From e2d3f2d663c1b55ccb1d478522b203374bc568cc Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Thu, 22 Jun 2023 13:58:47 -0700
Subject: [PATCH 1/7] Add ParagraphStyle.applyRoundingHack for SkParagraph

---
 lib/ui/text.dart                              |  6 +++-
 lib/ui/text/paragraph_builder.cc              |  4 ++-
 .../src/engine/canvaskit/canvaskit_api.dart   |  2 ++
 .../lib/src/engine/canvaskit/renderer.dart    |  3 +-
 lib/web_ui/lib/src/engine/canvaskit/text.dart |  4 +++
 lib/web_ui/lib/src/engine/html/renderer.dart  |  4 ++-
 lib/web_ui/lib/src/engine/renderer.dart       |  1 +
 .../engine/skwasm/skwasm_impl/paragraph.dart  |  2 ++
 .../raw/text/raw_paragraph_style.dart         |  3 ++
 .../engine/skwasm/skwasm_impl/renderer.dart   |  4 ++-
 .../engine/skwasm/skwasm_stub/renderer.dart   |  2 +-
 lib/web_ui/lib/text.dart                      |  2 ++
 lib/web_ui/skwasm/text/paragraph_style.cpp    |  5 +++
 testing/dart/paragraph_test.dart              | 34 +++++++++++++++++--
 .../txt/src/skia/paragraph_builder_skia.cc    |  1 +
 third_party/txt/src/txt/paragraph_style.h     |  8 +++++
 16 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/lib/ui/text.dart b/lib/ui/text.dart
index d163f3a078776..93d2c01f927f8 100644
--- a/lib/ui/text.dart
+++ b/lib/ui/text.dart
@@ -1762,6 +1762,7 @@ class ParagraphStyle {
     StrutStyle? strutStyle,
     String? ellipsis,
     Locale? locale,
+    bool applyRoundingHack = true,
   }) : _encoded = _encodeParagraphStyle(
          textAlign,
          textDirection,
@@ -1782,6 +1783,7 @@ class ParagraphStyle {
        _strutStyle = strutStyle,
        _ellipsis = ellipsis,
        _locale = locale,
+       _applyRoundingHack = applyRoundingHack,
        _leadingDistribution = textHeightBehavior?.leadingDistribution ?? TextLeadingDistribution.proportional;
 
   final Int32List _encoded;
@@ -1792,6 +1794,7 @@ class ParagraphStyle {
   final String? _ellipsis;
   final Locale? _locale;
   final TextLeadingDistribution _leadingDistribution;
+  final bool _applyRoundingHack;
 
   @override
   bool operator ==(Object other) {
@@ -1809,11 +1812,12 @@ class ParagraphStyle {
         && other._ellipsis == _ellipsis
         && other._locale == _locale
         && other._leadingDistribution == _leadingDistribution
+        && other._applyRoundingHack == _applyRoundingHack
         && _listEquals<int>(other._encoded, _encoded);
   }
 
   @override
-  int get hashCode => Object.hash(Object.hashAll(_encoded), _fontFamily, _fontSize, _height, _ellipsis, _locale, _leadingDistribution);
+  int get hashCode => Object.hash(Object.hashAll(_encoded), _fontFamily, _fontSize, _height, _ellipsis, _locale, _leadingDistribution, _applyRoundingHack);
 
   @override
   String toString() {
diff --git a/lib/ui/text/paragraph_builder.cc b/lib/ui/text/paragraph_builder.cc
index 3857a10572d62..5740ead7926c0 100644
--- a/lib/ui/text/paragraph_builder.cc
+++ b/lib/ui/text/paragraph_builder.cc
@@ -230,7 +230,8 @@ ParagraphBuilder::ParagraphBuilder(
     double fontSize,
     double height,
     const std::u16string& ellipsis,
-    const std::string& locale) {
+    const std::string& locale,
+    bool applyRoundingHack) {
   int32_t mask = 0;
   txt::ParagraphStyle style;
   {
@@ -291,6 +292,7 @@ ParagraphBuilder::ParagraphBuilder(
   if (mask & kPSLocaleMask) {
     style.locale = locale;
   }
+  style.apply_rounding_hack = applyRoundingHack;
 
   FontCollection& font_collection = UIDartState::Current()
                                         ->platform_configuration()
diff --git a/lib/web_ui/lib/src/engine/canvaskit/canvaskit_api.dart b/lib/web_ui/lib/src/engine/canvaskit/canvaskit_api.dart
index 4aa608f4e23c9..f486eaed0a301 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/canvaskit_api.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/canvaskit_api.dart
@@ -2722,6 +2722,8 @@ extension SkParagraphStylePropertiesExtension on SkParagraphStyleProperties {
   @JS('replaceTabCharacters')
   external set _replaceTabCharacters(JSBoolean? bool);
   set replaceTabCharacters(bool? bool) => _replaceTabCharacters = bool?.toJS;
+
+  external set applyRoundingHack(bool applyRoundingHack);
 }
 
 @JS()
diff --git a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
index 834446ef26d82..4ba883274ce1a 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
@@ -314,7 +314,8 @@ class CanvasKitRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale
+    ui.Locale? locale,
+    bool applyRoundingHack = true,
   }) => CkParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
diff --git a/lib/web_ui/lib/src/engine/canvaskit/text.dart b/lib/web_ui/lib/src/engine/canvaskit/text.dart
index f177031d6afcc..f8f3a4b33fa84 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/text.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/text.dart
@@ -32,6 +32,7 @@ class CkParagraphStyle implements ui.ParagraphStyle {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
+    bool applyRoundingHack = true,
   })  : skParagraphStyle = toSkParagraphStyle(
           textAlign,
           textDirection,
@@ -45,6 +46,7 @@ class CkParagraphStyle implements ui.ParagraphStyle {
           strutStyle,
           ellipsis,
           locale,
+          applyRoundingHack,
         ),
         _fontFamily = _effectiveFontFamily(fontFamily),
         _fontSize = fontSize,
@@ -144,6 +146,7 @@ class CkParagraphStyle implements ui.ParagraphStyle {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
+    bool applyRoundingHack,
   ) {
     final SkParagraphStyleProperties properties = SkParagraphStyleProperties();
 
