packages/webview_flutter/webview_flutter/example/lib/main.dart - mirrors/plugins - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 // ignore_for_file: public_member_api_docs

 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';

 import 'package:flutter/material.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:webview_flutter/webview_flutter.dart';

 void main() => runApp(const MaterialApp(home: WebViewExample()));

 const String kNavigationExamplePage = '''
 <!DOCTYPE html><html>
 <head><title>Navigation Delegate Example</title></head>
 <body>
 <p>
 The navigation delegate is set to block navigation to the youtube website.
 </p>
 <ul>
 <ul><a href="https://www.youtube.com/">https://www.youtube.com/</a></ul>
 <ul><a href="https://www.google.com/">https://www.google.com/</a></ul>
 </ul>
 </body>
 </html>
 ''';

 const String kLocalExamplePage = '''
 <!DOCTYPE html>
 <html lang="en">
 <head>
 <title>Load file or HTML string example</title>
 </head>
 <body>

 <h1>Local demo page</h1>
 <p>
   This is an example page used to demonstrate how to load a local file or HTML
   string using the <a href="https://pub.dev/packages/webview_flutter">Flutter
   webview</a> plugin.
 </p>

 </body>
 </html>
 ''';

 const String kTransparentBackgroundPage = '''
   <!DOCTYPE html>
   <html>
   <head>
     <title>Transparent background test</title>
   </head>
   <style type="text/css">
     body { background: transparent; margin: 0; padding: 0; }
     #container { position: relative; margin: 0; padding: 0; width: 100vw; height: 100vh; }
     #shape { background: red; width: 200px; height: 200px; margin: 0; padding: 0; position: absolute; top: calc(50% - 100px); left: calc(50% - 100px); }
     p { text-align: center; }
   </style>
   <body>
     <div id="container">
       <p>Transparent background test</p>
       <div id="shape"></div>
     </div>
   </body>
   </html>
 ''';

 class WebViewExample extends StatefulWidget {
   const WebViewExample({Key? key, this.cookieManager}) : super(key: key);

   final CookieManager? cookieManager;

   @override
   State<WebViewExample> createState() => _WebViewExampleState();
 }

 class _WebViewExampleState extends State<WebViewExample> {
   final Completer<WebViewController> _controller =
       Completer<WebViewController>();

   @override
   void initState() {
     super.initState();
     if (Platform.isAndroid) {
       WebView.platform = SurfaceAndroidWebView();
     }
   }

   @override
   Widget build(BuildContext context) {
     return Scaffold(
       backgroundColor: Colors.green,
       appBar: AppBar(
         title: const Text('Flutter WebView example'),
         // This drop down menu demonstrates that Flutter widgets can be shown over the web view.
         actions: <Widget>[
           NavigationControls(_controller.future),
           SampleMenu(_controller.future, widget.cookieManager),
         ],
       ),
       body: WebView(
         initialUrl: 'https://flutter.dev',
         javascriptMode: JavascriptMode.unrestricted,
         onWebViewCreated: (WebViewController webViewController) {
           _controller.complete(webViewController);
         },
         onProgress: (int progress) {
           print('WebView is loading (progress : $progress%)');
         },
         javascriptChannels: <JavascriptChannel>{
           _toasterJavascriptChannel(context),
         },
         navigationDelegate: (NavigationRequest request) {
           if (request.url.startsWith('https://www.youtube.com/')) {
             print('blocking navigation to $request}');
             return NavigationDecision.prevent;
           }
           print('allowing navigation to $request');
           return NavigationDecision.navigate;
         },
         onPageStarted: (String url) {
           print('Page started loading: $url');
         },
         onPageFinished: (String url) {
           print('Page finished loading: $url');
         },
         gestureNavigationEnabled: true,
         backgroundColor: const Color(0x00000000),
       ),
       floatingActionButton: favoriteButton(),
     );
   }

   JavascriptChannel _toasterJavascriptChannel(BuildContext context) {
     return JavascriptChannel(
         name: 'Toaster',
         onMessageReceived: (JavascriptMessage message) {
           ScaffoldMessenger.of(context).showSnackBar(
             SnackBar(content: Text(message.message)),
           );
         });
   }

