example_extended.dart

import 'package:blurhash/blurhash.dart' as blurhash;
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter blurhash',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter blurhash'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  // A correct blurhash
  static const hash =
      r"q.NK3Mt7WrofayazbHj[.TkCWBWCj[j@f6azIUWXjZWBWCjsoLayM{ofazayjZa#Wqj[kCWBj[bHWXj[jZWVt7WCs:ofa}axjZay";
  bool _showBlur = true;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            GestureDetector(
              onTap: () {
                setState(() {
                  _showBlur = !_showBlur;
                });
              },
              child: Stack(
                alignment: Alignment.center,
                children: <Widget>[
                  Image.asset(
                    "<put a valid file>",
                    width: 300,
                    height: 200,
                  ),
                  AnimatedOpacity(
                    opacity: _showBlur ? 1.0 : 0.0,
                    duration: const Duration(milliseconds: 300),
                    child:
                        Image.memory(blurhash.Decoder.decode(hash, 300, 200)),
                  ),
                ],
              ),
            ),
            SizedBox(
              height: 50,
            ),
            Text(
              "Tap image!",
              style: TextStyle(fontSize: 20),
            )
          ],
        ),
      ),
    );
  }
}