ScrollBar moves slower than the mouse when dragging it to scroll #112072
Description
This one is bit different from #111968. It happens with current main in cases where SliverList items extents keep increasing.
Main reason for this is that ScrollBar._updateScrollPosition adjusts viewport position by using relative scroll offset. In pathological cases like this the error keeps increasing to the point where not even overdrag is enough to reach end.
I'm wondering why ScrollBar is written like that. Setting pixels to minExtent + (absoluteScrollPosition * (maxExtent - minExtent)) would alleviate this (absoluteScrollPosition being in range of 0.0-1.0). But I'm not sure how this would work with overdrag.
import 'package:flutter/material.dart';
void main() {
runApp(const MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(),
));
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key});
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: [
SliverToBoxAdapter(
child: Container(
height: 2,
color: Colors.red,
),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(context, index) => Padding(
padding: const EdgeInsets.all(10),
child: Container(
color: Colors.green,
height: index.toDouble(),
),
),
childCount: 1000,
),
),
SliverToBoxAdapter(
child: Container(
height: 2,
color: Colors.red,
),
),
],
),
);
}
}