WebViewScaffold in Flutter

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

void main()=> runApp(MaterialApp(
  home:MyHomePage(),
  debugShowCheckedModeBanner: false,
  theme:ThemeData(
    primarySwatch: Colors.blue
  )
));

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

class _MyHomePageState extends State {

  TextEditingController controller=TextEditingController();
  FlutterWebviewPlugin flutterWebviewPlugin= FlutterWebviewPlugin();
  var url= "https://google.com";

  @override
  void initState() {
    super.initState();
    flutterWebviewPlugin.onStateChanged.listen((WebViewStateChanged wvs) {});
  }
    searchURL(){
    setState(() {
      url = "https://www."+controller.text;
      flutterWebviewPlugin.reloadUrl(url);
      controller.text=url;
    });
  }
  @override
  Widget build(BuildContext context) {
    return WebviewScaffold(
      url: url,
      withZoom: true,
      hidden: true,
      // initialChild: Container(
      //   child:Center(child: Text("Loading"),)
      // ),
      appBar: AppBar(
        backgroundColor: Colors.green,
        leading: Icon(Icons.search),
        title: TextField(
          controller: controller,
          textInputAction: TextInputAction.search,
          onSubmitted:(url)=>searchURL(),
          style: TextStyle(
            color: Colors.white
          ), 
          decoration: InputDecoration(
            hintText: "Search Here",
            hintStyle: TextStyle(color: Colors.white)
          ),
        ),
       actions: [
          IconButton(icon: Icon(Icons.arrow_back),
          onPressed: (){
            flutterWebviewPlugin.goBack();
            controller.text="";
          }
          ),
          IconButton(icon: Icon(Icons.arrow_forward),
          onPressed: searchURL,), 
        ],
      ),
    );
  }
}