wonders/lib/ui/common/measurable_widget.dart

27 lines
805 B
Dart

import 'dart:async';
import 'package:flutter/rendering.dart';
import 'package:wonders/common_libs.dart';
class MeasurableWidget extends SingleChildRenderObjectWidget {
const MeasurableWidget({super.key, required this.onChange, required Widget super.child});
final void Function(Size size) onChange;
@override
RenderObject createRenderObject(BuildContext context) => MeasureSizeRenderObject(onChange);
}
class MeasureSizeRenderObject extends RenderProxyBox {
MeasureSizeRenderObject(this.onChange);
void Function(Size size) onChange;
Size _prevSize = Size.zero;
@override
void performLayout() {
super.performLayout();
Size newSize = child?.size ?? Size.zero;
if (_prevSize == newSize) return;
_prevSize = newSize;
scheduleMicrotask(() => onChange(newSize));
}
}