feat: macOS support for FileOpenPicker

Author: MartinZikmund

src/Uno.UWP/Generated/3.0.0.0/Windows.Storage.Pickers/FileOpenPicker.cs

@@ -2,7 +2,7 @@
 #pragma warning disable 114 // new keyword hiding
 namespace Windows.Storage.Pickers
 {
-	#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || __MACOS__
+	#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || false
 	[global::Uno.NotImplemented]
 	#endif
 	public  partial class FileOpenPicker 
@@ -93,7 +93,7 @@ public  string CommitButtonText
 			}
 		}
 		#endif
-		#if false || false || NET461 || false || __NETSTD_REFERENCE__ || __MACOS__
+		#if false || false || NET461 || false || __NETSTD_REFERENCE__ || false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "NET461", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public FileOpenPicker() 
 		{
@@ -116,7 +116,7 @@ public  void PickMultipleFilesAndContinue()
 			global::Windows.Foundation.Metadata.ApiInformation.TryRaiseNotImplemented("Windows.Storage.Pickers.FileOpenPicker", "void FileOpenPicker.PickMultipleFilesAndContinue()");
 		}
 		#endif
-		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || __MACOS__
+		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "NET461", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public  global::Windows.Foundation.IAsyncOperation<global::Windows.Storage.StorageFile> PickSingleFileAsync( string pickerOperationId)
 		{
@@ -132,14 +132,14 @@ public  void PickMultipleFilesAndContinue()
 		// Forced skipping of method Windows.Storage.Pickers.FileOpenPicker.CommitButtonText.get
 		// Forced skipping of method Windows.Storage.Pickers.FileOpenPicker.CommitButtonText.set
 		// Forced skipping of method Windows.Storage.Pickers.FileOpenPicker.FileTypeFilter.get
-		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || __MACOS__
+		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "NET461", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public  global::Windows.Foundation.IAsyncOperation<global::Windows.Storage.StorageFile> PickSingleFileAsync()
 		{
 			throw new global::System.NotImplementedException("The member IAsyncOperation<StorageFile> FileOpenPicker.PickSingleFileAsync() is not implemented in Uno.");
 		}
 		#endif
-		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || __MACOS__
+		#if false || false || NET461 || false || false || __NETSTD_REFERENCE__ || false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "NET461", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public  global::Windows.Foundation.IAsyncOperation<global::System.Collections.Generic.IReadOnlyList<global::Windows.Storage.StorageFile>> PickMultipleFilesAsync()
 		{

src/Uno.UWP/Storage/Pickers/FileOpenPicker.cs

@@ -47,7 +47,7 @@ public string CommitButtonText
 			set => _commitButtonText = value ?? throw new ArgumentNullException(nameof(value));
 		}
 
-#if __SKIA__ || __WASM__ || __IOS__ || __ANDROID__
+#if __SKIA__ || __WASM__ || __IOS__ || __ANDROID__ || __MACOS__
 		public FileOpenPicker()
 		{
 			InitializePlatform();

src/Uno.UWP/Storage/Pickers/FileOpenPicker.macOS.cs

@@ -0,0 +1,52 @@
+#nullable enable
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using AppKit;
+using Foundation;
+
+namespace Windows.Storage.Pickers
+{
+	public partial class FileOpenPicker
+	{
+		private const int ModalResponseOk = 1;
+
+		private Task<StorageFile?> PickSingleFileTaskAsync(CancellationToken token)
+		{
+			var files = PickFiles(false, token);
+			return Task.FromResult<StorageFile?>(files.FirstOrDefault());
+		}
+
+		private Task<IReadOnlyList<StorageFile>> PickMultipleFilesTaskAsync(CancellationToken token) =>
+			Task.FromResult<IReadOnlyList<StorageFile>>(PickFiles(true, token));
+
+		private FilePickerSelectedFilesArray PickFiles(bool pickMultiple, CancellationToken token)
+		{
+			var openPanel = new NSOpenPanel
+			{
+				CanChooseFiles = true,
+				CanChooseDirectories = false,
+				AllowsMultipleSelection = pickMultiple,
+				AllowedFileTypes = FileTypeFilter.ToArray()
+			};
+
+			var result = openPanel.RunModal();
+
+			if (result == ModalResponseOk)
+			{
+				if (openPanel.Urls != null)
+				{
+					var files = openPanel.Urls
+						.Where(url => url?.Path != null)
+						.Select(url => StorageFile.GetFileFromPath(url.Path))
+						.ToArray();
+					return new FilePickerSelectedFilesArray(files);
+				}				
+			}
+			return FilePickerSelectedFilesArray.Empty;
+		}
+	}
+}

src/Uno.UWP/Storage/Pickers/FileSavePicker.macOS.cs

@@ -12,6 +12,8 @@ namespace Windows.Storage.Pickers
 {
 	public partial class FileSavePicker
 	{
+		private const int ModalResponseOk = 1;
+
 		private async Task<StorageFile?> PickSaveFileTaskAsync(CancellationToken token)
 		{
 			var savePicker = new NSSavePanel();
@@ -21,7 +23,7 @@ public partial class FileSavePicker
 			{
 				savePicker.NameFieldStringValue = SuggestedFileName;
 			}
-			if (savePicker.RunModal() == 1)
+			if (savePicker.RunModal() == ModalResponseOk)
 			{
 				return await StorageFile.GetFileFromPathAsync(savePicker.Url.Path);
 			}