Overhaul and migrate MediaStore

app/android/app/src/main/kotlin/com/nkming/nc_photos/MainActivity.kt

@@ -9,12 +9,6 @@ import io.flutter.plugin.common.MethodChannel
 class MainActivity : FlutterActivity() {
 	override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
 		super.configureFlutterEngine(flutterEngine)
-		MethodChannel(
-			flutterEngine.dartExecutor.binaryMessenger,
-			MediaStoreChannelHandler.CHANNEL
-		).setMethodCallHandler(
-			MediaStoreChannelHandler(this)
-		)
 		MethodChannel(
 			flutterEngine.dartExecutor.binaryMessenger,
 			SelfSignedCertChannelHandler.CHANNEL

app/android/app/src/main/kotlin/com/nkming/nc_photos/MediaStoreChannelHandler.kt

@@ -1,83 +0,0 @@
-package com.nkming.nc_photos
-
-import android.app.Activity
-import com.nkming.nc_photos.plugin.MediaStoreUtil
-import com.nkming.nc_photos.plugin.PermissionException
-import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel
-
-/*
- * Save downloaded item on device
- *
- * Methods:
- * Write binary content to a file in the Download directory. Return the Uri to
- * the file
- * fun saveFileToDownload(fileName: String, content: ByteArray): String
- */
-class MediaStoreChannelHandler(activity: Activity) :
-	MethodChannel.MethodCallHandler {
-	companion object {
-		@JvmStatic
-		val CHANNEL = "com.nkming.nc_photos/media_store"
-	}
-
-	override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
-		when (call.method) {
-			"saveFileToDownload" -> {
-				try {
-					saveFileToDownload(
-						call.argument("fileName")!!,
-						call.argument("content")!!,
-						result
-					)
-				} catch (e: Throwable) {
-					result.error("systemException", e.message, null)
-				}
-			}
-
-			"copyFileToDownload" -> {
-				try {
-					copyFileToDownload(
-						call.argument("toFileName")!!,
-						call.argument("fromFilePath")!!,
-						result
-					)
-				} catch (e: Throwable) {
-					result.error("systemException", e.message, null)
-				}
-			}
-
-			else -> result.notImplemented()
-		}
-	}
-
-	private fun saveFileToDownload(
-		fileName: String, content: ByteArray, result: MethodChannel.Result
-	) {
-		try {
-			val uri =
-				MediaStoreUtil.saveFileToDownload(_context, fileName, content)
-			result.success(uri.toString())
-		} catch (e: PermissionException) {
-			PermissionHandler.ensureWriteExternalStorage(_activity)
-			result.error("permissionError", "Permission not granted", null)
-		}
-	}
-
-	private fun copyFileToDownload(
-		toFileName: String, fromFilePath: String, result: MethodChannel.Result
-	) {
-		try {
-			val uri = MediaStoreUtil.copyFileToDownload(
-				_context, toFileName, fromFilePath
-			)
-			result.success(uri.toString())
-		} catch (e: PermissionException) {
-			PermissionHandler.ensureWriteExternalStorage(_activity)
-			result.error("permissionError", "Permission not granted", null)
-		}
-	}
-
-	private val _activity = activity
-	private val _context get() = _activity
-}

app/android/app/src/main/kotlin/com/nkming/nc_photos/PermissionHandler.kt

@@ -1,29 +0,0 @@
-package com.nkming.nc_photos
-
-import android.Manifest
-import android.app.Activity
-import android.content.pm.PackageManager
-import androidx.core.app.ActivityCompat
-import androidx.core.content.ContextCompat
-
-private const val PERMISSION_REQUEST_CODE = 11011
-
-class PermissionHandler {
-	companion object {
-		fun ensureWriteExternalStorage(activity: Activity): Boolean {
-			return if (ContextCompat.checkSelfPermission(
-					activity, Manifest.permission.WRITE_EXTERNAL_STORAGE
-				) != PackageManager.PERMISSION_GRANTED
-			) {
-				ActivityCompat.requestPermissions(
-					activity,
-					arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE),
-					PERMISSION_REQUEST_CODE
-				)
-				false
-			} else {
-				true
-			}
-		}
-	}
-}

app/lib/download_handler.dart

@@ -16,6 +16,7 @@ import 'package:nc_photos/mobile/platform.dart'
 import 'package:nc_photos/platform/k.dart' as platform_k;
 import 'package:nc_photos/snack_bar_manager.dart';
 import 'package:nc_photos/use_case/download_file.dart';
+import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 import 'package:tuple/tuple.dart';
 
 class DownloadHandler {

app/lib/exception.dart

@@ -34,22 +34,6 @@ class ApiException implements Exception {
   final dynamic message;
 }
 
