mastodon-app-ufficiale-ipho.../MastodonSDK/Sources/MastodonCore/Extension/NSItemProvider.swift

140 lines
5.0 KiB
Swift

//
// NSItemProvider.swift
//
//
// Created by MainasuK on 2021/11/19.
//
import Foundation
import UniformTypeIdentifiers
import MobileCoreServices
import PhotosUI
// load image with low memory usage
// Refs: https://christianselig.com/2020/09/phpickerviewcontroller-efficiently/
extension NSItemProvider {
public struct ImageLoadResult {
public let data: Data
public let type: UTType?
public init(data: Data, type: UTType?) {
self.data = data
self.type = type
}
}
public func loadImageData() async throws -> ImageLoadResult? {
try await withCheckedThrowingContinuation { continuation in
loadFileRepresentation(forTypeIdentifier: UTType.image.identifier) { url, error in
if let error = error {
continuation.resume(with: .failure(error))
return
}
guard let url = url else {
continuation.resume(with: .success(nil))
assertionFailure()
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 = [
kCGImageSourceCreateThumbnailFromImageAlways: true,
kCGImageSourceCreateThumbnailWithTransform: true,
kCGImageSourceThumbnailMaxPixelSize: maxPixelSize,
] as CFDictionary
guard let cgImage = CGImageSourceCreateThumbnailAtIndex(source, 0, downsampleOptions) else {
continuation.resume(with: .success(nil))
return
}
let data = NSMutableData()
guard let imageDestination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else {
continuation.resume(with: .success(nil))
assertionFailure()
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 result = ImageLoadResult(
data: data as Data,
type: cgImage.utType.flatMap { UTType($0 as String) }
)
continuation.resume(with: .success(result))
}
}
}
}
extension NSItemProvider {
public struct VideoLoadResult {
public let url: URL
public let sizeInBytes: UInt64
}
public func loadVideoData() async throws -> VideoLoadResult? {
try await withCheckedThrowingContinuation { continuation in
loadFileRepresentation(forTypeIdentifier: UTType.movie.identifier) { url, error in
if let error = error {
continuation.resume(with: .failure(error))
return
}
guard let url = url,
let attribute = try? FileManager.default.attributesOfItem(atPath: url.path),
let sizeInBytes = attribute[.size] as? UInt64
else {
continuation.resume(with: .success(nil))
assertionFailure()
return
}
do {
let fileURL = try FileManager.default.createTemporaryFileURL(
filename: UUID().uuidString,
pathExtension: url.pathExtension
)
try FileManager.default.copyItem(at: url, to: fileURL)
let result = VideoLoadResult(
url: fileURL,
sizeInBytes: sizeInBytes
)
continuation.resume(with: .success(result))
} catch {
continuation.resume(with: .failure(error))
}
} // end loadFileRepresentation
} // end try await withCheckedThrowingContinuation
} // end func
}