@@ -180,6 +183,7 @@ class CkParagraphStyle implements ui.ParagraphStyle {
     properties.replaceTabCharacters = true;
     properties.textStyle = toSkTextStyleProperties(
         fontFamily, fontSize, height, fontWeight, fontStyle);
+    properties.applyRoundingHack = applyRoundingHack;
 
     return canvasKit.ParagraphStyle(properties);
   }
diff --git a/lib/web_ui/lib/src/engine/html/renderer.dart b/lib/web_ui/lib/src/engine/html/renderer.dart
index 728c8bc367ce2..c7ad2c515466f 100644
--- a/lib/web_ui/lib/src/engine/html/renderer.dart
+++ b/lib/web_ui/lib/src/engine/html/renderer.dart
@@ -283,7 +283,9 @@ class HtmlRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale
+    ui.Locale? locale,
+    // Not used: the HTML renderer does not use SkParagraph.
+    bool applyRoundingHack = true,
   }) => EngineParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
diff --git a/lib/web_ui/lib/src/engine/renderer.dart b/lib/web_ui/lib/src/engine/renderer.dart
index 20fd055b1c13d..7309e7ee3cf48 100644
--- a/lib/web_ui/lib/src/engine/renderer.dart
+++ b/lib/web_ui/lib/src/engine/renderer.dart
@@ -210,6 +210,7 @@ abstract class Renderer {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
+    bool applyRoundingHack = true,
   });
 
   ui.StrutStyle createStrutStyle({
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
index c00c1bcac9b17..061eb1abded07 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
@@ -475,6 +475,7 @@ class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implem
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
+    bool applyRoundingHack = true,
   }) {
     final ParagraphStyleHandle handle = paragraphStyleCreate();
     if (textAlign != null) {
@@ -535,6 +536,7 @@ class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implem
       skStringFree(localeHandle);
     }
     paragraphStyleSetTextStyle(handle, textStyleHandle);
+    paragraphStyleSetApplyRoundingHack(handle, applyRoundingHack);
     return SkwasmParagraphStyle._(handle, textStyle, fontFamily);
   }
 
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
index e65a5f7690066..77a7d64328638 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
@@ -49,3 +49,6 @@ external void paragraphStyleSetStrutStyle(ParagraphStyleHandle handle, StrutStyl
 
 @Native<Void Function(ParagraphStyleHandle, TextStyleHandle)>(symbol: 'paragraphStyle_setTextStyle', isLeaf: true)
 external void paragraphStyleSetTextStyle(ParagraphStyleHandle handle, TextStyleHandle textStyle);
+
+@Native<Void Function(ParagraphStyleHandle, Bool)>(symbol: 'paragraphStyle_setApplyRoundingHack', isLeaf: true)
+external void paragraphStyleSetApplyRoundingHack(ParagraphStyleHandle handle, bool applyRoundingHack);
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
index e8228815ac806..3e57596613230 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
@@ -154,7 +154,8 @@ class SkwasmRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale
+    ui.Locale? locale,
+    bool applyRoundingHack = true,
   }) => SkwasmParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
@@ -168,6 +169,7 @@ class SkwasmRenderer implements Renderer {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
+    applyRoundingHack: applyRoundingHack,
   );
 
   @override
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
index 3d4823f49cc2c..14a2e511b139d 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
@@ -77,7 +77,7 @@ class SkwasmRenderer implements Renderer {
   }
 
   @override
-  ui.ParagraphStyle createParagraphStyle({ui.TextAlign? textAlign, ui.TextDirection? textDirection, int? maxLines, String? fontFamily, double? fontSize, double? height, ui.TextHeightBehavior? textHeightBehavior, ui.FontWeight? fontWeight, ui.FontStyle? fontStyle, ui.StrutStyle? strutStyle, String? ellipsis, ui.Locale? locale}) {
+  ui.ParagraphStyle createParagraphStyle({ui.TextAlign? textAlign, ui.TextDirection? textDirection, int? maxLines, String? fontFamily, double? fontSize, double? height, ui.TextHeightBehavior? textHeightBehavior, ui.FontWeight? fontWeight, ui.FontStyle? fontStyle, ui.StrutStyle? strutStyle, String? ellipsis, ui.Locale? locale, bool applyRoundingHack = true}) {
     throw UnimplementedError('Skwasm not implemented on this platform.');
   }
 
diff --git a/lib/web_ui/lib/text.dart b/lib/web_ui/lib/text.dart
index 491966a0f88c2..f91a26029c827 100644
--- a/lib/web_ui/lib/text.dart
+++ b/lib/web_ui/lib/text.dart
@@ -380,6 +380,7 @@ abstract class ParagraphStyle {
     StrutStyle? strutStyle,
     String? ellipsis,
     Locale? locale,
+    bool applyRoundingHack = true,
   }) => engine.renderer.createParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
@@ -393,6 +394,7 @@ abstract class ParagraphStyle {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
+    applyRoundingHack: applyRoundingHack,
   );
 }
 
