fade_in_widget.dart

import 'package:flutter/material.dart';

class FadeInWidget extends StatefulWidget {
  Widget? child;
  final Duration duration;

  FadeInWidget(
      {super.key,
      this.child,
      this.duration = const Duration(milliseconds: 50)});

  @override
  State<FadeInWidget> createState() => _FadeInWidgetState();
}

class _FadeInWidgetState extends State<FadeInWidget>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(duration: widget.duration, vsync: this);
    _animation = Tween<double>(begin: 0.0, end: 1.0).animate(_controller);
    _controller.forward();
  }

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

  @override
  Widget build(BuildContext context) {
    return AnimatedOpacity(
      duration: widget.duration,
      opacity: _animation.value,
      child: widget.child,
    );
  }
}