Flutter theme code from class 12.1

main.dart

import 'package:flutter/material.dart';
import 'package:theming/components/mybutton.dart';
import 'package:theming/theme/theme.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: lightTheme,
      darkTheme: darkTheme,

      home: const MyHomePage(
        title: 'Flutter Demo Home Page',
      ),
    );
  }
}

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

  final String title;

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

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

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

  @override
  Widget build(BuildContext context) {
    TextTheme base = Theme.of(context).textTheme;

    return Scaffold(
      appBar: AppBar(
        backgroundColor:
            Theme.of(context).colorScheme.error,
        title: Text(
          widget.title,
          style: Theme.of(context).textTheme.bodySmall,
        ),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              "I am special",
              style: Theme.of(
                context,
              ).textTheme.displayLarge?.copyWith(
                color:
                    Theme.of(context).colorScheme.error,
                fontSize: 40,
              ),
            ),
            MyButton(label: 'Press this!'),

            Text(
              'You have pushed the button this many times:',
              style:
                  Theme.of(
                    context,
                  ).textTheme.displayLarge,
            ),
            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.
    );
  }
}

mybutton.dart

// /lib/components/mybutton.dart

import 'package:flutter/material.dart';

class MyButton extends StatelessWidget {
  const MyButton({super.key, required this.label});

  final String label;

  @override
  Widget build(BuildContext context) {
    return OutlinedButton(
      style: ButtonStyle(
        foregroundColor: WidgetStatePropertyAll(
          Colors.yellow,
        ),
        backgroundColor: WidgetStateColor.resolveWith((
          states,
        ) {
          if (states.contains(WidgetState.pressed)) {
            return Colors.yellow;
          }
          return Colors.purpleAccent;
          //Colors.transparent
        }),
        textStyle: WidgetStateProperty.resolveWith((
          Set<WidgetState> states,
        ) {
          if (states.contains(WidgetState.pressed)) {
            return TextStyle(fontSize: 40);
          } else {
            return TextStyle(fontSize: 20);
          }
        }),
      ),
      onPressed: () {},
      child: Text(label),
    );
  }
}

theme.dart

// /lib/theme/theme.dart

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

ThemeData lightTheme = ThemeData(
  brightness: Brightness.light,
  colorScheme: ColorScheme(
    brightness: Brightness.light,
    primary: Colors.blue.shade300,
    onPrimary: Colors.blue.shade800,
    secondary: Colors.lime.shade300,
    onSecondary: Colors.lime.shade800,
    error: Colors.red.shade300,
    onError: Colors.red.shade800,
    surface: Colors.amber.shade300,
    onSurface: Colors.amber.shade800,
  ),
  textTheme: TextTheme(
    displayLarge: GoogleFonts.notoSans(
      fontSize: 70,
      fontWeight: FontWeight.w700,
    ),
    displayMedium: TextStyle(
      fontSize: 50,
      fontWeight: FontWeight.w500,
    ),
    displaySmall: TextStyle(
      fontSize: 40,
      fontWeight: FontWeight.w500,
    ),
    bodyLarge: TextStyle(
      fontSize: 30,
      fontWeight: FontWeight.w300,
    ),
    bodyMedium: TextStyle(
      fontSize: 24,
      fontWeight: FontWeight.w300,
    ),
    bodySmall: TextStyle(
      fontSize: 16,
      fontWeight: FontWeight.w300,
    ),
  ),
);

ThemeData darkTheme = ThemeData(
  brightness: Brightness.dark,
  colorScheme: ColorScheme(
    brightness: Brightness.dark,
    primary: Colors.blue.shade800,
    onPrimary: Colors.blue.shade300,
    secondary: Colors.lime.shade800,
    onSecondary: Colors.lime.shade300,
    error: Colors.red.shade800,
    onError: Colors.red.shade300,
    surface: Colors.amber.shade800,
    onSurface: Colors.amber.shade300,
  ),
  textTheme: TextTheme(
    displayLarge: GoogleFonts.notoSans(
      fontSize: 70,
      fontWeight: FontWeight.w700,
    ),
    displayMedium: TextStyle(
      fontSize: 50,
      fontWeight: FontWeight.w500,
    ),
    displaySmall: TextStyle(
      fontSize: 40,
      fontWeight: FontWeight.w500,
    ),
    bodyLarge: TextStyle(
      fontSize: 30,
      fontWeight: FontWeight.w300,
    ),
    bodyMedium: TextStyle(
      fontSize: 24,
      fontWeight: FontWeight.w300,
    ),
    bodySmall: TextStyle(
      fontSize: 16,
      fontWeight: FontWeight.w300,
    ),
  ),
);

theme.provider.dart

// /lib/theme/theme.provider.dart
import 'package:provider/provider.dart';
import 'package:flutter/material.dart';
import 'package:theming/theme/theme.dart';

class ThemeProvider with ChangeNotifier {
  ThemeData _themeData = lightTheme;

  ThemeData get themeData => _themeData;

  set themeData(ThemeData themeData) {
    _themeData = themeData;
    //update the private internal _themeData
    notifyListeners();
    //tell anyone who is using ThemeProvider themeData
  }

  void toggleTheme() {
    if (_themeData == lightTheme) {
      themeData = darkTheme;
    } else {
      themeData = lightTheme;
    }
  }
}


//mytheme = ThemeProvider.themeData calls get
// ThemeProvider.themeData = 876 calls set