diff --git a/lib/web_ui/skwasm/text/paragraph_style.cpp b/lib/web_ui/skwasm/text/paragraph_style.cpp
index 9a9dc82fac616..a319287bebeba 100644
--- a/lib/web_ui/skwasm/text/paragraph_style.cpp
+++ b/lib/web_ui/skwasm/text/paragraph_style.cpp
@@ -78,3 +78,8 @@ SKWASM_EXPORT void paragraphStyle_setTextStyle(ParagraphStyle* style,
                                                TextStyle* textStyle) {
   style->setTextStyle(*textStyle);
 }
+
+SKWASM_EXPORT void paragraphStyle_setApplyRoundingHack(ParagraphStyle* style,
+                                                       bool applyRoundingHack) {
+  style->setApplyRoundingHack(applyRoundingHack);
+}
diff --git a/testing/dart/paragraph_test.dart b/testing/dart/paragraph_test.dart
index 8c8e865770c59..48f6eb4b631e5 100644
--- a/testing/dart/paragraph_test.dart
+++ b/testing/dart/paragraph_test.dart
@@ -27,8 +27,7 @@ void main() {
       expect(paragraph.minIntrinsicWidth, closeTo(fontSize * 4.0, 0.001));
       expect(paragraph.maxIntrinsicWidth, closeTo(fontSize * 4.0, 0.001));
       expect(paragraph.alphabeticBaseline, closeTo(fontSize * .8, 0.001));
-      expect(
-        paragraph.ideographicBaseline,
+      expect(paragraph.ideographicBaseline,
         closeTo(paragraph.alphabeticBaseline * kAhemBaselineRatio, 0.001),
       );
     }
@@ -233,4 +232,35 @@ void main() {
       expect(callback, throwsStateError);
     }
   });
+
+    test('applyRoundingHack defaults to true', () {
+      const double fontSize = 1.25;
+      const String text = '12345';
+      assert((fontSize * text.length).truncate() != fontSize * text.length);
+      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
+      builder.addText('test');
+      final Paragraph paragraph = builder.build()
+        ..layout(const ParagraphConstraints(width: text.length * fontSize));
+
+      expect(paragraph.maxIntrinsicWidth, greaterThan(text.length * fontSize));
+      expect(paragraph.computeLineMetrics(), hasLength(2));
+    });
+
+    test('applyRoundingHack works', () {
+      const double fontSize = 1.25;
+      const String text = '12345';
+      assert((fontSize * text.length).truncate() != fontSize * text.length);
+      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
+      builder.addText('test');
+      final Paragraph paragraph = builder.build()
+        ..layout(const ParagraphConstraints(width: text.length * fontSize));
+
+      expect(paragraph.maxIntrinsicWidth, text.length * fontSize);
+      switch (paragraph.computeLineMetrics()) {
+        case [LineMetrics(width: final double width)]:
+          expect(width, text.length * fontSize);
+        case final List<LineMetrics> metrics:
+          expect(metrics, hasLength(1));
+      }
+    });
 }
diff --git a/third_party/txt/src/skia/paragraph_builder_skia.cc b/third_party/txt/src/skia/paragraph_builder_skia.cc
index 96d98f3f4c29f..641725ec6ccfb 100644
--- a/third_party/txt/src/skia/paragraph_builder_skia.cc
+++ b/third_party/txt/src/skia/paragraph_builder_skia.cc
@@ -138,6 +138,7 @@ skt::ParagraphStyle ParagraphBuilderSkia::TxtToSkia(const ParagraphStyle& txt) {
 
   skia.turnHintingOff();
   skia.setReplaceTabCharacters(true);
+  skia.setApplyRoundingHack(txt.apply_rounding_hack);
 
   return skia;
 }
diff --git a/third_party/txt/src/txt/paragraph_style.h b/third_party/txt/src/txt/paragraph_style.h
index 7c3043b8ad899..e1915323a0bd3 100644
--- a/third_party/txt/src/txt/paragraph_style.h
+++ b/third_party/txt/src/txt/paragraph_style.h
@@ -95,6 +95,14 @@ class ParagraphStyle {
   std::u16string ellipsis;
   std::string locale;
 
+  // Temporary flag that indicates whether the Paragraph should report its
+  // metrics with rounding hacks applied.
+  //
+  // This flag currently defaults to true and will be flipped to false once the
+  // migration is complete.
+  // TODO(LongCatIsLooong): https://github.com/flutter/flutter/issues/31707
+  bool apply_rounding_hack = true;
+
   TextStyle GetTextStyle() const;
 
   bool unlimited_lines() const;

From 997fc907a37cccdf8d0907508a61159471b662f4 Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Thu, 22 Jun 2023 17:42:24 -0700
Subject: [PATCH 2/7] dart:ui non-web

---
 lib/ui/dart_ui.cc                | 2 +-
 lib/ui/text.dart                 | 8 +++++---
 lib/ui/text/paragraph_builder.cc | 5 +++--
 lib/ui/text/paragraph_builder.h  | 6 ++++--
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/lib/ui/dart_ui.cc b/lib/ui/dart_ui.cc
index 77b126d797346..efb5af0a30a69 100644
--- a/lib/ui/dart_ui.cc
+++ b/lib/ui/dart_ui.cc
@@ -78,7 +78,7 @@ typedef CanvasPath Path;
   V(Gradient::Create, 1)                                              \
   V(ImageFilter::Create, 1)                                           \
   V(ImageShader::Create, 1)                                           \
-  V(ParagraphBuilder::Create, 9)                                      \
+  V(ParagraphBuilder::Create, 10)                                     \
   V(PathMeasure::Create, 3)                                           \
   V(Path::Create, 1)                                                  \
   V(PictureRecorder::Create, 1)                                       \
diff --git a/lib/ui/text.dart b/lib/ui/text.dart
index 93d2c01f927f8..4ed14b42919bb 100644
--- a/lib/ui/text.dart
+++ b/lib/ui/text.dart
@@ -3135,11 +3135,12 @@ base class _NativeParagraphBuilder extends NativeFieldWrapperClass1 implements P
         style._fontSize ?? 0,
         style._height ?? 0,
         style._ellipsis ?? '',
-        _encodeLocale(style._locale)
+        _encodeLocale(style._locale),
+        style._applyRoundingHack,
       );
   }
 
