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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

186
android/src/main/kotlin/io/swipelab/ux/FilePlugin.kt
View File

@@ -4,18 +4,31 @@ import android.app.Activity
import android.content.ActivityNotFoundException
import android.content.Context
import android.content.Intent
import android.graphics.Bitmap
import android.media.MediaMetadataRetriever
import android.net.Uri
import android.provider.OpenableColumns
import android.webkit.MimeTypeMap
import androidx.core.content.FileProvider
import io.flutter.embedding.engine.plugins.FlutterPlugin
import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel
import io.flutter.plugin.common.PluginRegistry
import java.io.ByteArrayOutputStream
import java.io.File
import java.io.FileOutputStream
class FilePlugin : NativePlugin, MethodChannel.MethodCallHandler {
class FilePlugin : NativePlugin, MethodChannel.MethodCallHandler,
PluginRegistry.ActivityResultListener {
private var methodChannel: MethodChannel? = null
private var context: Context? = null
private var activity: Activity? = null
private var activityBinding: ActivityPluginBinding? = null
/// Active pick request — set when [handlePick] launches the picker,
/// cleared in [onActivityResult]. Reentrancy is rejected.
private var pendingPickResult: MethodChannel.Result? = null
override fun onAttachedToEngine(binding: FlutterPlugin.FlutterPluginBinding) {
context = binding.applicationContext
@@ -32,16 +45,26 @@ class FilePlugin : NativePlugin, MethodChannel.MethodCallHandler {
override fun onAttachedToActivity(binding: ActivityPluginBinding) {
activity = binding.activity
activityBinding = binding
binding.addActivityResultListener(this)
}
override fun onDetachedFromActivity() {
activityBinding?.removeActivityResultListener(this)
activityBinding = null
activity = null
// If the activity tears down with a request still in flight, settle
// it cleanly rather than leaking the Result.
pendingPickResult?.success(null)
pendingPickResult = null
}
override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
when (call.method) {
"share" -> handleShare(call, result)
"open" -> handleOpen(call, result)
"pick" -> handlePick(call, result)
"videoThumbnail" -> handleVideoThumbnail(call, result)
else -> result.notImplemented()
}
}
@@ -101,6 +124,165 @@ class FilePlugin : NativePlugin, MethodChannel.MethodCallHandler {
}
}
private fun handlePick(call: MethodCall, result: MethodChannel.Result) {
val act = activity
?: return result.error("no_activity", "plugin not attached to an activity", null)
if (pendingPickResult != null) {
return result.error(
"in_progress", "a pick request is already in progress", null
)
}
val mimeTypes = (call.argument<List<*>>("mimeTypes"))
?.filterIsInstance<String>()
?.takeIf { it.isNotEmpty() }
val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
addCategory(Intent.CATEGORY_OPENABLE)
type = if (mimeTypes != null && mimeTypes.size == 1) mimeTypes[0] else "*/*"
if (mimeTypes != null && mimeTypes.size > 1) {
putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes.toTypedArray())
}
addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
}
pendingPickResult = result
try {
act.startActivityForResult(intent, REQUEST_CODE_PICK)
} catch (e: ActivityNotFoundException) {
pendingPickResult = null
result.error("no_picker", "no document picker available: ${e.message}", null)
}
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?): Boolean {
if (requestCode != REQUEST_CODE_PICK) return false
val r = pendingPickResult ?: return true
pendingPickResult = null
if (resultCode != Activity.RESULT_OK) {
r.success(null)
return true
}
val uri = data?.data
if (uri == null) {
r.success(null)
return true
}
val ctx = context
if (ctx == null) {
r.error("no_context", "lost application context", null)
return true
}
try {
