How to fix "The method 'CustomTimerPainter' isn't defined" error in Flutter?

I'm encountering the following error in my Flutter countdown timer implementation:

 59:48: Error: The method 'CustomTimerPainter' isn't defined for the class '_CountDownTimerState'.
 - '_CountDownTimerState' is from 'package:braintrinig/pages/Countdown_timer.dart' ('lib/pages/Countdown_timer.dart'). Try correcting the name to the name of an existing method, or defining a method named 'CustomTimerPainter'.
                    painter: CustomTimerPainter(

Relevant code:

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';

class CountDownTimer extends StatefulWidget {
  // ...
}

class _CountDownTimerState extends State<CountDownTimer> with TickerProviderStateMixin {
  // ... 

  @override
  Widget build(BuildContext context) {
    // ... 

            CustomPaint(
              painter: CustomTimerPainter( 
                 animation: controller,
                 backgroundColor: Colors.white,
                 color: themeData.indicatorColor,
              ),
            ),

    // ... 
  }
}

Things I've tried:

• Checked my imports (I don't see where CustomTimerPainter might be defined).

• Verified that the file with the CustomTimerPainter class is accessible and correctly imported.

Question: Can you help me determine why I'm getting this error and how to resolve it?

It checked that "CustomTimerPainter" is from circular_countdown_timer library. After you add this library, the problem you mentioned will be resolved.

I pasted your code to my project and install "circular_countdown_timer", I didn't see any error right now.

circular_countdown_timer pub.dev

1. Add circular_countdown_timer in your pubspec.yaml => get => update.

dependencies:
  circular_countdown_timer: ^0.2.2

2. Import this library into your dart file

import 'package:circular_countdown_timer/custom_timer_painter.dart';