AnimatedContainer Widget Examples

AnimatedContainer is an animated version of Flutter Container. It gradually changes its values over a defined duration. This widget automatically animate between the old and new values of properties such as height, box decoration when they change.

Bar chart animation

Each bar in the chart is an AnimatedContainer widget. The height is changeable.

import 'dart:math';

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  List<double> heights = [];

  @override
  void initState() {
    super.initState();

    for (var i = 0; i < 10; i++) {
      heights.add(1);
    }
  }

  void animateBarChart() {
    setState(() {
      for (var i = 0; i < 10; i++) {
        heights[i] = Random().nextInt(200).toDouble();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Bar Chart'),
      ),
      body: SafeArea(
          child: Container(
            height: 500,
            color: Colors.white,
            child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  ...List.generate(10, (index) {
                    return AnimatedContainer(
                      padding: EdgeInsets.all(16.0),
                      duration: Duration(seconds: 2),
                      width: 60,
                      height: heights[index],
                      color: index % 2 == 0 ? Colors.orange : Colors.green,
                      child: Text('${heights[index].toInt()}'),
                    );
                  })
                ],
            ),
          )),
      floatingActionButton: FloatingActionButton(
        onPressed: animateBarChart,
        child: Icon(Icons.play_arrow),
      ),
    );
  }
}

Animated BoxDecoration

import 'dart:math';

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  bool _start = true;

  @override
  void initState() {
    super.initState();
  }

  void animateBarChart() {
    setState(() {
      _start = !_start;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('AnimatedContainer BoxDecoration'),
      ),
      body: SafeArea(
          child: Container(
        color: Colors.blue,
        child: Center(
          child: AnimatedContainer(
            padding: EdgeInsets.all(16.0),
            duration: Duration(seconds: 2),
            width: _start ? 300 : 150,
            height: _start ? 300 : 150,
            child: Text(''),
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(_start ? 0 : 10),
              border: Border(
                top: BorderSide(color: _start ? Colors.black : Colors.white),
                bottom: BorderSide(color: _start ? Colors.black : Colors.white),
                left: BorderSide(color: _start ? Colors.black : Colors.white),
                right: BorderSide(color: _start ? Colors.black : Colors.white),
              ),
              color: _start ? Colors.green : Colors.redAccent,
              boxShadow: _start ? [
                BoxShadow(
                  color: Colors.grey,
                  spreadRadius: 5,
                  blurRadius: 7,
                  offset: Offset(0, 3), // changes position of shadow
                ),
              ] : [],
            ),
          ),
        ),
      )),
      floatingActionButton: FloatingActionButton(
        onPressed: animateBarChart,
        child: Icon(Icons.play_arrow),
      ),
    );
  }
}

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