val picked = copyUriToCache(ctx, uri)
r.success(picked)
} catch (e: Throwable) {
r.error("copy_failed", "could not stream-copy URI to cache: ${e.message}", null)
}
return true
}
/// Stream-copies the [uri]'s content (an SAF document) to a fresh file
/// in `cacheDir/ux_pick/`. Returns a map ready for the platform-channel
/// reply. Crucially, the bytes never live in JVM heap — they flow
/// `InputStream → 8KB buffer → FileOutputStream`.
private fun copyUriToCache(ctx: Context, uri: Uri): Map<String, Any?> {
val resolver = ctx.contentResolver
var displayName: String? = null
var size: Long? = null
resolver.query(
uri,
arrayOf(OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE),
null, null, null,
)?.use { c ->
if (c.moveToFirst()) {
val nameIdx = c.getColumnIndex(OpenableColumns.DISPLAY_NAME)
if (nameIdx >= 0 && !c.isNull(nameIdx)) displayName = c.getString(nameIdx)
val sizeIdx = c.getColumnIndex(OpenableColumns.SIZE)
if (sizeIdx >= 0 && !c.isNull(sizeIdx)) size = c.getLong(sizeIdx)
}
}
val safeName = (displayName ?: "picked").replace(Regex("[\\\\/:*?\"<>|]"), "_")
val mimeType = resolver.getType(uri)
val dir = File(ctx.cacheDir, "ux_pick").apply { mkdirs() }
val out = File(dir, "${System.currentTimeMillis()}_$safeName")
var copied = 0L
resolver.openInputStream(uri).use { input ->
requireNotNull(input) { "openInputStream returned null for $uri" }
FileOutputStream(out).use { output ->
val buf = ByteArray(8 * 1024)
while (true) {
val n = input.read(buf)
if (n <= 0) break
output.write(buf, 0, n)
copied += n
}
}
}
return mapOf(
"path" to out.absolutePath,
"name" to displayName,
"mimeType" to mimeType,
"size" to (size ?: copied),
)
}
private fun handleVideoThumbnail(call: MethodCall, result: MethodChannel.Result) {
val path = call.argument<String>("path")
?: return result.error("bad_args", "path is required", null)
val atMs = (call.argument<Number>("atMs") ?: 0).toLong()
val maxWidth = (call.argument<Number>("maxWidth") ?: 320).toInt()
val retriever = MediaMetadataRetriever()
try {
retriever.setDataSource(path)
// OPTION_CLOSEST_SYNC is fastest — picks the nearest keyframe.
// For atMs=0 this is the first frame, which is what callers
// typically want for a thumbnail.
val frame = retriever.getFrameAtTime(
atMs * 1000L, // µs
MediaMetadataRetriever.OPTION_CLOSEST_SYNC,
)
if (frame == null) {
result.success(null)
return
}
val scaled = scaleBitmap(frame, maxWidth)
try {
val baos = ByteArrayOutputStream()
scaled.compress(Bitmap.CompressFormat.PNG, 100, baos)
result.success(
mapOf<String, Any?>(
"png" to baos.toByteArray(),
"width" to scaled.width,
"height" to scaled.height,
),
)
} finally {
if (scaled !== frame) scaled.recycle()
frame.recycle()
}
} catch (e: Throwable) {
result.error("decode_failed", "could not extract frame: ${e.message}", null)
} finally {
try { retriever.release() } catch (_: Throwable) {}
}
}
/// Scales [bitmap] so its longer edge equals [maxWidth] while
/// preserving aspect ratio. Returns the original if already small enough.
private fun scaleBitmap(bitmap: Bitmap, maxWidth: Int): Bitmap {
val w = bitmap.width
val h = bitmap.height
val longEdge = maxOf(w, h)
if (longEdge <= maxWidth) return bitmap
val scale = maxWidth.toFloat() / longEdge
val outW = (w * scale).toInt().coerceAtLeast(1)
val outH = (h * scale).toInt().coerceAtLeast(1)
return Bitmap.createScaledBitmap(bitmap, outW, outH, true)
}
private fun inferMime(supplied: String?, path: String): String {
if (!supplied.isNullOrBlank() && supplied != "application/octet-stream") {
return supplied
@@ -116,6 +298,8 @@ class FilePlugin : NativePlugin, MethodChannel.MethodCallHandler {
}
companion object {
private const val REQUEST_CODE_PICK = 0xC51 // arbitrary, namespaced
private val textExtensions = setOf(
"dart", "swift", "kt", "kts", "java", "scala", "groovy",
"py", "rb", "php", "pl", "sh", "bash", "zsh", "fish",

