dependencies {
    classpath 'com.android.tools.build:gradle:3.3.1'
    ...
}

defaultConfig {
    ...
    minSdkVersion 24
    ...
}

dependencies:
  animated_qr_code_scanner:
    git:
      url: https://github.com/kiatuki/animated_qr_code_scanner.git
      ref: v0.1.7

$ flutter pub get

import 'package:animated_qr_code_scanner/animated_qr_code_scanner.dart';

class TestPage extends StatelessWidget {
  final AnimatedQRViewController controller = AnimatedQRViewController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          Expanded(
            child: AnimatedQRView(
              squareColor: Colors.green.withOpacity(0.25),
              animationDuration: const Duration(milliseconds: 400),
              onScanBeforeAnimation: (String str) {
                print('Callback at the beginning of animation: $str');
              },
              onScan: (String str) async {
                await showDialog(
                  context: context,
                  builder: (context) => AlertDialog(
                    title: Text("Callback at the end of animation: $str"),
                    actions: [
                      FlatButton(
                        child: Text('OK'),
                        onPressed: () {
                          Navigator.of(context).pop();
                          Navigator.of(context).pop();
                          Navigator.of(context).push(
                            MaterialPageRoute(
                              builder: (context) => Scaffold(
                                body: Align(
                                  alignment: Alignment.center,
                                  child: Text("$str"),
                                ),
                              ),
                            ),
                          );
                        },
                      ),
                      FlatButton(
                        child: Text('Rescan'),
                        onPressed: () {
                          Navigator.of(context).pop();
                          controller.resume();
                        },
                      ),
                    ],
                  ),
                );
              },
              controller: controller,
            ),
          ),
          Container(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                FlatButton(
                  color: Colors.blue,
                  child: Text('Flash'),
                  onPressed: () {
                    controller.toggleFlash();
                  },
                ),
                const SizedBox(width: 10),
                FlatButton(
                  color: Colors.blue,
                  child: Text('Flip'),
                  onPressed: () {
                    controller.flipCamera();
                  },
                ),
                const SizedBox(width: 10),
                FlatButton(
                  color: Colors.blue,
                  child: Text('Resume'),
                  onPressed: () {
                    controller.resume();
                  },
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

controller.toggleFlash();

controller.pause();

controller.resume();

AnimatedQRView(
    squareColor: Colors.teal.withOpacity(0.25),
    squareBorderColor: Colors.cyan,
    animationDuration: const Duration(milliseconds: 400),
    ...
),