Flutter Widget: TouchOpacity

TouchOpacity.dart

import 'package:flutter/widgets.dart';

class TouchOpacity extends StatefulWidget {
  final Widget child;
  final void Function()? onTap;

  const TouchOpacity({
    super.key,
    this.child = const SizedBox(),
    this.onTap,
  });

  @override
  createState() => _TouchOpacity();
}

class _TouchOpacity extends State<TouchOpacity> {
  var press = false;
  @override
  Widget build(BuildContext context) {
    return Listener(
      behavior: HitTestBehavior.opaque,
      onPointerDown: (e) => setState(() => press = true),
      onPointerUp: (e) => setState(() => press = false),
      child: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onTap: widget.onTap,
        child: Opacity(
          opacity: press ? .65 : 1,
          child: widget.child,
        ),
      ),
    );
  }
}