text_button_theme.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// Example of setting app TextButton style/theme from MaterialApp 
/// theme & themeDark

import 'package:flutter/material.dart';

const blue = Colors.blue;
const lightBlue = Color(0xFF64B5F6);
const darkBlue = Color(0xFF0D47A1);
const black = Colors.black87;
const white = Colors.white;
const green = Colors.green; //

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  State<MyApp> createState() => MyAppState();
  
  static MyAppState of(BuildContext context) => 
    context.findAncestorStateOfType<MyAppState>()!;
}

class MyAppState extends State<MyApp> {
  ThemeMode _mode = ThemeMode.light;  
  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData.from(
        colorScheme: ColorScheme.fromSeed(
          seedColor: Colors.blue,
          brightness: Brightness.light,
          //inverseSurface: Colors.green,
          primary: blue, /// ModeWidget bg active color, ActionButton active bgColor
          /// AppBar bgColor
          primaryContainer: blue,
          onPrimary: Colors.white,
          secondary: Colors.grey, /// used in [OfflineSaveIndicator]
          //onBackground: lightBlue,
          onSecondary: white, // FAB Icon color if FABTheme not provided like below
          surface: white, // Mode Widget BoxDecoration color, inactive
          onSurface: black, // Mode Widget Text color
        )
      ).copyWith(
          textButtonTheme: TextButtonThemeData(
            style: TextButton.styleFrom(primary: black)
          )
      ),
      darkTheme: ThemeData.from(
        colorScheme: ColorScheme.fromSeed(
          seedColor: Colors.blue,
          brightness: Brightness.dark,
          //surface: darkBlue,
          //inverseSurface: blue,
          primary: darkBlue,
          primaryContainer: darkBlue,
          onPrimary: white,
          secondary: lightBlue, /// used in [OfflineSaveIndicator]
          onBackground: lightBlue,
          onSecondary: white,
          surface: black, // Mode Widget BoxDecoration color, inactive
          onSurface: white, // Mode Widget Text color
        ),
      ).copyWith(
        textButtonTheme: TextButtonThemeData(
          style: TextButton.styleFrom(primary: white)
        )
      ),
      themeMode: _mode,
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
  
    void toggleBrightness() {
    setState(() {
      _mode = _mode == ThemeMode.light ? ThemeMode.dark : ThemeMode.light;
      print('Mode set: $_mode');
    });
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

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

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

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

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        actions: [
          IconButton(
            icon: const Icon(Icons.lightbulb), 
            onPressed: MyApp.of(context).toggleBrightness
          )
        ]
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
            TextButton(
              onPressed: _incrementCounter,
              child: const Text('The Button'),
            )
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => _openDialog(context),
        tooltip: 'Increment',
        child: const Icon(Icons.help),
      ),
    );
  }
  
  void _openDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Button Colors'),
          content: const SizedBox(
            height:100, 
            child: Center(
              child: Text('Look below')
            )
          ),
          actions: [
            TextButton(
              onPressed: Navigator.of(context).pop,
              child: const Text('Cancel'), 
            ),
            TextButton(
              onPressed: Navigator.of(context).pop,
              child: const Text('Submit'), 
            ),
          ]
        );
      }
    );
  }
}