StrutStyle for leading/lineheight adjustment on ParagraphStyle + TextStyle.setLetterSpacing and TextStyle.setWordSpacing

src/skia/Paragraph.cpp

@@ -13,6 +13,7 @@ void initParagraph(py::module &m) {
 py::class_<FontCollection, sk_sp<FontCollection>, SkRefCnt> font_collection(m, "textlayout_FontCollection");
 py::class_<ParagraphBuilder> paragraph_builder(m, "textlayout_ParagraphBuilder");
 py::class_<ParagraphStyle> paragraph_style(m, "textlayout_ParagraphStyle");
+py::class_<StrutStyle> strut_style(m, "textlayout_StrutStyle");
 py::class_<TextStyle> text_style(m, "textlayout_TextStyle");
 py::class_<Paragraph> paragraph(m, "textlayout_Paragraph");
 
@@ -82,6 +83,20 @@ paragraph_builder
     .def("Build", &ParagraphBuilder::Build)
     ;
 
+strut_style
+    .def(py::init())
+    .def("setStrutEnabled",
+        py::overload_cast<const bool>(&StrutStyle::setStrutEnabled),
+        R"docstring(
+        )docstring",
+        py::arg("strutenabled"))
+    .def("setLeading",
+        py::overload_cast<const SkScalar>(&StrutStyle::setLeading),
+        R"docstring(
+        )docstring",
+        py::arg("leading"))
+    ;
+
 paragraph_style
     .def(py::init())
     .def("setTextStyle",
@@ -94,6 +109,11 @@ paragraph_style
         R"docstring(
         )docstring",
         py::arg("align"))
+    .def("setStrutStyle",
+        py::overload_cast<StrutStyle>(&ParagraphStyle::setStrutStyle),
+        R"docstring(
+        )docstring",
+        py::arg("strutstyle"))
     ;
 
 font_collection
@@ -154,6 +174,16 @@ text_style
         R"docstring(
         )docstring",
         py::arg("locale"))
+    .def("setLetterSpacing",
+        py::overload_cast<SkScalar>(&TextStyle::setLetterSpacing),
+        R"docstring(
+        )docstring",
+        py::arg("letterspacing"))
+    .def("setWordSpacing",
+        py::overload_cast<SkScalar>(&TextStyle::setWordSpacing),
+        R"docstring(
+        )docstring",
+        py::arg("wordspacing"))
     .def("setDecoration",
         py::overload_cast<TextDecoration>(&TextStyle::setDecoration),
         R"docstring(
@@ -208,6 +238,7 @@ m.attr("textlayout").attr("FontCollection") = m.attr("textlayout_FontCollection"
 m.attr("textlayout").attr("ParagraphBuilder") = m.attr("textlayout_ParagraphBuilder");
 m.attr("textlayout").attr("ParagraphStyle") = m.attr("textlayout_ParagraphStyle");
 m.attr("textlayout").attr("Paragraph") = m.attr("textlayout_Paragraph");
+m.attr("textlayout").attr("StrutStyle") = m.attr("textlayout_StrutStyle");
 m.attr("textlayout").attr("TextStyle") = m.attr("textlayout_TextStyle");
 m.attr("textlayout").attr("TextAlign") = m.attr("textlayout_TextAlign");
 m.attr("textlayout").attr("TextDecoration") = m.attr("textlayout_TextDecoration");

src/skia/TextBlob.cpp

@@ -65,6 +65,10 @@ py::class_<SkTextBlob::Iter::Run>(iter, "Run")
 
 iter
     .def(py::init<const SkTextBlob&>())
+    .def("__iter__",
+        [] (SkTextBlob::Iter& it) {
+            return it;
+        })
     .def("__next__",
         [] (SkTextBlob::Iter& it) {
             SkTextBlob::Iter::Run run;

tests/test_paragraph.py

@@ -1,5 +1,6 @@
 import skia
 import pytest
+import operator
 
 @pytest.fixture(scope='session')
 def textlayout_font_collection():
@@ -17,6 +18,14 @@ def test_ParagraphStyle_init0(paragraph_style):
     assert isinstance(paragraph_style, skia.textlayout_ParagraphStyle)
 