-/// Platform permission is not granted by user
-class PermissionException implements Exception {
-  PermissionException([this.message]);
-
-  @override
-  toString() {
-    if (message == null) {
-      return "PermissionException";
-    } else {
-      return "PermissionException: $message";
-    }
-  }
-
-  final dynamic message;
-}
-
 /// The Nextcloud base URL address is invalid
 class InvalidBaseUrlException implements Exception {
   InvalidBaseUrlException([this.message]);

app/lib/mobile/android/media_store.dart

@@ -1,44 +0,0 @@
-import 'dart:typed_data';
-
-import 'package:flutter/services.dart';
-import 'package:nc_photos/exception.dart';
-
-class MediaStore {
-  static Future<String> saveFileToDownload(
-      String fileName, Uint8List fileContent) async {
-    try {
-      return (await _channel
-          .invokeMethod<String>("saveFileToDownload", <String, dynamic>{
-        "fileName": fileName,
-        "content": fileContent,
-      }))!;
-    } on PlatformException catch (e) {
-      if (e.code == _exceptionCodePermissionError) {
-        throw PermissionException();
-      } else {
-        rethrow;
-      }
-    }
-  }
-
-  static Future<String> copyFileToDownload(
-      String toFileName, String fromFilePath) async {
-    try {
-      return (await _channel
-          .invokeMethod<String>("copyFileToDownload", <String, dynamic>{
-        "toFileName": toFileName,
-        "fromFilePath": fromFilePath,
-      }))!;
-    } on PlatformException catch (e) {
-      if (e.code == _exceptionCodePermissionError) {
-        throw PermissionException();
-      } else {
-        rethrow;
-      }
-    }
-  }
-
-  static const _exceptionCodePermissionError = "permissionError";
-
-  static const _channel = MethodChannel("com.nkming.nc_photos/media_store");
-}

app/lib/mobile/download.dart

@@ -4,9 +4,9 @@ import 'dart:io';
 import 'package:http/http.dart' as http;
 import 'package:logging/logging.dart';
 import 'package:nc_photos/exception.dart';
-import 'package:nc_photos/mobile/android/media_store.dart';
 import 'package:nc_photos/platform/download.dart' as itf;
 import 'package:nc_photos/platform/k.dart' as platform_k;
+import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:uuid/uuid.dart';
 
@@ -92,13 +92,11 @@ class _AndroidDownload extends itf.Download {
       }
 
       // copy the file to the actual dir
-      final String path;
-      if (parentDir?.isNotEmpty == true) {
-        path = "$parentDir/$filename";
-      } else {
-        path = filename;
-      }
-      return await MediaStore.copyFileToDownload(path, file.path);
+      return await MediaStore.copyFileToDownload(
+        file.path,
+        filename: filename,
+        subDir: parentDir,
+      );
     } finally {
       file.delete();
     }

app/lib/mobile/file_saver.dart

@@ -1,8 +1,8 @@
 import 'dart:typed_data';
 
-import 'package:nc_photos/mobile/android/media_store.dart';
 import 'package:nc_photos/platform/file_saver.dart' as itf;
 import 'package:nc_photos/platform/k.dart' as platform_k;
+import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 
 class FileSaver extends itf.FileSaver {
   @override
@@ -15,5 +15,5 @@ class FileSaver extends itf.FileSaver {
   }
 
   Future<String> _saveFileAndroid(String filename, Uint8List content) =>
-      MediaStore.saveFileToDownload(filename, content);
+      MediaStore.saveFileToDownload(content, filename);
 }

app/lib/share_handler.dart

@@ -11,7 +11,6 @@ import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file/data_source.dart';
 import 'package:nc_photos/entity/share.dart';
 import 'package:nc_photos/entity/share/data_source.dart';
-import 'package:nc_photos/exception.dart';
 import 'package:nc_photos/exception_util.dart' as exception_util;
 import 'package:nc_photos/iterable_extension.dart';
 import 'package:nc_photos/k.dart' as k;
@@ -27,6 +26,7 @@ import 'package:nc_photos/widget/processing_dialog.dart';
 import 'package:nc_photos/widget/share_link_multiple_files_dialog.dart';
 import 'package:nc_photos/widget/share_method_dialog.dart';
 import 'package:nc_photos/widget/simple_input_dialog.dart';
+import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 import 'package:tuple/tuple.dart';
 
