cpd_first_demo/lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({super.key, required this.title});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  void _decrementCounter() {
    setState(() {
      _counter--;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: RawKeyboardListener(
        focusNode: FocusNode(),
        autofocus: true,
        onKey: (RawKeyEvent event) {
          if (event.isKeyPressed(LogicalKeyboardKey.keyD)) _decrementCounter();
          if (event.isKeyPressed(LogicalKeyboardKey.keyI)) _incrementCounter();
        },
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              const Text(
                'You have pushed the button this many times:',
              ),
              Text(
                '$_counter',
                style: Theme.of(context).textTheme.headlineMedium,
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: Stack(
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.only(left: 31),
            child: Align(
              alignment: Alignment.bottomLeft,
              child: FloatingActionButton(
                onPressed: _decrementCounter,
                tooltip: 'Decrement',
                child: const Icon(Icons.remove),
              ),
            ),
          ),
          Align(
            alignment: Alignment.bottomRight,
            child: FloatingActionButton(
              onPressed: _incrementCounter,
              tooltip: 'Increment',
              child: const Icon(Icons.add),
            ),
          ),
        ],
      ),
    );
  }
}