tween_animation_builder.0.dart 1.62 KB
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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';

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/// Flutter code sample for [TweenAnimationBuilder].
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void main() => runApp(const TweenAnimationBuilderExampleApp());
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class TweenAnimationBuilderExampleApp extends StatelessWidget {
  const TweenAnimationBuilderExampleApp({super.key});
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  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
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        appBar: AppBar(title: const Text('TweenAnimationBuilder Sample')),
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        body: const Center(
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          child: TweenAnimationBuilderExample(),
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        ),
      ),
    );
  }
}

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class TweenAnimationBuilderExample extends StatefulWidget {
  const TweenAnimationBuilderExample({super.key});
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  @override
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  State<TweenAnimationBuilderExample> createState() => _TweenAnimationBuilderExampleState();
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}

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class _TweenAnimationBuilderExampleState extends State<TweenAnimationBuilderExample> {
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  double targetValue = 24.0;

  @override
  Widget build(BuildContext context) {
    return TweenAnimationBuilder<double>(
      tween: Tween<double>(begin: 0, end: targetValue),
      duration: const Duration(seconds: 1),
      builder: (BuildContext context, double size, Widget? child) {
        return IconButton(
          iconSize: size,
          color: Colors.blue,
          icon: child!,
          onPressed: () {
            setState(() {
              targetValue = targetValue == 24.0 ? 48.0 : 24.0;
            });
          },
        );
      },
      child: const Icon(Icons.aspect_ratio),
    );
  }
}