   Widget favoriteButton() {
     return FutureBuilder<WebViewController>(
         future: _controller.future,
         builder: (BuildContext context,
             AsyncSnapshot<WebViewController> controller) {
           return FloatingActionButton(
             onPressed: () async {
               String? url;
               if (controller.hasData) {
                 url = await controller.data!.currentUrl();
               }
               ScaffoldMessenger.of(context).showSnackBar(
                 SnackBar(
                   content: Text(
                     controller.hasData
                         ? 'Favorited $url'
                         : 'Unable to favorite',
                   ),
                 ),
               );
             },
             child: const Icon(Icons.favorite),
           );
         });
   }
 }

 enum MenuOptions {
   showUserAgent,
   listCookies,
   clearCookies,
   addToCache,
   listCache,
   clearCache,
   navigationDelegate,
   doPostRequest,
   loadLocalFile,
   loadFlutterAsset,
   loadHtmlString,
   transparentBackground,
   setCookie,
 }

 class SampleMenu extends StatelessWidget {
   SampleMenu(this.controller, CookieManager? cookieManager, {Key? key})
       : cookieManager = cookieManager ?? CookieManager(),
         super(key: key);

   final Future<WebViewController> controller;
   late final CookieManager cookieManager;

   @override
   Widget build(BuildContext context) {
     return FutureBuilder<WebViewController>(
       future: controller,
       builder:
           (BuildContext context, AsyncSnapshot<WebViewController> controller) {
         return PopupMenuButton<MenuOptions>(
           key: const ValueKey<String>('ShowPopupMenu'),
           onSelected: (MenuOptions value) {
             switch (value) {
               case MenuOptions.showUserAgent:
                 _onShowUserAgent(controller.data!, context);
                 break;
               case MenuOptions.listCookies:
                 _onListCookies(controller.data!, context);
                 break;
               case MenuOptions.clearCookies:
                 _onClearCookies(context);
                 break;
               case MenuOptions.addToCache:
                 _onAddToCache(controller.data!, context);
                 break;
               case MenuOptions.listCache:
                 _onListCache(controller.data!, context);
                 break;
               case MenuOptions.clearCache:
                 _onClearCache(controller.data!, context);
                 break;
               case MenuOptions.navigationDelegate:
                 _onNavigationDelegateExample(controller.data!, context);
                 break;
               case MenuOptions.doPostRequest:
                 _onDoPostRequest(controller.data!, context);
                 break;
               case MenuOptions.loadLocalFile:
                 _onLoadLocalFileExample(controller.data!, context);
                 break;
               case MenuOptions.loadFlutterAsset:
                 _onLoadFlutterAssetExample(controller.data!, context);
                 break;
               case MenuOptions.loadHtmlString:
                 _onLoadHtmlStringExample(controller.data!, context);
                 break;
               case MenuOptions.transparentBackground:
                 _onTransparentBackground(controller.data!, context);
                 break;
               case MenuOptions.setCookie:
                 _onSetCookie(controller.data!, context);
                 break;
             }
           },
           itemBuilder: (BuildContext context) => <PopupMenuItem<MenuOptions>>[
             PopupMenuItem<MenuOptions>(
               value: MenuOptions.showUserAgent,
               enabled: controller.hasData,
               child: const Text('Show user agent'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.listCookies,
               child: Text('List cookies'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.clearCookies,
               child: Text('Clear cookies'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.addToCache,
               child: Text('Add to cache'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.listCache,
               child: Text('List cache'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.clearCache,
               child: Text('Clear cache'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.navigationDelegate,
               child: Text('Navigation Delegate example'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.doPostRequest,
               child: Text('Post Request'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.loadHtmlString,
               child: Text('Load HTML string'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.loadLocalFile,
               child: Text('Load local file'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.loadFlutterAsset,
               child: Text('Load Flutter Asset'),
             ),
             const PopupMenuItem<MenuOptions>(
               key: ValueKey<String>('ShowTransparentBackgroundExample'),
               value: MenuOptions.transparentBackground,
               child: Text('Transparent background example'),
             ),
             const PopupMenuItem<MenuOptions>(
               value: MenuOptions.setCookie,
               child: Text('Set cookie'),
             ),
           ],
         );
       },
     );
   }

