m3e_color_scheme 0.0.1

A Flutter package providing AOSP-aligned native color scheme generation and a dynamic_color package mapping fixup for Material 3.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:dynamic_color/dynamic_color.dart';
import 'package:m3e_color_scheme/m3e_color_scheme.dart';

import 'screens/m3e_dropdown_screen.dart';
import 'screens/m3e_button_screen.dart';
import 'screens/m3e_expandable_screen.dart';
import 'screens/m3e_card_screen.dart';
import 'screens/m3e_dismissible_screen.dart';
import 'screens/m3e_floating_toolbar_screen.dart';
import 'screens/m3e_slider_screen.dart';
import 'screens/m3e_progress_indicator_screen.dart';

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

final ValueNotifier<ThemeMode> themeNotifier = ValueNotifier(ThemeMode.system);

class ThemeSettings {
  final Color seedColor;
  final M3EColorVariant variant;
  final double contrastLevel;
  final bool useM3EColorScheme;
  final bool useSystemColor;

  ThemeSettings({
    required this.seedColor,
    required this.variant,
    required this.contrastLevel,
    required this.useM3EColorScheme,
    required this.useSystemColor,
  });

  ThemeSettings copyWith({
    Color? seedColor,
    M3EColorVariant? variant,
    double? contrastLevel,
    bool? useM3EColorScheme,
    bool? useSystemColor,
  }) {
    return ThemeSettings(
      seedColor: seedColor ?? this.seedColor,
      variant: variant ?? this.variant,
      contrastLevel: contrastLevel ?? this.contrastLevel,
      useM3EColorScheme: useM3EColorScheme ?? this.useM3EColorScheme,
      useSystemColor: useSystemColor ?? this.useSystemColor,
    );
  }
}

final ValueNotifier<ThemeSettings> themeSettingsNotifier = ValueNotifier(
  ThemeSettings(
    seedColor: Colors.deepPurple,
    variant: M3EColorVariant.tonalSpot,
    contrastLevel: 0.0,
    useM3EColorScheme: true,
    useSystemColor: true,
  ),
);

final Map<String, Color> seedColors = {
  'Purple': Colors.deepPurple,
  'Indigo': Colors.indigo,
  'Blue': Colors.blue,
  'Teal': Colors.teal,
  'Green': Colors.green,
  'Yellow': Colors.yellow,
  'Orange': Colors.orange,
  'Red': Colors.red,
  'Pink': Colors.pink,
};

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

  @override
  Widget build(BuildContext context) {
    return DynamicColorBuilder(
      builder: (lightDynamic, darkDynamic) {
        return ValueListenableBuilder<ThemeMode>(
          valueListenable: themeNotifier,
          builder: (context, ThemeMode currentMode, _) {
            return ValueListenableBuilder<ThemeSettings>(
              valueListenable: themeSettingsNotifier,
              builder: (context, ThemeSettings settings, _) {
                final systemLightColor = lightDynamic?.primary;
                final systemDarkColor = darkDynamic?.primary;

                final lightSeed =
                    (settings.useSystemColor && systemLightColor != null)
                    ? systemLightColor
                    : settings.seedColor;

                final darkSeed =
                    (settings.useSystemColor && systemDarkColor != null)
                    ? systemDarkColor
                    : settings.seedColor;

                final lightScheme = settings.useM3EColorScheme
                    ? M3EColorScheme.light(
                        seedColor: lightSeed,
                        systemColorScheme: settings.useSystemColor
                            ? lightDynamic
                            : null,
                        variant: settings.variant,
                        contrastLevel: settings.contrastLevel,
                      )
                    : ((settings.useSystemColor && lightDynamic != null)
                          ? lightDynamic
                          : ColorScheme.fromSeed(
                              seedColor: lightSeed,
                              brightness: Brightness.light,
                            ));

                final darkScheme = settings.useM3EColorScheme
                    ? M3EColorScheme.dark(
                        seedColor: darkSeed,
                        systemColorScheme: settings.useSystemColor
                            ? darkDynamic
                            : null,
                        variant: settings.variant,
                        contrastLevel: settings.contrastLevel,
                      )
                    : ((settings.useSystemColor && darkDynamic != null)
                          ? darkDynamic
                          : ColorScheme.fromSeed(
                              seedColor: darkSeed,
                              brightness: Brightness.dark,
                            ));

                return MaterialApp(
                  debugShowCheckedModeBanner: false,
                  title: 'M3E Card List Demo',
                  themeMode: currentMode,
                  theme: ThemeData(
                    colorScheme: lightScheme,
                    useMaterial3: true,
                  ),
                  darkTheme: ThemeData(
                    colorScheme: darkScheme,
                    useMaterial3: true,
                  ),
                  home: const ExampleHomePage(),
                );
              },
            );
          },
        );
      },
    );
  }
}