2
example/pubspec.lock
View File

@@ -502,7 +502,7 @@ packages:
path: ".."
relative: true
source: path
version: "0.7.0"
version: "0.8.0"
vector_math:
dependency: transitive
description:

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

94
lib/src/file.dart
View File

@@ -1,7 +1,43 @@
import 'dart:typed_data';
import 'dart:ui' show Rect;
import 'package:flutter/services.dart';
/// A single frame extracted from a video file. [pngBytes] is the encoded
/// PNG ready to embed in a thumbnail proto / paint via `Image.memory`;
/// [width] / [height] describe the encoded image, which may be smaller
/// than the source video due to the `maxWidth` constraint at extraction.
class UxVideoThumbnail {
const UxVideoThumbnail({
required this.pngBytes,
required this.width,
required this.height,
});
final Uint8List pngBytes;
final int width;
final int height;
}
/// A file the user picked. [path] is on local disk and readable by
/// `dart:io File` — for Android content:// URIs the native side
/// stream-copies the source to the app's cache; for iOS/macOS picks the
/// file is copied to the temp dir so the path is stable after the picker
/// dismisses. Bytes are never marshalled across the platform channel.
class UxPickedFile {
const UxPickedFile({
required this.path,
this.name,
this.mimeType,
this.size,
});
final String path;
final String? name;
final String? mimeType;
final int? size;
}
class UxFile {
UxFile._();
@@ -67,4 +103,62 @@ class UxFile {
});
return result ?? false;
}
/// Present the system file picker. Returns the picked file's local-disk
/// path (and optional metadata), or null if the user cancelled.
///
/// File content is **never** marshalled across the platform channel —
/// the native side only ships back the path. Use `dart:io` to read the
/// file: `File(picked.path).openRead()` etc.
///
/// [mimeTypes] filters the picker. Each entry can be a concrete type
/// (`image/png`), a wildcard (`image/*`), or `*/*`. Null = `[*/*]`.
/// Note: Apple platforms map MIME → UTType internally; common types
/// (`image/*`, `video/*`, `application/pdf`) work on all three. For
/// Apple-specific types prefer concrete MIME like `image/jpeg` over
/// wildcards.
static Future<UxPickedFile?> pick({
List<String>? mimeTypes,
}) async {
final result = await _channel.invokeMapMethod<String, Object?>('pick', {
if (mimeTypes != null) 'mimeTypes': mimeTypes,
});
if (result == null) return null;
final path = result['path'] as String?;
if (path == null) return null;
return UxPickedFile(
path: path,
name: result['name'] as String?,
mimeType: result['mimeType'] as String?,
size: (result['size'] as num?)?.toInt(),
);
}
/// Extract a single frame from the video at [path]. Returns null if the
/// platform's media decoder couldn't open the file (unsupported codec /
/// corrupt / not actually a video).
///
/// [atMs] picks the frame timestamp in milliseconds (default 0 = first
/// available keyframe). [maxWidth] caps the output's longer edge while
/// preserving aspect ratio.
static Future<UxVideoThumbnail?> videoThumbnail({
required String path,
int atMs = 0,
int maxWidth = 320,
}) async {
final result = await _channel.invokeMapMethod<String, Object?>(
'videoThumbnail',
<String, Object?>{
'path': path,
'atMs': atMs,
'maxWidth': maxWidth,
},
);
if (result == null) return null;
final bytes = result['png'] as Uint8List?;
final width = (result['width'] as num?)?.toInt();
final height = (result['height'] as num?)?.toInt();
if (bytes == null || width == null || height == null) return null;
return UxVideoThumbnail(pngBytes: bytes, width: width, height: height);
}
}

142
macos/Classes/FilePlugin.swift
View File

@@ -1,5 +1,7 @@
import FlutterMacOS
import AppKit
import AVFoundation
import CoreServices
import FlutterMacOS
import Quartz
public class FilePlugin: NSObject, NativePlugin {
@@ -15,12 +17,131 @@ 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
generator.maximumSize = CGSize(width: CGFloat(maxWidth), height: 0)
generator.requestedTimeToleranceBefore = CMTime(value: 500, timescale: 1000)
generator.requestedTimeToleranceAfter = CMTime(value: 500, timescale: 1000)
DispatchQueue.global(qos: .userInitiated).async {
do {
let cgImage = try generator.copyCGImage(
at: CMTime(value: Int64(atMs) * 1000, timescale: 1_000_000),
actualTime: nil,
)
let bitmap = NSBitmapImageRep(cgImage: cgImage)
guard let png = bitmap.representation(using: .png, properties: [:]) else {
DispatchQueue.main.async { result(nil) }
return
}
let reply: [String: Any] = [
"png": FlutterStandardTypedData(bytes: png),
"width": cgImage.width,
"height": cgImage.height,
]
DispatchQueue.main.async { result(reply) }
} catch {
DispatchQueue.main.async {
result(FlutterError(
code: "decode_failed",
message: "could not extract frame: \(error.localizedDescription)",
details: nil,
))
}
}
}
}
private func handlePick(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
let args = call.arguments as? [String: Any]
let mimeTypes = (args?["mimeTypes"] as? [String]) ?? []
let panel = NSOpenPanel()
panel.canChooseFiles = true
panel.canChooseDirectories = false
panel.allowsMultipleSelection = false
panel.resolvesAliases = true
let utis = utiStrings(forMimeTypes: mimeTypes)
// Empty / `public.data` only means "any" — leave allowed types unset
// so users can pick any file.
if !(utis.count == 1 && utis[0] == kUTTypeData as String) {
// `allowedFileTypes` accepts both UTI strings and bare file
// extensions. Deprecated on macOS 12+ but still functional.
panel.allowedFileTypes = utis
}
let host = UxWindow.flutterView?.window
let completion: (NSApplication.ModalResponse) -> Void = { response in
guard response == .OK, let url = panel.url 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,
])
}
if let host = host {
panel.beginSheetModal(for: host, completionHandler: completion)
} else {
panel.begin(completionHandler: completion)
}
}
/// Maps Dart-side MIME strings to legacy UTI strings (CoreServices,
/// macOS 10.15-compatible). Wildcards and unknown MIMEs degrade to
/// `public.data`.
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 handleShare(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
guard let args = call.arguments as? [String: Any],
let path = args["path"] as? String else {
@@ -77,6 +198,19 @@ public class FilePlugin: NSObject, NativePlugin {
}
}
/// MIME-type lookup from a filename extension via the legacy UTI machinery
/// (macOS 10.15 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
}
private final class UxQLPreviewResponder: NSView, QLPreviewPanelDataSource {
let url: URL
private weak var previousFirstResponder: NSResponder?