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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/scheduler.dart';
import 'package:flutter_test/flutter_test.dart' show collectAllElementsFrom;
import '../common.dart';
const int _kNumIters = 10000;
Future<void> main() async {
assert(false, "Don't run benchmarks in debug mode! Use 'flutter run --release'.");
runApp(MaterialApp(
home: Scaffold(
body: GridView.count(
crossAxisCount: 5,
children: List<Widget>.generate(25, (int index) {
return Center(
child: Scaffold(
appBar: AppBar(
title: Text('App $index'),
actions: const <Widget>[
Icon(Icons.help),
Icon(Icons.add),
Icon(Icons.ac_unit),
],
),
body: Column(
children: const <Widget>[
Text('Item 1'),
Text('Item 2'),
Text('Item 3'),
Text('Item 4'),
],
),
),
);
}),
),
),
));
// Wait for frame rendering to stabilize.
for (int i = 0; i < 5; i++) {
await SchedulerBinding.instance?.endOfFrame;
}
final Stopwatch watch = Stopwatch();
print('flutter_test allElements benchmark... (${WidgetsBinding.instance?.renderViewElement})');
// Make sure we get enough elements to process for consistent benchmark runs
int elementCount = collectAllElementsFrom(WidgetsBinding.instance!.renderViewElement!, skipOffstage: false).length;
while (elementCount < 2458) {
await Future<void>.delayed(Duration.zero);
elementCount = collectAllElementsFrom(WidgetsBinding.instance!.renderViewElement!, skipOffstage: false).length;
}
print('element count: $elementCount');
watch.start();
for (int i = 0; i < _kNumIters; i += 1) {
final List<Element> allElements = collectAllElementsFrom(
WidgetsBinding.instance!.renderViewElement!,
skipOffstage: false,
).toList();
allElements.clear();
}
watch.stop();
final BenchmarkResultPrinter printer = BenchmarkResultPrinter();
printer.addResult(
description: 'All elements iterate',
value: watch.elapsedMicroseconds / _kNumIters,
unit: 'µs per iteration',
name: 'all_elements_iteration',
);
printer.printToStdout();
}