// Copyright 2013 The Flutter Authors
// 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_android/webview_flutter_android.dart';
import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
void main() {
runApp(const MaterialApp(home: WebViewExample()));
}
const String kNavigationExamplePage = '''
Navigation Delegate Example
The navigation delegate is set to block navigation to the pub.dev website.
''';
const String kLocalExamplePage = '''
Load file or HTML string example
Local demo page
This is an example page used to demonstrate how to load a local file or HTML
string using the Flutter
webview plugin.
''';
const String kTransparentBackgroundPage = '''
Transparent background test
Transparent background test
''';
const String kLogExamplePage = '''
Load file or HTML string example
Local demo page
This page is used to test the forwarding of console logs to Dart.
Error
Warning
Info
Debug
Log
''';
const String kAlertTestPage = '''
Click the following button to see the effect
''';
const String kViewportMetaPage = '''
Viewport meta example
Viewport meta example
''';
class WebViewExample extends StatefulWidget {
const WebViewExample({super.key, this.cookieManager});
final PlatformWebViewCookieManager? cookieManager;
@override
State createState() => _WebViewExampleState();
}
class _WebViewExampleState extends State {
late final PlatformWebViewController _controller;
@override
void initState() {
super.initState();
_controller =
PlatformWebViewController(AndroidWebViewControllerCreationParams())
..setJavaScriptMode(JavaScriptMode.unrestricted)
..setBackgroundColor(const Color(0x80000000))
..setPlatformNavigationDelegate(
PlatformNavigationDelegate(
const PlatformNavigationDelegateCreationParams(),
)
..setOnProgress((int progress) {
debugPrint('WebView is loading (progress : $progress%)');
})
..setOnPageStarted((String url) {
debugPrint('Page started loading: $url');
})
..setOnPageFinished((String url) {
debugPrint('Page finished loading: $url');
})
..setOnHttpError((HttpResponseError error) {
debugPrint(
'HTTP error occured on page: ${error.response?.statusCode}',
);
})
..setOnWebResourceError((WebResourceError error) {
debugPrint('''
Page resource error:
code: ${error.errorCode}
description: ${error.description}
errorType: ${error.errorType}
isForMainFrame: ${error.isForMainFrame}
url: ${error.url}
''');
})
..setOnNavigationRequest((NavigationRequest request) {
if (request.url.contains('pub.dev')) {
debugPrint('blocking navigation to ${request.url}');
return NavigationDecision.prevent;
}
debugPrint('allowing navigation to ${request.url}');
return NavigationDecision.navigate;
})
..setOnUrlChange((UrlChange change) {
debugPrint('url change to ${change.url}');
})
..setOnHttpAuthRequest((HttpAuthRequest request) {
openDialog(request);
})
..setOnSSlAuthError((PlatformSslAuthError error) {
debugPrint(
'SSL error from ${(error as AndroidSslAuthError).url}',
);
error.cancel();
}),
)
..addJavaScriptChannel(
JavaScriptChannelParams(
name: 'Toaster',
onMessageReceived: (JavaScriptMessage message) {
ScaffoldMessenger.of(
context,
).showSnackBar(SnackBar(content: Text(message.message)));
},
),
)
..setOnPlatformPermissionRequest((
PlatformWebViewPermissionRequest request,
) {
debugPrint(
'requesting permissions for ${request.types.map((WebViewPermissionResourceType type) => type.name)}',
);
request.grant();
})
..loadRequest(
LoadRequestParams(uri: Uri.parse('https://flutter.dev')),
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: const Color(0xFF4CAF50),
appBar: AppBar(
title: const Text('Flutter WebView example'),
// This drop down menu demonstrates that Flutter widgets can be shown over the web view.
