2 files changed, 62 insertions, 0 deletions
diff --git a/lib/extensions/__init__.py b/lib/extensions/__init__.py
index 1b923a44..3012ca5a 100644
--- a/lib/extensions/__init__.py
+++ b/lib/extensions/__init__.py
@@ -16,6 +16,7 @@ from .convert_to_stroke import ConvertToStroke
 from .cut_satin import CutSatin
 from .cutwork_segmentation import CutworkSegmentation
 from .density_map import DensityMap
+from .display_stacking_order import DisplayStackingOrder
 from .duplicate_params import DuplicateParams
 from .element_info import ElementInfo
 from .fill_to_stroke import FillToStroke
@@ -71,6 +72,7 @@ __all__ = extensions = [ApplyThreadlist,
                         CutSatin,
                         CutworkSegmentation,
                         DensityMap,
+                        DisplayStackingOrder,
                         DuplicateParams,
                         ElementInfo,
                         FillToStroke,
diff --git a/lib/extensions/display_stacking_order.py b/lib/extensions/display_stacking_order.py
new file mode 100644
index 00000000..4056081d
--- /dev/null
+++ b/lib/extensions/display_stacking_order.py
@@ -0,0 +1,60 @@
+# Authors: see git history
+#
+# Copyright (c) 2022 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
+import inkex
+
+from ..i18n import _
+from ..svg.tags import INKSCAPE_GROUPMODE, INKSCAPE_LABEL
+from .base import InkstitchExtension
+
+
+class DisplayStackingOrder(InkstitchExtension):
+    def __init__(self, *args, **kwargs):
+        InkstitchExtension.__init__(self, *args, **kwargs)
+        self.arg_parser.add_argument("-s", "--font_size", type=int, default=4, dest="font_size")
+
+    def effect(self):
+        layer = self.create_layer()
+
+        nodes = self.get_nodes()
+        for i, node in enumerate(nodes):
+            if node.style['fill'] != 'none':
+                position = node.bounding_box(node.composed_transform()).minimum
+                self.insert_stacking_num(layer, i + 1, position)
+            else:
+                path = node.get_path().transform(node.composed_transform())
+                position = next(path.end_points)
+                self.insert_stacking_num(layer, i + 1, position)
+
+        # remove layer if empty
+        if len(layer) == 0:
+            self.svg.remove(layer)
+
+    def insert_stacking_num(self, layer, num, position):
+        text = inkex.TextElement(attrib={
+            'x': str(position[0]),
+            'y': str(position[1])
+        })
+        text.style = inkex.Style(f"text-anchor: middle;text-align: center;dominant-baseline: middle;font-size: { self.options.font_size }")
+        tspan = inkex.Tspan()
+        tspan.text = str(num)
+        text.add(tspan)
+        layer.add(text)
+
+    def create_layer(self):
+        layer = self.svg.find(".//*[@id='__inkstitch_stacking_order__']")
+
+        # Remove the existing layer
+        if layer is not None:
+            layer.getparent().remove(layer)
+
+        layer = inkex.Group(attrib={
+            'id': '__inkstitch_stacking_order__',
+            INKSCAPE_LABEL: _('Stacking Order'),
+            INKSCAPE_GROUPMODE: 'layer',
+        })
+        self.svg.append(layer)
+
+        return layer