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// 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/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';
void main() {
testWidgets('RenderAnimatedOpacityMixin does not drop layer when animating to 1', (WidgetTester tester) async {
RenderTestObject.paintCount = 0;
final AnimationController controller = AnimationController(vsync: const TestVSync(), duration: const Duration(seconds: 1));
final Tween<double> opacityTween = Tween<double>(begin: 0, end: 1);
await tester.pumpWidget(
Container(
color: Colors.red,
child: FadeTransition(
opacity: controller.drive(opacityTween),
child: const TestWidget(),
),
)
);
expect(RenderTestObject.paintCount, 0);
controller.forward();
await tester.pump();
await tester.pump(const Duration(milliseconds: 500));
expect(RenderTestObject.paintCount, 1);
await tester.pump();
await tester.pump(const Duration(milliseconds: 500));
expect(RenderTestObject.paintCount, 1);
controller.stop();
await tester.pump();
expect(RenderTestObject.paintCount, 1);
});
testWidgets('RenderAnimatedOpacityMixin avoids repainting child as it animates', (WidgetTester tester) async {
RenderTestObject.paintCount = 0;
final AnimationController controller = AnimationController(vsync: const TestVSync(), duration: const Duration(seconds: 1));
final Tween<double> opacityTween = Tween<double>(begin: 0, end: 0.99); // Layer is dropped at 1
await tester.pumpWidget(
Container(
color: Colors.red,
child: FadeTransition(
opacity: controller.drive(opacityTween),
child: const TestWidget(),
),
)
);
expect(RenderTestObject.paintCount, 0);
controller.forward();
await tester.pump();
await tester.pump(const Duration(milliseconds: 500));
expect(RenderTestObject.paintCount, 1);
await tester.pump();
await tester.pump(const Duration(milliseconds: 500));
expect(RenderTestObject.paintCount, 1);
controller.stop();
await tester.pump();
expect(RenderTestObject.paintCount, 1);
});
testWidgets('RenderAnimatedOpacityMixin allows opacity layer to be disposed when animating to 0 opacity', (WidgetTester tester) async {
RenderTestObject.paintCount = 0;
final AnimationController controller = AnimationController(vsync: const TestVSync(), duration: const Duration(seconds: 1));
final Tween<double> opacityTween = Tween<double>(begin: 0.99, end: 0);
await tester.pumpWidget(
Container(
color: Colors.red,
child: FadeTransition(
opacity: controller.drive(opacityTween),
child: const TestWidget(),
),
)
);
expect(RenderTestObject.paintCount, 1);
expect(tester.layers, contains(isA<OpacityLayer>()));
controller.forward();
await tester.pump();
await tester.pump(const Duration(seconds: 2));
expect(RenderTestObject.paintCount, 1);
controller.stop();
await tester.pump();
expect(tester.layers, isNot(contains(isA<OpacityLayer>())));
});
}
class TestWidget extends SingleChildRenderObjectWidget {
const TestWidget({super.key, super.child});
@override
RenderObject createRenderObject(BuildContext context) {
return RenderTestObject();
}
}
class RenderTestObject extends RenderProxyBox {
static int paintCount = 0;
@override
void paint(PaintingContext context, Offset offset) {
paintCount += 1;
super.paint(context, offset);
}
}