import ImageIOimport QuickLookimport UIKitimport UniformTypeIdentifiers private final class FilePreviewItem: NSObject, QLPreviewItem { var previewItemURL: URL? var previewItemTitle: String?} private final class FilePreviewController: QLPreviewController { var onAppear: (() -> Void)? override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) onAppear?() }} /// Quick Look owns image and document controls, zooming, and source-view transitions.final class T3NativeFilePresentation: NSObject, QLPreviewControllerDataSource, QLPreviewControllerDelegate, UIAdaptivePresentationControllerDelegate { let identifier: String private var controller: UIViewController? private let completion: (Error?) -> Void private weak var sources: T3PresentationSources? private let sourceIdentifier: String private let item = FilePreviewItem() private var loading: Task<Void, Never>? private var dismissRequested = false private var finished = false init(identifier: String, sources: T3PresentationSources, sourceIdentifier: String, completion: @escaping (Error?) -> Void) { self.identifier = identifier self.sources = sources self.sourceIdentifier = sourceIdentifier self.completion = completion super.init() } func present(url: URL, title: String, from presenter: UIViewController) { loading = Task { @MainActor [self] in do { let file = try await Self.prepareFile(url: url, title: title) guard !finished, !Task.isCancelled else { try? FileManager.default.removeItem(at: file.deletingLastPathComponent()) return } item.previewItemURL = file item.previewItemTitle = title let preview = FilePreviewController() preview.delegate = self preview.dataSource = self preview.onAppear = { [weak self] in self?.resumePendingDismissal() } controller = preview presenter.present(preview, animated: !UIAccessibility.isReduceMotionEnabled) { [self] in resumePendingDismissal() } preview.presentationController?.delegate = self } catch { finish(error: error) } } } func dismiss() { dismissRequested = true loading?.cancel() guard !finished else { return } guard let controller else { finish(); return } // Drain Close from viewDidAppear after opening or cancelling an interactive dismissal. // Starting a second modal transition while UIKit is settling the first can strand it. guard !controller.isBeingPresented, !controller.isBeingDismissed else { return } controller.dismiss(animated: !UIAccessibility.isReduceMotionEnabled) { [self] in finish() } } private func resumePendingDismissal() { // Appearance callbacks run before UIKit has cleared the current transition. DispatchQueue.main.async { [weak self] in if self?.dismissRequested == true { self?.dismiss() } } } func numberOfPreviewItems(in controller: QLPreviewController) -> Int { item.previewItemURL == nil ? 0 : 1 } func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem { item } func previewController(_ controller: QLPreviewController, transitionViewFor item: QLPreviewItem) -> UIView? { guard !UIAccessibility.isReduceMotionEnabled else { return nil } return sources?.view(for: sourceIdentifier) } func previewController(_ controller: QLPreviewController, frameFor item: QLPreviewItem, inSourceView view: AutoreleasingUnsafeMutablePointer<UIView?>) -> CGRect { guard !UIAccessibility.isReduceMotionEnabled, let source = sources?.view(for: sourceIdentifier) else { return .zero } view.pointee = source return source.bounds } func previewControllerDidDismiss(_ controller: QLPreviewController) { finish() } func presentationControllerDidDismiss(_ presentationController: UIPresentationController) { finish() } private func finish(error: Error? = nil) { guard !finished else { return } finished = true loading?.cancel() loading = nil if let file = item.previewItemURL { try? FileManager.default.removeItem(at: file.deletingLastPathComponent()) } item.previewItemURL = nil DispatchQueue.main.async { [completion] in completion(error) } } /// Copy original bytes so preview and sharing do not mutate a draft or workspace file. nonisolated private static func prepareFile(url: URL, title: String) async throws -> URL { try Task.checkCancellation() let directory = FileManager.default.temporaryDirectory.appendingPathComponent("t3-preview-\(UUID().uuidString)") try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true) do { let download = directory.appendingPathComponent("original") if url.isFileURL { try FileManager.default.copyItem(at: url, to: download) } else if url.scheme == "data" { try Data(contentsOf: url).write(to: download, options: .atomic) } else { guard ["https", "http"].contains(url.scheme?.lowercased() ?? "") else { throw URLError(.unsupportedURL) } let (temporaryFile, response) = try await URLSession.shared.download(from: url) guard let response = response as? HTTPURLResponse, (200..<300).contains(response.statusCode) else { throw URLError(.badServerResponse) } try FileManager.default.moveItem(at: temporaryFile, to: download) } try Task.checkCancellation() let type: UTType if let image = CGImageSourceCreateWithURL(download as CFURL, nil), CGImageSourceGetCount(image) > 0, let imageType = CGImageSourceGetType(image), let detectedType = UTType(imageType as String) { type = detectedType } else if CGPDFDocument(download as CFURL) != nil { type = .pdf } else { throw URLError(.cannotDecodeContentData) } let filename = URL(fileURLWithPath: title).lastPathComponent as NSString let originalExtension = filename.pathExtension let fileExtension = UTType(filenameExtension: originalExtension) == type ? originalExtension : type.preferredFilenameExtension ?? "png" let stem = filename.deletingPathExtension var name = String(stem.prefix(60)).components(separatedBy: .controlCharacters).joined(separator: "_") while name.utf8.count > 200 { name.removeLast() } let file = directory.appendingPathComponent("\(name.isEmpty ? "Preview" : name).\(fileExtension)") try FileManager.default.moveItem(at: download, to: file) return file } catch { try? FileManager.default.removeItem(at: directory) throw error } }}
import ImageIO
import QuickLook
import UIKit
import UniformTypeIdentifiers
private final class FilePreviewItem: NSObject, QLPreviewItem {
var previewItemURL: URL?
var previewItemTitle: String?
