Various coordinates can be tapped

coordinate_tap.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  String tex = 'You have pushed the button this many times:';
  final keys = GlobalKey();
  Rect rect = const Rect.fromLTRB(0, 0, 0, 0);

  @override
  void initState() {
    super.initState();
    Future.delayed(const Duration(seconds: 1), () {
      setState(() {
        rect = keys.globalPaintBounds ?? const Rect.fromLTRB(0, 0, 0, 0);
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Material(
      child: Stack(
        children: [
          GestureDetector(
            onTap: () {
              setState(() {
                /// not changed
                tex = '';
              });
            },
            child: Container(
              color: Colors.teal,
              transform: Matrix4.translationValues(40, 333, 0),
              width: 300,
              height: 20,
              child: Text(
                key: keys,
                tex,
              ),
            ),
          ),
          _widget(),
        ],
      ),
    );
  }

  Widget _widget() {
    return Positioned(
      top: rect.top,
      left: rect.left,
      child: GestureDetector(
        onTap: () {
          setState(() {
            tex = '';
          });
        },
        child: Container(
          color: Colors.transparent,
          width: rect.width,
          height: rect.height,
        ),
      ),
    );
  }
}

extension GlobalKeyEx on GlobalKey {
  Rect? get globalPaintBounds {
    final renderObject = currentContext?.findRenderObject();
    final translation = renderObject?.getTransformTo(null).getTranslation();
    if (translation != null && renderObject?.paintBounds != null) {
      return renderObject!.paintBounds
          .shift(Offset(translation.x, translation.y));
    } else {
      return null;
    }
  }
}

2023-02-27.6.29.57.mov