App Security Lock

A comprehensive Flutter plugin for implementing app security features including screen lock detection, background timeout, and lifecycle monitoring.

Features

• Screen Lock Detection: Automatically locks the app when the device screen is turned off
• Background Timeout: Locks the app after a specified time in the background
• Lifecycle Monitoring: Tracks app foreground/background state changes
• Cross-platform: Supports both iOS and Android
• Customizable: Flexible configuration options for different security needs

Platform Support

Platform	Support
iOS	✅
Android	✅

Installation

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

dependencies:
  app_security_lock: ^0.0.1

Then run:

flutter pub get

Usage

Basic Setup

import 'package:app_security_lock/app_security_lock.dart';

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final AppSecurityLock _appSecurityLock = AppSecurityLock();

  @override
  void initState() {
    super.initState();
    _initializeSecurityLock();
  }

  void _initializeSecurityLock() async {
    // Initialize the plugin with security settings
    await _appSecurityLock.init(
      isScreenLockEnabled: true,
      isBackgroundLockEnabled: true,
      backgroundTimeout: 30.0, // 30 seconds
    );

    // Set up lifecycle callbacks
    _appSecurityLock.setOnEnterForegroundCallback(() {
      print('App entered foreground');
    });

    _appSecurityLock.setOnEnterBackgroundCallback(() {
      print('App entered background');
    });

    _appSecurityLock.setOnAppLockedCallback(() {
      print('App is locked - show authentication screen');
      _showAuthenticationScreen();
    });

    _appSecurityLock.setOnAppUnlockedCallback(() {
      print('App is unlocked');
    });
  }

  void _showAuthenticationScreen() {
    // Implement your authentication UI here
    // For example, navigate to a biometric authentication screen
  }
}

Configuration Options

// Initialize with all options
await _appSecurityLock.init(
  isScreenLockEnabled: true,    // Lock app when screen turns off
  isBackgroundLockEnabled: true, // Lock app after background timeout
  backgroundTimeout: 60.0,      // Background timeout in seconds
);

Dynamic Configuration

// Enable/disable screen lock detection
_appSecurityLock.setScreenLockEnabled(true);

// Enable/disable background lock
_appSecurityLock.setBackgroundLockEnabled(true);

// Update background timeout (in seconds)
_appSecurityLock.setBackgroundTimeout(45.0);

// Manually lock the app
_appSecurityLock.setLockEnabled(true);

Lifecycle Callbacks

// App enters foreground
_appSecurityLock.setOnEnterForegroundCallback(() {
  // Handle foreground event
});

// App enters background
_appSecurityLock.setOnEnterBackgroundCallback(() {
  // Handle background event
});

// App gets locked
_appSecurityLock.setOnAppLockedCallback(() {
  // Show authentication screen
  Navigator.of(context).push(
    MaterialPageRoute(builder: (context) => AuthenticationScreen()),
  );
});

// App gets unlocked
_appSecurityLock.setOnAppUnlockedCallback(() {
  // App is now accessible
});

Complete Example

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

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final AppSecurityLock _appSecurityLock = AppSecurityLock();
  bool _isLocked = false;
  bool _isScreenLockEnabled = true;
  bool _isBackgroundLockEnabled = true;
  double _backgroundTimeout = 30.0;

  @override
  void initState() {
    super.initState();
    _setupSecurityLock();
  }

  void _setupSecurityLock() async {
    // Initialize with default settings
    await _appSecurityLock.init(
      isScreenLockEnabled: _isScreenLockEnabled,
      isBackgroundLockEnabled: _isBackgroundLockEnabled,
      backgroundTimeout: _backgroundTimeout,
    );

    // Setup callbacks
    _appSecurityLock.setOnAppLockedCallback(() {
      setState(() {
        _isLocked = true;
      });
    });

    _appSecurityLock.setOnAppUnlockedCallback(() {
      setState(() {
        _isLocked = false;
      });
    });
  }

  void _toggleScreenLock() {
    setState(() {
      _isScreenLockEnabled = !_isScreenLockEnabled;
    });
    _appSecurityLock.setScreenLockEnabled(_isScreenLockEnabled);
  }

  void _toggleBackgroundLock() {
    setState(() {
      _isBackgroundLockEnabled = !_isBackgroundLockEnabled;
    });
    _appSecurityLock.setBackgroundLockEnabled(_isBackgroundLockEnabled);
  }

  void _updateTimeout(double value) {
    setState(() {
      _backgroundTimeout = value;
    });
    _appSecurityLock.setBackgroundTimeout(_backgroundTimeout);
  }

  @override
  Widget build(BuildContext context) {
    if (_isLocked) {
      return MaterialApp(
        home: Scaffold(
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(Icons.lock, size: 64, color: Colors.red),
                Text('App is Locked', style: TextStyle(fontSize: 24)),
                ElevatedButton(
                  onPressed: () {
                    _appSecurityLock.setLockEnabled(false);
                  },
                  child: Text('Unlock'),
                ),
              ],
            ),
          ),
        ),
      );
    }

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('App Security Lock Demo')),
        body: Padding(
          padding: EdgeInsets.all(16),
          children: [
            SwitchListTile(
              title: Text('Screen Lock Detection'),
              subtitle: Text('Lock app when screen turns off'),
              value: _isScreenLockEnabled,
              onChanged: (value) => _toggleScreenLock(),
            ),
            SwitchListTile(
              title: Text('Background Lock'),
              subtitle: Text('Lock app after background timeout'),
              value: _isBackgroundLockEnabled,
              onChanged: (value) => _toggleBackgroundLock(),
            ),
            ListTile(
              title: Text('Background Timeout'),
              subtitle: Slider(
                value: _backgroundTimeout,
                min: 5.0,
                max: 300.0,
                divisions: 59,
                label: '${_backgroundTimeout.round()}s',
                onChanged: _updateTimeout,
              ),
            ),
            ElevatedButton(
              onPressed: () {
                _appSecurityLock.setLockEnabled(true);
              },
              child: Text('Lock App Manually'),
            ),
          ],
        ),
      ),
    );
  }
}

API Reference

Methods

Method	Description	Parameters
init()	Initialize the plugin	isScreenLockEnabled, isBackgroundLockEnabled, backgroundTimeout
setLockEnabled()	Manually lock/unlock the app	bool enabled
setScreenLockEnabled()	Enable/disable screen lock detection	bool enabled
setBackgroundLockEnabled()	Enable/disable background lock	bool enabled
setBackgroundTimeout()	Set background timeout duration	double timeoutSeconds

Callbacks

Callback	Description
setOnEnterForegroundCallback()	Called when app enters foreground
setOnEnterBackgroundCallback()	Called when app enters background
setOnAppLockedCallback()	Called when app gets locked
setOnAppUnlockedCallback()	Called when app gets unlocked

Platform-Specific Behavior

iOS

• Uses UIApplication lifecycle notifications
• Monitors screen brightness changes for lock detection
• Supports background timeout with timers

Android

• Uses Application.ActivityLifecycleCallbacks
• Monitors screen state with broadcast receivers (ACTION_SCREEN_OFF, ACTION_SCREEN_ON, ACTION_USER_PRESENT)
• Supports background timeout with handlers

License

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

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.