60794218

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  double posx = 100.0;
  double posy = 100.0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Stack(children: <Widget>[
        GestureDetector(
          onTap: onGreenClick,
          onTapDown: (TapDownDetails details) => onTapDown(context, details),
          child: Container(
            color: Colors.green,
            width: 400,
            height: 400,
          ),
        ),
        GestureDetector(
          onTapDown: (TapDownDetails details) => onTapDown(context, details),
          onTap: () {
            print('red clicked.');
            onGreenClick();
          },
          child: Container(
            color: Colors.red,
            width: 200,
            height: 200,
          ),
        ),
      ]),
    );
  }

  void onGreenClick()
  {
    print("Green clicked");
  }
  void onTapDown(BuildContext context, TapDownDetails details) {
    print('${details.globalPosition}');
    final RenderBox box = context.findRenderObject();
    final Offset localOffset = box.globalToLocal(details.globalPosition);
    setState(() {
      posx = localOffset.dx;
      posy = localOffset.dy;
    });
    if (posx < 100.0 && posy < 100.0) onGreenClick();
  }
}