Privacy Guard

A comprehensive Flutter privacy protection SDK.

Protect your users' sensitive data by preventing screenshots, detecting screen recordings, blurring app switcher previews, and hiding sensitive widgets—all through a clean, unified, platform-aware API.

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Why Privacy Guard?

Most packages solve only one of these problems. Privacy Guard brings them all under one roof with:

• Ready-to-use Widgets: Wrap your app in <PrivacyGuard> to auto-blur your UI in the OS background switcher.
• Platform-Safe Calls: Built-in checks (e.g., isScreenshotDetectionSupported) so your app never crashes on unsupported devices.
• Rich Event Streams: Get exact timestamps and platform details when screenshots or recordings occur.

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Feature Support Matrix

Feature	Android	iOS
Screenshot Prevention	✅	❌
Screenshot Detection	❌	✅
Screen Recording Detection	❌	✅
App Switcher Blur	✅	✅
Sensitive Widget Hiding	✅	✅

(Desktop and Web platforms are not yet supported and will safely throw a PlatformNotSupportedException if called).

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Installation

Add it to your pubspec.yaml:

dependencies:
  privacy_guard: ^0.0.1

Then run:

flutter pub get

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Quick Start

1. Initialize the Service

Before using any features, initialize the service in your main.dart:

import 'package:privacy_guard/privacy_guard.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await PrivacyGuard.initialize(); // <-- Add this
  runApp(MyApp());
}

2. The Easy Way: Wrap your App

Wrap your entire app (or specific sensitive screens) with the PrivacyGuard widget. It automatically listens to app lifecycle events and hides your app's content with a customizable locked screen when it goes into the background (e.g., in the OS recent apps list).

PrivacyGuard(
  child: MaterialApp(
    home: BankingDashboard(),
  ),
)

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Advanced Usage

Prevent Screenshots (Android)

If you are building a banking or secure messaging app, you can completely block screenshots.

// Block screenshots & screen recording
await PrivacyGuard.preventScreenshots();

// Allow them again later
await PrivacyGuard.allowScreenshots();

Detect Screenshots & Recordings (iOS)

iOS doesn't let you block screenshots, but it lets you know when they happen!

if (PrivacyGuard.isScreenshotDetectionSupported) {
  PrivacyGuard.onScreenshot.listen((event) {
    print('Screenshot taken at ${event.timestamp}!');
  });
}

if (PrivacyGuard.isRecordingDetectionSupported) {
  PrivacyGuard.onRecordingStarted.listen((event) => print('Recording started'));
  PrivacyGuard.onRecordingStopped.listen((event) => print('Recording stopped'));
}

Protect Specific UI Elements

Don't want to hide the whole screen? Obscure just the sensitive parts (like account balances or passwords) using SensitiveWidget. Users can tap to reveal or hide the content.

SensitiveWidget(
  child: Text('\$12,345.67', style: TextStyle(fontSize: 32)),
)

Manual App Switcher Blurring

If you aren't using the PrivacyGuard widget, you can manually trigger the blur effect:

await PrivacyGuard.blurAppSwitcher();
// Later...
await PrivacyGuard.removeAppSwitcherBlur();

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FAQ

Q: Why doesn't screenshot prevention work on iOS? A: Apple restricts this at the OS level. No app can completely prevent screenshots on iOS. However, you can detect them using our PrivacyGuard.onScreenshot stream.

Q: Why doesn't screenshot detection work on Android? A: Android doesn't expose a system-level event for this. Instead, Android provides FLAG_SECURE to completely prevent them, which you can use via PrivacyGuard.preventScreenshots().

Q: Can I customize the blur screen? A: Absolutely! The PrivacyGuard widget accepts an overlayWidget parameter so you can show a custom logo or "Locked" UI instead of the default lock icon.

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Contributing

Found a bug or want to add Web/Desktop support? Contributions are always welcome! Feel free to open an issue or submit a pull request.

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.