title: Using flutter webview as home and pressing back button closes Application
body: <p>I'm trying to use a webview in flutter as my home page for my application. Everything loads just fine, however hitting the back button doesn't send me to the previous web page in the webview, it just exits the application.</p>
  
  <pre><code>import 'package:flutter/material.dart';
  import 'package:webview_flutter/webview_flutter.dart';
  import 'package:url_launcher/url_launcher.dart';
  
  class _StudentPortalState extends State&lt;StudentPortal&gt;{
  
    _launchURL(url) async {
  
    if (await canLaunch(url)) {
      await launch(url);
    } else {
      throw 'Could not launch $url';
    }
  }
    Widget build (BuildContext context){
      return Scaffold(
        body: WebView(
                javascriptMode: JavascriptMode.unrestricted,
                initialUrl: 'https://sites.google.com/ttmsa.org/ttmsa/home',
  
                navigationDelegate: (NavigationRequest request) {
  
                  if(request.url.contains("intent:")) {
  
                    _launchURL('https://forms.gle/XfNbn1Ph9xFdUaKeA');
                    return NavigationDecision.prevent;
                  }
                  return NavigationDecision.navigate;
                },   
        ),
  
      );
    }
  }`
  </code></pre>