fix: register drawing line values in Python

CHANGELOG.md

@@ -16,6 +16,9 @@ The release run heads these entries with the version and opens a fresh
 
 ## Unreleased
 
+- Python `Frame.line()` returns a bound `DrawingLine` with its endpoints instead
+  of raising a conversion error.
+
 - Spreadsheet rendering bounds columns as well as rows by the cell budget and
   avoids rescanning blank spans for every empty cell.
 

python/src/bind_document.cpp

@@ -311,6 +311,13 @@ void odr_python::bind_document(py::module_ &m) {
       .def_readwrite("width", &odr::DrawingPath::width)
       .def_readwrite("height", &odr::DrawingPath::height);
 
+  py::class_<odr::DrawingLine>(m, "DrawingLine")
+      .def(py::init<>())
+      .def_readwrite("x1", &odr::DrawingLine::x1)
+      .def_readwrite("y1", &odr::DrawingLine::y1)
+      .def_readwrite("x2", &odr::DrawingLine::x2)
+      .def_readwrite("y2", &odr::DrawingLine::y2);
+
   py::class_<odr::DrawingTransform>(m, "DrawingTransform")
       .def(py::init<>())
       .def_readwrite("a", &odr::DrawingTransform::a)

python/tests/test_document.py

@@ -457,3 +457,26 @@ def test_recalculate_computes_the_stale_formulas(tmp_path):
     assert result.changed()[0].column == 1
     assert repr(result.changed()[0]) == "SheetPosition(0!B1)"
     assert document.recalculate().changed() == []
+
+
+def test_frame_line_exposes_its_endpoints():
+    source = b"""<office:document
+        xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0"
+        xmlns:draw="urn:oasis:names:tc:opendocument:xmlns:drawing:1.0"
+        xmlns:svg="urn:oasis:names:tc:opendocument:xmlns:svg-compatible:1.0"
+        office:mimetype="application/vnd.oasis.opendocument.graphics">
+      <office:body><office:drawing><draw:page>
+        <draw:line svg:x1="1cm" svg:y1="2cm" svg:x2="3cm" svg:y2="4cm"/>
+        <draw:rect svg:width="1cm" svg:height="1cm"/>
+      </draw:page></office:drawing></office:body>
+    </office:document>"""
+    document = pyodr.open(pyodr.File.from_memory(source)).as_document_file().document()
+    frames = list(document.root_element().first_child())
+    line = frames[0].as_frame().line()
+    assert [str(line.x1), str(line.y1), str(line.x2), str(line.y2)] == [
+        "1cm",
+        "2cm",
+        "3cm",
+        "4cm",
+    ]
+    assert frames[1].as_frame().line() is None