/// 返回顶部
library;

import 'package:flutter/material.dart';

class Backtop extends StatelessWidget {
  const Backtop({
    super.key,
    required this.controller,
    required this.offset,
    this.distance = 1000.0,
  });

  final ScrollController controller;
  /// 滚动位置
  final double offset;
  /// 距离顶部多远显示
  final double distance;

  @override
  Widget build(BuildContext context){
    return AnimatedOpacity(
      opacity: offset > distance ? 1.0 : 0.0,
      duration: Duration(milliseconds: 200),
      child: IconButton(
        onPressed: (){
          controller.animateTo(0, duration: Duration(milliseconds: 300), curve: Curves.easeInOut);
        },
        icon: Icon(Icons.arrow_upward_rounded, size: 20.0,),
        style: ButtonStyle(
          backgroundColor: WidgetStateProperty.all(Colors.grey[100]),
        ),
      ),
    );
  }
}