import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(
    home: MyApp(),
  ));
}

class MyApp extends StatefulWidget {
  @override
  _State createState() => _State();
}

class _State extends State<MyApp> {
  double _volume = 0;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Custom Ink Icon'),
      ),
      body: Center(
        child: Ink(
          decoration: ShapeDecoration(
            color: Colors.blue,
            shape: CircleBorder(),
          ),
          child: IconButton(
            icon: Icon(Icons.add),
            color: Colors.white,
            onPressed: () {},
          ),
        ),
      ),
    );
  }
}