examples/api/lib/widgets/transitions/size_transition.0.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.

// Template: dev/snippets/config/templates/stateful_widget_material_ticker.tmpl
//
// Comment lines marked with "▼▼▼" and "▲▲▲" are used for authoring
// of samples, and may be ignored if you are just exploring the sample.

// Flutter code sample for SizeTransition
//
//***************************************************************************
//* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker)

// This code defines a widget that uses [SizeTransition] to change the size
// of [FlutterLogo] continually. It is built with a [Scaffold]
// where the internal widget has space to change its size.

//* ▲▲▲▲▲▲▲▲ description ▲▲▲▲▲▲▲▲ (do not modify or remove section marker)
//***************************************************************************

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

/// This is the main application widget.
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatefulWidget(),
    );
  }
}

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

/// This is the private State class that goes with MyStatefulWidget.
/// AnimationControllers can be created with `vsync: this` because of TickerProviderStateMixin.
class _MyStatefulWidgetState extends State<MyStatefulWidget>
    with TickerProviderStateMixin {
//********************************************************************
//* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker)

  late final AnimationController _controller = AnimationController(
    duration: const Duration(seconds: 3),
    vsync: this,
  )..repeat();
  late final Animation<double> _animation = CurvedAnimation(
    parent: _controller,
    curve: Curves.fastOutSlowIn,
  );

  @override
  void dispose() {
    super.dispose();
    _controller.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SizeTransition(
        sizeFactor: _animation,
        axis: Axis.horizontal,
        axisAlignment: -1,
        child: const Center(
          child: FlutterLogo(size: 200.0),
        ),
      ),
    );
  }

//* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker)
//********************************************************************

}