Use STL type for FT2Font fallback list

QuLogic · QuLogic · commit 35458ae554a1 · 2024-09-10T04:01:49.000-04:00
This allows pybind11 to generate the type hints for us, and it also
takes care of checking the list and its contents are the right type.
diff --git a/lib/matplotlib/tests/test_ft2font.py b/lib/matplotlib/tests/test_ft2font.py
@@ -152,10 +152,10 @@ def test_ft2font_invalid_args(tmp_path):
     with pytest.raises(ValueError, match='hinting_factor must be greater than 0'):
         ft2font.FT2Font(file, 0)
 
-    with pytest.raises(TypeError, match='Fallback list must be a list'):
+    with pytest.raises(TypeError, match='incompatible constructor arguments'):
         # failing to be a list will fail before the 0
         ft2font.FT2Font(file, _fallback_list=(0,))  # type: ignore[arg-type]
-    with pytest.raises(TypeError, match='Fallback fonts must be FT2Font objects.'):
+    with pytest.raises(TypeError, match='incompatible constructor arguments'):
         ft2font.FT2Font(file, _fallback_list=[0])  # type: ignore[list-item]
 
     # kerning_factor argument.
diff --git a/src/ft2font_wrapper.cpp b/src/ft2font_wrapper.cpp
@@ -172,7 +172,8 @@ const char *PyFT2Font_init__doc__ =
 
 static PyFT2Font *
 PyFT2Font_init(py::object filename, long hinting_factor = 8,
-               py::object fallback_list_or_none = py::none(), int kerning_factor = 0)
+               std::optional<std::vector<PyFT2Font *>> fallback_list = std::nullopt,
+               int kerning_factor = 0)
 {
     if (hinting_factor <= 0) {
         throw py::value_error("hinting_factor must be greater than 0");
@@ -192,24 +193,13 @@ PyFT2Font_init(py::object filename, long hinting_factor = 8,
     open_args.stream = &self->stream;
 
     std::vector<FT2Font *> fallback_fonts;
-    if (!fallback_list_or_none.is_none()) {
-        if (!py::isinstance<py::list>(fallback_list_or_none)) {
-            throw py::type_error("Fallback list must be a list");
-        }
-        auto fallback_list = fallback_list_or_none.cast<py::list>();
-
-        // go through fallbacks once to make sure the types are right
-        for (auto item : fallback_list) {
-            if (!py::isinstance<PyFT2Font>(item)) {
-                throw py::type_error("Fallback fonts must be FT2Font objects.");
-            }
-        }
-        // go through a second time to add them to our lists
-        for (auto item : fallback_list) {
+    if (fallback_list) {
+        // go through fallbacks to add them to our lists
+        for (auto item : fallback_list.value()) {
             self->fallbacks.append(item);
             // Also (locally) cache the underlying FT2Font objects. As long as
             // the Python objects are kept alive, these pointer are good.
-            FT2Font *fback = py::cast<PyFT2Font *>(item)->x;
+            FT2Font *fback = item->x;
             fallback_fonts.push_back(fback);
         }
     }