 
+@pytest.fixture(scope='session')
+def strut_style():
+    return skia.textlayout.StrutStyle()
+
+def test_StrutStyle_init0(strut_style):
+    assert isinstance(strut_style, skia.textlayout_StrutStyle)
+
+
 @pytest.fixture(scope='session')
 def textlayout_text_style():
     return skia.textlayout.TextStyle()
@@ -61,3 +70,108 @@ def test_Paragraph_linebreak(paragraph_builder, textlayout_text_style, textlayou
     paragraph = builder.Build()
     paragraph.layout(300)
     assert (paragraph.Height > 0) and (paragraph.Height > paragraph.LongestLine * 2)
+
+
+@pytest.mark.parametrize('test_operator, spec_a, spec_b', [
+    (operator.eq, (False, 1.0), (True, 1.0)),
+    (operator.eq, (True, 0), (True, 1.0)),
+    (operator.eq, (True, 0.5), (True, 1.0)),
+    (operator.lt, (True, 1.0), (True, 2.0)),
+    (operator.lt, (True, 2.0), (True, 3.0)),
+])
+def test_Paragraph_strutHeight(paragraph_builder, textlayout_text_style, textlayout_font_collection, paragraph_style, test_operator, strut_style, spec_a, spec_b):
+    paint = skia.Paint()
+    paint.setColor(skia.ColorBLACK)
+    paint.setAntiAlias(True)
+
+    textlayout_text_style.setFontSize(50)
+    textlayout_text_style.setForegroundPaint(paint)
+
+    textlayout_font_collection.setDefaultFontManager(skia.FontMgr())
+
+    def graf_with_strut(enabled, leading_factor):
+        strut_style.setStrutEnabled(enabled)
+        strut_style.setLeading(leading_factor)
+        paragraph_style.setStrutStyle(strut_style)
+
+        builder = skia.textlayout.ParagraphBuilder.make(
+            paragraph_style, textlayout_font_collection, skia.Unicodes.ICU.Make()
+        )
+        builder.pushStyle(textlayout_text_style)
+
+        builder.addText("o\no")
+        paragraph = builder.Build()
+        paragraph.layout(300)
+
+        return paragraph
+
+    paragraph_a_height = graf_with_strut(*spec_a).Height
+    paragraph_b_height = graf_with_strut(*spec_b).Height
+
+    assert test_operator(paragraph_a_height, paragraph_b_height)
+
+
+@pytest.mark.parametrize('spacing_a, spacing_b', [
+    (-1, 0),
+    (0, 1),
+    (1, 2),
+    (2, 3),
+    (-1, 1),
+])
+def test_Paragraph_letterSpacing(paragraph_builder, textlayout_text_style, textlayout_font_collection, paragraph_style, strut_style, spacing_a, spacing_b):
+    paint = skia.Paint()
+    paint.setColor(skia.ColorBLACK)
+    paint.setAntiAlias(True)
+
+    textlayout_font_collection.setDefaultFontManager(skia.FontMgr())
+
+    def graf_with_letterspacing(letterspacing):
+        textlayout_text_style.setFontSize(50)
+        textlayout_text_style.setForegroundPaint(paint)
+        textlayout_text_style.setLetterSpacing(letterspacing)
+
+        builder = skia.textlayout.ParagraphBuilder.make(
+            paragraph_style, textlayout_font_collection, skia.Unicodes.ICU.Make()
+        )
+        builder.pushStyle(textlayout_text_style)
+
+        builder.addText("ooo")
+        paragraph = builder.Build()
+        paragraph.layout(300)
+
+        return paragraph
+
+    assert graf_with_letterspacing(spacing_a).LongestLine < graf_with_letterspacing(spacing_b).LongestLine
+
+
+@pytest.mark.parametrize('spacing_a, spacing_b', [
+    (-1, 0),
+    (0, 1),
+    (1, 2),
+    (2, 3),
+    (-1, 1),
+])
+def test_Paragraph_wordSpacing(paragraph_builder, textlayout_text_style, textlayout_font_collection, paragraph_style, strut_style, spacing_a, spacing_b):
+    paint = skia.Paint()
+    paint.setColor(skia.ColorBLACK)
+    paint.setAntiAlias(True)
+
+    textlayout_font_collection.setDefaultFontManager(skia.FontMgr())
+
+    def graf_with_word_spacing(letterspacing):
+        textlayout_text_style.setFontSize(50)
+        textlayout_text_style.setForegroundPaint(paint)
+        textlayout_text_style.setWordSpacing(letterspacing)
+
+        builder = skia.textlayout.ParagraphBuilder.make(
+            paragraph_style, textlayout_font_collection, skia.Unicodes.ICU.Make()
+        )
+        builder.pushStyle(textlayout_text_style)
+
+        builder.addText("word word word")
+        paragraph = builder.Build()
+        paragraph.layout(300)
+
+        return paragraph
+
+    assert graf_with_word_spacing(spacing_a).LongestLine < graf_with_word_spacing(spacing_b).LongestLine