Flutter 조금 Tips ~ 화면 위에 팝업을 표시 ~

코드

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> {
  bool _isTapClose = false;

  void _onTapCloseButton() {
    setState(() {
      _isTapClose = true;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Stack(
          children: <Widget>[
            Container(
                margin: EdgeInsets.only(top: (_isTapClose ? 0.0 : 50.0)),
                color: Colors.yellow,
                child: getList()),
            (_isTapClose ? Container() : UpperPop()),
          ],
        ));
  }

  Widget UpperPop() {
    final TextStyle textStyle = TextStyle(fontSize: 20);
    final TextStyle textButtonStyle =
        TextStyle(fontSize: 20, color: Colors.blue);
    final Size displaySize = MediaQuery.of(context).size;

    return Container(
        height: (50),
        width: displaySize.width,
        child: Row(
          children: <Widget>[
            Expanded(child: Text('Upper Pop Test', style: textStyle)),
            FlatButton(
              onPressed: () {
                _onTapCloseButton();
              },
              child: Text(
                "Close",
                style: textButtonStyle,
              ),
            ),
          ],
        ));
  }

  Widget getList() {
    return ListView(children: <Widget>[
      Text('Item'),
    ]);
  }
}

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