forked from jsnbuchanan/crowd-funder-for-time-pwa
508 lines
12 KiB
Markdown
508 lines
12 KiB
Markdown
# Camera Implementation Documentation
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## Overview
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This document describes how camera functionality is implemented across the TimeSafari application. The application uses cameras for several purposes:
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1. QR Code scanning for contact sharing and verification
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2. Photo capture for gift records
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3. Profile photo management
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4. Shared photo handling
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5. Image upload and processing
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## Components
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### QRScannerDialog.vue
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Primary component for QR code scanning in web browsers.
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**Key Features:**
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- Uses `qrcode-stream` for web-based QR scanning
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- Supports both front and back cameras
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- Provides real-time camera status feedback
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- Implements error handling with user-friendly messages
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- Includes camera switching functionality
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**Camera Access Flow:**
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1. Checks for camera API availability
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2. Enumerates available video devices
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3. Requests camera permissions
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4. Initializes camera stream with preferred settings
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5. Handles various error conditions with specific messages
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### PhotoDialog.vue
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Component for photo capture and selection.
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**Key Features:**
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- Cross-platform photo capture interface
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- Image cropping capabilities
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- File selection fallback
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- Unified interface for different platforms
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- Progress feedback during upload
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- Comprehensive error handling
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**Camera Access Flow:**
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1. User initiates photo capture
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2. Platform-specific camera access is requested
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3. Image is captured or selected
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4. Optional cropping is performed
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5. Image is processed and uploaded
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6. URL is returned to caller
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### ImageMethodDialog.vue
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Component for selecting image input method.
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**Key Features:**
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- Multiple input methods (camera, file upload, URL)
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- Unified interface for image selection
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- Integration with PhotoDialog for processing
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- Support for image cropping
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- URL-based image handling
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**Camera Access Flow:**
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1. User selects camera option
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2. PhotoDialog is opened for capture
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3. Captured image is processed
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4. Image is returned to parent component
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### SharedPhotoView.vue
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Component for handling shared photos.
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**Key Features:**
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- Processes incoming shared photos
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- Options to use photo for gifts or profile
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- Image preview and confirmation
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- Server upload integration
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- Temporary storage management
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**Photo Processing Flow:**
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1. Photo is shared to application
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2. Stored temporarily in IndexedDB
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3. User chooses usage (gift/profile)
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4. Image is processed accordingly
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5. Server upload is performed
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### ContactQRScanShowView.vue
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Component for QR code scanning in contact sharing.
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**Key Features:**
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- QR code scanning interface
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- Camera controls (start/stop)
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- Platform-specific implementations
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- Error handling and status feedback
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**Camera Access Flow:**
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1. User initiates scanning
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2. Camera permissions are checked
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3. Camera stream is initialized
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4. QR codes are detected in real-time
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5. Results are processed
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## Services
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### QRScanner Services
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#### WebDialogQRScanner
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Web-based implementation of QR scanning.
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**Key Methods:**
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- `checkPermissions()`: Verifies camera permission status
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- `requestPermissions()`: Requests camera access
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- `isSupported()`: Checks for camera API support
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- Handles various error conditions with specific messages
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#### CapacitorQRScanner
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Native implementation using Capacitor's MLKit.
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**Key Features:**
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- Uses `@capacitor-mlkit/barcode-scanning`
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- Supports both front and back cameras
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- Implements permission management
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- Provides continuous scanning capability
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### Platform Services
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#### WebPlatformService
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Web-specific implementation of platform features.
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**Camera Capabilities:**
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- Uses HTML5 file input with capture attribute for mobile
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- Uses getUserMedia API for desktop webcam access
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- Falls back to file selection if camera unavailable
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- Processes captured images for consistent format
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- Handles both mobile and desktop browser environments
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#### CapacitorPlatformService
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Native implementation using Capacitor.
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**Camera Features:**
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- Uses `Camera.getPhoto()` for native camera access
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- Supports image editing
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- Configures high-quality image capture
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- Handles base64 image processing
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- Provides native camera UI
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#### ElectronPlatformService
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Desktop implementation (currently unimplemented).
