Perf test for color filter with saveLayer (#52063)

dev/benchmarks/macrobenchmarks/lib/common.dart

@@ -11,3 +11,4 @@ const String kPictureCacheRouteName = '/picture_cache';
 const String kLargeImagesRouteName = '/large_images';
 const String kTextRouteName = '/text';
 const String kAnimatedPlaceholderRouteName = '/animated_placeholder';
+const String kColorFilterAndFadeRouteName = '/color_filter_and_fade';

dev/benchmarks/macrobenchmarks/lib/main.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter/material.dart';
+import 'package:macrobenchmarks/src/color_filter_and_fade.dart';
 import 'package:macrobenchmarks/src/large_images.dart';
 import 'package:macrobenchmarks/src/picture_cache.dart';
 
@@ -38,6 +39,7 @@ class MacrobenchmarksApp extends StatelessWidget {
         kLargeImagesRouteName: (BuildContext context) => LargeImagesPage(),
         kTextRouteName: (BuildContext context) => TextPage(),
         kAnimatedPlaceholderRouteName: (BuildContext context) => AnimatedPlaceholderPage(),
+        kColorFilterAndFadeRouteName: (BuildContext context) => ColorFilterAndFadePage(),
       },
     );
   }
@@ -115,6 +117,13 @@ class HomePage extends StatelessWidget {
               Navigator.pushNamed(context, kAnimatedPlaceholderRouteName);
             },
           ),
+          RaisedButton(
+            key: const Key(kColorFilterAndFadeRouteName),
+            child: const Text('Color Filter and Fade'),
+            onPressed: () {
+              Navigator.pushNamed(context, kColorFilterAndFadeRouteName);
+            },
+          ),
         ],
       ),
     );

