如何在flutter中拥有像这样的双向夹具视图？

import 'package:flutter/material.dart';

class DualHandleView extends StatefulWidget {
  @override
  _DualHandleViewState createState() => _DualHandleViewState();
}

class _DualHandleViewState extends State<DualHandleView> {
  double _leftHandlePosition = 0.0;
  double _rightHandlePosition = 1.0;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onPanUpdate: (details) {
        setState(() {
          _leftHandlePosition += details.delta.dx / context.size.width;
          _rightHandlePosition += details.delta.dx / context.size.width;
          _leftHandlePosition = _leftHandlePosition.clamp(0.0, 1.0);
          _rightHandlePosition = _rightHandlePosition.clamp(0.0, 1.0);
        });
      },
      child: Container(
        color: Colors.grey[300],
        child: Stack(
          children: [
            Positioned(
              left: _leftHandlePosition * context.size.width,
              child: GestureDetector(
                onPanUpdate: (details) {
                  setState(() {
                    _leftHandlePosition += details.delta.dx / context.size.width;
                    _leftHandlePosition = _leftHandlePosition.clamp(0.0, _rightHandlePosition);
                  });
                },
                child: Container(
                  width: 20.0,
                  height: context.size.height,
                  color: Colors.blue,
                ),
              ),
            ),
            Positioned(
              left: _rightHandlePosition * context.size.width,
              child: GestureDetector(
                onPanUpdate: (details) {
                  setState(() {
                    _rightHandlePosition += details.delta.dx / context.size.width;
                    _rightHandlePosition = _rightHandlePosition.clamp(_leftHandlePosition, 1.0);
                  });
                },
                child: Container(
                  width: 20.0,
                  height: context.size.height,
                  color: Colors.red,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}