131 lines
4.6 KiB
Python
131 lines
4.6 KiB
Python
# -*- coding: utf-8 -*-
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#
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# Copyright (c) 2020 Martin Owens <doctormo@gmail.com>
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# Sergei Izmailov <sergei.a.izmailov@gmail.com>
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# Thomas Holder <thomas.holder@schrodinger.com>
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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"""Utilities for parsing SVG documents.
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.. versionadded:: 1.2
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Separated out from :py:mod:`inkex.elements._base`"""
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from collections import defaultdict
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from typing import DefaultDict, List, Any, Type, TYPE_CHECKING
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from lxml import etree
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if TYPE_CHECKING:
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from ..elements._base import BaseElement
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from ._utils import splitNS, addNS
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from ..utils import errormsg
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from ..localization import inkex_gettext as _
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class NodeBasedLookup(etree.PythonElementClassLookup):
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"""
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We choose what kind of Elements we should return for each element, providing useful
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SVG based API to our extensions system.
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"""
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default: Type["BaseElement"]
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# (ns,tag) -> list(cls) ; ascending priority
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lookup_table: DefaultDict[str, List[Any]] = defaultdict()
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@classmethod
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def register_class(cls, klass):
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"""Register the given class using it's attached tag name"""
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key = addNS(*splitNS(klass.tag_name)[::-1])
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old = cls.lookup_table.get(key, [])
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old.append(klass)
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cls.lookup_table[key] = old
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@classmethod
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def find_class(cls, xpath):
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"""Find the class for this type of element defined by an xpath
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.. versionadded:: 1.1"""
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if isinstance(xpath, type):
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return xpath
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for kls in cls.lookup_table[addNS(*splitNS(xpath.split("/")[-1])[::-1])]:
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# TODO: We could create a apply the xpath attrs to the test element
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# to narrow the search, but this does everything we need right now.
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test_element = kls()
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if kls.is_class_element(test_element):
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return kls
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raise KeyError(f"Could not find svg tag for '{xpath}'")
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def lookup(self, doc, element): # pylint: disable=unused-argument
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"""Lookup called by lxml when assigning elements their object class"""
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try:
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try:
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options = self.lookup_table[element.tag]
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except KeyError:
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if not element.tag.startswith("{"):
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tag = addNS(*splitNS(element.tag)[::-1])
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options = self.lookup_table[tag]
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else:
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return self.default
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for kls in reversed(options):
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if kls.is_class_element(element): # pylint: disable=protected-access
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return kls
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except AttributeError:
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# Handle <!-- Comment -->
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return None
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return self.default
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SVG_PARSER = etree.XMLParser(huge_tree=True, strip_cdata=False, recover=True)
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SVG_PARSER.set_element_class_lookup(NodeBasedLookup())
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def load_svg(stream):
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"""Load SVG file using the SVG_PARSER"""
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if (isinstance(stream, str) and stream.lstrip().startswith("<")) or (
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isinstance(stream, bytes) and stream.lstrip().startswith(b"<")
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):
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parsed = etree.ElementTree(etree.fromstring(stream, parser=SVG_PARSER))
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else:
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parsed = etree.parse(stream, parser=SVG_PARSER)
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if len(SVG_PARSER.error_log) > 0:
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errormsg(
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_(
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"A parsing error occurred, which means you are likely working with "
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"a non-conformant SVG file. The following errors were found:\n"
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)
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)
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for __, element in enumerate(SVG_PARSER.error_log):
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errormsg(
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_(
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"{error_message}. Line {line_number}, column {column_number}",
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).format(
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error_message=element.message,
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line_number=element.line,
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column_number=element.column,
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)
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)
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errormsg(
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_(
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"\nProcessing will continue; however we encourage you to fix your"
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" file manually."
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)
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)
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return parsed
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