 /// Handle sharing to other apps

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/K.kt

@@ -5,6 +5,7 @@ interface K {
 		const val DOWNLOAD_NOTIFICATION_ID_MIN = 1000
 		const val DOWNLOAD_NOTIFICATION_ID_MAX = 2000
 
+		const val PERMISSION_REQUEST_CODE = 11011
 		const val LIB_ID = "com.nkming.nc_photos.plugin"
 
 		const val ACTION_DOWNLOAD_CANCEL = "${LIB_ID}.ACTION_DOWNLOAD_CANCEL"

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/MediaStoreChannelHandler.kt

@@ -0,0 +1,118 @@
+package com.nkming.nc_photos.plugin
+
+import android.app.Activity
+import android.content.Context
+import android.net.Uri
+import io.flutter.embedding.engine.plugins.activity.ActivityAware
+import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
+import io.flutter.plugin.common.MethodCall
+import io.flutter.plugin.common.MethodChannel
+import java.io.File
+
+/*
+ * Save downloaded item on device
+ *
+ * Methods:
+ * Write binary content to a file in the Download directory. Return the Uri to
+ * the file
+ * fun saveFileToDownload(content: ByteArray, filename: String, subDir: String?): String
+ */
+class MediaStoreChannelHandler(context: Context) :
+	MethodChannel.MethodCallHandler, ActivityAware {
+	companion object {
+		const val METHOD_CHANNEL = "${K.LIB_ID}/media_store_method"
+
+		private const val TAG = "MediaStoreChannelHandler"
+	}
+
+	override fun onAttachedToActivity(binding: ActivityPluginBinding) {
+		activity = binding.activity
+	}
+
+	override fun onReattachedToActivityForConfigChanges(
+		binding: ActivityPluginBinding
+	) {
+		activity = binding.activity
+	}
+
+	override fun onDetachedFromActivity() {
+		activity = null
+	}
+
+	override fun onDetachedFromActivityForConfigChanges() {
+		activity = null
+	}
+
+	override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
+		when (call.method) {
+			"saveFileToDownload" -> {
+				try {
+					saveFileToDownload(
+						call.argument("content")!!, call.argument("filename")!!,
+						call.argument("subDir"), result
+					)
+				} catch (e: Throwable) {
+					result.error("systemException", e.message, null)
+				}
+			}
+
+			"copyFileToDownload" -> {
+				try {
+					copyFileToDownload(
+						call.argument("fromFile")!!, call.argument("filename"),
+						call.argument("subDir"), result
+					)
+				} catch (e: Throwable) {
+					result.error("systemException", e.message, null)
+				}
+			}
+
+			else -> result.notImplemented()
+		}
+	}
+
+	private fun saveFileToDownload(
+		content: ByteArray, filename: String, subDir: String?,
+		result: MethodChannel.Result
+	) {
+		try {
+			val uri = MediaStoreUtil.saveFileToDownload(
+				context, content, filename, subDir
+			)
+			result.success(uri.toString())
+		} catch (e: PermissionException) {
+			activity?.let { PermissionUtil.requestWriteExternalStorage(it) }
+			result.error("permissionError", "Permission not granted", null)
+		}
+	}
+
+	private fun copyFileToDownload(
+		fromFile: String, filename: String?, subDir: String?,
+		result: MethodChannel.Result
+	) {
+		try {
+			val fromUri = inputToUri(fromFile)
+			val uri = MediaStoreUtil.copyFileToDownload(
+				context, fromUri, filename, subDir
+			)
+			result.success(uri.toString())
+		} catch (e: PermissionException) {
+			activity?.let { PermissionUtil.requestWriteExternalStorage(it) }
+			result.error("permissionError", "Permission not granted", null)
+		}
+	}
+
+	private fun inputToUri(fromFile: String): Uri {
+		val testUri = Uri.parse(fromFile)
+		return if (testUri.scheme == null) {
+			// is a file path
+			Uri.fromFile(File(fromFile))
+		} else {
+			// is a uri
+			Uri.parse(fromFile)
+		}
+	}
+
+	private val context = context
+	private var activity: Activity? = null
+}

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/MediaStoreUtil.kt

@@ -1,65 +1,84 @@
 package com.nkming.nc_photos.plugin
 
-import android.Manifest
 import android.content.ContentValues
 import android.content.Context
 import android.content.Intent
-import android.content.pm.PackageManager
 import android.net.Uri
 import android.os.Build
 import android.os.Environment
 import android.provider.MediaStore
 import androidx.annotation.RequiresApi
-import androidx.core.content.ContextCompat
 import androidx.core.content.FileProvider
 import java.io.*
 
