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file: add path-only pick + native video thumbnail

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Two new methods on `UxFile`, both designed to keep large file content
out of the platform-channel buffer (the failure mode of file_selector
on Android: a ~200 MB video PUT through the Pigeon codec OOM'd the
JVM via `byte[size]` allocation in `FileSelectorApiImpl`).

`UxFile.pick({mimeTypes})` returns `UxPickedFile?` with `path`, `name`,
`mimeType`, `size`. The platform channel reply carries only the
metadata; bytes never cross.
  - Android: `ACTION_OPEN_DOCUMENT` + `EXTRA_MIME_TYPES`, registered
    as `ActivityResultListener`. On result, stream-copies the SAF
    content URI to `cacheDir/ux_pick/<ts>_<safeName>` via an 8 KB
    buffer (no full-file allocation in JVM heap), returns the cache
    path.
  - iOS: `UIDocumentPickerViewController(documentTypes:in: .import)`
    — `.import` mode copies the picked file into the app's
    Documents/Inbox so the URL is stable. Strong-retained delegate
    (the picker's delegate ref is weak).
  - macOS: `NSOpenPanel` with `allowedFileTypes`. Sheet-modal when a
    Flutter window exists; free-modal otherwise.

`UxFile.videoThumbnail({path, atMs, maxWidth})` returns
`UxVideoThumbnail?` (PNG bytes + dims).
  - Android: `MediaMetadataRetriever.getFrameAtTime(..., OPTION_CLOSEST_SYNC)`,
    `Bitmap.createScaledBitmap` to maxWidth, PNG-encode via
    `ByteArrayOutputStream`, recycle bitmaps in `finally`, release
    retriever in `finally`.
  - iOS: `AVAssetImageGenerator` with `appliesPreferredTrackTransform = true`,
    `maximumSize = (maxWidth, 0)` (preserve aspect), ±500 ms tolerance
    for keyframe alignment, decode on `userInitiated` queue.
  - macOS: same generator, encoded via `NSBitmapImageRep`.

Compatible with the package's existing iOS 13 / macOS 10.15 deployment
targets — uses legacy `kUTType*` + `UTTypeCreatePreferredIdentifierForTag`
instead of `UTType` (iOS 14 / macOS 11).
This commit is contained in:
agra
2026-05-02 13:14:21 +03:00
parent a7735fdbb1
commit afc7e9c872
5 changed files with 581 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

