LockView

An Android image viewer with lock functionality, gesture controls, and automatic device-unlock integration that prevents accidental interactions.

Built in collaboration with Claude Code

Motivation for Development

When entering a client's factory for work, a digital contractor ID (an image) is required for access. The process involves opening the contractor ID image, handing the phone to the security guard to scan the barcode on the image, and then having a security sticker applied to the phone's camera. During this procedure, the phone is often accidentally touched, sometimes nearly resulting in the deletion of the contractor ID image or the exposure of personal photos. These issues occur due to accidental gestures triggering the back function or pressing buttons unintentionally. This led to the decision to develop this application, which has successfully resolved this troublesome issue.

Screenshots

Main Screen	Image Selected	Image Scaled	Locked State
Unlocked State	Light Theme	Rotation Mode Enabled	Rotation Action
Locked Control Setting

Features

🔒 Smart Lock System

• Lock Protection: Secure your images with a single tap - all gestures and interactions are disabled when locked
• Auto-Unlock: Automatically unlocks when you unlock your device
• Persistent State: Lock state is maintained across app restarts and screen rotations

🖼️ Advanced Image Viewer

• Gesture Controls: Intuitive pinch-to-zoom, pan, rotation, and double-tap zoom
• Rotation Support: Two-finger rotation gesture with toggle button
• Locked Controls: Optional gesture controls (zoom, pan, rotate) even when locked
• Smart Boundaries: Intelligent pan limits prevent images from moving off-screen
• High Performance: Smooth animations and responsive controls
• Format Support: Works with all common image formats (JPG, PNG, GIF, etc.)

🎨 Customization

• Theme Options: Choose between Light, Dark, or System theme
• Dynamic Colors: Material You support on Android 12+ for personalized theming
• Multi-Language: English and Traditional Chinese with instant language switching
• No Restart Required: Theme and language changes apply immediately

📱 Modern Android Design

• Built with Jetpack Compose and Material 3
• Follows Android best practices and architecture guidelines
• Optimized for Android 7.0 (API 24) through Android 15 (API 36)

Installation

From Google Play Store

From Source

1. Clone the repository:

   git clone https://github.com/zac15987/LockView.git
   cd LockView
   

2. Open the project in Android Studio

3. Build and run:

   • For Windows/WSL: cmd.exe /c "gradlew installDebug"
   • For Mac/Linux: ./gradlew installDebug

APK Installation

1. Download the latest APK from the Releases page
2. Enable "Install from Unknown Sources" in your device settings
3. Install the APK

Usage

1. Select an Image: Tap the "Select Image" button to choose an image from your gallery
2. Lock/Unlock: Use the lock button to secure your image
3. Zoom & Pan: When unlocked, use pinch gestures to zoom and drag to pan
4. Rotate: Use two-finger rotation gesture (toggle with rotation button)
5. Locked Controls: Enable in settings to allow gestures while locked
6. Auto-Unlock: Lock your device and unlock it - the image will automatically unlock
7. Settings: Access theme, language, and locked controls options from the menu

Development

Prerequisites

• Android Studio Ladybug or newer
• JDK 11 or higher
• Android SDK with API 36

Architecture

• UI Framework: Jetpack Compose with Material 3
• Architecture Pattern: MVVM with Repository pattern
• State Management: StateFlow and Compose state
• Dependency Injection: Manual DI with ViewModel factories
• Data Persistence: DataStore Preferences

Building

# Windows/WSL
cmd.exe /c "gradlew assembleDebug"     # Debug build
cmd.exe /c "gradlew assembleRelease"   # Release build

# Mac/Linux
./gradlew assembleDebug
./gradlew assembleRelease

Signing Configuration

For release builds, you'll need to configure signing:

1. Copy keystore.properties.template to keystore.properties:

   cp keystore.properties.template keystore.properties
   

2. Edit keystore.properties with your signing information:

   storePassword=your_keystore_password
   keyPassword=your_key_password
   keyAlias=your_key_alias
   storeFile=path/to/your/keystore.keystore
   

3. Place your keystore file in the specified location

Important: Never commit keystore.properties or your .keystore files to version control. These files are already added to .gitignore for security.

Testing

# Run all tests
cmd.exe /c "gradlew test"

# Run lint checks
cmd.exe /c "gradlew lint"

Contributing

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

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

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

Acknowledgments

• Built with Jetpack Compose
• Image loading by Coil
• Icons from Material Design Icons

Third-Party Libraries

This app uses the following open-source libraries:

ImageViewer for Jetpack Compose

• Author: ZhangKe (0xZhangKe)
• Repository: https://github.com/0xZhangKe/ImageViewer
• License: Apache License 2.0
• Usage: Gesture detection and zoom/pan functionality adapted for LockView's requirements

Android Jetpack Libraries

• AndroidX Core, Lifecycle, Activity Compose
• Jetpack Compose UI & Material 3
• DataStore Preferences
• License: Apache License 2.0

Additional Dependencies

• Coil - Image loading library (Apache License 2.0)
• Accompanist Permissions - Permission handling (Apache License 2.0)

For detailed license information, see docs/licenses/THIRD_PARTY_LICENSES.md

Privacy

LockView respects your privacy:

• No data collection or analytics
• No network permissions required
• Images remain on your device
• No cloud storage or sharing features

Support

For bug reports and feature requests, please open an issue.