Flutter Clock

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: Scaffold(
        body: Center(
            child: SizedBox(
          height: 300,
          width: 300,
          child: Container(
            color: Colors.amber[600],
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                SizedBox(height: 50),
                SizeProviderWidget(
                  onChildSize: (size) {
                    print(size);
                    print(
                        "Da könnte man jetzt ein stateful Widget nehmen und die width der Sized Box der zweiten row updaten");
                  },
                  child: Row(
                    crossAxisAlignment: CrossAxisAlignment.end,
                    mainAxisAlignment: MainAxisAlignment.end,
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      Container(
                        child: Text("18",
                            style: TextStyle(
                              fontSize: 90,
                              height: 0.2,
                            )),
                      ),
                      Padding(
                        padding: EdgeInsets.only(right: 6),
                        child: Text("hrs",
                            style: TextStyle(
                              fontSize: 20,
                              height: 1,
                            )),
                      ),
                    ],
                  ),
                ),
                SizedBox(
                  width: 131,
                  child: Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisAlignment: MainAxisAlignment.end,
                    children: <Widget>[
                      Text("50",
                          style: TextStyle(
                            fontSize: 45,
                            height: 1,
                          )),
                      Text("min",
                          style: TextStyle(
                            fontSize: 20,
                            height: 1,
                          )),
                      // 2nd spacer
                    ],
                  ),
                ),

                // 2nd spacer
              ],
            ),
          ),
        )),
      ),
    );
  }
}

class SizeProviderWidget extends StatefulWidget {
  final Widget child;
  final Function(Size) onChildSize;

  const SizeProviderWidget({Key key, this.onChildSize, this.child})
      : super(key: key);
  @override
  _SizeProviderWidgetState createState() => _SizeProviderWidgetState();
}

class _SizeProviderWidgetState extends State<SizeProviderWidget> {
  @override
  void initState() {
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      widget.onChildSize(context.size);
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return widget.child;
  }
}