PhotoConcurrencyManager

A concurrent photo loading and caching manager for iOS that provides efficient photo asset handling with support for both high and low-quality image loading states.

Features

• ✨ Concurrent photo loading with async/await support
• 🎯 Multiple image quality delivery modes (low/high quality)
• 💾 Built-in memory caching
• 🔄 Prefetching support for smooth scrolling
• 📱 iCloud photo access handling
• 🎨 Flexible image loading configurations
• 🏃‍♂️ Performance optimized for scrolling

Installation

Swift Package Manager

Add the following to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/sozohoy/PhotoConcurrencyManager", from: "1.0.0")
]

Usage

Basic Usage

let manager = PhotoConcurrencyManager()

// Request photo library authorization
let isAuthorized = await manager.requestAuthorization()

// Load an image
let stream = manager.loadImage(
    asset: photoAsset,
    targetSize: CGSize(width: 300, height: 300),
    contentMode: .aspectFill,
    configuration: .thumbnail
)

for try await quality in stream {
    switch quality {
    case .low(let image):
        // Handle low quality image (e.g., show as placeholder)
    case .high(let image):
        // Handle high quality image
    }
}

Prefetching Images

// Start prefetching
manager.prefetchImages(
    for: assets,
    targetSize: CGSize(width: 300, height: 300),
    contentMode: .aspectFill,
    configuration: .scrolling
)

// Cancel prefetching when needed
manager.cancelPrefetching(
    for: assets,
    targetSize: CGSize(width: 300, height: 300),
    contentMode: .aspectFill,
    configuration: .scrolling
)

Loading Images While Scrolling

let image = try await manager.loadImageWhenScrolling(
    asset: asset,
    targetSize: CGSize(width: 300, height: 300),
    contentMode: .aspectFill,
    configuration: .scrolling
)

Configuration Options

Image Quality Configuration

The library provides several preset configurations:

// Default configuration for optimal quality/performance balance
.opportunisticFit

// High quality synchronous loading
.highQualitySync

// Fast loading for thumbnails
.thumbnail

// Optimized for scroll performance
.scrolling

Custom Configuration

Create custom configurations by specifying:

• Synchronous/Asynchronous loading
• Delivery mode (fast/opportunistic/high quality)
• Content mode (aspect fit/fill)
• iCloud access mode
• Resize mode
• Version requirements

let customConfig = PhotoImageOptions.Configuration(
    synchronousMode: .async,
    deliveryMode: .highQuality,
    contentMode: .aspectFill,
    iCloudAccessMode: .allowed,
    resizeMode: .exact,
    version: .current
)

Error Handling

The library provides detailed error cases:

public enum ImageLoadingError: Error {
    case loadingFailed(Error)
    case cancelled
    case noImage
    case unauthorized
}

Performance Considerations

• Built-in memory cache management with configurable size limits
• Automatic cache cleanup
• Optimized for scroll performance with dedicated configurations
• Prefetching support for smooth scrolling experiences

Requirements

• iOS 16.0+
• Swift 6.0+
• Xcode 14.0+

License

This library is released under the MIT license. See LICENSE for details.

Contributing

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