import 'package:flutter/material.dart';

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

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

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

  final String title;

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

class _MyHomePageState extends State {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Padding(
        padding: const EdgeInsets.all(50.0),
        child: ClipPath(
          child: Container(
            color: Colors.amber,
          ),
          clipper: _MyClipper(),
        ),
      ),
    );
  }
}

class _MyClipper extends CustomClipper {
  @override
  Path getClip(Size size) {
    final path = Path();
    path.lineTo(0, 0);
    path.lineTo(size.width, 0);
    path.lineTo(size.width, size.height * 0.8);
    path.lineTo(size.width * 0.8, size.height);
    path.lineTo(size.width * 0.2, size.height);
    path.lineTo(0, size.height * 0.8);
    path.lineTo(0, 0);

    path.close();
    return path;
  }

  @override
  bool shouldReclip(CustomClipper oldClipper) => false;
}