fluffychat/lib/pangea/pages/class_analytics/measure_able.dart

import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';

class MeasurableWidget extends StatefulWidget {
  final Widget child;

  Function? triggerMeasure;
  final Function(Size? size, Offset? position) onChange;

  MeasurableWidget({super.key, required this.onChange, required this.child});

  @override
  _WidgetSizeState createState() => _WidgetSizeState();
}

class _WidgetSizeState extends State<MeasurableWidget> {
  var widgetKey = GlobalKey();
  Offset? oldPosition;
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  void postFrameCallback(_) {
    final context = widgetKey.currentContext;
    if (context == null) return;

    final newSize = context.size;

    final RenderBox? box =
        widgetKey.currentContext?.findRenderObject() as RenderBox?;
    final Offset? position = box?.localToGlobal(Offset.zero);

    if (oldPosition != null) {
      if (oldPosition!.dx == position!.dx && oldPosition!.dy == position.dy) {
        return;
      }
    }
    oldPosition = position;

    widget.onChange(newSize, position);
  }

  @override
  Widget build(BuildContext context) {
    SchedulerBinding.instance.addPostFrameCallback(postFrameCallback);
    return Container(
      key: widgetKey,
      child: widget.child,
    );
  }
}