self.use_cache = {}
self.cursor_position = [0, 0]
self.cursor_d_position = [0, 0]
self.text_path_width = 0
self.parse_defs(self.tree)
self.inherit_defs()
def get_intrinsic_size(self, font_size):
"""Get intrinsic size of the image."""
intrinsic_width = self.tree.get('width', '100%')
if '%' in intrinsic_width:
intrinsic_width = None
else:
intrinsic_width = size(intrinsic_width, font_size)
intrinsic_height = self.tree.get('height', '100%')
if '%' in intrinsic_height:
intrinsic_height = None
else:
intrinsic_height = size(intrinsic_height, font_size)
return intrinsic_width, intrinsic_height
def get_viewbox(self):
"""Get document viewBox as a tuple of floats."""
return self.tree.get_viewbox()
def point(self, x, y, font_size):
"""Compute size of an x/y or width/height couple."""
return (
size(x, font_size, self.inner_width),
size(y, font_size, self.inner_height))
def length(self, length, font_size):
"""Compute size of an arbirtary attribute."""
return size(length, font_size, self.inner_diagonal)
def draw(self, stream, concrete_width, concrete_height, base_url,
url_fetcher, context):
"""Draw image on a stream."""
self.stream = stream
self.concrete_width = concrete_width
self.concrete_height = concrete_height
self.normalized_diagonal = (
hypot(concrete_width, concrete_height) / sqrt(2))
viewbox = self.get_viewbox()
if viewbox:
self.inner_width, self.inner_height = viewbox[2], viewbox[3]
else:
self.inner_width = self.concrete_width
self.inner_height = self.concrete_height
self.inner_diagonal = (
hypot(self.inner_width, self.inner_height) / sqrt(2))
self.base_url = base_url
self.url_fetcher = url_fetcher
self.context = context
self.draw_node(self.tree, size('12pt'))
def draw_node(self, node, font_size, fill_stroke=True):
"""Draw a node."""
if node.tag == 'defs':
return
# Update font size
font_size = size(node.get('font-size', '1em'), font_size, font_size)
original_streams = []
if fill_stroke:
self.stream.push_state()
# Apply filters
filter_ = self.filters.get(parse_url(node.get('filter')).fragment)
if filter_:
apply_filters(self, node, filter_, font_size)
# Apply transform attribute
self.transform(node.get('transform'), font_size)
# Create substream for opacity
opacity = alpha_value(node.get('opacity', 1))
if fill_stroke and 0 <= opacity < 1:
original_streams.append(self.stream)
box = self.calculate_bounding_box(node, font_size)
if not is_valid_bounding_box(box):
box = (0, 0, self.inner_width, self.inner_height)
self.stream = self.stream.add_group(*box)
# Clip
clip_path = parse_url(node.get('clip-path')).fragment
if clip_path and clip_path in self.paths:
old_ctm = self.stream.ctm
clip_path = self.paths[clip_path]
if clip_path.get('clipPathUnits') == 'objectBoundingBox':
x, y = self.point(node.get('x'), node.get('y'), font_size)
width, height = self.point(
node.get('width'), node.get('height'), font_size)
self.stream.transform(a=width, d=height, e=x, f=y)
original_tag = clip_path._etree_node.tag
clip_path._etree_node.tag = 'g'
self.draw_node(clip_path, font_size, fill_stroke=False)
clip_path._etree_node.tag = original_tag
# At least set the clipping area to an empty path, so that its
# totally clipped when the clipping path is empty.
self.stream.rectangle(0, 0, 0, 0)
self.stream.clip()
self.stream.end()
new_ctm = self.stream.ctm
if new_ctm.determinant:
self.stream.transform(*(old_ctm @ new_ctm.invert).values)
# Handle text anchor
if node.tag == 'text':
text_anchor = node.get('text-anchor')
children = tuple(node)
if children and not node.text:
text_anchor = children[0].get('text-anchor')
if node.tag == 'text' and text_anchor in ('middle', 'end'):
group = self.stream.add_group(0, 0, 0, 0) # BBox set after drawing
original_streams.append(self.stream)
self.stream = group
# Set text bounding box
if node.display and TAGS.get(node.tag) == text:
node.text_bounding_box = EMPTY_BOUNDING_BOX
# Draw node
if node.visible and node.tag in TAGS:
with suppress(PointError):
TAGS[node.tag](self, node, font_size)
# Draw node children
if node.display and node.tag not in DEF_TYPES:
for child in node:
self.draw_node(child, font_size, fill_stroke)
visible_text_child = (
TAGS.get(node.tag) == text and
TAGS.get(child.tag) == text and
child.visible)
if visible_text_child:
if not is_valid_bounding_box(child.text_bounding_box):
continue
x1, y1 = child.text_bounding_box[:2]
x2 = x1 + child.text_bounding_box[2]
y2 = y1 + child.text_bounding_box[3]
node.text_bounding_box = extend_bounding_box(
node.text_bounding_box, ((x1, y1), (x2, y2)))
# Handle text anchor
if node.tag == 'text' and text_anchor in ('middle', 'end'):
group_id = self.stream.id
self.stream = original_streams.pop()
self.stream.push_state()
if is_valid_bounding_box(node.text_bounding_box):
x, y, width, height = node.text_bounding_box
# Add extra space to include ink extents
group.extra['BBox'][:] = (
x - font_size, y - font_size,
x + width + font_size, y + height + font_size)
x_align = width / 2 if text_anchor == 'middle' else width
self.stream.transform(e=-x_align)
self.stream.draw_x_object(group_id)
self.stream.pop_state()
# Apply mask
mask = self.masks.get(parse_url(node.get('mask')).fragment)
if mask:
paint_mask(self, node, mask, opacity)
# Fill and stroke
if fill_stroke:
self.fill_stroke(node, font_size)
# Draw markers
self.draw_markers(node, font_size, fill_stroke)
# Apply opacity stream and restore original stream
if fill_stroke and 0 <= opacity < 1:
group_id = self.stream.id
self.stream = original_streams.pop()
self.stream.set_alpha(opacity, stroke=True, fill=True)
self.stream.draw_x_object(group_id)
# Clean text tag
if node.tag == 'text':
self.cursor_position = [0, 0]
self.cursor_d_position = [0, 0]
self.text_path_width = 0
if fill_stroke:
self.stream.pop_state()
def draw_markers(self, node, font_size, fill_stroke):
"""Draw markers defined in a node."""