-  @Native<Void Function(Handle, Handle, Handle, Handle, Handle, Double, Double, Handle, Handle)>(symbol: 'ParagraphBuilder::Create')
+  @Native<Void Function(Handle, Handle, Handle, Handle, Handle, Double, Double, Handle, Handle, Bool)>(symbol: 'ParagraphBuilder::Create')
   external void _constructor(
       Int32List encoded,
       ByteData? strutData,
@@ -3148,7 +3149,8 @@ base class _NativeParagraphBuilder extends NativeFieldWrapperClass1 implements P
       double fontSize,
       double height,
       String ellipsis,
-      String locale);
+      String locale,
+      bool applyRoundingHack);
 
   @override
   int get placeholderCount => _placeholderCount;
diff --git a/lib/ui/text/paragraph_builder.cc b/lib/ui/text/paragraph_builder.cc
index 5740ead7926c0..eb01511772d49 100644
--- a/lib/ui/text/paragraph_builder.cc
+++ b/lib/ui/text/paragraph_builder.cc
@@ -151,11 +151,12 @@ void ParagraphBuilder::Create(Dart_Handle wrapper,
                               double fontSize,
                               double height,
                               const std::u16string& ellipsis,
-                              const std::string& locale) {
+                              const std::string& locale,
+                              bool applyRoundingHack) {
   UIDartState::ThrowIfUIOperationsProhibited();
   auto res = fml::MakeRefCounted<ParagraphBuilder>(
       encoded_handle, strutData, fontFamily, strutFontFamilies, fontSize,
-      height, ellipsis, locale);
+      height, ellipsis, locale, applyRoundingHack);
   res->AssociateWithDartWrapper(wrapper);
 }
 
diff --git a/lib/ui/text/paragraph_builder.h b/lib/ui/text/paragraph_builder.h
index 0018f969da68f..6fc7c58ad97aa 100644
--- a/lib/ui/text/paragraph_builder.h
+++ b/lib/ui/text/paragraph_builder.h
@@ -30,7 +30,8 @@ class ParagraphBuilder : public RefCountedDartWrappable<ParagraphBuilder> {
                      double fontSize,
                      double height,
                      const std::u16string& ellipsis,
-                     const std::string& locale);
+                     const std::string& locale,
+                     bool applyRoundingHack);
 
   ~ParagraphBuilder() override;
 
@@ -76,7 +77,8 @@ class ParagraphBuilder : public RefCountedDartWrappable<ParagraphBuilder> {
                             double fontSize,
                             double height,
                             const std::u16string& ellipsis,
-                            const std::string& locale);
+                            const std::string& locale,
+                            bool applyRoundingHack);
 
   std::unique_ptr<txt::ParagraphBuilder> m_paragraphBuilder;
 };

From 6de46a37c829e17ac73bbfb9d9b4251a25eeb7ef Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Thu, 22 Jun 2023 18:34:16 -0700
Subject: [PATCH 3/7] fix tests

---
 testing/dart/paragraph_test.dart | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/testing/dart/paragraph_test.dart b/testing/dart/paragraph_test.dart
index d174ad4652cb0..7fbe06406b41e 100644
--- a/testing/dart/paragraph_test.dart
+++ b/testing/dart/paragraph_test.dart
@@ -239,7 +239,7 @@ void main() {
       const String text = '12345';
       assert((fontSize * text.length).truncate() != fontSize * text.length);
       final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
-      builder.addText('test');
+      builder.addText(text);
       final Paragraph paragraph = builder.build()
         ..layout(const ParagraphConstraints(width: text.length * fontSize));
 
@@ -252,7 +252,7 @@ void main() {
       const String text = '12345';
       assert((fontSize * text.length).truncate() != fontSize * text.length);
       final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
-      builder.addText('test');
+      builder.addText(text);
       final Paragraph paragraph = builder.build()
         ..layout(const ParagraphConstraints(width: text.length * fontSize));
 

From 43c80b938f6d8b29479ac42ac1d0d014045f0a45 Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Thu, 22 Jun 2023 18:40:02 -0700
Subject: [PATCH 4/7] tests

---
 .../lib/src/engine/canvaskit/renderer.dart    |  1 +
 lib/web_ui/test/canvaskit/text_test.dart      | 35 ++++++++++-
 testing/dart/paragraph_test.dart              | 59 +++++++++----------
 3 files changed, 64 insertions(+), 31 deletions(-)

diff --git a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
index 4ba883274ce1a..6ab2296300252 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
@@ -329,6 +329,7 @@ class CanvasKitRenderer implements Renderer {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
+    applyRoundingHack: applyRoundingHack,
   );
 