+class MediaStoreCopyWriter(data: InputStream) {
+	operator fun invoke(ostream: OutputStream) {
+		data.copyTo(ostream)
+	}
+
+	private val data = data
+}
+
 interface MediaStoreUtil {
 	companion object {
 		/**
 		 * Save the @c content as a file under the user Download dir
 		 *
 		 * @param context
-		 * @param filename Filename of the new file
 		 * @param content
+		 * @param filename Filename of the new file
+		 * @param subDir
 		 * @return Uri of the created file
 		 */
 		fun saveFileToDownload(
-			context: Context, filename: String, content: ByteArray
+			context: Context, content: ByteArray, filename: String,
+			subDir: String? = null
 		): Uri {
-			val stream = ByteArrayInputStream(content)
-			return writeFileToDownload(context, filename, stream)
+			return ByteArrayInputStream(content).use {
+				writeFileToDownload(
+					context, MediaStoreCopyWriter(it)::invoke, filename, subDir
+				)
+			}
 		}
 
 		/**
 		 * Copy a file from @c fromFilePath to the user Download dir
 		 *
 		 * @param context
-		 * @param toFilename Filename of the new file
-		 * @param fromFilePath Path of the file to be copied
+		 * @param fromFile Path of the file to be copied
+		 * @param filename Filename of the new file. If null, the same filename
+		 * @param subDir
+		 * will be used
 		 * @return Uri of the created file
 		 */
 		fun copyFileToDownload(
-			context: Context, toFilename: String, fromFilePath: String
+			context: Context, fromFile: Uri, filename: String? = null,
+			subDir: String? = null
 		): Uri {
-			val file = File(fromFilePath)
-			val stream = file.inputStream()
-			return writeFileToDownload(context, toFilename, stream)
+			return context.contentResolver.openInputStream(fromFile)!!.use {
+				writeFileToDownload(
+					context, MediaStoreCopyWriter(it)::invoke,
+					filename ?: UriUtil.resolveFilename(context, fromFile)!!,
+					subDir
+				)
+			}
 		}
 
-		private fun writeFileToDownload(
-			context: Context, filename: String, data: InputStream
+		fun writeFileToDownload(
+			context: Context, writer: (OutputStream) -> Unit, filename: String,
+			subDir: String? = null
 		): Uri {
 			return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-				writeFileToDownload29(context, filename, data)
+				writeFileToDownload29(context, writer, filename, subDir)
 			} else {
-				writeFileToDownload0(context, filename, data)
+				writeFileToDownload0(context, writer, filename, subDir)
 			}
 		}
 
 		@RequiresApi(Build.VERSION_CODES.Q)
 		private fun writeFileToDownload29(
-			context: Context, filename: String, data: InputStream
+			context: Context, writer: (OutputStream) -> Unit, filename: String,
+			subDir: String?
 		): Uri {
 			// Add a media item that other apps shouldn't see until the item is
 			// fully written to the media store.
@@ -69,13 +88,12 @@ interface MediaStoreUtil {
 			val collection = MediaStore.Downloads.getContentUri(
 				MediaStore.VOLUME_EXTERNAL_PRIMARY
 			)
-			val file = File(filename)
 			val details = ContentValues().apply {
-				put(MediaStore.Downloads.DISPLAY_NAME, file.name)
-				if (file.parent != null) {
+				put(MediaStore.Downloads.DISPLAY_NAME, filename)
+				if (subDir != null) {
 					put(
 						MediaStore.Downloads.RELATIVE_PATH,
-						"${Environment.DIRECTORY_DOWNLOADS}/${file.parent}"
+						"${Environment.DIRECTORY_DOWNLOADS}/$subDir"
 					)
 				}
 			}
@@ -87,19 +105,17 @@ interface MediaStoreUtil {
 				BufferedOutputStream(
 					FileOutputStream(pfd!!.fileDescriptor)
 				).use { stream ->
-					data.copyTo(stream)
+					writer(stream)
 				}
 			}
 			return contentUri
 		}
 
 		private fun writeFileToDownload0(
-			context: Context, filename: String, data: InputStream
+			context: Context, writer: (OutputStream) -> Unit, filename: String,
+			subDir: String?
 		): Uri {
-			if (ContextCompat.checkSelfPermission(
-					context, Manifest.permission.WRITE_EXTERNAL_STORAGE
-				) != PackageManager.PERMISSION_GRANTED
-			) {
+			if (!PermissionUtil.hasWriteExternalStorage(context)) {
 				throw PermissionException("Permission not granted")
 			}
 