actions: [
NavigationControls(webViewController: _controller),
SampleMenu(
webViewController: _controller,
cookieManager: widget.cookieManager,
),
],
),
body: PlatformWebViewWidget(
PlatformWebViewWidgetCreationParams(controller: _controller),
).build(context),
floatingActionButton: favoriteButton(),
);
}
Widget favoriteButton() {
return FloatingActionButton(
onPressed: () async {
final String? url = await _controller.currentUrl();
if (mounted) {
ScaffoldMessenger.of(
context,
).showSnackBar(SnackBar(content: Text('Favorited $url')));
}
},
child: const Icon(Icons.favorite),
);
}
Future openDialog(HttpAuthRequest httpRequest) async {
final TextEditingController usernameTextController =
TextEditingController();
final TextEditingController passwordTextController =
TextEditingController();
return showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('${httpRequest.host}: ${httpRequest.realm ?? '-'}'),
content: Column(
mainAxisSize: MainAxisSize.min,
children: [
TextField(
decoration: const InputDecoration(labelText: 'Username'),
autofocus: true,
controller: usernameTextController,
),
TextField(
decoration: const InputDecoration(labelText: 'Password'),
controller: passwordTextController,
),
],
),
actions: [
TextButton(
onPressed: () {
httpRequest.onProceed(
WebViewCredential(
user: usernameTextController.text,
password: passwordTextController.text,
),
);
Navigator.of(context).pop();
},
child: const Text('Authenticate'),
),
],
);
},
);
}
}
enum MenuOptions {
showUserAgent,
listCookies,
clearCookies,
addToCache,
listCache,
clearCache,
navigationDelegate,
doPostRequest,
loadLocalFile,
loadFlutterAsset,
loadHtmlString,
transparentBackground,
setCookie,
videoExample,
logExample,
basicAuthentication,
javaScriptAlert,
viewportMeta,
}
class SampleMenu extends StatelessWidget {
SampleMenu({
super.key,
required this.webViewController,
PlatformWebViewCookieManager? cookieManager,
}) : cookieManager =
cookieManager ??
PlatformWebViewCookieManager(
const PlatformWebViewCookieManagerCreationParams(),
);
final PlatformWebViewController webViewController;
late final PlatformWebViewCookieManager cookieManager;
@override
Widget build(BuildContext context) {
return PopupMenuButton(
key: const ValueKey('ShowPopupMenu'),
onSelected: (MenuOptions value) {
switch (value) {
case MenuOptions.showUserAgent:
_onShowUserAgent();
case MenuOptions.listCookies:
_onListCookies(context);
case MenuOptions.clearCookies:
_onClearCookies(context);
case MenuOptions.addToCache:
_onAddToCache(context);
case MenuOptions.listCache:
_onListCache();
case MenuOptions.clearCache:
_onClearCache(context);
case MenuOptions.navigationDelegate:
_onNavigationDelegateExample();
case MenuOptions.doPostRequest:
_onDoPostRequest();
case MenuOptions.loadLocalFile:
_onLoadLocalFileExample();
case MenuOptions.loadFlutterAsset:
_onLoadFlutterAssetExample();
case MenuOptions.loadHtmlString:
_onLoadHtmlStringExample();
case MenuOptions.transparentBackground:
_onTransparentBackground();
case MenuOptions.setCookie:
_onSetCookie();
case MenuOptions.videoExample:
_onVideoExample(context);
case MenuOptions.logExample:
_onLogExample();
case MenuOptions.basicAuthentication:
_promptForUrl(context);
case MenuOptions.javaScriptAlert:
_onJavaScriptAlertExample(context);
case MenuOptions.viewportMeta:
_onViewportMetaExample();
}
},
itemBuilder: (BuildContext context) => >[
const PopupMenuItem(
value: MenuOptions.showUserAgent,
child: Text('Show user agent'),
),
const PopupMenuItem(
value: MenuOptions.listCookies,
child: Text('List cookies'),
),
const PopupMenuItem(
value: MenuOptions.clearCookies,
child: Text('Clear cookies'),
),
const PopupMenuItem(
value: MenuOptions.addToCache,
child: Text('Add to cache'),
),
const PopupMenuItem(
value: MenuOptions.listCache,
child: Text('List cache'),
),
const PopupMenuItem(
value: MenuOptions.clearCache,
child: Text('Clear cache'),
),
const PopupMenuItem(
value: MenuOptions.navigationDelegate,
child: Text('Navigation Delegate example'),
),
const PopupMenuItem(
value: MenuOptions.doPostRequest,
child: Text('Post Request'),
),
const PopupMenuItem(
value: MenuOptions.loadHtmlString,
child: Text('Load HTML string'),
),
const PopupMenuItem(
value: MenuOptions.loadLocalFile,
child: Text('Load local file'),
),
const PopupMenuItem(
value: MenuOptions.loadFlutterAsset,
child: Text('Load Flutter Asset'),
),
const PopupMenuItem(
value: MenuOptions.setCookie,
child: Text('Set cookie'),
),
const PopupMenuItem(
key: ValueKey('ShowTransparentBackgroundExample'),
value: MenuOptions.transparentBackground,
child: Text('Transparent background example'),
),
const PopupMenuItem(
value: MenuOptions.logExample,
child: Text('Log example'),
),
const PopupMenuItem(
value: MenuOptions.videoExample,
child: Text('Video example'),
),
const PopupMenuItem(
value: MenuOptions.basicAuthentication,
child: Text('Basic Authentication Example'),
),
const PopupMenuItem(
value: MenuOptions.javaScriptAlert,
child: Text('JavaScript Alert Example'),
),
const PopupMenuItem(
value: MenuOptions.viewportMeta,
child: Text('Viewport meta example'),
),
],
);
}
Future _onShowUserAgent() {
// Send a message with the user agent string to the Toaster JavaScript channel we registered
// with the WebView.