   Future<void> _onShowUserAgent(
       WebViewController controller, BuildContext context) async {
     // Send a message with the user agent string to the Toaster JavaScript channel we registered
     // with the WebView.
     await controller.runJavascript(
         'Toaster.postMessage("User Agent: " + navigator.userAgent);');
   }

   Future<void> _onListCookies(
       WebViewController controller, BuildContext context) async {
     final String cookies =
         await controller.runJavascriptReturningResult('document.cookie');
     ScaffoldMessenger.of(context).showSnackBar(SnackBar(
       content: Column(
         mainAxisAlignment: MainAxisAlignment.end,
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           const Text('Cookies:'),
           _getCookieList(cookies),
         ],
       ),
     ));
   }

   Future<void> _onAddToCache(
       WebViewController controller, BuildContext context) async {
     await controller.runJavascript(
         'caches.open("test_caches_entry"); localStorage["test_localStorage"] = "dummy_entry";');
     ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
       content: Text('Added a test entry to cache.'),
     ));
   }

   Future<void> _onListCache(
       WebViewController controller, BuildContext context) async {
     await controller.runJavascript('caches.keys()'
         // ignore: missing_whitespace_between_adjacent_strings
         '.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))'
         '.then((caches) => Toaster.postMessage(caches))');
   }

   Future<void> _onClearCache(
       WebViewController controller, BuildContext context) async {
     await controller.clearCache();
     ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
       content: Text('Cache cleared.'),
     ));
   }

   Future<void> _onClearCookies(BuildContext context) async {
     final bool hadCookies = await cookieManager.clearCookies();
     String message = 'There were cookies. Now, they are gone!';
     if (!hadCookies) {
       message = 'There are no cookies.';
     }
     ScaffoldMessenger.of(context).showSnackBar(SnackBar(
       content: Text(message),
     ));
   }

   Future<void> _onNavigationDelegateExample(
       WebViewController controller, BuildContext context) async {
     final String contentBase64 =
         base64Encode(const Utf8Encoder().convert(kNavigationExamplePage));
     await controller.loadUrl('data:text/html;base64,$contentBase64');
   }

   Future<void> _onSetCookie(
       WebViewController controller, BuildContext context) async {
     await cookieManager.setCookie(
       const WebViewCookie(
           name: 'foo', value: 'bar', domain: 'httpbin.org', path: '/anything'),
     );
     await controller.loadUrl('https://httpbin.org/anything');
   }

   Future<void> _onDoPostRequest(
       WebViewController controller, BuildContext context) async {
     final WebViewRequest request = WebViewRequest(
       uri: Uri.parse('https://httpbin.org/post'),
       method: WebViewRequestMethod.post,
       headers: <String, String>{'foo': 'bar', 'Content-Type': 'text/plain'},
       body: Uint8List.fromList('Test Body'.codeUnits),
     );
     await controller.loadRequest(request);
   }

   Future<void> _onLoadLocalFileExample(
       WebViewController controller, BuildContext context) async {
     final String pathToIndex = await _prepareLocalFile();

     await controller.loadFile(pathToIndex);
   }

   Future<void> _onLoadFlutterAssetExample(
       WebViewController controller, BuildContext context) async {
     await controller.loadFlutterAsset('assets/www/index.html');
   }

   Future<void> _onLoadHtmlStringExample(
       WebViewController controller, BuildContext context) async {
     await controller.loadHtmlString(kLocalExamplePage);
   }

   Future<void> _onTransparentBackground(
       WebViewController controller, BuildContext context) async {
     await controller.loadHtmlString(kTransparentBackgroundPage);
   }