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

  Widget _buildNavCard(
    BuildContext context, {
    required String title,
    required String subtitle,
    required IconData icon,
    required Widget destination,
  }) {
    final cs = Theme.of(context).colorScheme;
    return Card(
      elevation: 0,
      margin: const EdgeInsets.only(bottom: 16),
      color: cs.surfaceContainer,
      clipBehavior: Clip.antiAlias,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(24)),
      child: InkWell(
        onTap: () {
          Navigator.of(
            context,
          ).push(MaterialPageRoute(builder: (context) => destination));
        },
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Row(
            children: [
              Container(
                padding: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: cs.primaryContainer,
                  shape: BoxShape.circle,
                ),
                child: Icon(icon, color: cs.onPrimaryContainer, size: 28),
              ),
              const SizedBox(width: 20),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      title,
                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 4),
                    Text(
                      subtitle,
                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
                        color: cs.onSurfaceVariant,
                      ),
                    ),
                  ],
                ),
              ),
              Icon(Icons.chevron_right, color: cs.onSurfaceVariant),
            ],
          ),
        ),
      ),
    );
  }

  void _showThemeSettings(BuildContext context) {
    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      backgroundColor: Colors.transparent,
      builder: (context) {
        return const ThemeSettingsSheet();
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Theme.of(context).colorScheme.surfaceContainerLowest,
      appBar: AppBar(
        title: const Text('M3E Component Library'),
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        actions: [
          IconButton(
            icon: const Icon(Icons.palette_outlined),
            onPressed: () => _showThemeSettings(context),
            tooltip: 'Theme Customizer',
          ),
          IconButton(
            icon: Icon(
              Theme.of(context).brightness == Brightness.light
                  ? Icons.dark_mode
                  : Icons.light_mode,
            ),
            onPressed: () {
              themeNotifier.value =
                  Theme.of(context).brightness == Brightness.light
                  ? ThemeMode.dark
                  : ThemeMode.light;
            },
          ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.all(24),
        children: [
          Padding(
            padding: const EdgeInsets.only(bottom: 32, left: 8, right: 8),
            child: Text(
              'Explore the Expressive Component Library built for beautiful and responsive Flutter applications.',
              style: Theme.of(context).textTheme.bodyLarge?.copyWith(
                color: Theme.of(context).colorScheme.onSurfaceVariant,
              ),
            ),
          ),
          _buildNavCard(
            context,
            title: 'M3E Cards',
            subtitle:
                'Standard expressive cards with custom splash states and radius bounds',
            icon: Icons.list_alt_rounded,
            destination: const M3ECardScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Dismissible',
            subtitle:
                'Archive or delete data using robust, highly-damped dismissible lists',
            icon: Icons.swipe_rounded,
            destination: const DismissibleM3EScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Expandable',
            subtitle:
                'Richly animated spring expansion lists covering Columns, Slivers, and ListViews',
            icon: Icons.expand_circle_down_rounded,
            destination: const ExpandableM3EScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Dropdown',
            subtitle:
                'Smooth OverlayPortal powered dropdowns with fluid chip morphing',
            icon: Icons.arrow_drop_down_circle_rounded,
            destination: const DropdownM3EScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Buttons',
            subtitle:
                'Expressive button system with neighbor squish, shape morphing, and overflow management',
            icon: Icons.smart_button_rounded,
            destination: const ButtonM3EScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Floating Toolbar',
            subtitle:
                'Expressive floating toolbars with morphing FAB and exit-always scroll physics',
            icon: Icons.subtitles_rounded,
            destination: const FloatingToolbarM3EScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Slider',
            subtitle:
                'Premium expressive sliders with dual-thumb ranges, ticks, custom decorations & haptics',
            icon: Icons.linear_scale_rounded,
            destination: const M3ESliderScreen(),
          ),
          _buildNavCard(
            context,
            title: 'M3E Progress Indicators',
            subtitle:
                'Expressive progress indicators including standard and wavy linear/circular rings',
            icon: Icons.hourglass_empty_rounded,
            destination: const M3EProgressIndicatorScreen(),
          ),
        ],
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final cs = theme.colorScheme;