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**Status:**
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- Camera functionality not yet implemented
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- Planned to use Electron's media APIs
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- Will support desktop camera access
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## Camera Usage Scenarios
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### Gift Photo Capture
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**Implementation:**
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- Uses PhotoDialog for capture/selection
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- Supports multiple input methods
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- Optional image cropping
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- Server upload with authentication
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- Integration with gift records
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**Flow:**
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1. User initiates photo capture from gift details
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2. ImageMethodDialog presents input options
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3. PhotoDialog handles capture/selection
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4. Image is processed and uploaded
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5. URL is attached to gift record
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### Profile Photo Management
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**Implementation:**
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- Uses same PhotoDialog component
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- Enforces square aspect ratio
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- Requires image cropping
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- Updates user profile settings
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- Handles profile image updates
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**Flow:**
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1. User initiates profile photo update
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2. PhotoDialog opens with cropping enabled
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3. Image is captured/selected
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4. User crops to square aspect ratio
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5. Image is uploaded and profile updated
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### Shared Photo Processing
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**Implementation:**
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- Handles incoming shared photos
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- Temporary storage in IndexedDB
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- Options for photo usage
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- Server upload integration
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- Cleanup after processing
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**Flow:**
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1. Photo is shared to application
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2. Stored temporarily in IndexedDB
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3. SharedPhotoView presents options
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4. User chooses usage (gift/profile)
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5. Image is processed accordingly
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### QR Code Scanning
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**Implementation:**
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- Platform-specific scanning components
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- Real-time camera feed processing
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- QR code detection and validation
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- Contact information processing
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- Error handling and retry
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**Flow:**
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1. User initiates QR scanning
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2. Camera permissions are checked
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3. Camera stream is initialized
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4. QR codes are detected
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5. Contact information is processed
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### QR Code Workflow
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**Implementation Details:**
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The QR code scanning workflow is implemented across multiple components and services to provide a seamless experience for contact sharing and verification. The system supports both web-based and native implementations through platform-specific services.
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#### QR Code Generation
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**Contact QR Codes:**
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- Generated using `qrcode.vue` component
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- Contains encrypted contact information
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- Includes user ID and verification data
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- Supports offline sharing
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- Implements error correction
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**QR Code Format:**
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```json
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{
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"type": "contact",
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"userId": "encrypted_user_id",
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"timestamp": "creation_time",
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"version": "qr_code_version",
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"data": "encrypted_contact_data"
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}
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```
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#### QR Code Scanning Workflow
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**1. Initiation:**
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- User selects "Scan QR Code" option
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- Platform-specific scanner is initialized
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- Camera permissions are verified
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- Appropriate scanner component is loaded
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**2. Platform-Specific Implementation:**
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*Web Implementation:*
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- Uses `qrcode-stream` for real-time scanning
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- Supports both front and back cameras
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- Implements continuous scanning
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- Provides visual feedback for scanning status
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- Handles browser compatibility issues
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*Native Implementation (Capacitor):*
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- Uses `@capacitor-mlkit/barcode-scanning`
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- Leverages native camera capabilities
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- Provides optimized scanning performance
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- Supports multiple barcode formats
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- Implements native permission handling
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**3. Scanning Process:**
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- Camera stream is initialized
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- Real-time frame analysis begins
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- QR codes are detected and decoded
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- Validation of QR code format
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- Processing of contact information
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**4. Contact Processing:**
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- Decryption of contact data
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- Validation of user information
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- Verification of timestamp
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- Check for duplicate contacts
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- Processing of shared data
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**5. Error Handling:**
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- Invalid QR code format
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- Expired QR codes
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- Duplicate contact attempts
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- Network connectivity issues
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- Permission denials
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- Camera access problems
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**6. Success Flow:**
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- Contact information is extracted
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- User is prompted for confirmation
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- Contact is added to user's list
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- Success notification is displayed
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- Camera resources are cleaned up
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#### Security Measures
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**QR Code Security:**
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- Encryption of contact data
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- Timestamp validation
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- Version checking
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- User verification
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- Rate limiting for scans
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**Data Protection:**
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- Secure transmission of contact data
