63 lines
1.7 KiB
Dart
63 lines
1.7 KiB
Dart
// Copyright 2014 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'dart:math' as math;
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import 'package:flutter/material.dart';
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/// Flutter code sample for [AnimatedWidget].
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void main() => runApp(const AnimatedWidgetExampleApp());
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class AnimatedWidgetExampleApp extends StatelessWidget {
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const AnimatedWidgetExampleApp({super.key});
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@override
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Widget build(BuildContext context) {
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return const MaterialApp(home: AnimatedWidgetExample());
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}
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}
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class SpinningContainer extends AnimatedWidget {
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const SpinningContainer({super.key, required AnimationController controller})
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: super(listenable: controller);
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Animation<double> get _progress => listenable as Animation<double>;
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@override
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Widget build(BuildContext context) {
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return Transform.rotate(
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angle: _progress.value * 2.0 * math.pi,
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child: Container(width: 200.0, height: 200.0, color: Colors.green),
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);
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}
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}
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class AnimatedWidgetExample extends StatefulWidget {
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const AnimatedWidgetExample({super.key});
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@override
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State<AnimatedWidgetExample> createState() => _AnimatedWidgetExampleState();
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}
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/// [AnimationController]s can be created with `vsync: this` because of
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/// [TickerProviderStateMixin].
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class _AnimatedWidgetExampleState extends State<AnimatedWidgetExample>
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with TickerProviderStateMixin {
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late final AnimationController _controller = AnimationController(
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duration: const Duration(seconds: 10),
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vsync: this,
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)..repeat();
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@override
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void dispose() {
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_controller.dispose();
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super.dispose();
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}
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@override
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Widget build(BuildContext context) {
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return SpinningContainer(controller: _controller);
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}
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}
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