// // ItemProviderLoader.swift // MastodonCore // // Created by MainasuK Cirno on 2021-3-18. // import Foundation import Combine import MobileCoreServices import PhotosUI import MastodonSDK // load image with low memory usage // Refs: https://christianselig.com/2020/09/phpickerviewcontroller-efficiently/ public enum ItemProviderLoader { public static func loadImageData(from result: PHPickerResult) -> Future { loadImageData(from: result.itemProvider) } public static func loadImageData(from itemProvider: NSItemProvider) -> Future { Future { promise in itemProvider.loadFileRepresentation(forTypeIdentifier: UTType.image.identifier) { url, error in if let error = error { promise(.failure(error)) return } guard let url = url else { promise(.success(nil)) return } let sourceOptions = [kCGImageSourceShouldCache: false] as CFDictionary guard let source = CGImageSourceCreateWithURL(url as CFURL, sourceOptions) else { return } #if APP_EXTENSION let maxPixelSize: Int = 4096 // not limit but may upload fail #else let maxPixelSize: Int = 1536 // fit 120MB RAM limit #endif let downsampleOptions: [CFString: Any] = [ kCGImageSourceCreateThumbnailFromImageAlways: true, kCGImageSourceCreateThumbnailWithTransform: true, kCGImageSourceThumbnailMaxPixelSize: maxPixelSize, ] guard let cgImage = CGImageSourceCreateThumbnailAtIndex(source, 0, downsampleOptions as CFDictionary) else { // fallback to loadItem when create thumbnail failure itemProvider.loadItem(forTypeIdentifier: UTType.image.identifier, options: nil) { image, error in if let error = error { promise(.failure(error)) } guard let image = image as? UIImage, let data = image.jpegData(compressionQuality: 0.75) else { promise(.success(nil)) assertionFailure() return } let file = Mastodon.Query.MediaAttachment.jpeg(data) promise(.success(file)) } // end itemProvider.loadItem return } let data = NSMutableData() guard let imageDestination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else { promise(.success(nil)) return } let isPNG: Bool = { guard let utType = cgImage.utType else { return false } return (utType as String) == UTType.png.identifier }() let destinationProperties = [ kCGImageDestinationLossyCompressionQuality: isPNG ? 1.0 : 0.75 ] as CFDictionary CGImageDestinationAddImage(imageDestination, cgImage, destinationProperties) CGImageDestinationFinalize(imageDestination) let file = Mastodon.Query.MediaAttachment.jpeg(data as Data) promise(.success(file)) } } } } extension ItemProviderLoader { public static func loadVideoData(from result: PHPickerResult) -> Future { loadVideoData(from: result.itemProvider) } public static func loadVideoData(from itemProvider: NSItemProvider) -> Future { Future { promise in itemProvider.loadFileRepresentation(forTypeIdentifier: UTType.movie.identifier) { url, error in if let error = error { promise(.failure(error)) return } guard let url = url else { promise(.success(nil)) return } let fileName = UUID().uuidString let tempDirectoryURL = FileManager.default.temporaryDirectory let fileURL = tempDirectoryURL.appendingPathComponent(fileName).appendingPathExtension(url.pathExtension) do { try FileManager.default.createDirectory(at: tempDirectoryURL, withIntermediateDirectories: true, attributes: nil) try FileManager.default.copyItem(at: url, to: fileURL) let file = Mastodon.Query.MediaAttachment.other(fileURL, fileExtension: fileURL.pathExtension, mimeType: UTType.movie.preferredMIMEType ?? "video/mp4") promise(.success(file)) } catch { promise(.failure(error)) } } } } }