   @override
diff --git a/lib/web_ui/test/canvaskit/text_test.dart b/lib/web_ui/test/canvaskit/text_test.dart
index d14ad7b75e83d..ad8403e4526f7 100644
--- a/lib/web_ui/test/canvaskit/text_test.dart
+++ b/lib/web_ui/test/canvaskit/text_test.dart
@@ -122,7 +122,40 @@ void testMain() {
         }
       });
     });
+
+    test('applyRoundingHack defaults to true', () {
+      const double fontSize = 1.25;
+      const String text = '12345';
+      assert((fontSize * text.length).truncate() != fontSize * text.length);
+      final ui.ParagraphBuilder builder = ui.ParagraphBuilder(
+        ui.ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest'),
+      );
+      builder.addText(text);
+      final ui.Paragraph paragraph = builder.build()
+        ..layout(const ui.ParagraphConstraints(width: text.length * fontSize));
+
+      expect(paragraph.computeLineMetrics(), hasLength(2));
+    });
+
+    test('applyRoundingHack works', () {
+      const double fontSize = 1.25;
+      const String text = '12345';
+      assert((fontSize * text.length).truncate() != fontSize * text.length);
+      final ui.ParagraphBuilder builder = ui.ParagraphBuilder(
+        ui.ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest', applyRoundingHack: false),
+      );
+      builder.addText(text);
+      final ui.Paragraph paragraph = builder.build()
+        ..layout(const ui.ParagraphConstraints(width: text.length * fontSize));
+
+      expect(paragraph.maxIntrinsicWidth, text.length * fontSize);
+      switch (paragraph.computeLineMetrics()) {
+        case [ui.LineMetrics(width: final double width)]:
+          expect(width, text.length * fontSize);
+        case final List<ui.LineMetrics> metrics:
+          expect(metrics, hasLength(1));
+      }
+    });
     // TODO(hterkelsen): https://github.com/flutter/flutter/issues/71520
   }, skip: isSafari || isFirefox);
-
 }
diff --git a/testing/dart/paragraph_test.dart b/testing/dart/paragraph_test.dart
index 7fbe06406b41e..c3d4ac6978adb 100644
--- a/testing/dart/paragraph_test.dart
+++ b/testing/dart/paragraph_test.dart
@@ -234,34 +234,33 @@ void main() {
     }
   });
 
-    test('applyRoundingHack defaults to true', () {
-      const double fontSize = 1.25;
-      const String text = '12345';
-      assert((fontSize * text.length).truncate() != fontSize * text.length);
-      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
-      builder.addText(text);
-      final Paragraph paragraph = builder.build()
-        ..layout(const ParagraphConstraints(width: text.length * fontSize));
-
-      expect(paragraph.maxIntrinsicWidth, greaterThan(text.length * fontSize));
-      expect(paragraph.computeLineMetrics(), hasLength(2));
-    });
-
-    test('applyRoundingHack works', () {
-      const double fontSize = 1.25;
-      const String text = '12345';
-      assert((fontSize * text.length).truncate() != fontSize * text.length);
-      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
-      builder.addText(text);
-      final Paragraph paragraph = builder.build()
-        ..layout(const ParagraphConstraints(width: text.length * fontSize));
-
-      expect(paragraph.maxIntrinsicWidth, text.length * fontSize);
-      switch (paragraph.computeLineMetrics()) {
-        case [LineMetrics(width: final double width)]:
-          expect(width, text.length * fontSize);
-        case final List<LineMetrics> metrics:
-          expect(metrics, hasLength(1));
-      }
-    });
+  test('applyRoundingHack defaults to true', () {
+    const double fontSize = 1.25;
+    const String text = '12345';
+    assert((fontSize * text.length).truncate() != fontSize * text.length);
+    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
+    builder.addText(text);
+    final Paragraph paragraph = builder.build()
+      ..layout(const ParagraphConstraints(width: text.length * fontSize));
+
+    expect(paragraph.computeLineMetrics(), hasLength(2));
+  });
+
+  test('applyRoundingHack works', () {
+    const double fontSize = 1.25;
+    const String text = '12345';
+    assert((fontSize * text.length).truncate() != fontSize * text.length);
+    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
+    builder.addText(text);
+    final Paragraph paragraph = builder.build()
+      ..layout(const ParagraphConstraints(width: text.length * fontSize));
+
+    expect(paragraph.maxIntrinsicWidth, text.length * fontSize);
+    switch (paragraph.computeLineMetrics()) {
+      case [LineMetrics(width: final double width)]:
+        expect(width, text.length * fontSize);
+      case final List<LineMetrics> metrics:
+        expect(metrics, hasLength(1));
+    }
+  });
 }

From 622fffae20d9fa301432a344c8d66562ef8de5b1 Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Fri, 23 Jun 2023 11:45:33 -0700
Subject: [PATCH 5/7] Merge remote-tracking branch 'upstream/main' into
 apply-rounding-hack-plumbing

---
 lib/ui/text.dart                              | 24 ++++++++++++++++++-
 .../lib/src/engine/canvaskit/renderer.dart    |  3 +--
 lib/web_ui/lib/src/engine/html/renderer.dart  |  2 --
 lib/web_ui/lib/src/engine/renderer.dart       |  1 -
 .../engine/skwasm/skwasm_impl/paragraph.dart  |  2 --
 .../raw/text/raw_paragraph_style.dart         |  3 ---
 .../engine/skwasm/skwasm_impl/renderer.dart   |  2 --
 .../engine/skwasm/skwasm_stub/renderer.dart   |  2 +-
 lib/web_ui/lib/text.dart                      | 15 ++++++++++--
 lib/web_ui/skwasm/text/paragraph_style.cpp    |  5 ----
 lib/web_ui/test/canvaskit/text_test.dart      | 19 ++++-----------
 testing/dart/paragraph_test.dart              | 17 ++++---------
 12 files changed, 46 insertions(+), 49 deletions(-)

diff --git a/lib/ui/text.dart b/lib/ui/text.dart
index 4ed14b42919bb..0d3a586c877a8 100644
--- a/lib/ui/text.dart
+++ b/lib/ui/text.dart
@@ -2801,7 +2801,7 @@ abstract class Paragraph {
   /// This only returns a valid value if asserts are enabled, and must not be
   /// used otherwise.
   bool get debugDisposed;
- }
+}
 
