1 files changed, 126 insertions, 0 deletions
diff --git a/share/extensions/inkex/elements/_groups.py b/share/extensions/inkex/elements/_groups.py
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+++ b/share/extensions/inkex/elements/_groups.py
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+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2020 Martin Owens <doctormo@gmail.com>
+#                    Sergei Izmailov <sergei.a.izmailov@gmail.com>
+#                    Ryan Jarvis <ryan@shopboxretail.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# pylint: disable=arguments-differ
+"""
+Interface for all group based elements such as Groups, Use, Markers etc.
+"""
+
+from lxml import etree  # pylint: disable=unused-import
+
+from ..paths import Path
+from ..transforms import Transform
+
+from ._utils import addNS
+from ._base import ShapeElement
+
+try:
+    from typing import Optional  # pylint: disable=unused-import
+except ImportError:
+    pass
+
+
+class GroupBase(ShapeElement):
+    """Base Group element"""
+
+    def get_path(self):
+        ret = Path()
+        for child in self:
+            if isinstance(child, ShapeElement):
+                ret += child.path.transform(child.transform)
+        return ret
+
+    def shape_box(self, transform=None):
+        bbox = None
+        effective_transform = Transform(transform) @ self.transform
+        for child in self:
+            if isinstance(child, ShapeElement):
+                child_bbox = child.bounding_box(transform=effective_transform)
+                if child_bbox is not None:
+                    bbox += child_bbox
+        return bbox
+
+
+class Group(GroupBase):
+    """Any group element (layer or regular group)"""
+
+    tag_name = "g"
+
+    @classmethod
+    def new(cls, label, *children, **attrs):
+        attrs["inkscape:label"] = label
+        return super().new(*children, **attrs)
+
+    def effective_style(self):
+        """A blend of each child's style mixed together (last child wins)"""
+        style = self.style
+        for child in self:
+            style.update(child.effective_style())
+        return style
+
+    @property
+    def groupmode(self):
+        """Return the type of group this is"""
+        return self.get("inkscape:groupmode", "group")
+
+
+class Layer(Group):
+    """Inkscape extension of svg:g"""
+
+    def _init(self):
+        self.set("inkscape:groupmode", "layer")
+
+    @classmethod
+    def is_class_element(cls, elem):
+        # type: (etree.Element) -> bool
+        return elem.attrib.get(addNS("inkscape:groupmode"), None) == "layer"
+
+
+class Anchor(GroupBase):
+    """An anchor or link tag"""
+
+    tag_name = "a"
+
+    @classmethod
+    def new(cls, href, *children, **attrs):
+        attrs["xlink:href"] = href
+        return super().new(*children, **attrs)
+
+
+class ClipPath(GroupBase):
+    """A path used to clip objects"""
+
+    tag_name = "clipPath"
+
+
+class Marker(GroupBase):
+    """The <marker> element defines the graphic that is to be used for drawing
+    arrowheads or polymarkers on a given <path>, <line>, <polyline> or <polygon>
+    element."""
+
+    tag_name = "marker"
+
+
+class Mask(GroupBase):
+    """An alpha mask for compositing an object into the background
+
+    .. versionadded:: 1.2"""
+
+    tag_name = "mask"