41 lines
965 B
Dart
41 lines
965 B
Dart
import 'package:flutter/material.dart';
|
|
|
|
class ScrollOverBuilder extends StatefulWidget {
|
|
final Widget Function(bool isOver) builder;
|
|
|
|
const ScrollOverBuilder({
|
|
super.key,
|
|
required this.builder,
|
|
});
|
|
|
|
@override
|
|
State<ScrollOverBuilder> createState() => _ScrollOverBuilderState();
|
|
}
|
|
|
|
class _ScrollOverBuilderState extends State<ScrollOverBuilder> {
|
|
final isOverNotifier = ValueNotifier<bool>(false);
|
|
|
|
|
|
@override
|
|
void dispose() {
|
|
super.dispose();
|
|
isOverNotifier.dispose();
|
|
}
|
|
|
|
@override
|
|
Widget build(BuildContext context) {
|
|
return NotificationListener<ScrollMetricsNotification>(
|
|
onNotification: (scrollNotification) {
|
|
isOverNotifier.value = scrollNotification.metrics.maxScrollExtent > 0;
|
|
return true;
|
|
},
|
|
child: ValueListenableBuilder<bool>(
|
|
valueListenable: isOverNotifier,
|
|
builder: (_, isOver, __) {
|
|
return widget.builder(isOver);
|
|
},
|
|
),
|
|
);
|
|
}
|
|
}
|