models as design tokens in a theme extension

snippet.dart

// Copyright 2026 Fredrick Allan Grott. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// Modified from m3e_design package
// Copyright (c) 2025 Emily Moonstone
// MIT Licnese

// ignore_for_file: prefer_constructors_over_static_methods

import 'package:flutter/material.dart';
import 'package:material_expressive_collection/src/tokens/m_3_e_custom__shapes.dart';
import 'package:material_expressive_collection/src/tokens/m_3_e_custom_color_tokens.dart';
import 'package:material_expressive_collection/src/tokens/m_3_e_custom_motion.dart';
import 'package:material_expressive_collection/src/tokens/m_3_e_custom_spacing.dart';
import 'package:material_expressive_collection/src/tokens/m_3_e_custom_typography_tokens.dart';

/// Typically it is used in this manner:
///
/// ```dart
/// @override
///  Widget build(BuildContext context) {
///    final light = ColorScheme.fromSeed(
///        seedColor: Colors.purple, brightness: Brightness.light);
///    final dark = ColorScheme.fromSeed(
///        seedColor: Colors.purple, brightness: Brightness.dark);
///    return MaterialApp(
///      title: 'M3E Gallery',
///      theme: light.toM3EThemeData(override: m3eOverride, base: themeDataWithCustomComponentThemes ),
///      darkTheme: dark.toM3EThemeData(),
///      themeMode: _mode,
///      home: GalleryHome(
///        isDark: _mode == ThemeMode.dark,
///        onToggleBrightness: _toggleMode,
///      ),
///      debugShowCheckedModeBanner: false,
///    );
///  }
/// ```
///
/// Typically an m3eOverride is used so as to provide the custom GoogleFont stuff via the
/// text theme and the expressive text themes and ThemeData base to supply the custom 
/// component themes especially if you use FlexColorScheme package to generate 
/// component themes.
@immutable
class M3ETheme extends ThemeExtension<M3ETheme> {
  final M3ECustomColors colors;
  final M3ECustomTypography typography;
  final M3ECustomShapes shapes;
  final M3ECustomSpacing spacing;
  final M3EMotion motion;

  const M3ETheme({
    required this.colors,
    required this.typography,
    required this.shapes,
    required this.spacing,
    required this.motion,
  });