   Widget _getCookieList(String cookies) {
     if (cookies == null || cookies == '""') {
       return Container();
     }
     final List<String> cookieList = cookies.split(';');
     final Iterable<Text> cookieWidgets =
         cookieList.map((String cookie) => Text(cookie));
     return Column(
       mainAxisAlignment: MainAxisAlignment.end,
       mainAxisSize: MainAxisSize.min,
       children: cookieWidgets.toList(),
     );
   }

   static Future<String> _prepareLocalFile() async {
     final String tmpDir = (await getTemporaryDirectory()).path;
     final File indexFile = File(
         <String>{tmpDir, 'www', 'index.html'}.join(Platform.pathSeparator));

     await indexFile.create(recursive: true);
     await indexFile.writeAsString(kLocalExamplePage);

     return indexFile.path;
   }
 }

 class NavigationControls extends StatelessWidget {
   const NavigationControls(this._webViewControllerFuture, {Key? key})
       : assert(_webViewControllerFuture != null),
         super(key: key);

   final Future<WebViewController> _webViewControllerFuture;

   @override
   Widget build(BuildContext context) {
     return FutureBuilder<WebViewController>(
       future: _webViewControllerFuture,
       builder:
           (BuildContext context, AsyncSnapshot<WebViewController> snapshot) {
         final bool webViewReady =
             snapshot.connectionState == ConnectionState.done;
         final WebViewController? controller = snapshot.data;
         return Row(
           children: <Widget>[
             IconButton(
               icon: const Icon(Icons.arrow_back_ios),
               onPressed: !webViewReady
                   ? null
                   : () async {
                       if (await controller!.canGoBack()) {
                         await controller.goBack();
                       } else {
                         ScaffoldMessenger.of(context).showSnackBar(
                           const SnackBar(content: Text('No back history item')),
                         );
                         return;
                       }
                     },
             ),
             IconButton(
               icon: const Icon(Icons.arrow_forward_ios),
               onPressed: !webViewReady
                   ? null
                   : () async {
                       if (await controller!.canGoForward()) {
                         await controller.goForward();
                       } else {
                         ScaffoldMessenger.of(context).showSnackBar(
                           const SnackBar(
                               content: Text('No forward history item')),
                         );
                         return;
                       }
                     },
             ),
             IconButton(
               icon: const Icon(Icons.replay),
               onPressed: !webViewReady
                   ? null
                   : () {
                       controller!.reload();
                     },
             ),
           ],
         );
       },
     );
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	// ignore_for_file: public_member_api_docs

	import 'dart:async';
	import 'dart:convert';
	import 'dart:io';
	import 'dart:typed_data';

	import 'package:flutter/material.dart';
	import 'package:path_provider/path_provider.dart';
	import 'package:webview_flutter/webview_flutter.dart';

	void main() => runApp(const MaterialApp(home: WebViewExample()));

	const String kNavigationExamplePage = '''
	<!DOCTYPE html><html>
	<head><title>Navigation Delegate Example</title></head>
	<body>
	<p>
	The navigation delegate is set to block navigation to the youtube website.
	</p>
	<ul>
	<ul><a href="https://www.youtube.com/">https://www.youtube.com/</a></ul>
	<ul><a href="https://www.google.com/">https://www.google.com/</a></ul>
	</ul>
	</body>
	</html>
	''';

	const String kLocalExamplePage = '''
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<title>Load file or HTML string example</title>
	</head>
	<body>

	<h1>Local demo page</h1>
	<p>
	This is an example page used to demonstrate how to load a local file or HTML
	string using the <a href="https://pub.dev/packages/webview_flutter">Flutter
	webview</a> plugin.
	</p>

	</body>
	</html>
	''';

	const String kTransparentBackgroundPage = '''
	<!DOCTYPE html>
	<html>
	<head>
	<title>Transparent background test</title>
	</head>
	<style type="text/css">
	body { background: transparent; margin: 0; padding: 0; }
	#container { position: relative; margin: 0; padding: 0; width: 100vw; height: 100vh; }
	#shape { background: red; width: 200px; height: 200px; margin: 0; padding: 0; position: absolute; top: calc(50% - 100px); left: calc(50% - 100px); }
	p { text-align: center; }
	</style>
	<body>
	<div id="container">
	<p>Transparent background test</p>
	<div id="shape"></div>
	</div>
	</body>
	</html>
	''';

	class WebViewExample extends StatefulWidget {
	const WebViewExample({Key? key, this.cookieManager}) : super(key: key);

	final CookieManager? cookieManager;

