Obter tamanho de widget RenderBox
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
typedef void OnWidgetSizeChange(Size size);
class MeasureSizeRenderObject extends RenderProxyBox {
Size oldSize;
final OnWidgetSizeChange onChange;
MeasureSizeRenderObject(this.onChange);
@override
void performLayout() {
super.performLayout();
Size newSize = child.size;
if (oldSize == newSize) return;
oldSize = newSize;
WidgetsBinding.instance.addPostFrameCallback((_) {
onChange(newSize);
});
}
}
class MeasureSize extends SingleChildRenderObjectWidget {
final OnWidgetSizeChange onChange;
const MeasureSize({
Key key,
@required this.onChange,
@required Widget child,
}) : super(key: key, child: child);
@override
RenderObject createRenderObject(BuildContext context) {
return MeasureSizeRenderObject(onChange);
}
}
Stupid Snake
