Изменил название пакета, начал работу по регистрации магазина

lib/main.dart

@@ -1,115 +1,14 @@
-import 'dart:async';
-
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
+import 'registration.dart';
 
 const String _name = "Ivan Murashov";
 
 void main() {
-  runApp(new DemoApp());
+  runApp(new Checker());
 }
 
-class DemoApp extends StatelessWidget {
+class Checker extends StatelessWidget {
   @override Widget build(BuildContext context) {
-    return new MaterialApp(title: "DemoApp", home: new ChatScreen());
-  }
-}
-
-class ChatScreen extends StatefulWidget {
-  @override State createState() => new ChatScreenState();
-}
-
-class ChatScreenState extends State<ChatScreen> {
-
-  static const platform = const MethodChannel('com.yourcompany.checker/scanner');
-  final List<ChatMessage> _messages = <ChatMessage>[];
-  final TextEditingController _textController = new TextEditingController();
-
-  @override Widget build(BuildContext context) {
-    return new Scaffold(appBar: new AppBar(
-        title: new Text("DemoApp")), body: _buildScreen());
-  }
-
-  Widget _buildScreen() {
-    return new Column(children: <Widget>[
-      new Flexible(child: new ListView.builder(
-        padding: new EdgeInsets.all(8.0),
-        reverse: true,
-        itemBuilder: (_, int index) => _messages[index],
-        itemCount: _messages.length)),
-      new Divider(height: 1.0),
-      new Container(decoration: _getDecoratedScreenComposer(),
-          child: _buildStyledTextComposer())
-    ]);
-  }
-
-  BoxDecoration _getDecoratedScreenComposer() {
-    return new BoxDecoration(color: Theme.of(context).cardColor);
-  }
-
-  Widget _buildStyledTextComposer() {
-    return new IconTheme(data: _getIconThemeData(), child: _buildTextComposer());
-  }
-
-  IconThemeData _getIconThemeData() {
-    return new IconThemeData(color: Theme.of(context).accentColor);
-  }
-
-  Widget _buildTextComposer() {
-    return new Container(margin: const EdgeInsets.symmetric(horizontal: 8.0),
-      child: _buildInputFieldRow());
-  }
-
-  Row _buildInputFieldRow() {
-    var textField = new InputDecoration.collapsed(hintText: "Send a message");
-    return new Row(children: <Widget>[
-      new Flexible(child: new TextField(controller: _textController,
-                                        onSubmitted: _handleSubmitted,
-                                        decoration: textField)),
-      new Container(margin: new EdgeInsets.symmetric(horizontal: 4.0),
-                    child: new IconButton(icon: new Icon(Icons.send),
-                    onPressed: () => startScanner()))
-//                    onPressed: () => _handleSubmitted(_textController.text)))
-    ]);
-  }
-
-  Future<Null> startScanner() async {
-    try {
-      platform.invokeMethod('startScanner');
-    } on PlatformException catch (e) {
-
-    }
-  }
-
-  void _handleSubmitted(String text) {
-    _textController.clear();
-    ChatMessage message = new ChatMessage(text);
-    setState(() {_messages.insert(0, message);});
-  }
-}
-
-class ChatMessage extends StatelessWidget {
-
-  final String text;
-
-  ChatMessage(this.text);
-
-  @override Widget build(BuildContext context) {
-    return new Container(margin: const EdgeInsets.symmetric(vertical: 8.0),
-                        child: _getMessageRow(context));
-  }
-
-  Widget _getMessageRow(BuildContext context) {
-    return new Row(crossAxisAlignment: CrossAxisAlignment.start,
-        children: <Widget>[
-          new Container(margin: const EdgeInsets.only(right: 16.0),
-              child: new CircleAvatar(child: new Text(_name[0]))),
-          new Column(crossAxisAlignment: CrossAxisAlignment.start,
-              children: <Widget>[
-                new Text(_name, style: Theme.of(context).textTheme.subhead),
-                new Container(margin: const EdgeInsets.only(top: 4.0),
-                    child: new Text(text))
-              ])
-        ]);
+    return new MaterialApp(title: "DemoApp", home: new RegistrationScreen());
   }
 }

lib/registration.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'dart:async';
+
+/// Экран регистрации магазина и кассы.
+class RegistrationScreen extends StatefulWidget {
+  @override State createState() => new _RegistrationScreenState();
+}
+
+class _RegistrationScreenState extends State<RegistrationScreen> {
+
+  static const platform = const MethodChannel('com.dinnect.checker/scanner');
+
+  @override Widget build(BuildContext context) {
+    return new Scaffold(appBar: new AppBar(
+        title: new Text("Регистрация магазина")), body: _buildScreen());
+  }
+
+  /// На экране будет отображаться Column, с отцентрированными виджетами.
+  Widget _buildScreen() {
+    return new Center(child: new Column(children: _getChildren()));
+  }
+
+  Future<Null> startScanner() async {
+    try {
+      platform.invokeMethod('startScanner');
+    } on PlatformException {
+
+    }
+  }
+
+  void _handleSubmitted(String text) {
+
+  }
+
+  List<Widget> _getChildren() {
+    return<Widget>[
+      _getLogo(),
+      _getInputField("ID кассы"),
+      _getInputField("Номер кассы"),
+    ];
+  }
+
+  Row _getLogo() {
+    return new Row(
+      // TODO: Два Image() с логотипом
+    );
+  }
+
+  Container _getInputField(String hint) {
+    return new Container(padding: new EdgeInsets.all(8.0),
+        child: new TextField(decoration: new InputDecoration(hintText: hint))) ;
+  }
+}