Flutter Adaptive Assist

A Flutter plugin that provides unified access to platform-specific accessibility settings, enabling developers to create truly adaptive user interfaces that respect system accessibility preferences.

Features

🎨 Monochrome Mode Detection - Detect when users have enabled grayscale/color correction
🎬 Reduce Motion Support - Respond to user preferences for reduced animations
📝 Bold Text Detection - Identify when users prefer bold text (iOS)
🌗 High Contrast Mode - Detect high contrast preferences
📏 Text Scale Factor - Access the system's text size multiplier
📡 Reactive Streams - Listen to real-time changes in accessibility settings
🔒 Type-Safe - Full null-safety support
🧪 Testable - Built with testing in mind

Platform Support

Feature	Android	iOS
Monochrome Mode	✅ (API 21+)	✅ (iOS 13.0+)
Reduce Motion	✅ (API 21+)	✅ (iOS 13.0+)
Bold Text	❌	✅ (iOS 13.0+)
High Contrast	✅ (API 21+)	✅ (iOS 13.0+)
Text Scale Factor	✅ (API 21+)	✅ (iOS 13.0+)

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  flutter_adaptive_assist: ^1.0.0

Then run:

flutter pub get

Usage

Basic Setup

Initialize the plugin early in your app (e.g., in main()):

import 'package:flutter_adaptive_assist/adaptive_assist.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  AdaptiveAssist.ensureInitialized();
  runApp(MyApp());
}

Check Current Settings

// Check individual settings
final isMonochrome = await AdaptiveAssist.getMonochromeModeEnabled();

if (isMonochrome) {
  // Apply monochrome-friendly color scheme
}

// Or get all settings at once (more efficient)
final config = await AdaptiveAssist.getConfig();

if (config.monochromeModeEnabled) {
  // Apply monochrome-friendly colors
}

if (config.reduceMotionEnabled) {
  // Disable or simplify animations
}

if (config.textScaleFactor > 1.5) {
  // Adjust layout for larger text
}

Listen to Changes

@override
void initState() {
  super.initState();
  
  // Listen to monochrome mode changes
  AdaptiveAssist.monochromeModeEnabledStream.listen((isEnabled) {
    setState(() {
      _isMonochrome = isEnabled;
    });
  });
}

Complete Example

import 'package:flutter/material.dart';
import 'package:flutter_adaptive_assist/adaptive_assist.dart';

class AdaptiveHomePage extends StatefulWidget {
  @override
  _AdaptiveHomePageState createState() => _AdaptiveHomePageState();
}

class _AdaptiveHomePageState extends State<AdaptiveHomePage> {
  AdaptiveConfig _config = AdaptiveConfig();

  @override
  void initState() {
    super.initState();
    _loadConfig();
    
    // Listen to changes
    AdaptiveAssist.monochromeModeEnabledStream.listen((enabled) {
      _loadConfig();
    });
  }

  Future<void> _loadConfig() async {
    final config = await AdaptiveAssist.getConfig();
    setState(() {
      _config = config;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Adaptive UI Demo'),
      ),
      body: AnimatedContainer(
        duration: _config.reduceMotionEnabled 
            ? Duration.zero 
            : Duration(milliseconds: 300),
        color: _config.monochromeModeEnabled 
            ? Colors.grey[300] 
            : Colors.blue[100],
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text(
                'Accessibility Status',
                style: TextStyle(
                  fontSize: 20 * _config.textScaleFactor,
                  fontWeight: _config.boldTextEnabled 
                      ? FontWeight.bold 
                      : FontWeight.normal,
                ),
              ),
              SizedBox(height: 20),
              _buildStatusCard('Monochrome Mode', _config.monochromeModeEnabled),
              _buildStatusCard('Reduce Motion', _config.reduceMotionEnabled),
              _buildStatusCard('Bold Text', _config.boldTextEnabled),
              _buildStatusCard('High Contrast', _config.highContrastEnabled),
              _buildStatusCard('Text Scale', '${_config.textScaleFactor.toStringAsFixed(2)}x'),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildStatusCard(String label, dynamic value) {
    return Card(
      margin: EdgeInsets.symmetric(horizontal: 20, vertical: 8),
      child: Padding(
        padding: EdgeInsets.all(16),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text(label),
            Text(
              value.toString(),
              style: TextStyle(fontWeight: FontWeight.bold),
            ),
          ],
        ),
      ),
    );
  }

  @override
  void dispose() {
    // Optional: dispose if you want to clean up
    // AdaptiveAssist.dispose();
    super.dispose();
  }
}

API Reference

AdaptiveAssist

Methods

static void ensureInitialized() - Initialize the plugin (safe to call multiple times)
static Future<bool> getMonochromeModeEnabled() - Check if monochrome mode is enabled
static Future<AdaptiveConfig> getConfig() - Get all accessibility settings at once
static void clearCache() - Force fresh platform queries on next call
static void dispose() - Clean up resources (typically called on app disposal)

Streams

static Stream<bool> monochromeModeEnabledStream - Stream of monochrome mode changes

AdaptiveConfig

A data class containing all accessibility settings:

class AdaptiveConfig {
  final bool reduceMotionEnabled;
  final bool monochromeModeEnabled;
  final bool boldTextEnabled;
  final bool highContrastEnabled;
  final double textScaleFactor;
}

Testing

The plugin is designed to be testable. Use the provided test channel for unit tests:

import 'package:flutter_test/flutter_test.dart';
import 'package:flutter_adaptive_assist/adaptive_assist.dart';

void main() {
  setUp(() {
    AdaptiveAssist.reset();
    
    // Set up mock channel
    final testChannel = MethodChannel('flutter_adaptive_assist');
    AdaptiveAssist.testChannel = testChannel;
    
    // Mock responses
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(testChannel, (call) async {
      if (call.method == 'getMonochromeModeEnabled') {
        return true;
      }
      return null;
    });
  });

  test('getMonochromeModeEnabled returns mocked value', () async {
    final result = await AdaptiveAssist.getMonochromeModeEnabled();
    expect(result, true);
  });
}

Platform-Specific Notes

Android

Monochrome Mode: Checks both Color Correction (Daltonizer) and Color Inversion settings
Reduce Motion: Checks if animation scales are set to very low values (< 0.1)
Bold Text: Not available system-wide on Android (returns false)
High Contrast: Available on Android 5.0+ (API 21)
Minimum SDK: API 21 (Android 5.0 Lollipop)

iOS

Monochrome Mode: Uses UIAccessibility.isGrayscaleEnabled
Reduce Motion: Uses UIAccessibility.isReduceMotionEnabled
Bold Text: Uses UIAccessibility.isBoldTextEnabled
High Contrast: Uses UIAccessibility.isDarkerSystemColorsEnabled (iOS 13.0+)
Text Scale Factor: Maps UIApplication.shared.preferredContentSizeCategory to numeric values
Minimum Version: iOS 13.0

Performance Considerations

The plugin caches values to minimize platform calls
Cache is automatically updated when settings change
Use getConfig() instead of multiple individual calls when you need several values
Streams are broadcast streams - safe to have multiple listeners

Troubleshooting

Stream not emitting values

Make sure you call AdaptiveAssist.ensureInitialized() before subscribing to streams.

Values not updating on Android

Check that your app has the necessary permissions and that ContentObserver registration succeeded (check logs).

iOS notifications not working

Ensure you're testing on a real device, as some accessibility features may not work correctly in the simulator.

Contributing

Contributions are welcome! Please read the contributing guidelines before submitting PRs.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Credits

Developed with ❤️ for the Flutter community.