webview_flutter 3.0.1 webview_flutter: ^3.0.1 copied to clipboard
A Flutter plugin that provides a WebView widget on Android and iOS.
// 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(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 {
@override
_WebViewExampleState 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),
],
),
// We're using a Builder here so we have a context that is below the Scaffold
// to allow calling Scaffold.of(context) so we can show a snackbar.
body: Builder(builder: (BuildContext context) {
return 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) {
// ignore: deprecated_member_use
Scaffold.of(context).showSnackBar(
SnackBar(content: Text(message.message)),
);
});
}
Widget favoriteButton() {
return FutureBuilder<WebViewController>(
future: _controller.future,
builder: (BuildContext context,
AsyncSnapshot<WebViewController> controller) {
if (controller.hasData) {
return FloatingActionButton(
onPressed: () async {
final String url = (await controller.data!.currentUrl())!;
// ignore: deprecated_member_use
Scaffold.of(context).showSnackBar(
SnackBar(content: Text('Favorited $url')),
);
},
child: const Icon(Icons.favorite),
);
}
return Container();
});
}
}
enum MenuOptions {
showUserAgent,
listCookies,
clearCookies,
addToCache,
listCache,
clearCache,
navigationDelegate,
doPostRequest,
loadLocalFile,
loadFlutterAsset,
loadHtmlString,
transparentBackground,
setCookie,
}
class SampleMenu extends StatelessWidget {
SampleMenu(this.controller);
final Future<WebViewController> controller;
final CookieManager 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,
child: const Text('Show user agent'),
enabled: controller.hasData,
),
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');
// ignore: deprecated_member_use
Scaffold.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";');
// ignore: deprecated_member_use
Scaffold.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()'
'.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))'
'.then((caches) => Toaster.postMessage(caches))');
}
Future<void> _onClearCache(
WebViewController controller, BuildContext context) async {
await controller.clearCache();
// ignore: deprecated_member_use
Scaffold.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.';
}
// ignore: deprecated_member_use
Scaffold.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)
: assert(_webViewControllerFuture != null);
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 {
// ignore: deprecated_member_use
Scaffold.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 {
// ignore: deprecated_member_use
Scaffold.of(context).showSnackBar(
const SnackBar(
content: Text('No forward history item')),
);
return;
}
},
),
IconButton(
icon: const Icon(Icons.replay),
onPressed: !webViewReady
? null
: () {
controller!.reload();
},
),
],
);
},
);
}
}