dev/benchmarks/macrobenchmarks/lib/src/color_filter_and_fade.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:ui' as ui;
+import 'dart:ui';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter/rendering.dart';
+
+// This tests whether the Opacity layer raster cache works with color filters.
+// See https://github.com/flutter/flutter/issues/51975.
+class ColorFilterAndFadePage extends StatefulWidget {
+  @override
+  _ColorFilterAndFadePageState createState() => _ColorFilterAndFadePageState();
+}
+
+class _ColorFilterAndFadePageState extends State<ColorFilterAndFadePage> with TickerProviderStateMixin {
+  @override
+  Widget build(BuildContext context) {
+    final Widget shadowWidget = _ShadowWidget(
+      width: 24,
+      height: 24,
+      useColorFilter: _useColorFilter,
+      shadow: ui.Shadow(
+        color: Colors.black45,
+        offset: const Offset(0.0, 2.0),
+        blurRadius: 4.0,
+      ),
+    );
+
+    final Widget row = Row(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: <Widget>[
+        shadowWidget,
+        const SizedBox(width: 12),
+        shadowWidget,
+        const SizedBox(width: 12),
+        shadowWidget,
+        const SizedBox(width: 12),
+        shadowWidget,
+        const SizedBox(width: 12),
+        shadowWidget,
+        const SizedBox(width: 12),
+      ],
+    );
+
+    final Widget column = Column(mainAxisAlignment: MainAxisAlignment.center,
+        children: <Widget>[
+          row,
+          const SizedBox(height: 12),
+          row,
+          const SizedBox(height: 12),
+          row,
+          const SizedBox(height: 12),
+          row,
+          const SizedBox(height: 12),
+        ],
+    );
+
+    final Widget fadeTransition = FadeTransition(
+      opacity: _opacityAnimation,
+      // This RepaintBoundary is necessary to not let the opacity change
+      // invalidate the layer raster cache below. This is necessary with
+      // or without the color filter.
+      child: RepaintBoundary(
+        child: column,
+      ),
+    );
+
+    return Scaffold(
+        backgroundColor: Colors.lightBlue,
+        body: Center(
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: <Widget>[
+                fadeTransition,
+                Container(height: 20),
+                const Text('Use Color Filter:'),
+                Checkbox(
+                  value: _useColorFilter,
+                  onChanged: (bool value) {
+                    setState(() {
+                      _useColorFilter = value;
+                    });
+                  },
+                ),
+              ],
+            ),
+        ),
+    );
+  }
+
+  // Create a looping fade-in fade-out animation for opacity.
+  void _initAnimation() {
+    _controller = AnimationController(duration: const Duration(seconds: 3), vsync: this);
+    _opacityAnimation = Tween<double>(begin: 0.0, end: 1.0).animate(_controller);
+    _opacityAnimation.addStatusListener((AnimationStatus status) {
+      if (status == AnimationStatus.completed) {
+        _controller.reverse();
+      } else if (status == AnimationStatus.dismissed) {
+        _controller.forward();
+      }
+    });
+    _controller.forward();
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    _initAnimation();
+  }
+
+  AnimationController _controller;
+  Animation<double> _opacityAnimation;
+  bool _useColorFilter = true;
+}
+
+class _ShadowWidget extends StatelessWidget {
+  const _ShadowWidget({
+    @required this.width,
+    @required this.height,
+    @required this.useColorFilter,
+    @required this.shadow,
+  });
+
+  final double width;
+  final double height;
+  final bool useColorFilter;
+  final Shadow shadow;
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox(
+      width: width,
+      height: height,
+      child: CustomPaint(
+        painter: _ShadowPainter(
+          useColorFilter: useColorFilter,
+          shadow: shadow,
+        ),
+        size: Size(width, height),
+        isComplex: true,
+        willChange: false,
+      ),
+    );
+  }
+}
+
+class _ShadowPainter extends CustomPainter {
+  const _ShadowPainter({this.useColorFilter, @required this.shadow});
+
+  final bool useColorFilter;
+  final Shadow shadow;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final Rect rect = Offset.zero & size;
+
+    final Paint paint = Paint();
+    if (useColorFilter) {
+      paint.colorFilter = ColorFilter.mode(shadow.color, BlendMode.srcIn);
+    }
+
+    canvas.saveLayer(null, paint);
+    canvas.translate(shadow.offset.dx, shadow.offset.dy);
+    canvas.drawRect(rect, Paint());
+    canvas.drawRect(rect, Paint()..maskFilter = MaskFilter.blur(BlurStyle.normal, shadow.blurSigma));
+    canvas.restore();
+
+    canvas.drawRect(rect, Paint()..color = useColorFilter ? Colors.white : Colors.black);
+  }
+
+  @override
+  bool shouldRepaint(_ShadowPainter oldDelegate) => oldDelegate.useColorFilter != useColorFilter;
+}

dev/benchmarks/macrobenchmarks/test_driver/color_filter_and_fade_perf.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_driver/driver_extension.dart';
+import 'package:macrobenchmarks/main.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  app.main();
+}

dev/benchmarks/macrobenchmarks/test_driver/color_filter_and_fade_perf_test.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:macrobenchmarks/common.dart';
+
+import 'util.dart';
+
+void main() {
+  macroPerfTest(
+    'color_filter_and_fade_perf',
+    kColorFilterAndFadeRouteName,
+    pageDelay: const Duration(seconds: 1),
+    duration: const Duration(seconds: 10),
+  );
+}

dev/devicelab/bin/tasks/color_filter_and_fade_perf__timeline_summary.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+import 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.android;
+  await task(createColorFilterAndFadePerfTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -173,6 +173,14 @@ TaskFunction createTextfieldPerfTest() {
   ).run;
 }
 
+TaskFunction createColorFilterAndFadePerfTest() {
+  return PerfTest(
+    '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks',
+    'test_driver/color_filter_and_fade_perf.dart',
+    'color_filter_and_fade_perf',
+  ).run;
+}
+
 
 /// Measure application startup performance.
 class StartupTest {

dev/devicelab/manifest.yaml

@@ -190,6 +190,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
+  color_filter_and_fade_perf__timeline_summary:
+    description: >
+      Measures the runtime performance of color filter with fade on Android.
+    stage: devicelab
+    required_agent_capabilities: ["mac/android"]
+
   flavors_test:
     description: >
       Checks that flavored builds work on Android.