flutter/examples/api/lib/widgets/transitions/sliver_fade_transition.0.dart
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---------

Co-authored-by: Kate Lovett <katelovett@google.com>
Co-authored-by: LongCatIsLooong <31859944+LongCatIsLooong@users.noreply.github.com>
2024-12-19 20:06:21 +00:00

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Dart

// 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';
/// Flutter code sample for [SliverFadeTransition].
void main() => runApp(const SliverFadeTransitionExampleApp());
class SliverFadeTransitionExampleApp extends StatelessWidget {
const SliverFadeTransitionExampleApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: const Text('SliverFadeTransition Sample')),
body: const Center(child: SliverFadeTransitionExample()),
),
);
}
}
class SliverFadeTransitionExample extends StatefulWidget {
const SliverFadeTransitionExample({super.key});
@override
State<SliverFadeTransitionExample> createState() => _SliverFadeTransitionExampleState();
}
class _SliverFadeTransitionExampleState extends State<SliverFadeTransitionExample>
with SingleTickerProviderStateMixin {
late final AnimationController controller = AnimationController(
duration: const Duration(milliseconds: 1000),
vsync: this,
);
late final Animation<double> animation = CurvedAnimation(
parent: controller,
curve: Curves.easeIn,
);
@override
void initState() {
super.initState();
animation.addStatusListener((AnimationStatus status) {
if (status == AnimationStatus.completed) {
controller.reverse();
} else if (status == AnimationStatus.dismissed) {
controller.forward();
}
});
controller.forward();
}
@override
void dispose() {
controller.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return CustomScrollView(
slivers: <Widget>[
SliverFadeTransition(
opacity: animation,
sliver: SliverFixedExtentList(
itemExtent: 100.0,
delegate: SliverChildBuilderDelegate((BuildContext context, int index) {
return Container(color: index.isEven ? Colors.indigo[200] : Colors.orange[200]);
}, childCount: 5),
),
),
],
);
}
}