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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';
import 'rendering_tester.dart';
int countSemanticsChildren(RenderObject object) {
int count = 0;
object.visitChildrenForSemantics((RenderObject child) {
count += 1;
});
return count;
}
void main() {
TestRenderingFlutterBinding.ensureInitialized();
test('RenderOpacity and children and semantics', () {
final RenderOpacity box = RenderOpacity(
child: RenderParagraph(
const TextSpan(),
textDirection: TextDirection.ltr,
),
);
expect(countSemanticsChildren(box), 1);
box.opacity = 0.5;
expect(countSemanticsChildren(box), 1);
box.opacity = 0.25;
expect(countSemanticsChildren(box), 1);
box.opacity = 0.125;
expect(countSemanticsChildren(box), 1);
box.opacity = 0.0;
expect(countSemanticsChildren(box), 0);
box.opacity = 0.125;
expect(countSemanticsChildren(box), 1);
box.opacity = 0.0;
expect(countSemanticsChildren(box), 0);
});
test('RenderOpacity and children and semantics', () {
final AnimationController controller = AnimationController(vsync: const TestVSync());
final RenderAnimatedOpacity box = RenderAnimatedOpacity(
opacity: controller,
child: RenderParagraph(
const TextSpan(),
textDirection: TextDirection.ltr,
),
);
expect(countSemanticsChildren(box), 0); // controller defaults to 0.0
controller.value = 0.2; // has no effect, box isn't subscribed yet
expect(countSemanticsChildren(box), 0);
controller.value = 1.0; // ditto
expect(countSemanticsChildren(box), 0); // alpha is still 0
layout(box); // this causes the box to attach, which makes it subscribe
expect(countSemanticsChildren(box), 1);
controller.value = 1.0;
expect(countSemanticsChildren(box), 1);
controller.value = 0.5;
expect(countSemanticsChildren(box), 1);
controller.value = 0.25;
expect(countSemanticsChildren(box), 1);
controller.value = 0.125;
expect(countSemanticsChildren(box), 1);
controller.value = 0.0;
expect(countSemanticsChildren(box), 0);
controller.value = 0.125;
expect(countSemanticsChildren(box), 1);
controller.value = 0.0;
expect(countSemanticsChildren(box), 0);
});
}