 @pragma('vm:entry-point')
 base class _NativeParagraph extends NativeFieldWrapperClass1 implements Paragraph {
@@ -3018,6 +3018,28 @@ abstract class ParagraphBuilder {
   /// [Paragraph].
   factory ParagraphBuilder(ParagraphStyle style) = _NativeParagraphBuilder;
 
+  /// Whether the rounding hack enabled by default in SkParagraph and TextPainter
+  /// is disabled.
+  ///
+  /// Do not rely on this getter as it exists for migration purposes only and
+  /// will soon be removed.
+  static bool get shouldDisableRoundingHack {
+    return const bool.hasEnvironment('SKPARAGRAPH_REMOVE_ROUNDING_HACK')
+        || _roundingHackDisabledInDebugMode;
+  }
+  static bool _roundingHackDisabledInDebugMode = true;
+
+  /// Only works in debug mode. Do not call this method as it is for migration
+  /// purposes only and will soon be removed.
+  static void setDisableRoundingHack(bool disableRoundingHack) {
+    // bool.hasEnvironment does not work in internal tests so an additional flag
+    // is needed for tests.
+    assert(() {
+      _roundingHackDisabledInDebugMode = disableRoundingHack;
+      return true;
+    }());
+  }
+
   /// The number of placeholders currently in the paragraph.
   int get placeholderCount;
 
diff --git a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
index 6ab2296300252..045a73d935531 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
@@ -315,7 +315,6 @@ class CanvasKitRenderer implements Renderer {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
-    bool applyRoundingHack = true,
   }) => CkParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
@@ -329,7 +328,7 @@ class CanvasKitRenderer implements Renderer {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
-    applyRoundingHack: applyRoundingHack,
+    applyRoundingHack: !ui.ParagraphBuilder.shouldDisableRoundingHack,
   );
 
   @override
diff --git a/lib/web_ui/lib/src/engine/html/renderer.dart b/lib/web_ui/lib/src/engine/html/renderer.dart
index c7ad2c515466f..75818266d1f7e 100644
--- a/lib/web_ui/lib/src/engine/html/renderer.dart
+++ b/lib/web_ui/lib/src/engine/html/renderer.dart
@@ -284,8 +284,6 @@ class HtmlRenderer implements Renderer {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
-    // Not used: the HTML renderer does not use SkParagraph.
-    bool applyRoundingHack = true,
   }) => EngineParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
diff --git a/lib/web_ui/lib/src/engine/renderer.dart b/lib/web_ui/lib/src/engine/renderer.dart
index 7309e7ee3cf48..20fd055b1c13d 100644
--- a/lib/web_ui/lib/src/engine/renderer.dart
+++ b/lib/web_ui/lib/src/engine/renderer.dart
@@ -210,7 +210,6 @@ abstract class Renderer {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
-    bool applyRoundingHack = true,
   });
 
   ui.StrutStyle createStrutStyle({
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
index 061eb1abded07..c00c1bcac9b17 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart
@@ -475,7 +475,6 @@ class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implem
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
-    bool applyRoundingHack = true,
   }) {
     final ParagraphStyleHandle handle = paragraphStyleCreate();
     if (textAlign != null) {
@@ -536,7 +535,6 @@ class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implem
       skStringFree(localeHandle);
     }
     paragraphStyleSetTextStyle(handle, textStyleHandle);
-    paragraphStyleSetApplyRoundingHack(handle, applyRoundingHack);
     return SkwasmParagraphStyle._(handle, textStyle, fontFamily);
   }
 
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
index 77a7d64328638..e65a5f7690066 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/text/raw_paragraph_style.dart
@@ -49,6 +49,3 @@ external void paragraphStyleSetStrutStyle(ParagraphStyleHandle handle, StrutStyl
 
 @Native<Void Function(ParagraphStyleHandle, TextStyleHandle)>(symbol: 'paragraphStyle_setTextStyle', isLeaf: true)
 external void paragraphStyleSetTextStyle(ParagraphStyleHandle handle, TextStyleHandle textStyle);
-
-@Native<Void Function(ParagraphStyleHandle, Bool)>(symbol: 'paragraphStyle_setApplyRoundingHack', isLeaf: true)
-external void paragraphStyleSetApplyRoundingHack(ParagraphStyleHandle handle, bool applyRoundingHack);
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
index 3e57596613230..c31228dd5cd43 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
@@ -155,7 +155,6 @@ class SkwasmRenderer implements Renderer {
     ui.StrutStyle? strutStyle,
     String? ellipsis,
     ui.Locale? locale,
-    bool applyRoundingHack = true,
   }) => SkwasmParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
@@ -169,7 +168,6 @@ class SkwasmRenderer implements Renderer {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
-    applyRoundingHack: applyRoundingHack,
   );
 
   @override
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
index 14a2e511b139d..3d4823f49cc2c 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_stub/renderer.dart
@@ -77,7 +77,7 @@ class SkwasmRenderer implements Renderer {
   }
 