166
ios/Classes/FilePlugin.swift
View File

@@ -1,10 +1,13 @@
import AVFoundation
import Flutter
import MobileCoreServices
import QuickLook
import UIKit
public class FilePlugin: NSObject, NativePlugin {
private var channel: FlutterMethodChannel?
private var previewDataSource: FilePreviewDataSource?
private var pickerDelegate: UxDocumentPickerDelegate?
public func register(with registrar: FlutterPluginRegistrar) {
let c = FlutterMethodChannel(name: "ux/file", binaryMessenger: registrar.messenger())
@@ -16,9 +19,60 @@ public class FilePlugin: NSObject, NativePlugin {
private func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
switch call.method {
case "share": handleShare(call, result: result)
case "open": handleOpen(call, result: result)
default: result(FlutterMethodNotImplemented)
case "share": handleShare(call, result: result)
case "open": handleOpen(call, result: result)
case "pick": handlePick(call, result: result)
case "videoThumbnail": handleVideoThumbnail(call, result: result)
default: result(FlutterMethodNotImplemented)
}
}
private func handleVideoThumbnail(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
guard let args = call.arguments as? [String: Any],
let path = args["path"] as? String else {
return result(FlutterError(code: "bad_args", message: "path is required", details: nil))
}
let atMs = (args["atMs"] as? NSNumber)?.intValue ?? 0
let maxWidth = (args["maxWidth"] as? NSNumber)?.intValue ?? 320
let url = URL(fileURLWithPath: path)
let asset = AVURLAsset(url: url)
let generator = AVAssetImageGenerator(asset: asset)
generator.appliesPreferredTrackTransform = true
// 0 on either axis = preserve aspect ratio at the bound.
generator.maximumSize = CGSize(width: CGFloat(maxWidth), height: 0)
// Tolerate a few hundred ms of slop so we can land on a keyframe.
generator.requestedTimeToleranceBefore = CMTime(value: 500, timescale: 1000)
generator.requestedTimeToleranceAfter = CMTime(value: 500, timescale: 1000)
// Background-thread the decode; method-channel reply marshalls back
// to the platform thread automatically.
DispatchQueue.global(qos: .userInitiated).async {
do {
let cgImage = try generator.copyCGImage(
at: CMTime(value: Int64(atMs) * 1000, timescale: 1_000_000),
actualTime: nil,
)
let uiImage = UIImage(cgImage: cgImage)
guard let png = uiImage.pngData() else {
DispatchQueue.main.async { result(nil) }
return
}
let reply: [String: Any] = [
"png": FlutterStandardTypedData(bytes: png),
"width": Int(uiImage.size.width * uiImage.scale),
"height": Int(uiImage.size.height * uiImage.scale),
]
DispatchQueue.main.async { result(reply) }
} catch {
DispatchQueue.main.async {
result(FlutterError(
code: "decode_failed",
message: "could not extract frame: \(error.localizedDescription)",
details: nil,
))
}
}
}
}
@@ -58,6 +112,58 @@ public class FilePlugin: NSObject, NativePlugin {
}
}
private func handlePick(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
guard let topVC = UxWindow.topViewController else {
return result(FlutterError(code: "no_view", message: "no top view controller", details: nil))
}
let args = call.arguments as? [String: Any]
let mimeTypes = (args?["mimeTypes"] as? [String]) ?? []
let utis = utiStrings(forMimeTypes: mimeTypes)
// `.import` mode copies the picked file into the app's Documents/Inbox
// so the URL is stable after the picker dismisses (matches Android's
// cache-copy semantics).
let picker = UIDocumentPickerViewController(documentTypes: utis, in: .import)
picker.allowsMultipleSelection = false
let delegate = UxDocumentPickerDelegate(result: result) { [weak self] in
self?.pickerDelegate = nil
}
// The delegate is weak on UIDocumentPickerViewController; keep a strong ref.
pickerDelegate = delegate
picker.delegate = delegate
topVC.present(picker, animated: true, completion: nil)
}
/// Maps Dart-side MIME strings (e.g. `image/png`, `image/*`, `*/*`) to
/// legacy UTI strings. Compatible with iOS 13+ (UTType requires 14+).
/// Wildcards and unknown MIMEs degrade to `public.data` (the universal
/// "any data" UTI) so the picker still appears.
private func utiStrings(forMimeTypes mimes: [String]) -> [String] {
if mimes.isEmpty { return [kUTTypeData as String] }
var out: [String] = []
for m in mimes {
if m == "*/*" { return [kUTTypeData as String] }
if m.hasSuffix("/*") {
switch String(m.dropLast(2)) {
case "image": out.append(kUTTypeImage as String)
case "video": out.append(kUTTypeMovie as String)
case "audio": out.append(kUTTypeAudio as String)
case "text": out.append(kUTTypeText as String)
case "application": out.append(kUTTypeData as String)
default: out.append(kUTTypeData as String)
}
continue
}
if let unmanaged = UTTypeCreatePreferredIdentifierForTag(
kUTTagClassMIMEType, m as CFString, nil
) {
out.append(unmanaged.takeRetainedValue() as String)
}
}
return out.isEmpty ? [kUTTypeData as String] : out
}
private func handleOpen(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
guard let args = call.arguments as? [String: Any],
let path = args["path"] as? String else {
@@ -92,6 +198,60 @@ private final class FilePreviewDataSource: NSObject, QLPreviewControllerDataSour
}
}
/// MIME-type lookup from a filename extension via the legacy UTI machinery
/// (iOS 13 compatible).
fileprivate func mimeFromExtension(_ ext: String) -> String? {
guard !ext.isEmpty else { return nil }
guard let uti = UTTypeCreatePreferredIdentifierForTag(
kUTTagClassFilenameExtension, ext as CFString, nil
)?.takeRetainedValue() else { return nil }
guard let mime = UTTypeCopyPreferredTagWithClass(
uti, kUTTagClassMIMEType
)?.takeRetainedValue() else { return nil }
return mime as String
}
/// Picker delegate that converts a [UIDocumentPickerViewController] result
/// into the Dart-side reply map. `.import` mode copies the picked file
/// into the app's Documents/Inbox, so the URL is stable.
private final class UxDocumentPickerDelegate: NSObject, UIDocumentPickerDelegate {
let result: FlutterResult
let onDone: () -> Void
private var settled = false
init(result: @escaping FlutterResult, onDone: @escaping () -> Void) {
self.result = result
self.onDone = onDone
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
guard !settled else { return }
settled = true
defer { onDone() }
guard let url = urls.first else {
result(nil)
return
}
let path = url.path
let attrs = try? FileManager.default.attributesOfItem(atPath: path)
let size = (attrs?[.size] as? NSNumber)?.intValue
let mime = mimeFromExtension(url.pathExtension)
result([
"path": path,
"name": url.lastPathComponent,
"mimeType": mime as Any,
"size": size as Any,
])
}
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
guard !settled else { return }
settled = true
defer { onDone() }
result(nil)
}
}
private final class FileActivityItemSource: NSObject, UIActivityItemSource {
let url: URL
let title: String