@@ -107,19 +123,19 @@ interface MediaStoreUtil {
 			val path = Environment.getExternalStoragePublicDirectory(
 				Environment.DIRECTORY_DOWNLOADS
 			)
-			var file = File(path, filename)
+			val prefix = if (subDir != null) "$subDir/" else ""
+			var file = File(path, prefix + filename)
+			val baseFilename = file.nameWithoutExtension
 			var count = 1
 			while (file.exists()) {
-				val f = File(filename)
 				file = File(
-					path,
-					"${f.nameWithoutExtension} ($count).${f.extension}"
+					path, prefix + "$baseFilename ($count).${file.extension}"
 				)
 				++count
 			}
 			file.parentFile?.mkdirs()
 			BufferedOutputStream(FileOutputStream(file)).use { stream ->
-				data.copyTo(stream)
+				writer(stream)
 			}
 
 			val fileUri = Uri.fromFile(file)
@@ -138,6 +154,5 @@ interface MediaStoreUtil {
 			}
 			context.sendBroadcast(scanIntent)
 		}
-
 	}
 }

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/NcPhotosPlugin.kt

@@ -2,10 +2,12 @@ package com.nkming.nc_photos.plugin
 
 import androidx.annotation.NonNull
 import io.flutter.embedding.engine.plugins.FlutterPlugin
+import io.flutter.embedding.engine.plugins.activity.ActivityAware
+import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.EventChannel
 import io.flutter.plugin.common.MethodChannel
 
-class NcPhotosPlugin : FlutterPlugin {
+class NcPhotosPlugin : FlutterPlugin, ActivityAware {
 	override fun onAttachedToEngine(
 		@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding
 	) {
@@ -36,6 +38,14 @@ class NcPhotosPlugin : FlutterPlugin {
 			NativeEventChannelHandler.METHOD_CHANNEL
 		)
 		nativeEventMethodChannel.setMethodCallHandler(nativeEventHandler)
+
+		mediaStoreChannelHandler =
+			MediaStoreChannelHandler(flutterPluginBinding.applicationContext)
+		mediaStoreMethodChannel = MethodChannel(
+			flutterPluginBinding.binaryMessenger,
+			MediaStoreChannelHandler.METHOD_CHANNEL
+		)
+		mediaStoreMethodChannel.setMethodCallHandler(mediaStoreChannelHandler)
 	}
 
 	override fun onDetachedFromEngine(
@@ -46,12 +56,33 @@ class NcPhotosPlugin : FlutterPlugin {
 		notificationChannel.setMethodCallHandler(null)
 		nativeEventChannel.setStreamHandler(null)
 		nativeEventMethodChannel.setMethodCallHandler(null)
+		mediaStoreMethodChannel.setMethodCallHandler(null)
+	}
+
+	override fun onAttachedToActivity(binding: ActivityPluginBinding) {
+		mediaStoreChannelHandler.onAttachedToActivity(binding)
+	}
+
+	override fun onReattachedToActivityForConfigChanges(
+		binding: ActivityPluginBinding
+	) {
+		mediaStoreChannelHandler.onReattachedToActivityForConfigChanges(binding)
+	}
+
+	override fun onDetachedFromActivity() {
+		mediaStoreChannelHandler.onDetachedFromActivity()
+	}
+
+	override fun onDetachedFromActivityForConfigChanges() {
+		mediaStoreChannelHandler.onDetachedFromActivityForConfigChanges()
 	}
 
 	private lateinit var lockChannel: MethodChannel
 	private lateinit var notificationChannel: MethodChannel
 	private lateinit var nativeEventChannel: EventChannel
 	private lateinit var nativeEventMethodChannel: MethodChannel
+	private lateinit var mediaStoreMethodChannel: MethodChannel
 
 	private lateinit var lockChannelHandler: LockChannelHandler
+	private lateinit var mediaStoreChannelHandler: MediaStoreChannelHandler
 }