    return ValueListenableBuilder<ThemeSettings>(
      valueListenable: themeSettingsNotifier,
      builder: (context, settings, _) {
        return Container(
          padding: const EdgeInsets.fromLTRB(24, 16, 24, 32),
          decoration: BoxDecoration(
            color: cs.surfaceContainerHigh,
            borderRadius: const BorderRadius.vertical(top: Radius.circular(28)),
          ),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Center(
                child: Container(
                  width: 32,
                  height: 4,
                  decoration: BoxDecoration(
                    color: cs.outlineVariant,
                    borderRadius: BorderRadius.circular(2),
                  ),
                ),
              ),
              const SizedBox(height: 20),
              Text(
                'Theme Settings',
                style: theme.textTheme.titleLarge?.copyWith(
                  fontWeight: FontWeight.bold,
                ),
              ),
              const SizedBox(height: 16),

              SwitchListTile(
                contentPadding: EdgeInsets.zero,
                title: const Text('Enable M3E Color Scheme'),
                subtitle: const Text('AOSP ColorSpec2026 overrides'),
                value: settings.useM3EColorScheme,
                onChanged: (val) {
                  themeSettingsNotifier.value = settings.copyWith(
                    useM3EColorScheme: val,
                  );
                },
              ),

              SwitchListTile(
                contentPadding: EdgeInsets.zero,
                title: const Text('Use System Dynamic Colors'),
                subtitle: const Text(
                  'Syncs with wallpaper colors if supported',
                ),
                value: settings.useSystemColor,
                onChanged: (val) {
                  themeSettingsNotifier.value = settings.copyWith(
                    useSystemColor: val,
                  );
                },
              ),

              if (!settings.useSystemColor) ...[
                const SizedBox(height: 12),
                Text('Manual Seed Color', style: theme.textTheme.titleSmall),
                const SizedBox(height: 8),
                SizedBox(
                  height: 48,
                  child: ListView(
                    scrollDirection: Axis.horizontal,
                    children: seedColors.entries.map((entry) {
                      final isSelected = settings.seedColor == entry.value;
                      return Padding(
                        padding: const EdgeInsets.only(right: 12),
                        child: GestureDetector(
                          onTap: () {
                            themeSettingsNotifier.value = settings.copyWith(
                              seedColor: entry.value,
                            );
                          },
                          child: Container(
                            width: 38,
                            height: 38,
                            decoration: BoxDecoration(
                              color: entry.value,
                              shape: BoxShape.circle,
                              border: isSelected
                                  ? Border.all(color: cs.onSurface, width: 3)
                                  : null,
                            ),
                          ),
                        ),
                      );
                    }).toList(),
                  ),
                ),
              ],

              if (settings.useM3EColorScheme) ...[
                const SizedBox(height: 16),
                Row(
                  children: [
                    const Text('Color Variant: '),
                    const Spacer(),
                    DropdownButton<M3EColorVariant>(
                      value: settings.variant,
                      onChanged: (val) {
                        if (val != null) {
                          themeSettingsNotifier.value = settings.copyWith(
                            variant: val,
                          );
                        }
                      },
                      items: M3EColorVariant.values.map((v) {
                        return DropdownMenuItem(value: v, child: Text(v.name));
                      }).toList(),
                    ),
                  ],
                ),
                const SizedBox(height: 12),
                Row(
                  children: [
                    const Text('Contrast Level: '),
                    Expanded(
                      child: Slider(
                        value: settings.contrastLevel,
                        min: -1.0,
                        max: 1.0,
                        divisions: 8,
                        label: settings.contrastLevel.toStringAsFixed(2),
                        onChanged: (val) {
                          themeSettingsNotifier.value = settings.copyWith(
                            contrastLevel: val,
                          );
                        },
                      ),
                    ),
                    Text(settings.contrastLevel.toStringAsFixed(2)),
                  ],
                ),
              ],
            ],
          ),
        );
      },
    );
  }
}