	@override
	State<WebViewExample> createState() => _WebViewExampleState();
	}

	class _WebViewExampleState extends State<WebViewExample> {
	final Completer<WebViewController> _controller =
	Completer<WebViewController>();

	@override
	void initState() {
	super.initState();
	if (Platform.isAndroid) {
	WebView.platform = SurfaceAndroidWebView();
	}
	}

	@override
	Widget build(BuildContext context) {
	return Scaffold(
	backgroundColor: Colors.green,
	appBar: AppBar(
	title: const Text('Flutter WebView example'),
	// This drop down menu demonstrates that Flutter widgets can be shown over the web view.
	actions: <Widget>[
	NavigationControls(_controller.future),
	SampleMenu(_controller.future, widget.cookieManager),
	],
	),
	body: WebView(
	initialUrl: 'https://flutter.dev',
	javascriptMode: JavascriptMode.unrestricted,
	onWebViewCreated: (WebViewController webViewController) {
	_controller.complete(webViewController);
	},
	onProgress: (int progress) {
	print('WebView is loading (progress : $progress%)');
	},
	javascriptChannels: <JavascriptChannel>{
	_toasterJavascriptChannel(context),
	},
	navigationDelegate: (NavigationRequest request) {
	if (request.url.startsWith('https://www.youtube.com/')) {
	print('blocking navigation to $request}');
	return NavigationDecision.prevent;
	}
	print('allowing navigation to $request');
	return NavigationDecision.navigate;
	},
	onPageStarted: (String url) {
	print('Page started loading: $url');
	},
	onPageFinished: (String url) {
	print('Page finished loading: $url');
	},
	gestureNavigationEnabled: true,
	backgroundColor: const Color(0x00000000),
	),
	floatingActionButton: favoriteButton(),
	);
	}

	JavascriptChannel _toasterJavascriptChannel(BuildContext context) {
	return JavascriptChannel(
	name: 'Toaster',
	onMessageReceived: (JavascriptMessage message) {
	ScaffoldMessenger.of(context).showSnackBar(
	SnackBar(content: Text(message.message)),
	);
	});
	}

	Widget favoriteButton() {
	return FutureBuilder<WebViewController>(
	future: _controller.future,
	builder: (BuildContext context,
	AsyncSnapshot<WebViewController> controller) {
	return FloatingActionButton(
	onPressed: () async {
	String? url;
	if (controller.hasData) {
	url = await controller.data!.currentUrl();
	}
	ScaffoldMessenger.of(context).showSnackBar(
	SnackBar(
	content: Text(
	controller.hasData
	? 'Favorited $url'
	: 'Unable to favorite',
	),
	),
	);
	},
	child: const Icon(Icons.favorite),
	);
	});
	}
	}

	enum MenuOptions {
	showUserAgent,
	listCookies,
	clearCookies,
	addToCache,
	listCache,
	clearCache,
	navigationDelegate,
	doPostRequest,
	loadLocalFile,
	loadFlutterAsset,
	loadHtmlString,
	transparentBackground,
	setCookie,
	}

	class SampleMenu extends StatelessWidget {
	SampleMenu(this.controller, CookieManager? cookieManager, {Key? key})
	: cookieManager = cookieManager ?? CookieManager(),
	super(key: key);

	final Future<WebViewController> controller;
	late final CookieManager cookieManager;