if not node.vertices:
return
markers = {}
common_marker = parse_url(node.get('marker')).fragment
for position in ('start', 'mid', 'end'):
attribute = f'marker-{position}'
if attribute in node.attrib:
markers[position] = parse_url(node.attrib[attribute]).fragment
else:
markers[position] = common_marker
angle1, angle2 = None, None
position = 'start'
while node.vertices:
# Calculate position and angle
point = node.vertices.pop(0)
angles = node.vertices.pop(0) if node.vertices else None
if angles:
if position == 'start':
angle = pi - angles[0]
else:
angle = (angle2 + pi - angles[0]) / 2
angle1, angle2 = angles
else:
angle = angle2
position = 'end'
# Draw marker
marker = markers[position]
if not marker:
position = 'mid' if angles else 'start'
continue
marker_node = self.markers.get(marker)
# Calculate position, scale and clipping
translate_x, translate_y = self.point(
marker_node.get('refX'), marker_node.get('refY'),
font_size)
marker_width, marker_height = self.point(
marker_node.get('markerWidth', 3),
marker_node.get('markerHeight', 3),
font_size)
if 'viewBox' in marker_node.attrib:
scale_x, scale_y, _, _ = preserve_ratio(
self, marker_node, font_size, marker_width, marker_height)
clip_x, clip_y, viewbox_width, viewbox_height = (
marker_node.get_viewbox())
align = marker_node.get(
'preserveAspectRatio', 'xMidYMid').split(' ')[0]
if align == 'none':
x_position = y_position = 'min'
else:
x_position = align[1:4].lower()
y_position = align[5:].lower()
if x_position == 'mid':
clip_x += (viewbox_width - marker_width / scale_x) / 2
elif x_position == 'max':
clip_x += viewbox_width - marker_width / scale_x
if y_position == 'mid':
clip_y += (
viewbox_height - marker_height / scale_y) / 2
elif y_position == 'max':
clip_y += viewbox_height - marker_height / scale_y
clip_box = (
clip_x, clip_y,
marker_width / scale_x, marker_height / scale_y)
else:
scale_x = scale_y = 1
clip_box = (0, 0, marker_width, marker_height)
# Scale
if marker_node.get('markerUnits') != 'userSpaceOnUse':
scale = self.length(node.get('stroke-width', 1), font_size)
scale_x *= scale
scale_y *= scale
# Override angle
node_angle = marker_node.get('orient', 0)
if node_angle not in ('auto', 'auto-start-reverse'):
angle = radians(float(node_angle))
elif node_angle == 'auto-start-reverse' and position == 'start':
angle += radians(180)
# Draw marker path
for child in marker_node:
self.stream.push_state()
self.stream.transform(
scale_x * cos(angle), scale_x * sin(angle),
-scale_y * sin(angle), scale_y * cos(angle),
*point)
self.stream.transform(e=-translate_x, f=-translate_y)
overflow = marker_node.get('overflow', 'hidden')
if overflow in ('hidden', 'scroll'):
self.stream.rectangle(*clip_box)
self.stream.clip()
self.stream.end()
self.draw_node(child, font_size, fill_stroke)
self.stream.pop_state()
position = 'mid' if angles else 'start'
@staticmethod
def get_paint(value):
"""Get paint fill or stroke attribute with a color or a URL."""
if not value or value == 'none':
return None, None
value = value.strip()
match = re.compile(r'(url\(.+\)) *(.*)').search(value)
if match:
source = parse_url(match.group(1)).fragment
color = match.group(2) or None
else:
source = None
color = value or None
return source, color
def fill_stroke(self, node, font_size, text=False):
"""Paint fill and stroke for a node."""
