Fix path.contains failure when devicepixelratio != 1.0 (#15743)

* Fix path contains failure due to devicepixelratio

lib/web_ui/lib/src/engine/surface/painting.dart

@@ -89,7 +89,8 @@ class SurfacePaint implements ui.Paint {
       _paintData = _paintData.clone();
       _frozen = false;
     }
-    _paintData.color = value.runtimeType == ui.Color ? value : ui.Color(value.value);
+    _paintData.color =
+        value.runtimeType == ui.Color ? value : ui.Color(value.value);
   }
 
   @override
@@ -286,8 +287,7 @@ class SurfacePath implements ui.Path {
   ///
   /// This copy is fast and does not require additional memory unless either
   /// the `source` path or the path returned by this constructor are modified.
-  SurfacePath.from(SurfacePath source)
-      : subpaths = _deepCopy(source.subpaths);
+  SurfacePath.from(SurfacePath source) : subpaths = _deepCopy(source.subpaths);
 
   SurfacePath._shallowCopy(SurfacePath source)
       : subpaths = List<Subpath>.from(source.subpaths);
@@ -418,8 +418,8 @@ class SurfacePath implements ui.Path {
   void relativeCubicTo(
       double x1, double y1, double x2, double y2, double x3, double y3) {
     _ensurePathStarted();
-    _commands.add(BezierCurveTo(x1 + _currentX, y1 + _currentY,
-        x2 + _currentX, y2 + _currentY, x3 + _currentX, y3 + _currentY));
+    _commands.add(BezierCurveTo(x1 + _currentX, y1 + _currentY, x2 + _currentX,
+        y2 + _currentY, x3 + _currentX, y3 + _currentY));
     _setCurrentPoint(x3 + _currentX, y3 + _currentY);
   }
 
@@ -431,7 +431,7 @@ class SurfacePath implements ui.Path {
   @override
   void conicTo(double x1, double y1, double x2, double y2, double w) {
     final List<ui.Offset> quads =
-    Conic(_currentX, _currentY, x1, y1, x2, y2, w).toQuads();
+        Conic(_currentX, _currentY, x1, y1, x2, y2, w).toQuads();
     final int len = quads.length;
     for (int i = 1; i < len; i += 2) {
       quadraticBezierTo(
@@ -504,12 +504,12 @@ class SurfacePath implements ui.Path {
   /// as reference for implementation.
   @override
   void arcToPoint(
-      ui.Offset arcEnd, {
-        ui.Radius radius = ui.Radius.zero,
-        double rotation = 0.0,
-        bool largeArc = false,
-        bool clockwise = true,
-      }) {
+    ui.Offset arcEnd, {
+    ui.Radius radius = ui.Radius.zero,
+    double rotation = 0.0,
+    bool largeArc = false,
+    bool clockwise = true,
+  }) {
     assert(offsetIsValid(arcEnd));
     assert(radiusIsValid(radius));
     // _currentX, _currentY are the coordinates of start point on path,
@@ -631,15 +631,16 @@ class SurfacePath implements ui.Path {
   /// describe an arc.
   @override
   void relativeArcToPoint(
-      ui.Offset arcEndDelta, {
-        ui.Radius radius = ui.Radius.zero,
-        double rotation = 0.0,
-        bool largeArc = false,
-        bool clockwise = true,
-      }) {
+    ui.Offset arcEndDelta, {
+    ui.Radius radius = ui.Radius.zero,
+    double rotation = 0.0,
+    bool largeArc = false,
+    bool clockwise = true,
+  }) {
     assert(offsetIsValid(arcEndDelta));
     assert(radiusIsValid(radius));
-    arcToPoint(ui.Offset(_currentX + arcEndDelta.dx, _currentY + arcEndDelta.dy),
+    arcToPoint(
+        ui.Offset(_currentX + arcEndDelta.dx, _currentY + arcEndDelta.dy),
         radius: radius,
         rotation: rotation,
         largeArc: largeArc,
@@ -652,8 +653,7 @@ class SurfacePath implements ui.Path {
   void addRect(ui.Rect rect) {
     assert(rectIsValid(rect));
     _openNewSubpath(rect.left, rect.top);
-    _commands
-        .add(RectCommand(rect.left, rect.top, rect.width, rect.height));
+    _commands.add(RectCommand(rect.left, rect.top, rect.width, rect.height));
   }
 
   /// Adds a new subpath that consists of a curve that forms the
@@ -767,7 +767,8 @@ class SurfacePath implements ui.Path {
     }
   }
 
-  void _addPathWithMatrix(SurfacePath path, double dx, double dy, Float64List matrix) {
+  void _addPathWithMatrix(
+      SurfacePath path, double dx, double dy, Float64List matrix) {
     final Matrix4 transform = Matrix4.fromFloat64List(matrix);
     transform.translate(dx, dy);
     subpaths.addAll(path.transform(transform.storage).subpaths);
@@ -909,16 +910,25 @@ class SurfacePath implements ui.Path {
           }
           return true;
         }
+        // TODO: For improved performance, handle Ellipse special case.
       }
     }
-    final ui.Size size = window.physicalSize / window.devicePixelRatio;
+    final ui.Size size = window.physicalSize;
+    // If device pixel ratio has changed we can't reuse prior raw recorder.
+    if (_rawRecorder != null &&
+        _rawRecorder._devicePixelRatio !=
+            EngineWindow.browserDevicePixelRatio) {
+      _rawRecorder = null;
+    }
     _rawRecorder ??= ui.RawRecordingCanvas(size);
     // Account for the shift due to padding.
     _rawRecorder.translate(-BitmapCanvas.kPaddingPixels.toDouble(),
         -BitmapCanvas.kPaddingPixels.toDouble());
     _rawRecorder.drawPath(
         this, (SurfacePaint()..color = const ui.Color(0xFF000000)).paintData);
-    final bool result = _rawRecorder._canvasPool.context.isPointInPath(pointX, pointY);
+    final double recorderDevicePixelRatio = _rawRecorder._devicePixelRatio;
+    final bool result = _rawRecorder._canvasPool.context.isPointInPath(
+        pointX * recorderDevicePixelRatio, pointY * recorderDevicePixelRatio);
     _rawRecorder.dispose();
     return result;
   }

lib/web_ui/test/path_test.dart

@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 import 'package:test/test.dart';
-import 'package:ui/ui.dart';
+import 'dart:js_util' as js_util;
+import 'dart:html' as html;
+import 'package:ui/ui.dart' hide window;
 import 'package:ui/src/engine.dart';
 
 import 'matchers.dart';
@@ -252,4 +254,21 @@ void main() {
     // Expect original path to stay the same.
     expect(path.getBounds(), const Rect.fromLTRB(25, 30, 100, 200));
   });
+
+  // Regression test for https://github.com/flutter/flutter/issues/44470
+  test('Should handle contains for devicepixelratio != 1.0', () {
+    js_util.setProperty(html.window, 'devicePixelRatio', 4.0);
+    window.debugOverrideDevicePixelRatio(4.0);
+    final path = Path()
+      ..moveTo(50, 0)
+      ..lineTo(100, 100)
+      ..lineTo(0, 100)
+      ..lineTo(50, 0)
+      ..close();
+    expect(path.contains(Offset(50, 50)), isTrue);
+    js_util.setProperty(html.window, 'devicePixelRatio', 1.0);
+    window.debugOverrideDevicePixelRatio(1.0);
+    // TODO: Investigate failure on CI. Locally this passes.
+    // [Exception... "Failure"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"
+  }, skip: browserEngine == BrowserEngine.firefox);
 }