	@override
	Widget build(BuildContext context) {
	return FutureBuilder<WebViewController>(
	future: controller,
	builder:
	(BuildContext context, AsyncSnapshot<WebViewController> controller) {
	return PopupMenuButton<MenuOptions>(
	key: const ValueKey<String>('ShowPopupMenu'),
	onSelected: (MenuOptions value) {
	switch (value) {
	case MenuOptions.showUserAgent:
	_onShowUserAgent(controller.data!, context);
	break;
	case MenuOptions.listCookies:
	_onListCookies(controller.data!, context);
	break;
	case MenuOptions.clearCookies:
	_onClearCookies(context);
	break;
	case MenuOptions.addToCache:
	_onAddToCache(controller.data!, context);
	break;
	case MenuOptions.listCache:
	_onListCache(controller.data!, context);
	break;
	case MenuOptions.clearCache:
	_onClearCache(controller.data!, context);
	break;
	case MenuOptions.navigationDelegate:
	_onNavigationDelegateExample(controller.data!, context);
	break;
	case MenuOptions.doPostRequest:
	_onDoPostRequest(controller.data!, context);
	break;
	case MenuOptions.loadLocalFile:
	_onLoadLocalFileExample(controller.data!, context);
	break;
	case MenuOptions.loadFlutterAsset:
	_onLoadFlutterAssetExample(controller.data!, context);
	break;
	case MenuOptions.loadHtmlString:
	_onLoadHtmlStringExample(controller.data!, context);
	break;
	case MenuOptions.transparentBackground:
	_onTransparentBackground(controller.data!, context);
	break;
	case MenuOptions.setCookie:
	_onSetCookie(controller.data!, context);
	break;
	}
	},
	itemBuilder: (BuildContext context) => <PopupMenuItem<MenuOptions>>[
	PopupMenuItem<MenuOptions>(
	value: MenuOptions.showUserAgent,
	enabled: controller.hasData,
	child: const Text('Show user agent'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.listCookies,
	child: Text('List cookies'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.clearCookies,
	child: Text('Clear cookies'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.addToCache,
	child: Text('Add to cache'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.listCache,
	child: Text('List cache'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.clearCache,
	child: Text('Clear cache'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.navigationDelegate,
	child: Text('Navigation Delegate example'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.doPostRequest,
	child: Text('Post Request'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.loadHtmlString,
	child: Text('Load HTML string'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.loadLocalFile,
	child: Text('Load local file'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.loadFlutterAsset,
	child: Text('Load Flutter Asset'),
	),
	const PopupMenuItem<MenuOptions>(
	key: ValueKey<String>('ShowTransparentBackgroundExample'),
	value: MenuOptions.transparentBackground,
	child: Text('Transparent background example'),
	),
	const PopupMenuItem<MenuOptions>(
	value: MenuOptions.setCookie,
	child: Text('Set cookie'),
	),
	],
	);
	},
	);
	}

	Future<void> _onShowUserAgent(
	WebViewController controller, BuildContext context) async {
	// Send a message with the user agent string to the Toaster JavaScript channel we registered
	// with the WebView.
	await controller.runJavascript(
	'Toaster.postMessage("User Agent: " + navigator.userAgent);');
	}

	Future<void> _onListCookies(
	WebViewController controller, BuildContext context) async {
	final String cookies =
	await controller.runJavascriptReturningResult('document.cookie');
	ScaffoldMessenger.of(context).showSnackBar(SnackBar(
	content: Column(
	mainAxisAlignment: MainAxisAlignment.end,
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[
	const Text('Cookies:'),
	_getCookieList(cookies),
	],
	),
	));
	}

	Future<void> _onAddToCache(
	WebViewController controller, BuildContext context) async {
	await controller.runJavascript(
	'caches.open("test_caches_entry"); localStorage["test_localStorage"] = "dummy_entry";');
	ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
	content: Text('Added a test entry to cache.'),
	));
	}

	Future<void> _onListCache(
	WebViewController controller, BuildContext context) async {
	await controller.runJavascript('caches.keys()'
	// ignore: missing_whitespace_between_adjacent_strings
	'.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))'
	'.then((caches) => Toaster.postMessage(caches))');
	}

	Future<void> _onClearCache(
	WebViewController controller, BuildContext context) async {
	await controller.clearCache();
	ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
	content: Text('Cache cleared.'),
	));
	}

	Future<void> _onClearCookies(BuildContext context) async {
	final bool hadCookies = await cookieManager.clearCookies();
	String message = 'There were cookies. Now, they are gone!';
	if (!hadCookies) {
	message = 'There are no cookies.';
	}
	ScaffoldMessenger.of(context).showSnackBar(SnackBar(
	content: Text(message),
	));
	}

