Modal Bottom Sheet

modal_bottom_sheet.dart

  awesomeWidget(BuildContext context) {
    var verticalGestures = Factory<VerticalDragGestureRecognizer>(() => VerticalDragGestureRecognizer());
    var gestureSet = {verticalGestures};

    final Completer<WebViewController> _controller = Completer<WebViewController>();

    Future<void> _loadHtmlString(Completer<WebViewController> controller, BuildContext context) async {
      WebViewController _controller = await controller.future;
      await _controller.loadHtmlString(webview_content);
    }

    return showModalBottomSheet<void>(
        backgroundColor: Colors.transparent,
        context: context,
        builder: (BuildContext context) {
          return Container(
            decoration: const BoxDecoration(
                color: Colors.amber,
                borderRadius: BorderRadius.only(
                  topLeft: Radius.circular(50),
                  topRight: Radius.circular(50),
                )),
            height: MediaQuery.of(context).size.height * 0.8,
            child: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.start,
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  ElevatedButton(
                    child: const Text('Close BottomSheet'),
                    onPressed: () => Navigator.pop(context),
                  ),
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.all(12.0),
                      child: WebView(
                        initialUrl: 'https://flutter.dev',
                        javascriptMode: JavascriptMode.unrestricted,
                        onWebViewCreated: (WebViewController webViewController) async {
                          _controller.complete(webViewController);

                          _loadHtmlString(_controller, context);
                        },
                        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');
                        },
                        gestureNavigationEnabled: true,
                        gestureRecognizers: gestureSet,
                        backgroundColor: const Color(0x00000000),
                      ),
                    ),
                  )
                ],
              ),
            ),
          );
        },
        isScrollControlled: true);
  }