}
private final class FilePreviewController: QLPreviewController {
var onAppear: (() -> Void)?
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
onAppear?()
}
}
/// Quick Look owns image and document controls, zooming, and source-view transitions.
final class T3NativeFilePresentation: NSObject, QLPreviewControllerDataSource,
QLPreviewControllerDelegate, UIAdaptivePresentationControllerDelegate {
let identifier: String
private var controller: UIViewController?
private let completion: (Error?) -> Void
private weak var sources: T3PresentationSources?
private let sourceIdentifier: String
private let item = FilePreviewItem()
private var loading: Task<Void, Never>?
private var dismissRequested = false
private var finished = false
init(identifier: String, sources: T3PresentationSources, sourceIdentifier: String, completion: @escaping (Error?) -> Void) {
self.identifier = identifier
self.sources = sources
self.sourceIdentifier = sourceIdentifier
self.completion = completion
super.init()
}
func present(url: URL, title: String, from presenter: UIViewController) {
loading = Task { @MainActor [self] in
do {
let file = try await Self.prepareFile(url: url, title: title)
guard !finished, !Task.isCancelled else {
try? FileManager.default.removeItem(at: file.deletingLastPathComponent())
return
}
item.previewItemURL = file
item.previewItemTitle = title
let preview = FilePreviewController()
preview.delegate = self
preview.dataSource = self
preview.onAppear = { [weak self] in self?.resumePendingDismissal() }
controller = preview
presenter.present(preview, animated: !UIAccessibility.isReduceMotionEnabled) { [self] in
resumePendingDismissal()
}
preview.presentationController?.delegate = self
} catch {
finish(error: error)
}
}
}
func dismiss() {
dismissRequested = true
loading?.cancel()
guard !finished else { return }
guard let controller else { finish(); return }
// Drain Close from viewDidAppear after opening or cancelling an interactive dismissal.
// Starting a second modal transition while UIKit is settling the first can strand it.
guard !controller.isBeingPresented, !controller.isBeingDismissed else { return }
controller.dismiss(animated: !UIAccessibility.isReduceMotionEnabled) { [self] in finish() }
}
private func resumePendingDismissal() {
// Appearance callbacks run before UIKit has cleared the current transition.
DispatchQueue.main.async { [weak self] in
if self?.dismissRequested == true { self?.dismiss() }
}
}
func numberOfPreviewItems(in controller: QLPreviewController) -> Int { item.previewItemURL == nil ? 0 : 1 }
func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
item
}
func previewController(_ controller: QLPreviewController, transitionViewFor item: QLPreviewItem) -> UIView? {
guard !UIAccessibility.isReduceMotionEnabled else { return nil }
return sources?.view(for: sourceIdentifier)
}
func previewController(_ controller: QLPreviewController, frameFor item: QLPreviewItem,
inSourceView view: AutoreleasingUnsafeMutablePointer<UIView?>) -> CGRect {
guard !UIAccessibility.isReduceMotionEnabled, let source = sources?.view(for: sourceIdentifier) else { return .zero }
view.pointee = source
return source.bounds
}
func previewControllerDidDismiss(_ controller: QLPreviewController) { finish() }
func presentationControllerDidDismiss(_ presentationController: UIPresentationController) { finish() }
private func finish(error: Error? = nil) {
guard !finished else { return }
finished = true
loading?.cancel()
loading = nil
if let file = item.previewItemURL {
try? FileManager.default.removeItem(at: file.deletingLastPathComponent())
}
item.previewItemURL = nil
DispatchQueue.main.async { [completion] in completion(error) }
}
/// Copy original bytes so preview and sharing do not mutate a draft or workspace file.
nonisolated private static func prepareFile(url: URL, title: String) async throws -> URL {
try Task.checkCancellation()
let directory = FileManager.default.temporaryDirectory.appendingPathComponent("t3-preview-\(UUID().uuidString)")
try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
do {
let download = directory.appendingPathComponent("original")
if url.isFileURL {
try FileManager.default.copyItem(at: url, to: download)
} else if url.scheme == "data" {
try Data(contentsOf: url).write(to: download, options: .atomic)
} else {
guard ["https", "http"].contains(url.scheme?.lowercased() ?? "") else {
throw URLError(.unsupportedURL)
}
let (temporaryFile, response) = try await URLSession.shared.download(from: url)
guard let response = response as? HTTPURLResponse, (200..<300).contains(response.statusCode) else {
throw URLError(.badServerResponse)
}
try FileManager.default.moveItem(at: temporaryFile, to: download)
}
try Task.checkCancellation()
let type: UTType
if let image = CGImageSourceCreateWithURL(download as CFURL, nil),
CGImageSourceGetCount(image) > 0, let imageType = CGImageSourceGetType(image),
let detectedType = UTType(imageType as String) {
type = detectedType
} else if CGPDFDocument(download as CFURL) != nil {
type = .pdf
} else {
throw URLError(.cannotDecodeContentData)
}
let filename = URL(fileURLWithPath: title).lastPathComponent as NSString
let originalExtension = filename.pathExtension
let fileExtension = UTType(filenameExtension: originalExtension) == type
? originalExtension : type.preferredFilenameExtension ?? "png"
let stem = filename.deletingPathExtension
var name = String(stem.prefix(60)).components(separatedBy: .controlCharacters).joined(separator: "_")
while name.utf8.count > 200 { name.removeLast() }
let file = directory.appendingPathComponent("\(name.isEmpty ? "Preview" : name).\(fileExtension)")
try FileManager.default.moveItem(at: download, to: file)
return file
} catch {
try? FileManager.default.removeItem(at: directory)
throw error
}
}
}