How to find out if a scrollbar is visible/attached in flutter?

Question

I want to add space/padding for a scrollbar when it is visible.

How can I find out, if a scrollbar is visible in a flutter widget?

Answer 1

this lib can help you to do it https://pub.dev/packages/visibility_detector

@override
Widget build(BuildContext context) {
  return VisibilityDetector(
    key: Key('my-widget-key'),
    onVisibilityChanged: (visibilityInfo) {
      var visiblePercentage = visibilityInfo.visibleFraction * 100;
      debugPrint(
          'Widget ${visibilityInfo.key} is ${visiblePercentage}% visible');
    },
    child: someOtherWidget,
  );
}

Answer 2

Through the following I could find out if there is a scrollbar

NotificationListener<ScrollMetricsNotification>(
      onNotification: (notification) {
        setState(() {
          hasScrollbar = (notification.metrics.maxScrollExtent > 0);
        });
      },

and when hasScrollbar is true I add padding for it:

padding: hasScrollbar ? myThemeData.screenPadding.copyWith(right: 20.scaled()) : myThemeData.screenPadding,