// 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_scaffold_center.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 AnimatedPositioned // //*************************************************************************** //* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) // The following example transitions an AnimatedPositioned // between two states. It adjusts the `height`, `width`, and // [Positioned] properties when tapped. //* ▲▲▲▲▲▲▲▲ 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 MaterialApp( title: _title, home: Scaffold( appBar: AppBar(title: const Text(_title)), body: const Center( child: 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. class _MyStatefulWidgetState extends State<MyStatefulWidget> { //******************************************************************** //* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) bool selected = false; @override Widget build(BuildContext context) { return SizedBox( width: 200, height: 350, child: Stack( children: <Widget>[ AnimatedPositioned( width: selected ? 200.0 : 50.0, height: selected ? 50.0 : 200.0, top: selected ? 50.0 : 150.0, duration: const Duration(seconds: 2), curve: Curves.fastOutSlowIn, child: GestureDetector( onTap: () { setState(() { selected = !selected; }); }, child: Container( color: Colors.blue, child: const Center(child: Text('Tap me')), ), ), ), ], ), ); } //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) //******************************************************************** }