Onclick Of Icon Opens Menu And Change Its Text In Flutter

import 'package:flutter/material.dart';
import 'package:circular_menu/circular_menu.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: "My App",
      home: MyHomePage(),
    );
  }
}


class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with SingleTickerProviderStateMixin {

  String _colorName = 'No';
  Color _color = Colors.black;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          centerTitle: true,
          backgroundColor: Colors.deepPurple[300],
          title: Text(' Circular Menu TopLeft with '),
        ),
        body: CircularMenu(
          alignment: Alignment.bottomRight,
          backgroundWidget: Center(
            child: RichText(
              text: TextSpan(
                style: TextStyle(color: Colors.black, fontSize: 28),
                children: <TextSpan>[
                  TextSpan(
                    text: _colorName,
                    style:
                    TextStyle(color: _color, fontWeight: FontWeight.bold),
                  ),
                  TextSpan(text: ' button is clicked.'),
                ],
              ),
            ),
          ),
          toggleButtonColor: Colors.deepPurple[300],
          items: [
            CircularMenuItem(
                icon: Icons.home,
                color: Colors.green,
                onTap: () {
                  setState(() {
                    _color = Colors.green;
                    _colorName = 'Green';
                  });
                }),
            CircularMenuItem(
                icon: Icons.search,
                color: Colors.blue,
                onTap: () {
                  setState(() {
                    _color = Colors.blue;
                    _colorName = 'Blue';
                  });
                }),
            CircularMenuItem(
                icon: Icons.settings,
                color: Colors.orange,
                onTap: () {
                  setState(() {
                    _color = Colors.orange;
                    _colorName = 'Orange';
                  });
                }),
          ],
        ),
      ),
    );
  }
}