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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 'dart:async';
import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
Widget _buildScroller({ required List<String> log }) {
return NotificationListener<ScrollNotification>(
onNotification: (ScrollNotification notification) {
if (notification is ScrollStartNotification) {
log.add('scroll-start');
} else if (notification is ScrollUpdateNotification) {
log.add('scroll-update');
} else if (notification is ScrollEndNotification) {
log.add('scroll-end');
}
return false;
},
child: const SingleChildScrollView(
child: SizedBox(width: 1000.0, height: 1000.0),
),
);
}
void main() {
Completer<void> animateTo(WidgetTester tester, double newScrollOffset, { required Duration duration }) {
final Completer<void> completer = Completer<void>();
final ScrollableState scrollable = tester.state(find.byType(Scrollable));
scrollable.position.animateTo(newScrollOffset, duration: duration, curve: Curves.linear).whenComplete(completer.complete);
return completer;
}
void jumpTo(WidgetTester tester, double newScrollOffset) {
final ScrollableState scrollable = tester.state(find.byType(Scrollable));
scrollable.position.jumpTo(newScrollOffset);
}
testWidgets('Scroll event drag', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
final TestGesture gesture = await tester.startGesture(const Offset(100.0, 100.0));
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(seconds: 1));
expect(log, equals(<String>['scroll-start']));
await gesture.moveBy(const Offset(-10.0, -10.0));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
await tester.pump(const Duration(seconds: 1));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
await gesture.up();
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end']));
await tester.pump(const Duration(seconds: 1));
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end']));
});
testWidgets('Scroll animateTo', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
final Completer<void> completer = animateTo(tester, 100.0, duration: const Duration(seconds: 1));
expect(completer.isCompleted, isFalse);
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
await tester.pump(const Duration(milliseconds: 1500));
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-update', 'scroll-end']));
expect(completer.isCompleted, isTrue);
});
testWidgets('Scroll jumpTo', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
jumpTo(tester, 100.0);
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end']));
await tester.pump();
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end']));
});
testWidgets('Scroll jumpTo during animation', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
final Completer<void> completer = animateTo(tester, 100.0, duration: const Duration(seconds: 1));
expect(completer.isCompleted, isFalse);
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
expect(completer.isCompleted, isFalse);
jumpTo(tester, 100.0);
expect(completer.isCompleted, isFalse);
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end', 'scroll-start', 'scroll-update', 'scroll-end']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end', 'scroll-start', 'scroll-update', 'scroll-end']));
expect(completer.isCompleted, isTrue);
await tester.pump(const Duration(milliseconds: 1500));
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-end', 'scroll-start', 'scroll-update', 'scroll-end']));
expect(completer.isCompleted, isTrue);
});
testWidgets('Scroll scrollTo during animation', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
Completer<void> completer = animateTo(tester, 100.0, duration: const Duration(seconds: 1));
expect(completer.isCompleted, isFalse);
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
expect(completer.isCompleted, isFalse);
completer = animateTo(tester, 100.0, duration: const Duration(seconds: 1));
expect(completer.isCompleted, isFalse);
expect(log, equals(<String>['scroll-start', 'scroll-update']));
await tester.pump(const Duration(milliseconds: 100));
expect(log, equals(<String>['scroll-start', 'scroll-update']));
await tester.pump(const Duration(milliseconds: 1500));
expect(log, equals(<String>['scroll-start', 'scroll-update', 'scroll-update', 'scroll-end']));
expect(completer.isCompleted, isTrue);
});
testWidgets('fling, fling generates two start/end pairs', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
// The ideal behavior here would be a single start/end pair, but for
// simplicity of implementation we compromise here and accept two. Should
// you find a way to make this work with just one without complicating the
// API, feel free to change the expectation here.
expect(log, equals(<String>[]));
await tester.flingFrom(const Offset(100.0, 100.0), const Offset(-50.0, -50.0), 500.0);
await tester.pump(const Duration(seconds: 1));
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start']));
await tester.flingFrom(const Offset(100.0, 100.0), const Offset(-50.0, -50.0), 500.0);
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start', 'scroll-end', 'scroll-start']));
await tester.pump(const Duration(seconds: 1));
await tester.pump(const Duration(seconds: 1));
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start', 'scroll-end', 'scroll-start', 'scroll-end']));
});
testWidgets('fling, pause, fling generates two start/end pairs', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
await tester.flingFrom(const Offset(100.0, 100.0), const Offset(-50.0, -50.0), 500.0);
await tester.pump(const Duration(seconds: 1));
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start']));
await tester.pump(const Duration(minutes: 1));
await tester.flingFrom(const Offset(100.0, 100.0), const Offset(-50.0, -50.0), 500.0);
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start', 'scroll-end', 'scroll-start']));
await tester.pump(const Duration(seconds: 1));
await tester.pump(const Duration(seconds: 1));
log.removeWhere((String value) => value == 'scroll-update');
expect(log, equals(<String>['scroll-start', 'scroll-end', 'scroll-start', 'scroll-end']));
});
testWidgets('fling up ends', (WidgetTester tester) async {
final List<String> log = <String>[];
await tester.pumpWidget(_buildScroller(log: log));
expect(log, equals(<String>[]));
await tester.flingFrom(const Offset(100.0, 100.0), const Offset(50.0, 50.0), 500.0);
await tester.pump(const Duration(seconds: 1));
await tester.pump(const Duration(seconds: 1));
await tester.pump(const Duration(seconds: 1));
expect(log.first, equals('scroll-start'));
expect(log.last, equals('scroll-end'));
log.removeWhere((String value) => value == 'scroll-update');
expect(log.length, equals(2));
expect(tester.state<ScrollableState>(find.byType(Scrollable)).position.pixels, equals(0.0));
});
}