buttonni atrofida color aylanib yuradi ga custom widget
import 'dart:math' as math;

import 'package:sell_market/path_file/all_path_file.dart';

sealed class AppColors{
  static const white=Colors.white;
  static const transparent=Colors.transparent;
  static const black=Colors.black;
  static final red=Color(0xFFFF1F38);
  static final red3=Color(0xFFF01FFF);
  static final red2=Color(0xFFE61090);

}

class AnimatedBorderButton extends StatefulWidget {
  final String text;
  final VoidCallback onPressed;

  const AnimatedBorderButton({
    super.key,
    required this.text,
    required this.onPressed,
  });

  @override
  State<AnimatedBorderButton> createState() => _AnimatedBorderButtonState();
}

class _AnimatedBorderButtonState extends State<AnimatedBorderButton>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(seconds: 3),
    )..repeat();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (context, child) {
        return CustomPaint(
          painter: _GradientBorderPainter(angle: _controller.value * 2 * math.pi),
          child: child,
        );
      },
      child: GestureDetector(
        onTap: widget.onPressed,
        child: Container(
          padding:EdgeInsetsGeometry.all(14),
          child: Center(
            child: Text(
              widget.text,
              style: const TextStyle(
                color: Colors.white,
                fontSize: 18,
              ),
            ),
          ),
        ),
      ),
    );
  }
}

class _GradientBorderPainter extends CustomPainter {
  final double angle;

  _GradientBorderPainter({required this.angle});

  @override
  void paint(Canvas canvas, Size size) {
    final rect = Offset.zero & size;

    final gradient = SweepGradient(
      startAngle: angle,
      endAngle: angle + 2 * math.pi,
      /// color ni berish kere
      colors:  [AppColors.red,AppColors.white,AppColors.red3],
    //  colors: const [Colors.blue, Colors.green, Colors.red, Colors.orange, Colors.blue],
    );

    final paint = Paint()
      ..shader = gradient.createShader(rect)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 3;

    final rrect = RRect.fromRectAndRadius(rect.deflate(1), const Radius.circular(12));
    canvas.drawRRect(rrect, paint);
  }

  @override
  bool shouldRepaint(covariant _GradientBorderPainter oldDelegate) {
    return oldDelegate.angle != angle;
  }
}
/// example
AnimatedBorderButton(
  text: "Continue",
  onPressed: () {
    print("Button pressed!");
  },
),

version 2 
import 'dart:math' as math;
import 'package:flutter/material.dart';

class AnimatedBorderButton extends StatefulWidget {
  final String text;
  final VoidCallback onPressed;

  const AnimatedBorderButton({
    super.key,
    required this.text,
    required this.onPressed,
  });

  @override
  State<AnimatedBorderButton> createState() => _AnimatedBorderButtonState();
}

class _AnimatedBorderButtonState extends State<AnimatedBorderButton>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _rotation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,

      duration: const Duration(seconds: 5),
    )..repeat();

    _rotation = CurvedAnimation(
      parent: _controller,
      curve: Curves.easeInToLinear, 
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _rotation,
      builder: (context, child) {
        return Container(
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(12),
            gradient: SweepGradient(
              startAngle: 0,
              endAngle: math.pi * 2,
              transform: GradientRotation(_rotation.value * 2 * math.pi),
              colors: const [
                Colors.blue,
                Colors.purple,
                Colors.red,
                Colors.orange,
                Colors.white,
                Colors.blue,
              ],
            ),
          ),
          child: Padding(
            padding: const EdgeInsets.all(7),
            child: Container(
              decoration: BoxDecoration(
                color: Colors.black,
                borderRadius: BorderRadius.circular(10),
              ),
              child: TextButton(
                onPressed: widget.onPressed,
                child: Text(
                  widget.text,
                  style: const TextStyle(color: Colors.white, fontSize: 18),
                ),
              ),
            ),
          ),
        );
      },
    );
  }
}