webview_win_floating

Flutter webView for Windows. It's also a plugin that implements the interface of webview_flutter.

Platform Support

This package itself support only Windows.

But use it with webview_flutter, you can write once then support Windows / Android / iOS at the same time.

Android / iOS webview is supported by webview_flutter

Features & Limitations

This package place a native Windows WebView2 component on the window, no texture involved.

That's why it called "floating". In Windows, Flutter widgets cannot show on top of the webview.

However, since it is a native WebView2 component, without texture involved, the display speed is the same with native WebView2.

Feature:

fast display speed (no texture)
support fullscreen
support cross-platform (Windows / Android / iOS)

Limitations: (only in Windows)

all the Flutter widgets cannot show on top of the webview
cannot push a new route on top of the webview
focus switch between webview and flutter widgets (via Tab key) is not support (only in Windows)
The webview can be put in a scrollable widget, but you may need to assign a ScrollController to the scrollable widget (to enable reposition the webview when scrolling).
The webview cannot be clipped by Flutter. So if the webview is put in a scrollable, and the webview is outside of the scrollable, the webview is still visible. (However, if the scrollable is filled with the window size, then this issue can be ignored)

Hmm... there are so many limitations.

So try this package only if the limitations mentioned above is not a concern for you, or your app really need cross-platform, or other packages cannot satisfy your requirement (ex. cannot build pass, text blur, low display fps, large ~200MB dll size, security issue when cannot updating the webview core, etc).

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  webview_win_floating: ^1.0.0
  webview_flutter: ^4.0.1

dependencies:
  webview_win_floating:
    git:
      url: https://github.com/jakky1/webview_win_floating.git
      ref: master
  webview_flutter: ^4.0.1

Problem shootting for building fail

If you build fail with this package, and the error message has the keyword "MSB3073":

run "flutter build ." in command line in [Administrator] mode

Usage

Use webview now

NOTE: all the interface are supplied by webview_flutter

final controller = WebViewController();

@override
void initState() {
  super.initState();
  controller.setJavaScriptMode(JavaScriptMode.unrestricted);
  controller.loadRequest(Uri.parse("https://www.google.com/"));
}

@override
Widget build(BuildContext context) {
  return WebViewWidget(controller: controller);
}

enable javascript

don't forgot to add this line if you want to enable javascript:

controller.setJavaScriptMode(JavaScriptMode.unrestricted);

restricted user navigation

For example, to disable the facebook / twitter links in youtube website:

controller.setNavigationDelegate(NavigationDelegate(

  onNavigationRequest: (request) {
    return request.url.contains("youtube")
      ? NavigationDecision.navigate
      : NavigationDecision.prevent;
  },

  onPageStarted: (url) => print("onPageStarted: $url"),
  onPageFinished: (url) => print("onPageFinished: $url"),
  onWebResourceError: (error) =>
      print("onWebResourceError: ${error.description}"),
));

Communication with javascript

Hint: you can rename the name 'myChannelName' in the following code

controller.addJavaScriptChannel("myChannelName",
  onMessageReceived: (JavaScriptMessage jmsg) {
    String message = jmsg.message;
    print(message);  // print "This message is from javascript"
  }
);

controller.loadHtmlString(htmlContent);
controller.runJavascript("callByDart(100)");


var htmlContent = '''
<html>
<body>
<script>
function callByDart(int value) {
    console.log("callByDart: " + value);
}
myChannelName.postMessage("This message is from javascript");
</script>
</body>
</html>
''';

controller operations

controller.loadRequest(uri)
controller.runJavascript( jsStr )
controller.runJavaScriptReturningResult( jsStr ) // return javascript function's return value
controller.reload()
controller.canGoBack()
controller.goBack()
controller.goForward()
controller.canGoForward()
controller.currentUrl()
controller.clearCache()

dispose controller (cleanup webview instance)

controller = null;
// and make sure no any WebViewWidget keep that controller object.

After official API interface webview_flutter: 4.0.0, controller is disposed after the WebViewController object is garbage collected.

So the controller object may not be disposed immediately when no any pointer keep the controller object.

set user data folder

For WebViewController:

String cacheDir = "c:\\test";
var params = WindowsPlatformWebViewControllerCreationParams(
    userDataFolder: cacheDir);
var controller = WebViewController.fromPlatformCreationParams(params);

For WinWebViewController:

final controller = WinWebViewController(userDataFolder: "c:\\cache_webview");

Build with InnoSetup

Or if application installed in "C:/Program Files/" or other read-only dir

If your application build with InnoSetup, or can be installed in "C:/Program Files/" or other read-only system directory, the webview cannot create data folder in read-only directory, so it won't work.

In this case, you should specify user data folder as mentioned above.

standalone mode

If your app only runs on Windows, and you want to remove library dependencies as many as possible, you can modify pubspec.yaml file:

dependencies:
  webview_win_floating: ^1.0.0
  # webview_flutter: ^4.0.1  # mark this line for Windows only app

and modify all the following class name in your code:

WebViewWidget -> WinWebViewWidget  // add "Win" prefix
WebViewController -> WinWebViewController  // add "Win" prefix
NavigationDelegate  -> WinNavigationDelegate  // add "Win" prefix

just only modify class names. All the properties / method are the same with webview_flutter

There are some Windows-only API:

controller.openDevTools()
onHistoryChanged` callback in WinNavigationDelegate
controller.dispose()

TroubleShooting

javascript 'history.back()' issue

If javascript history.back() is used in your project, please remove NavigationDelegate.onNavigationRequest() implementation in your code, which causes the history.back() work incorrectly.

Example

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

void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final controller = WebViewController();

  @override
  void initState() {
    super.initState();
    controller.setJavaScriptMode(JavaScriptMode.unrestricted);
    controller.setBackgroundColor(Colors.cyanAccent);
    controller.setNavigationDelegate(NavigationDelegate(
      onNavigationRequest: (request) {
        if (request.url.startsWith("https://www.google.com")) {
          return NavigationDecision.navigate;
        } else {
          log("prevent user navigate out of google website!");
          return NavigationDecision.prevent;
        }
      },
      onPageStarted: (url) => print("onPageStarted: $url"),
      onPageFinished: (url) => print("onPageFinished: $url"),
      onWebResourceError: (error) =>
          print("onWebResourceError: ${error.description}"),
    ));
    controller.loadRequest(Uri.parse("https://www.google.com/"));
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Windows Webview example app'),
        ),
        body: WebViewWidget(controller: controller),
      ),
    );
  }
}