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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/semantics.dart';
import 'package:flutter_test/flutter_test.dart';
void main() {
testWidgets('Listeners are called when semantics are turned on with ensureSemantics', (WidgetTester tester) async {
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
final List<bool> status = <bool>[];
void listener() {
status.add(SemanticsBinding.instance.semanticsEnabled);
}
SemanticsBinding.instance.addSemanticsEnabledListener(listener);
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
final SemanticsHandle handle1 = SemanticsBinding.instance.ensureSemantics();
expect(status.single, isTrue);
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
status.clear();
final SemanticsHandle handle2 = SemanticsBinding.instance.ensureSemantics();
expect(status, isEmpty); // Listener didn't fire again.
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
expect(tester.binding.platformDispatcher.semanticsEnabled, isFalse);
tester.binding.platformDispatcher.semanticsEnabledTestValue = true;
expect(tester.binding.platformDispatcher.semanticsEnabled, isTrue);
tester.binding.platformDispatcher.clearSemanticsEnabledTestValue();
expect(tester.binding.platformDispatcher.semanticsEnabled, isFalse);
expect(status, isEmpty); // Listener didn't fire again.
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
handle1.dispose();
expect(status, isEmpty); // Listener didn't fire.
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
handle2.dispose();
expect(status.single, isFalse);
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
}, semanticsEnabled: false);
testWidgets('Listeners are called when semantics are turned on by platform', (WidgetTester tester) async {
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
final List<bool> status = <bool>[];
void listener() {
status.add(SemanticsBinding.instance.semanticsEnabled);
}
SemanticsBinding.instance.addSemanticsEnabledListener(listener);
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
tester.binding.platformDispatcher.semanticsEnabledTestValue = true;
expect(status.single, isTrue);
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
status.clear();
final SemanticsHandle handle = SemanticsBinding.instance.ensureSemantics();
handle.dispose();
expect(status, isEmpty); // Listener didn't fire.
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
tester.binding.platformDispatcher.clearSemanticsEnabledTestValue();
expect(status.single, isFalse);
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
}, semanticsEnabled: false);
testWidgets('SemanticsBinding.ensureSemantics triggers creation of semantics owner.', (WidgetTester tester) async {
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
expect(tester.binding.pipelineOwner.semanticsOwner, isNull);
final SemanticsHandle handle = SemanticsBinding.instance.ensureSemantics();
expect(SemanticsBinding.instance.semanticsEnabled, isTrue);
expect(tester.binding.pipelineOwner.semanticsOwner, isNotNull);
handle.dispose();
expect(SemanticsBinding.instance.semanticsEnabled, isFalse);
expect(tester.binding.pipelineOwner.semanticsOwner, isNull);
}, semanticsEnabled: false);
}