   @override
-  ui.ParagraphStyle createParagraphStyle({ui.TextAlign? textAlign, ui.TextDirection? textDirection, int? maxLines, String? fontFamily, double? fontSize, double? height, ui.TextHeightBehavior? textHeightBehavior, ui.FontWeight? fontWeight, ui.FontStyle? fontStyle, ui.StrutStyle? strutStyle, String? ellipsis, ui.Locale? locale, bool applyRoundingHack = true}) {
+  ui.ParagraphStyle createParagraphStyle({ui.TextAlign? textAlign, ui.TextDirection? textDirection, int? maxLines, String? fontFamily, double? fontSize, double? height, ui.TextHeightBehavior? textHeightBehavior, ui.FontWeight? fontWeight, ui.FontStyle? fontStyle, ui.StrutStyle? strutStyle, String? ellipsis, ui.Locale? locale}) {
     throw UnimplementedError('Skwasm not implemented on this platform.');
   }
 
diff --git a/lib/web_ui/lib/text.dart b/lib/web_ui/lib/text.dart
index f91a26029c827..dea0c720db9ec 100644
--- a/lib/web_ui/lib/text.dart
+++ b/lib/web_ui/lib/text.dart
@@ -380,7 +380,6 @@ abstract class ParagraphStyle {
     StrutStyle? strutStyle,
     String? ellipsis,
     Locale? locale,
-    bool applyRoundingHack = true,
   }) => engine.renderer.createParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
@@ -394,7 +393,6 @@ abstract class ParagraphStyle {
     strutStyle: strutStyle,
     ellipsis: ellipsis,
     locale: locale,
-    applyRoundingHack: applyRoundingHack,
   );
 }
 
@@ -687,6 +685,19 @@ abstract class Paragraph {
 abstract class ParagraphBuilder {
   factory ParagraphBuilder(ParagraphStyle style) =>
     engine.renderer.createParagraphBuilder(style);
+
+  static bool get shouldDisableRoundingHack {
+    return const bool.hasEnvironment('SKPARAGRAPH_REMOVE_ROUNDING_HACK')
+        || _roundingHackDisabledInDebugMode;
+  }
+  static bool _roundingHackDisabledInDebugMode = true;
+  static void setDisableRoundingHack(bool disableRoundingHack) {
+    assert(() {
+      _roundingHackDisabledInDebugMode = disableRoundingHack;
+      return true;
+    }());
+  }
+
   void pushStyle(TextStyle style);
   void pop();
   void addText(String text);
diff --git a/lib/web_ui/skwasm/text/paragraph_style.cpp b/lib/web_ui/skwasm/text/paragraph_style.cpp
index a319287bebeba..9a9dc82fac616 100644
--- a/lib/web_ui/skwasm/text/paragraph_style.cpp
+++ b/lib/web_ui/skwasm/text/paragraph_style.cpp
@@ -78,8 +78,3 @@ SKWASM_EXPORT void paragraphStyle_setTextStyle(ParagraphStyle* style,
                                                TextStyle* textStyle) {
   style->setTextStyle(*textStyle);
 }
-
-SKWASM_EXPORT void paragraphStyle_setApplyRoundingHack(ParagraphStyle* style,
-                                                       bool applyRoundingHack) {
-  style->setApplyRoundingHack(applyRoundingHack);
-}
diff --git a/lib/web_ui/test/canvaskit/text_test.dart b/lib/web_ui/test/canvaskit/text_test.dart
index ad8403e4526f7..e9f4797fb498c 100644
--- a/lib/web_ui/test/canvaskit/text_test.dart
+++ b/lib/web_ui/test/canvaskit/text_test.dart
@@ -123,26 +123,14 @@ void testMain() {
       });
     });
 
-    test('applyRoundingHack defaults to true', () {
-      const double fontSize = 1.25;
-      const String text = '12345';
-      assert((fontSize * text.length).truncate() != fontSize * text.length);
-      final ui.ParagraphBuilder builder = ui.ParagraphBuilder(
-        ui.ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest'),
-      );
-      builder.addText(text);
-      final ui.Paragraph paragraph = builder.build()
-        ..layout(const ui.ParagraphConstraints(width: text.length * fontSize));
-
-      expect(paragraph.computeLineMetrics(), hasLength(2));
-    });
-
     test('applyRoundingHack works', () {
       const double fontSize = 1.25;
       const String text = '12345';
       assert((fontSize * text.length).truncate() != fontSize * text.length);
+      final bool roundingHackWasDisabled = ui.ParagraphBuilder.shouldDisableRoundingHack;
+      ui.ParagraphBuilder.setDisableRoundingHack(true);
       final ui.ParagraphBuilder builder = ui.ParagraphBuilder(
-        ui.ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest', applyRoundingHack: false),
+        ui.ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest'),
       );
       builder.addText(text);
       final ui.Paragraph paragraph = builder.build()
@@ -155,6 +143,7 @@ void testMain() {
         case final List<ui.LineMetrics> metrics:
           expect(metrics, hasLength(1));
       }
+      ui.ParagraphBuilder.setDisableRoundingHack(roundingHackWasDisabled);
     });
     // TODO(hterkelsen): https://github.com/flutter/flutter/issues/71520
   }, skip: isSafari || isFirefox);
diff --git a/testing/dart/paragraph_test.dart b/testing/dart/paragraph_test.dart
index c3d4ac6978adb..ec8a30cd1cad8 100644
--- a/testing/dart/paragraph_test.dart
+++ b/testing/dart/paragraph_test.dart
@@ -234,22 +234,12 @@ void main() {
     }
   });
 
