1 files changed, 67 insertions, 0 deletions
diff --git a/lib/extensions/selection_to_guide_line.py b/lib/extensions/selection_to_guide_line.py
new file mode 100644
index 00000000..85a44bb1
--- /dev/null
+++ b/lib/extensions/selection_to_guide_line.py
@@ -0,0 +1,67 @@
+# Authors: see git history
+#
+# Copyright (c) 2021 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
+import inkex
+from lxml import etree
+
+from ..i18n import _
+from ..svg.tags import SVG_PATH_TAG, SVG_POLYLINE_TAG, SVG_DEFS_TAG
+from .base import InkstitchExtension
+
+
+class SelectionToGuideLine(InkstitchExtension):
+
+    def effect(self):
+        if not self.get_elements():
+            return
+
+        if not self.svg.selected:
+            inkex.errormsg(_("Please select one object to be marked as a guide line."))
+            return
+
+        if len(self.get_nodes())!=1:
+            inkex.errormsg(_("Please select only one object to be marked as a guide line."))
+            return
+
+        for guide_line in self.get_nodes():
+            if guide_line.tag in (SVG_PATH_TAG, SVG_POLYLINE_TAG):
+                self.set_marker(guide_line)
+
+    def set_marker(self, node):
+        xpath = ".//marker[@id='inkstitch-guide-line-marker']"
+        guide_line_marker = self.document.xpath(xpath)
+
+        if not guide_line_marker:
+            # get or create def element
+            defs = self.document.find(SVG_DEFS_TAG)
+            if defs is None:
+                defs = etree.SubElement(self.document, SVG_DEFS_TAG)
+
+            # insert marker
+            marker = """<marker
+                      refX="10"
+                      refY="5"
+                      orient="auto"
+                      id="inkstitch-guide-line-marker">
+                     <g
+                        id="inkstitch-guide-line-group">
+                       <path
+                          style="fill:#fafafa;stroke:#ff00ff;stroke-width:0.5;stroke-linecap:round;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:1, 1;stroke-dashoffset:0;stroke-opacity:1;fill-opacity:0.8;"
+                          d="M 10.12911,5.2916678 A 4.8374424,4.8374426 0 0 1 5.2916656,10.12911 4.8374424,4.8374426 0 0 1 0.45422399,5.2916678 4.8374424,4.8374426 0 0 1 5.2916656,0.45422399 4.8374424,4.8374426 0 0 1 10.12911,5.2916678 Z"
+                          id="inkstitch-guide-line-marker-circle" />
+                       <path
+                          style="fill:none;stroke:#ff00ff;stroke-width:0.4;stroke-linecap:round;stroke-miterlimit:4;"
+                          id="inkstitch-guide-line-marker-spiral"
+                          d="M 4.9673651,5.7245662 C 4.7549848,5.7646159 4.6247356,5.522384 4.6430021,5.3419847 4.6765851,5.0103151 5.036231,4.835347 5.3381858,4.8987426 5.7863901,4.9928495 6.0126802,5.4853625 5.9002872,5.9065088 5.7495249,6.4714237 5.1195537,6.7504036 4.5799191,6.5874894 3.898118,6.3816539 3.5659013,5.6122905 3.7800789,4.9545192 4.0402258,4.1556558 4.9498996,3.7699484 5.7256318,4.035839 6.6416744,4.3498087 7.0810483,5.4003986 6.7631909,6.2939744 6.395633,7.3272552 5.2038143,7.8204128 4.1924535,7.4503931 3.0418762,7.0294421 2.4948761,5.6961604 2.9171752,4.567073 3.3914021,3.2991406 4.8663228,2.6982592 6.1130974,3.1729158 7.4983851,3.7003207 8.1531869,5.3169977 7.6260947,6.6814205 7.0456093,8.1841025 5.2870784,8.8928844 3.8050073,8.3132966 2.1849115,7.6797506 1.4221671,5.7793073 2.0542715,4.1796074 2.7408201,2.4420977 4.7832541,1.6253548 6.5005435,2.310012 8.3554869,3.0495434 9.2262638,5.2339874 8.4890181,7.0688861 8.4256397,7.2266036 8.3515789,7.379984 8.2675333,7.5277183" />
+                     </g>
+                     </marker>"""  # noqa: E501
+            defs.append(etree.fromstring(marker))
+
+        # attach marker to node
+        style = node.get('style') or ''
+        style = style.split(";")
+        style = [i for i in style if not i.startswith('marker-start')]
+        style.append('marker-start:url(#inkstitch-guide-line-marker)')
+        node.set('style', ";".join(style))