flutter/packages/flutter/test/widgets/binding_test.dart
2017-05-24 18:18:53 -07:00

35 lines
1.1 KiB
Dart

// Copyright 2017 The Chromium 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:typed_data';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';
class MemoryPressureObserver extends WidgetsBindingObserver {
bool sawMemoryPressure = false;
@override
void didHaveMemoryPressure() {
sawMemoryPressure = true;
}
}
void main() {
setUp(() {
WidgetsFlutterBinding.ensureInitialized();
});
testWidgets('didHaveMemoryPressure callback', (WidgetTester tester) async {
final MemoryPressureObserver observer = new MemoryPressureObserver();
WidgetsBinding.instance.addObserver(observer);
final ByteData message = const JSONMessageCodec().encodeMessage(
<String, dynamic>{'type': 'memoryPressure'});
await BinaryMessages.handlePlatformMessage('flutter/system', message, (_) {});
expect(observer.sawMemoryPressure, true);
WidgetsBinding.instance.removeObserver(observer);
});
}