if node.tag in ('text', 'textPath', 'a') and not text:
return
# Get fill data
fill_source, fill_color = self.get_paint(node.get('fill', 'black'))
fill_opacity = alpha_value(node.get('fill-opacity', 1))
fill_drawn = draw_gradient_or_pattern(
self, node, fill_source, font_size, fill_opacity, stroke=False)
if fill_color and not fill_drawn:
red, green, blue, alpha = color(fill_color)
self.stream.set_color_rgb(red, green, blue)
self.stream.set_alpha(alpha * fill_opacity)
fill = fill_color or fill_drawn
# Get stroke data
stroke_source, stroke_color = self.get_paint(node.get('stroke'))
stroke_opacity = alpha_value(node.get('stroke-opacity', 1))
stroke_drawn = draw_gradient_or_pattern(
self, node, stroke_source, font_size, stroke_opacity, stroke=True)
if stroke_color and not stroke_drawn:
red, green, blue, alpha = color(stroke_color)
self.stream.set_color_rgb(red, green, blue, stroke=True)
self.stream.set_alpha(alpha * stroke_opacity, stroke=True)
stroke = stroke_color or stroke_drawn
stroke_width = self.length(node.get('stroke-width', '1px'), font_size)
if stroke_width:
self.stream.set_line_width(stroke_width)
else:
stroke = None
# Apply dash array
dash_array = tuple(
self.length(value, font_size) for value in
normalize(node.get('stroke-dasharray')).split() if value != 'none')
dash_condition = (
dash_array and
not all(value == 0 for value in dash_array) and
not any(value < 0 for value in dash_array))
if dash_condition:
offset = self.length(node.get('stroke-dashoffset'), font_size)
if offset < 0:
sum_dashes = sum(float(value) for value in dash_array)
offset = sum_dashes - abs(offset) % sum_dashes
self.stream.set_dash(dash_array, offset)
# Apply line cap
line_cap = node.get('stroke-linecap', 'butt')
if line_cap == 'round':
line_cap = 1
elif line_cap == 'square':
line_cap = 2
else:
line_cap = 0
self.stream.set_line_cap(line_cap)
# Apply line join
line_join = node.get('stroke-linejoin', 'miter')
if line_join == 'round':
line_join = 1
elif line_join == 'bevel':
line_join = 2
else:
line_join = 0
self.stream.set_line_join(line_join)
# Apply miter limit
miter_limit = float(node.get('stroke-miterlimit', 4))
if miter_limit < 0:
miter_limit = 4
self.stream.set_miter_limit(miter_limit)
# Fill and stroke
even_odd = node.get('fill-rule') == 'evenodd'
if text:
if stroke and fill:
text_rendering = 2
elif stroke:
text_rendering = 1
elif fill:
text_rendering = 0
else:
text_rendering = 3
self.stream.set_text_rendering(text_rendering)
else:
if fill and stroke:
self.stream.fill_and_stroke(even_odd)
elif stroke:
self.stream.stroke()
elif fill:
self.stream.fill(even_odd)
else:
self.stream.end()
def transform(self, transform_string, font_size):
"""Apply a transformation string to the node."""
if not transform_string:
return
matrix = transform(transform_string, font_size, self.inner_diagonal)
if matrix.determinant:
self.stream.transform(*matrix.values)
def parse_defs(self, node):
"""Parse defs included in a tree."""
for def_type in DEF_TYPES:
if def_type in node.tag.lower() and 'id' in node.attrib:
getattr(self, f'{def_type}s')[node.attrib['id']] = node
for child in node:
self.parse_defs(child)
def inherit_defs(self):
"""Handle inheritance of different defined elements lists."""
for defs in (self.gradients, self.patterns):
for element in defs.values():
self.inherit_element(element, defs)
def inherit_element(self, element, defs):
"""Recursively handle inheritance of defined element."""
href = element.get_href(self.url)
if not href:
return
element.del_href()
parent = defs.get(parse_url(href).fragment)
if not parent:
return
self.inherit_element(parent, defs)
for key, value in parent.attrib.items():
if key not in element.attrib:
element.attrib[key] = value
if next(iter(element), None) is None:
element.override_iter(parent.__iter__())
def calculate_bounding_box(self, node, font_size, stroke=True):
"""Calculate the bounding box of a node."""
if stroke or node.bounding_box is None:
box = bounding_box(self, node, font_size, stroke)
if is_valid_bounding_box(box) and 0 not in box[2:]:
if stroke:
return box
node.bounding_box = box
return node.bounding_box
class Pattern(SVG):
"""SVG node applied as a pattern."""
def __init__(self, tree, svg):
super().__init__(tree._etree_node, svg.url)
self.svg = svg
self.tree = tree
def draw_node(self, node, font_size, fill_stroke=True):
# Store the original tree in self.tree when calling draw(), so that we
# can reach defs outside the pattern
if node == self.tree:
self.tree = self.svg.tree
super().draw_node(node, font_size, fill_stroke=True)