The Counter App with a prints() functions highlighting the system & user events

counter_app_with_prints.dart

//
import 'package:flutter/foundation.dart';
import 'package:flutter/material.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: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({super.key, this.title}) {
    if (kDebugMode) {
      print(
          ">>>>>>>>>>>>>>>>>>>>>>>>>   MyHomePage being created. Constructor called.");
    }
  }
  final String? title;
  @override
  State createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  // constructor
  _MyHomePageState() : super() {
    if (kDebugMode) {
      print(
          ">>>>>>>>>>>>>>>>>>>>>>>>>   _MyHomePageState being created. Constructor called.");
    }
  }
  int _counter = 0;

  @override
  void initState() {
    super.initState();
    if (kDebugMode) {
      print(">>>>>>>>>>>>>>>>>>>>>>>>>   _MyHomePageState initState() called.");
    }
  }

  @override
  Widget build(BuildContext context) {
    if (kDebugMode) {
      print(">>>>>>>>>>>>>>>>>>>>>>>>>   _MyHomePageState build() called!");
    }
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title ?? ''),
      ),
      body: 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: FloatingActionButton(
        onPressed: () {
          if (kDebugMode) {
            print(
                ">>>>>>>>>>>>>>>>>>>>>>>>>   'Floating Blue' button pressed. Function setState() called.");
          }
          setState(() {
            _counter++;
          });
        },
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}