	Future<void> _onNavigationDelegateExample(
	WebViewController controller, BuildContext context) async {
	final String contentBase64 =
	base64Encode(const Utf8Encoder().convert(kNavigationExamplePage));
	await controller.loadUrl('data:text/html;base64,$contentBase64');
	}

	Future<void> _onSetCookie(
	WebViewController controller, BuildContext context) async {
	await cookieManager.setCookie(
	const WebViewCookie(
	name: 'foo', value: 'bar', domain: 'httpbin.org', path: '/anything'),
	);
	await controller.loadUrl('https://httpbin.org/anything');
	}

	Future<void> _onDoPostRequest(
	WebViewController controller, BuildContext context) async {
	final WebViewRequest request = WebViewRequest(
	uri: Uri.parse('https://httpbin.org/post'),
	method: WebViewRequestMethod.post,
	headers: <String, String>{'foo': 'bar', 'Content-Type': 'text/plain'},
	body: Uint8List.fromList('Test Body'.codeUnits),
	);
	await controller.loadRequest(request);
	}

	Future<void> _onLoadLocalFileExample(
	WebViewController controller, BuildContext context) async {
	final String pathToIndex = await _prepareLocalFile();

	await controller.loadFile(pathToIndex);
	}

	Future<void> _onLoadFlutterAssetExample(
	WebViewController controller, BuildContext context) async {
	await controller.loadFlutterAsset('assets/www/index.html');
	}

	Future<void> _onLoadHtmlStringExample(
	WebViewController controller, BuildContext context) async {
	await controller.loadHtmlString(kLocalExamplePage);
	}

	Future<void> _onTransparentBackground(
	WebViewController controller, BuildContext context) async {
	await controller.loadHtmlString(kTransparentBackgroundPage);
	}

	Widget _getCookieList(String cookies) {
	if (cookies == null \|\| cookies == '""') {
	return Container();
	}
	final List<String> cookieList = cookies.split(';');
	final Iterable<Text> cookieWidgets =
	cookieList.map((String cookie) => Text(cookie));
	return Column(
	mainAxisAlignment: MainAxisAlignment.end,
	mainAxisSize: MainAxisSize.min,
	children: cookieWidgets.toList(),
	);
	}

	static Future<String> _prepareLocalFile() async {
	final String tmpDir = (await getTemporaryDirectory()).path;
	final File indexFile = File(
	<String>{tmpDir, 'www', 'index.html'}.join(Platform.pathSeparator));

	await indexFile.create(recursive: true);
	await indexFile.writeAsString(kLocalExamplePage);

	return indexFile.path;
	}
	}

	class NavigationControls extends StatelessWidget {
	const NavigationControls(this._webViewControllerFuture, {Key? key})
	: assert(_webViewControllerFuture != null),
	super(key: key);

	final Future<WebViewController> _webViewControllerFuture;

	@override
	Widget build(BuildContext context) {
	return FutureBuilder<WebViewController>(
	future: _webViewControllerFuture,
	builder:
	(BuildContext context, AsyncSnapshot<WebViewController> snapshot) {
	final bool webViewReady =
	snapshot.connectionState == ConnectionState.done;
	final WebViewController? controller = snapshot.data;
	return Row(
	children: <Widget>[
	IconButton(
	icon: const Icon(Icons.arrow_back_ios),
	onPressed: !webViewReady
	? null
	: () async {
	if (await controller!.canGoBack()) {
	await controller.goBack();
	} else {
	ScaffoldMessenger.of(context).showSnackBar(
	const SnackBar(content: Text('No back history item')),
	);
	return;
	}
	},
	),
	IconButton(
	icon: const Icon(Icons.arrow_forward_ios),
	onPressed: !webViewReady
	? null
	: () async {
	if (await controller!.canGoForward()) {
	await controller.goForward();
	} else {
	ScaffoldMessenger.of(context).showSnackBar(
	const SnackBar(
	content: Text('No forward history item')),
	);
	return;
	}
	},
	),
	IconButton(
	icon: const Icon(Icons.replay),
	onPressed: !webViewReady
	? null
	: () {
	controller!.reload();
	},
	),
	],
	);
	},
	);
	}
	}