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Diffstat (limited to 'lib')
| -rw-r--r-- | lib/main.dart | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/lib/main.dart b/lib/main.dart new file mode 100644 index 0000000..8e94089 --- /dev/null +++ b/lib/main.dart @@ -0,0 +1,125 @@ +import 'package:flutter/material.dart'; + +void main() { + runApp(const MyApp()); +} + +class MyApp extends StatelessWidget { + const MyApp({super.key}); + + // This widget is the root of your application. + @override + Widget build(BuildContext context) { + return MaterialApp( + title: 'Flutter Demo', + theme: ThemeData( + // This is the theme of your application. + // + // TRY THIS: Try running your application with "flutter run". You'll see + // the application has a purple toolbar. Then, without quitting the app, + // try changing the seedColor in the colorScheme below to Colors.green + // and then invoke "hot reload" (save your changes or press the "hot + // reload" button in a Flutter-supported IDE, or press "r" if you used + // the command line to start the app). + // + // Notice that the counter didn't reset back to zero; the application + // state is not lost during the reload. To reset the state, use hot + // restart instead. + // + // This works for code too, not just values: Most code changes can be + // tested with just a hot reload. + colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple), + useMaterial3: true, + ), + home: const MyHomePage(title: 'Flutter Demo Home Page'), + ); + } +} + +class MyHomePage extends StatefulWidget { + const MyHomePage({super.key, required this.title}); + + // This widget is the home page of your application. It is stateful, meaning + // that it has a State object (defined below) that contains fields that affect + // how it looks. + + // This class is the configuration for the state. It holds the values (in this + // case the title) provided by the parent (in this case the App widget) and + // used by the build method of the State. Fields in a Widget subclass are + // always marked "final". + + final String title; + + @override + State<MyHomePage> createState() => _MyHomePageState(); +} + +class _MyHomePageState extends State<MyHomePage> { + int _counter = 0; + + void _incrementCounter() { + setState(() { + // This call to setState tells the Flutter framework that something has + // changed in this State, which causes it to rerun the build method below + // so that the display can reflect the updated values. If we changed + // _counter without calling setState(), then the build method would not be + // called again, and so nothing would appear to happen. + _counter++; + }); + } + + @override + Widget build(BuildContext context) { + // This method is rerun every time setState is called, for instance as done + // by the _incrementCounter method above. + // + // The Flutter framework has been optimized to make rerunning build methods + // fast, so that you can just rebuild anything that needs updating rather + // than having to individually change instances of widgets. + return Scaffold( + appBar: AppBar( + // TRY THIS: Try changing the color here to a specific color (to + // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar + // change color while the other colors stay the same. + backgroundColor: Theme.of(context).colorScheme.inversePrimary, + // Here we take the value from the MyHomePage object that was created by + // the App.build method, and use it to set our appbar title. + title: Text(widget.title), + ), + body: Center( + // Center is a layout widget. It takes a single child and positions it + // in the middle of the parent. + child: Column( + // Column is also a layout widget. It takes a list of children and + // arranges them vertically. By default, it sizes itself to fit its + // children horizontally, and tries to be as tall as its parent. + // + // Column has various properties to control how it sizes itself and + // how it positions its children. Here we use mainAxisAlignment to + // center the children vertically; the main axis here is the vertical + // axis because Columns are vertical (the cross axis would be + // horizontal). + // + // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint" + // action in the IDE, or press "p" in the console), to see the + // wireframe for each widget. + mainAxisAlignment: MainAxisAlignment.center, + children: <Widget>[ + const Text( + 'You have pushed the button this many times:', + ), + Text( + '$_counter', + style: Theme.of(context).textTheme.headlineMedium, + ), + ], + ), + ), + floatingActionButton: FloatingActionButton( + onPressed: _incrementCounter, + tooltip: 'Increment', + child: const Icon(Icons.add), + ), // This trailing comma makes auto-formatting nicer for build methods. + ); + } +} |