-  test('applyRoundingHack defaults to true', () {
-    const double fontSize = 1.25;
-    const String text = '12345';
-    assert((fontSize * text.length).truncate() != fontSize * text.length);
-    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
-    builder.addText(text);
-    final Paragraph paragraph = builder.build()
-      ..layout(const ParagraphConstraints(width: text.length * fontSize));
-
-    expect(paragraph.computeLineMetrics(), hasLength(2));
-  });
-
-  test('applyRoundingHack works', () {
+  test('disableRoundingHack works', () {
     const double fontSize = 1.25;
     const String text = '12345';
     assert((fontSize * text.length).truncate() != fontSize * text.length);
+    final bool roundingHackWasDisabled = ParagraphBuilder.shouldDisableRoundingHack;
+    ParagraphBuilder.setDisableRoundingHack(true);
     final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
     builder.addText(text);
     final Paragraph paragraph = builder.build()
@@ -262,5 +252,6 @@ void main() {
       case final List<LineMetrics> metrics:
         expect(metrics, hasLength(1));
     }
+    ParagraphBuilder.setDisableRoundingHack(roundingHackWasDisabled);
   });
 }

From 75ce8aeabe52095a7559a6f540312a176c110b65 Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Fri, 23 Jun 2023 11:47:45 -0700
Subject: [PATCH 6/7] remove additional changes

---
 lib/ui/text.dart                                          | 8 ++------
 lib/web_ui/lib/src/engine/canvaskit/renderer.dart         | 2 +-
 lib/web_ui/lib/src/engine/html/renderer.dart              | 2 +-
 .../lib/src/engine/skwasm/skwasm_impl/renderer.dart       | 2 +-
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/lib/ui/text.dart b/lib/ui/text.dart
index 0d3a586c877a8..c109c420b2343 100644
--- a/lib/ui/text.dart
+++ b/lib/ui/text.dart
@@ -1762,7 +1762,6 @@ class ParagraphStyle {
     StrutStyle? strutStyle,
     String? ellipsis,
     Locale? locale,
-    bool applyRoundingHack = true,
   }) : _encoded = _encodeParagraphStyle(
          textAlign,
          textDirection,
@@ -1783,7 +1782,6 @@ class ParagraphStyle {
        _strutStyle = strutStyle,
        _ellipsis = ellipsis,
        _locale = locale,
-       _applyRoundingHack = applyRoundingHack,
        _leadingDistribution = textHeightBehavior?.leadingDistribution ?? TextLeadingDistribution.proportional;
 
   final Int32List _encoded;
@@ -1794,7 +1792,6 @@ class ParagraphStyle {
   final String? _ellipsis;
   final Locale? _locale;
   final TextLeadingDistribution _leadingDistribution;
-  final bool _applyRoundingHack;
 
   @override
   bool operator ==(Object other) {
@@ -1812,12 +1809,11 @@ class ParagraphStyle {
         && other._ellipsis == _ellipsis
         && other._locale == _locale
         && other._leadingDistribution == _leadingDistribution
-        && other._applyRoundingHack == _applyRoundingHack
         && _listEquals<int>(other._encoded, _encoded);
   }
 
   @override
-  int get hashCode => Object.hash(Object.hashAll(_encoded), _fontFamily, _fontSize, _height, _ellipsis, _locale, _leadingDistribution, _applyRoundingHack);
+  int get hashCode => Object.hash(Object.hashAll(_encoded), _fontFamily, _fontSize, _height, _ellipsis, _locale, _leadingDistribution);
 
   @override
   String toString() {
@@ -3158,7 +3154,7 @@ base class _NativeParagraphBuilder extends NativeFieldWrapperClass1 implements P
         style._height ?? 0,
         style._ellipsis ?? '',
         _encodeLocale(style._locale),
-        style._applyRoundingHack,
+        !ParagraphBuilder.shouldDisableRoundingHack,
       );
   }
 
diff --git a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
index 045a73d935531..96da491f69af4 100644
--- a/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
+++ b/lib/web_ui/lib/src/engine/canvaskit/renderer.dart
@@ -314,7 +314,7 @@ class CanvasKitRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale,
+    ui.Locale? locale
   }) => CkParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
diff --git a/lib/web_ui/lib/src/engine/html/renderer.dart b/lib/web_ui/lib/src/engine/html/renderer.dart
index 75818266d1f7e..728c8bc367ce2 100644
--- a/lib/web_ui/lib/src/engine/html/renderer.dart
+++ b/lib/web_ui/lib/src/engine/html/renderer.dart
@@ -283,7 +283,7 @@ class HtmlRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale,
+    ui.Locale? locale
   }) => EngineParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
index c31228dd5cd43..e8228815ac806 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/renderer.dart
@@ -154,7 +154,7 @@ class SkwasmRenderer implements Renderer {
     ui.FontStyle? fontStyle,
     ui.StrutStyle? strutStyle,
     String? ellipsis,
-    ui.Locale? locale,
+    ui.Locale? locale
   }) => SkwasmParagraphStyle(
     textAlign: textAlign,
     textDirection: textDirection,

From 6215574dbebeaa8244b35c6efd0af4d1dc42feb4 Mon Sep 17 00:00:00 2001
From: LongCat is Looong <31859944+LongCatIsLooong@users.noreply.github.com>
Date: Fri, 23 Jun 2023 12:01:09 -0700
Subject: [PATCH 7/7] fix tests

---
 testing/dart/paragraph_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testing/dart/paragraph_test.dart b/testing/dart/paragraph_test.dart
index ec8a30cd1cad8..075bfa2993c4f 100644
--- a/testing/dart/paragraph_test.dart
+++ b/testing/dart/paragraph_test.dart
@@ -240,7 +240,7 @@ void main() {
     assert((fontSize * text.length).truncate() != fontSize * text.length);
     final bool roundingHackWasDisabled = ParagraphBuilder.shouldDisableRoundingHack;
     ParagraphBuilder.setDisableRoundingHack(true);
-    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, applyRoundingHack: false));
+    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize));
     builder.addText(text);
     final Paragraph paragraph = builder.build()
       ..layout(const ParagraphConstraints(width: text.length * fontSize));