webview_flutter_android 2.6.0 webview_flutter_android: ^2.6.0 copied to clipboard
A Flutter plugin that provides a WebView widget on Android.
// 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 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_driver/driver_extension.dart';
import 'package:path_provider/path_provider.dart';
import 'package:webview_flutter_android/webview_surface_android.dart';
import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
import 'navigation_decision.dart';
import 'navigation_request.dart';
import 'web_view.dart';
void appMain() {
enableFlutterDriverExtension();
main();
}
void main() {
// Configure the [WebView] to use the [SurfaceAndroidWebView]
// implementation instead of the default [AndroidWebView].
WebView.platform = SurfaceAndroidWebView();
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 kExamplePage = '''
<!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: #FF0000; width: 200px; height: 100%; margin: 0; padding: 0; position: absolute; top: 0; bottom: 0; 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}) : super(key: key);
@override
_WebViewExampleState createState() => _WebViewExampleState();
}
class _WebViewExampleState extends State<_WebViewExample> {
final Completer<WebViewController> _controller =
Completer<WebViewController>();
@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: <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',
onWebViewCreated: (WebViewController controller) {
_controller.complete(controller);
},
onProgress: (int progress) {
print('WebView is loading (progress : $progress%)');
},
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');
},
javascriptChannels: _createJavascriptChannels(context),
javascriptMode: JavascriptMode.unrestricted,
userAgent: 'Custom_User_Agent',
backgroundColor: const Color(0x80000000),
);
}),
floatingActionButton: favoriteButton(),
);
}
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();
});
}
}
Set<JavascriptChannel> _createJavascriptChannels(BuildContext context) {
return <JavascriptChannel>{
JavascriptChannel(
name: 'Snackbar',
onMessageReceived: (JavascriptMessage message) {
ScaffoldMessenger.of(context)
.showSnackBar(SnackBar(content: Text(message.message)));
}),
};
}
enum _MenuOptions {
showUserAgent,
listCookies,
clearCookies,
addToCache,
listCache,
clearCache,
navigationDelegate,
loadFlutterAsset,
loadLocalFile,
loadHtmlString,
transparentBackground,
}
class _SampleMenu extends StatelessWidget {
const _SampleMenu(this.controller);
final Future<WebViewController> controller;
@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(controller.data!, 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.loadFlutterAsset:
_onLoadFlutterAssetExample(controller.data!, context);
break;
case _MenuOptions.loadLocalFile:
_onLoadLocalFileExample(controller.data!, context);
break;
case _MenuOptions.loadHtmlString:
_onLoadHtmlStringExample(controller.data!, context);
break;
case _MenuOptions.transparentBackground:
_onTransparentBackground(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.loadFlutterAsset,
child: Text('Load Flutter Asset'),
),
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>(
key: ValueKey<String>('ShowTransparentBackgroundExample'),
value: _MenuOptions.transparentBackground,
child: Text('Transparent background example'),
),
],
);
},
);
}
Future<void> _onShowUserAgent(
WebViewController controller, BuildContext context) async {
// Send a message with the user agent string to the Snackbar JavaScript channel we registered
// with the WebView.
await controller.runJavascript(
'Snackbar.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) => Snackbar.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(
WebViewController controller, BuildContext context) async {
final bool hadCookies = await WebView.platform.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> _onLoadFlutterAssetExample(
WebViewController controller, BuildContext context) async {
await controller.loadFlutterAsset('assets/www/index.html');
}
Future<void> _onLoadLocalFileExample(
WebViewController controller, BuildContext context) async {
final String pathToIndex = await _prepareLocalFile();
await controller.loadFile(pathToIndex);
}
Future<void> _onLoadHtmlStringExample(
WebViewController controller, BuildContext context) async {
await controller.loadHtmlString(kExamplePage);
}
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('$tmpDir/www/index.html');
await Directory('$tmpDir/www').create(recursive: true);
await indexFile.writeAsString(kExamplePage);
return indexFile.path;
}
Future<void> _onTransparentBackground(
WebViewController controller, BuildContext context) async {
await controller.loadHtmlString(kTransparentBackgroundPage);
}
}
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();
},
),
],
);
},
);
}
}
/// Callback type for handling messages sent from JavaScript running in a web view.
typedef JavascriptMessageHandler = void Function(JavascriptMessage message);