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/PermissionUtil.kt

@@ -0,0 +1,36 @@
+package com.nkming.nc_photos.plugin
+
+import android.Manifest
+import android.app.Activity
+import android.content.Context
+import android.content.pm.PackageManager
+import androidx.core.app.ActivityCompat
+import androidx.core.content.ContextCompat
+
+interface PermissionUtil {
+	companion object {
+		fun request(activity: Activity, vararg permissions: String) {
+			ActivityCompat.requestPermissions(
+				activity, permissions, K.PERMISSION_REQUEST_CODE
+			)
+		}
+
+		fun hasReadExternalStorage(context: Context): Boolean {
+			return ContextCompat.checkSelfPermission(
+				context, Manifest.permission.READ_EXTERNAL_STORAGE
+			) == PackageManager.PERMISSION_GRANTED
+		}
+
+		fun requestReadExternalStorage(activity: Activity) =
+			request(activity, Manifest.permission.READ_EXTERNAL_STORAGE)
+
+		fun hasWriteExternalStorage(context: Context): Boolean {
+			return ContextCompat.checkSelfPermission(
+				context, Manifest.permission.WRITE_EXTERNAL_STORAGE
+			) == PackageManager.PERMISSION_GRANTED
+		}
+
+		fun requestWriteExternalStorage(activity: Activity) =
+			request(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE)
+	}
+}

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/UriUtil.kt

@@ -0,0 +1,34 @@
+package com.nkming.nc_photos.plugin
+
+import android.content.Context
+import android.net.Uri
+import android.provider.MediaStore
+import android.util.Log
+
+interface UriUtil {
+	companion object {
+		fun resolveFilename(context: Context, uri: Uri): String? {
+			return if (uri.scheme == "file") {
+				uri.lastPathSegment!!
+			} else {
+				context.contentResolver.query(
+					uri, arrayOf(MediaStore.MediaColumns.DISPLAY_NAME), null,
+					null, null
+				).use {
+					if (it == null || !it.moveToFirst()) {
+						Log.i(TAG, "Uri not found: $uri")
+						null
+					} else {
+						it.getString(
+							it.getColumnIndexOrThrow(
+								MediaStore.MediaColumns.DISPLAY_NAME
+							)
+						)
+					}
+				}
+			}
+		}
+
+		private const val TAG = "UriUtil"
+	}
+}

plugin/lib/nc_photos_plugin.dart

@@ -1,5 +1,7 @@
 library nc_photos_plugin;
 
+export 'src/exception.dart';
 export 'src/lock.dart';
+export 'src/media_store.dart';
 export 'src/native_event.dart';
 export 'src/notification.dart';

plugin/lib/src/exception.dart

@@ -0,0 +1,15 @@
+/// Platform permission is not granted by user
+class PermissionException implements Exception {
+  const PermissionException([this.message]);
+
+  @override
+  toString() {
+    if (message == null) {
+      return "PermissionException";
+    } else {
+      return "PermissionException: $message";
+    }
+  }
+
+  final dynamic message;
+}

plugin/lib/src/media_store.dart

@@ -0,0 +1,57 @@
+import 'dart:typed_data';
+
+import 'package:flutter/services.dart';
+import 'package:nc_photos_plugin/src/exception.dart';
+import 'package:nc_photos_plugin/src/k.dart' as k;
+
+class MediaStore {
+  static Future<String> saveFileToDownload(
+    Uint8List content,
+    String filename, {
+    String? subDir,
+  }) async {
+    try {
+      return (await _methodChannel
+          .invokeMethod<String>("saveFileToDownload", <String, dynamic>{
+        "content": content,
+        "filename": filename,
+        "subDir": subDir,
+      }))!;
+    } on PlatformException catch (e) {
+      if (e.code == _exceptionCodePermissionError) {
+        throw const PermissionException();
+      } else {
+        rethrow;
+      }
+    }
+  }
+
+  /// Copy a file to the user Download dir
+  ///
+  /// [fromFile] must be either a path or a content uri. If [filename] is not
+  /// null, it will be used instead of the source filename
+  static Future<String> copyFileToDownload(
+    String fromFile, {
+    String? filename,
+    String? subDir,
+  }) async {
+    try {
+      return (await _methodChannel
+          .invokeMethod<String>("copyFileToDownload", <String, dynamic>{
+        "fromFile": fromFile,
+        "filename": filename,
+        "subDir": subDir,
+      }))!;
+    } on PlatformException catch (e) {
+      if (e.code == _exceptionCodePermissionError) {
+        throw const PermissionException();
+      } else {
+        rethrow;
+      }
+    }
+  }
+
+  static const _methodChannel = MethodChannel("${k.libId}/media_store_method");
+
+  static const _exceptionCodePermissionError = "permissionError";
+}