iosWebViewFix/example/lib/webview_example.screen.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_inappbrowser/flutter_inappbrowser.dart';

class MyInappBrowser extends InAppBrowser {

 @override
 Future onBrowserCreated() async {
   print("\n\nBrowser Ready!\n\n");
 }

 @override
 Future onLoadStart(String url) async {
   print("\n\nStarted $url\n\n");
 }

 @override
 Future onLoadStop(String url) async {
   print("\n\nStopped $url\n\n");
 }

 @override
 Future onScrollChanged(int x, int y) async {
   print("Scrolled: x:$x y:$y");
 }

 @override
 void onLoadError(String url, int code, String message) {
   print("Can't load $url.. Error: $message");
 }

 @override
 void onProgressChanged(int progress) {
   print("Progress: $progress");
 }

 @override
 void onExit() {
   print("\n\nBrowser closed!\n\n");
 }

 @override
 void shouldOverrideUrlLoading(String url) {
   print("\n\n override $url\n\n");
   this.webViewController.loadUrl(url);
 }

 @override
 void onLoadResource(LoadedResource response) {
   print("Started at: " +
       response.startTime.toString() +
       "ms ---> duration: " +
       response.duration.toString() +
       "ms " +
       response.url);
 }

 @override
 void onConsoleMessage(ConsoleMessage consoleMessage) {
   print("""
    console output:
      sourceURL: ${consoleMessage.sourceURL}
      lineNumber: ${consoleMessage.lineNumber}
      message: ${consoleMessage.message}
      messageLevel: ${consoleMessage.messageLevel.toValue()}
   """);
 }

 @override
 void onDownloadStart(String url) {
   print("Download of " + url);
 }

 @override
 Future<CustomSchemeResponse> onLoadResourceCustomScheme(String scheme, String url) async {
   print("custom scheme: " + scheme);
 }

 @override
 Future<GeolocationPermissionShowPromptResponse> onGeolocationPermissionsShowPrompt(String origin) async {
   print("request Geolocation permission API");
 }

 @override
 Future<JsAlertResponse> onJsAlert(String message) async {
   return new JsAlertResponse(handledByClient: false, message: "coma iam");
 }

 @override
 Future<JsConfirmResponse> onJsConfirm(String message) {

 }

 @override
 Future<JsPromptResponse> onJsPrompt(String message, String defaultValue) {

 }
}

class WebviewExampleScreen extends StatefulWidget {
  final MyInappBrowser browser = new MyInappBrowser();
  static BuildContext context = null;

  @override
  _WebviewExampleScreenState createState() => new _WebviewExampleScreenState();
}

class _WebviewExampleScreenState extends State<WebviewExampleScreen> {
  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    WebviewExampleScreen.context = context;
    return new Center(
      child: new RaisedButton(
          onPressed: ()  {
            widget.browser.openFile(
              "assets/index.html",
              //url: "https://www.google.com/",
              options: InAppBrowserClassOptions(
                inAppWebViewWidgetOptions: InAppWebViewWidgetOptions(
                  inAppWebViewOptions: InAppWebViewOptions(
                    useShouldOverrideUrlLoading: true,
                    useOnLoadResource: true,
                  )
                )
              )
            );
          },
          child: Text("Open Webview Browser")),
    );
  }
}