Color picker slider for bottomsheet

ColorSlider.dart

import 'package:flutter/material.dart';

class ColorSlider extends StatefulWidget {
  final void Function(Color)  callBackColorTapped ;
  final Color noteColor ;
  ColorSlider({@required this.callBackColorTapped, @required this.noteColor});
  @override
  _ColorSliderState createState() => _ColorSliderState();
}

class _ColorSliderState extends State<ColorSlider> {

  final colors = [
    Color(0xffffffff), // classic white
    Color(0xfff28b81), // light pink
    Color(0xfff7bd02), // yellow
    Color(0xfffbf476), // light yellow
    Color(0xffcdff90), // light green
    Color(0xffa7feeb), // turquoise
    Color(0xffcbf0f8), // light cyan
    Color(0xffafcbfa), // light blue
    Color(0xffd7aefc), // plum
    Color(0xfffbcfe9), // misty rose
    Color(0xffe6c9a9), // light brown
    Color(0xffe9eaee)  // light gray
  ];

   final Color borderColor = Color(0xffd3d3d3);
   final Color foregroundColor = Color(0xff595959);

  final _check = Icon(Icons.check);
  Color noteColor;
  
  int indexOfCurrentColor;
  @override void initState() {
    super.initState();
    this.noteColor = widget.noteColor;
    indexOfCurrentColor = colors.indexOf(noteColor);
  }

  @override
  Widget build(BuildContext context) {
    return ListView(
      scrollDirection: Axis.horizontal,
      children:
      List.generate(colors.length, (index)
      {
        return
          GestureDetector(
              onTap: ()=> _colorChangeTapped(index),
              child: Padding(
                  padding: EdgeInsets.only(left: 6, right: 6),
                  child:Container(
                  child: new CircleAvatar(
                    child: _checkOrNot(index),
                    foregroundColor: foregroundColor,
                    backgroundColor: colors[index],
                  ),
                  width: 38.0,
                  height: 38.0,
                  padding: const EdgeInsets.all(1.0), // border width
                  decoration: new BoxDecoration(
                    color: borderColor, // border color
                    shape: BoxShape.circle,
                  )
              ) )
          );
      })
      ,);
  }

  void _colorChangeTapped(int indexOfColor) {
    setState(() {
      noteColor = colors[indexOfColor];
      indexOfCurrentColor = indexOfColor;
      widget.callBackColorTapped(colors[indexOfColor]);
    });
  }

  Widget _checkOrNot(int index){
    if (indexOfCurrentColor == index) {
      return _check;
    }
    return null;
  }

}