return webViewController.runJavaScript(
'Toaster.postMessage("User Agent: " + navigator.userAgent);',
);
}
Future _onListCookies(BuildContext context) async {
final String cookies =
await webViewController.runJavaScriptReturningResult('document.cookie')
as String;
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(
content: Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: [const Text('Cookies:'), _getCookieList(cookies)],
),
),
);
}
}
Future _onAddToCache(BuildContext context) async {
await webViewController.runJavaScript(
'caches.open("test_caches_entry"); localStorage["test_localStorage"] = "dummy_entry";',
);
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('Added a test entry to cache.')),
);
}
}
Future _onListCache() {
return webViewController.runJavaScript(
'caches.keys()'
// ignore: missing_whitespace_between_adjacent_strings
'.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))'
'.then((caches) => Toaster.postMessage(caches))',
);
}
Future _onClearCache(BuildContext context) async {
await webViewController.clearCache();
await webViewController.clearLocalStorage();
if (context.mounted) {
ScaffoldMessenger.of(
context,
).showSnackBar(const SnackBar(content: Text('Cache cleared.')));
}
}
Future _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.';
}
if (context.mounted) {
ScaffoldMessenger.of(
context,
).showSnackBar(SnackBar(content: Text(message)));
}
}
Future _onNavigationDelegateExample() {
final String contentBase64 = base64Encode(
const Utf8Encoder().convert(kNavigationExamplePage),
);
return webViewController.loadRequest(
LoadRequestParams(uri: Uri.parse('data:text/html;base64,$contentBase64')),
);
}
Future _onSetCookie() async {
await cookieManager.setCookie(
const WebViewCookie(
name: 'foo',
value: 'bar',
domain: 'httpbin.org',
path: '/anything',
),
);
await webViewController.loadRequest(
LoadRequestParams(uri: Uri.parse('https://httpbin.org/anything')),
);
}
Future _onVideoExample(BuildContext context) {
final AndroidWebViewController androidController =
webViewController as AndroidWebViewController;
// #docregion fullscreen_example
androidController.setCustomWidgetCallbacks(
onShowCustomWidget: (Widget widget, OnHideCustomWidgetCallback callback) {
Navigator.of(context).push(
MaterialPageRoute(
builder: (BuildContext context) => widget,
fullscreenDialog: true,
),
);
},
onHideCustomWidget: () {
Navigator.of(context).pop();
},
);
// #enddocregion fullscreen_example
return androidController.loadRequest(
LoadRequestParams(
uri: Uri.parse('https://www.youtube.com/watch?v=4AoFA19gbLo'),
),
);
}
Future _onDoPostRequest() {
return webViewController.loadRequest(
LoadRequestParams(
uri: Uri.parse('https://httpbin.org/post'),
method: LoadRequestMethod.post,
headers: const {
'foo': 'bar',
'Content-Type': 'text/plain',
},
body: Uint8List.fromList('Test Body'.codeUnits),
),
);
}
Future _onLoadLocalFileExample() async {
final String pathToIndex = await _prepareLocalFile();
await webViewController.loadFile(pathToIndex);
}
Future _onLoadFlutterAssetExample() {
return webViewController.loadFlutterAsset('assets/www/index.html');
}
Future _onLoadHtmlStringExample() {
return webViewController.loadHtmlString(kLocalExamplePage);
}
Future _onTransparentBackground() {
return webViewController.loadHtmlString(kTransparentBackgroundPage);
}
Future _onJavaScriptAlertExample(BuildContext context) {
webViewController.setOnJavaScriptAlertDialog((
JavaScriptAlertDialogRequest request,
) async {
await _showAlert(context, request.message);
});
webViewController.setOnJavaScriptConfirmDialog((
JavaScriptConfirmDialogRequest request,
) async {
final bool result = await _showConfirm(context, request.message);
return result;
});
webViewController.setOnJavaScriptTextInputDialog((
