main.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      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> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Container(
          child: SingleChildScrollView(
            scrollDirection: Axis.horizontal,
            child: Row(
              children: <Widget>[
                MyCard(color: Colors.red),
                MyCard(color: Colors.blue),
                MyCard(color: Colors.green),
                MyCard(color: Colors.orange),
                MyCard(color: Colors.lime),
                MyCard(color: Colors.yellow),
                MyCard(color: Colors.black),
                MyCard(color: Colors.amber),
                MyCard(color: Colors.brown),
                MyCard(color: Colors.indigo),
                MyCard(color: Colors.grey),
                MyCard(color: Colors.white),
                MyCard(color: Colors.purple),
                MyCard(color: Colors.teal),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class MyCard extends StatelessWidget {
  final Color color;

  const MyCard({Key key, this.color}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Card(
      clipBehavior: Clip.antiAlias,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(
          18.0,
        ),
      ),
      child: GestureDetector(
        onTap: () {
          showDialog(
              context: context,
              builder: (BuildContext context) {
                return AlertDialog(
                    title: Text('Color'),
                    content: Text(color.toString()),
                    actions: <Widget>[
                      RaisedButton(
                          child: Text('CLOSE'),
                          onPressed: () {
                            Navigator.pop(context);
                          })
                    ]);
              });
        },
        child: Container(
          color: color,
          height: MediaQuery.of(context).size.height * 0.35,
          width: MediaQuery.of(context).size.width * 0.25,
        ),
      ),
    );
  }
}