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- Validation of QR code authenticity
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- Prevention of duplicate scans
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- Protection against malicious codes
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- Secure storage of contact information
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#### User Experience
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**Scanning Interface:**
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- Clear visual feedback
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- Camera preview
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- Scanning status indicators
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- Error messages
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- Success confirmations
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**Accessibility:**
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- Support for different screen sizes
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- Clear instructions
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- Error recovery options
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- Alternative input methods
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- Offline capability
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#### Performance Considerations
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**Optimization:**
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- Efficient camera resource usage
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- Quick QR code detection
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- Minimal processing overhead
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- Battery usage optimization
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- Memory management
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**Platform-Specific Optimizations:**
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- Web: Optimized for browser performance
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- Native: Leverages device capabilities
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- Desktop: Efficient resource usage
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- Mobile: Battery and performance balance
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## Platform-Specific Considerations
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### iOS
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- Requires `NSCameraUsageDescription` in Info.plist
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- Supports both front and back cameras
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- Implements proper permission handling
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- Uses native camera UI through Capacitor
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- Handles photo library access
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### Android
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- Requires camera permissions in manifest
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- Supports both front and back cameras
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- Handles permission requests through Capacitor
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- Uses native camera UI
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- Manages photo library access
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### Web
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- Requires HTTPS for camera access
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- Implements fallback mechanisms
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- Handles browser compatibility issues
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- Uses getUserMedia API on desktop
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- Uses file input with capture on mobile
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- Supports multiple input methods
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## Error Handling
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### Common Error Scenarios
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1. No camera found
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2. Permission denied
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3. Camera in use by another application
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4. HTTPS required
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5. Browser compatibility issues
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6. Upload failures
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7. Image processing errors
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### Error Response
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- User-friendly error messages
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- Troubleshooting tips
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- Clear instructions for resolution
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- Platform-specific guidance
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- Graceful fallbacks
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## Security Considerations
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### Permission Management
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- Explicit permission requests
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- Permission state tracking
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- Graceful handling of denied permissions
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- Platform-specific permission handling
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- Secure permission storage
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### Data Handling
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- Secure image processing
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- Proper cleanup of camera resources
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- No persistent storage of camera data
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- Secure server upload
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- Temporary storage management
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## Best Practices
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### Camera Access
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1. Always check for camera availability
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2. Request permissions explicitly
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3. Handle all error conditions
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4. Provide clear user feedback
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5. Implement proper cleanup
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6. Use platform-specific optimizations
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### Performance
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1. Optimize camera resolution
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2. Implement proper resource cleanup
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3. Handle camera switching efficiently
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4. Manage memory usage
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5. Optimize image processing
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6. Handle upload efficiently
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### User Experience
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1. Clear status indicators
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2. Intuitive camera controls
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3. Helpful error messages
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4. Smooth camera switching
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5. Responsive UI feedback
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6. Platform-appropriate UI
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## Future Improvements
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### Planned Enhancements
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1. Implement Electron camera support
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2. Add advanced camera features
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3. Improve error handling
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4. Enhance user feedback
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5. Optimize performance
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6. Add image compression options
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### Known Issues
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1. Electron camera implementation pending
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2. Some browser compatibility limitations
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3. Platform-specific quirks to address
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4. Mobile browser camera access limitations
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5. Image upload performance on slow connections
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## Dependencies
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### Key Packages
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- `@capacitor-mlkit/barcode-scanning`
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- `qrcode-stream`
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- `vue-picture-cropper`
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- `@capacitor/camera`
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- Platform-specific camera APIs
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## Testing
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### Test Scenarios
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1. Permission handling
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2. Camera switching
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3. Error conditions
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4. Platform compatibility
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5. Performance metrics
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6. Upload scenarios
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7. Image processing
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### Test Environment
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- Multiple browsers
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- iOS and Android devices
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- Desktop platforms
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- Various network conditions
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- Different camera configurations
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