JavaScriptTextInputDialogRequest request,
) async {
final String result = await _showTextInput(
context,
request.message,
request.defaultText,
);
return result;
});
return webViewController.loadHtmlString(kAlertTestPage);
}
Widget _getCookieList(String cookies) {
if (cookies == '""') {
return Container();
}
final List cookieList = cookies.split(';');
final Iterable cookieWidgets = cookieList.map(
(String cookie) => Text(cookie),
);
return Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: cookieWidgets.toList(),
);
}
static Future _prepareLocalFile() async {
final String tmpDir = (await getTemporaryDirectory()).path;
final File indexFile = File(
{tmpDir, 'www', 'index.html'}.join(Platform.pathSeparator),
);
await indexFile.create(recursive: true);
await indexFile.writeAsString(kLocalExamplePage);
return indexFile.path;
}
Future _onLogExample() {
webViewController.setOnConsoleMessage((
JavaScriptConsoleMessage consoleMessage,
) {
debugPrint(
'== JS == ${consoleMessage.level.name}: ${consoleMessage.message}',
);
});
return webViewController.loadHtmlString(kLogExamplePage);
}
Future _promptForUrl(BuildContext context) {
final TextEditingController urlTextController = TextEditingController();
return showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: const Text('Input URL to visit'),
content: TextField(
decoration: const InputDecoration(labelText: 'URL'),
autofocus: true,
controller: urlTextController,
),
actions: [
TextButton(
onPressed: () {
if (urlTextController.text.isNotEmpty) {
final Uri? uri = Uri.tryParse(urlTextController.text);
if (uri != null && uri.scheme.isNotEmpty) {
webViewController.loadRequest(LoadRequestParams(uri: uri));
Navigator.pop(context);
}
}
},
child: const Text('Visit'),
),
],
);
},
);
}
Future _showAlert(BuildContext context, String message) async {
return showDialog(
context: context,
builder: (BuildContext ctx) {
return AlertDialog(
content: Text(message),
actions: [
TextButton(
onPressed: () {
Navigator.of(ctx).pop();
},
child: const Text('OK'),
),
],
);
},
);
}
Future _showConfirm(BuildContext context, String message) async {
return await showDialog(
context: context,
builder: (BuildContext ctx) {
return AlertDialog(
content: Text(message),
actions: [
TextButton(
onPressed: () {
Navigator.of(ctx).pop(false);
},
child: const Text('Cancel'),
),
TextButton(
onPressed: () {
Navigator.of(ctx).pop(true);
},
child: const Text('OK'),
),
],
);
},
) ??
false;
}
Future _showTextInput(
BuildContext context,
String message,
String? defaultText,
) async {
return await showDialog(
context: context,
builder: (BuildContext ctx) {
return AlertDialog(
content: Text(message),
actions: [
TextButton(
onPressed: () {
Navigator.of(ctx).pop('Text test');
},
child: const Text('Enter'),
),
],
);
},
) ??
'';
}
Future _onViewportMetaExample() {
return webViewController.loadHtmlString(kViewportMetaPage);
}
}
class NavigationControls extends StatelessWidget {
const NavigationControls({super.key, required this.webViewController});
final PlatformWebViewController webViewController;
@override
Widget build(BuildContext context) {
return Row(
children: [
IconButton(
icon: const Icon(Icons.arrow_back_ios),
onPressed: () async {
if (await webViewController.canGoBack()) {
await webViewController.goBack();
} else {
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('No back history item')),
);
}
}
},
),
IconButton(
icon: const Icon(Icons.arrow_forward_ios),
onPressed: () async {
if (await webViewController.canGoForward()) {
await webViewController.goForward();
} else {
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('No forward history item')),
);
}
}
},
),
IconButton(
icon: const Icon(Icons.replay),
onPressed: () => webViewController.reload(),
),
],
);
}
}
