[libTxt] multi-codeunit glyph hit test minor fix (flutter#25270)

esarbanis · Mar 29, 2021 · 4c8e49d · 4c8e49d
1 parent dac726c
commit 4c8e49d
Show file tree

Hide file tree

Showing 2 changed files with 45 additions and 2 deletions.
diff --git a/third_party/txt/src/txt/paragraph_txt.cc b/third_party/txt/src/txt/paragraph_txt.cc
@@ -1927,8 +1927,7 @@ Paragraph::PositionWithAffinity ParagraphTxt::GetGlyphPositionAtCoordinate(
   }
 
   if (gp == nullptr) {
-    const GlyphPosition& last_glyph = line_glyph_position.back();
-    return PositionWithAffinity(last_glyph.code_units.end, UPSTREAM);
+    gp = &line_glyph_position.back();
   }
 
   // Find the direction of the run that contains this glyph.

diff --git a/third_party/txt/tests/paragraph_unittests.cc b/third_party/txt/tests/paragraph_unittests.cc
@@ -2465,6 +2465,50 @@ TEST_F(ParagraphTest, DISABLE_ON_WINDOWS(LeftAlignParagraph)) {
   ASSERT_TRUE(Snapshot());
 }
 
+TEST_F(ParagraphTest, DISABLE_ON_WINDOWS(LeftAlignRTLParagraphHitTest)) {
+  // Regression test for https://github.com/flutter/flutter/issues/54969.
+  const char* text = "بمباركة التقليدية قام عن. تصفح";
+  auto icu_text = icu::UnicodeString::fromUTF8(text);
+  std::u16string u16_text(icu_text.getBuffer(),
+                          icu_text.getBuffer() + icu_text.length());
+
+  txt::ParagraphStyle paragraph_style;
+  paragraph_style.max_lines = 1;
+  paragraph_style.text_align = TextAlign::left;
+  paragraph_style.text_direction = TextDirection::rtl;
+  txt::ParagraphBuilderTxt builder(paragraph_style, GetTestFontCollection());
+
+  txt::TextStyle text_style;
+  text_style.font_families = std::vector<std::string>(1, "Roboto");
+  text_style.font_size = 26;
+  text_style.letter_spacing = 1;
+  text_style.word_spacing = 5;
+  text_style.color = SK_ColorBLACK;
+  text_style.height = 1;
+  text_style.decoration = TextDecoration::kUnderline;
+  text_style.decoration_color = SK_ColorBLACK;
+  builder.PushStyle(text_style);
+
+  builder.AddText(u16_text);
+
+  builder.Pop();
+
+  auto paragraph = BuildParagraph(builder);
+  paragraph->Layout(GetTestCanvasWidth());
+
+  paragraph->Paint(GetCanvas(), 0, 0);
+
+  ASSERT_TRUE(Snapshot());
+
+  // Tests for GetGlyphPositionAtCoordinate()
+  ASSERT_EQ(
+      paragraph->GetGlyphPositionAtCoordinate(GetTestCanvasWidth() - 0.5, 0.5)
+          .position,
+      0ull);
+
+  ASSERT_TRUE(Snapshot());
+}
+
 TEST_F(ParagraphTest, DISABLE_ON_WINDOWS(RightAlignParagraph)) {
   const char* text =
       "This is a very long sentence to test if the text will properly wrap "