feat: DataTransferManager support on iOS

- Adds support for DataTransferManager on iOS
- Includes ShareUIOptions for target rect and dark/light theme

src/SamplesApp/UITests.Shared/Windows_ApplicationModel/DataTransfer/DataTransferManagerTests.xaml

@@ -13,9 +13,10 @@
 			<RowDefinition Height="*" />
 			<RowDefinition Height="300" />
 		</Grid.RowDefinitions>
-		<StackPanel>
+		<StackPanel Spacing="8">
 			<TextBox Header="Title" Text="{x:Bind ViewModel.Title, Mode=TwoWay}" />
 			<TextBox Header="Description" Text="{x:Bind ViewModel.Description, Mode=TwoWay}" />
+			<CheckBox x:Name="DarkThemeCheckBox" IsChecked="{x:Bind ViewModel.SetDarkTheme, Mode=TwoWay}" IsThreeState="True" Content="Dark theme" />
 
 			<TextBlock Text="Data" Style="{ThemeResource HeaderTextBlockStyle}" />
 			<TextBox Header="Text" Text="{x:Bind ViewModel.Text, Mode=TwoWay}" />

src/SamplesApp/UITests.Shared/Windows_ApplicationModel/DataTransfer/DataTransferManagerTests.xaml.cs

@@ -36,6 +36,7 @@ public class DataTransferManagerTestsViewModel : ViewModelBase
 		private string _uriText = null;
 		private string _applicationLink = null;
 		private string _webLink = null;
+		private bool? _setDarkTheme = null;
 
 		public DataTransferManagerTestsViewModel(CoreDispatcher dispatcher) : base(dispatcher)
 		{
@@ -76,6 +77,16 @@ public string Description
 			}
 		}
 
+		public bool? SetDarkTheme
+		{
+			get => _setDarkTheme;
+			set
+			{
+				_setDarkTheme = value;
+				RaisePropertyChanged();
+			}
+		}
+
 		public string Text
 		{
 			get => _text;
@@ -116,7 +127,26 @@ public string WebLink
 			}
 		}
 
-		private void ShowUI() => DataTransferManager.ShowShareUI();
+		private void ShowUI() => DataTransferManager.ShowShareUI(new ShareUIOptions()
+		{
+			Theme = GetTheme()
+		});
+
+		private ShareUITheme GetTheme()
+		{
+			if (SetDarkTheme == null)
+			{
+				return ShareUITheme.Default;
+			}
+			else if (SetDarkTheme == true)
+			{
+				return ShareUITheme.Dark;
+			}
+			else
+			{
+				return ShareUITheme.Light;
+			}
+		}
 
 		private void ClearEventLog() => EventLog.Clear();
 

src/Uno.UI/UI/Xaml/Application.cs

@@ -110,6 +110,8 @@ private ApplicationTheme? InternalRequestedTheme
 			set
 			{
 				_requestedTheme = value;
+				// Sync with core application's theme
+				CoreApplication.RequestedTheme = value == ApplicationTheme.Dark ? SystemTheme.Dark : SystemTheme.Light;
 				UpdateRequestedThemesForResources();
 			}
 		}

src/Uno.UWP/ApplicationModel/Core/CoreApplication.cs

@@ -1,6 +1,7 @@
 #pragma warning disable 108 // new keyword hiding
 #pragma warning disable 114 // new keyword hiding
 using System.Collections.Generic;
+using Uno.Helpers.Theming;
 
 namespace Windows.ApplicationModel.Core
 {
@@ -48,5 +49,11 @@ public static IReadOnlyList<CoreApplicationView> Views
 				return _views;
 			}
 		}
+
+		/// <summary>
+		/// This property is kept in sync with the Application.RequestedTheme to enable
+		/// native UI elements in non Uno.UWP to resolve the currently set Application theme.
+		/// </summary>
+		internal static SystemTheme RequestedTheme { get; set; }
 	}
 }

src/Uno.UWP/ApplicationModel/DataTransfer/DataTransferManager.cs

@@ -1,15 +1,68 @@
-#if __WASM__
+#nullable enable
+
+#if __WASM__ || __IOS__
+using System;
 using Windows.Foundation;
+using Uno.Logging;
+using Microsoft.Extensions.Logging;
+using Uno.Extensions;
+using System.Threading.Tasks;
 
 namespace Windows.ApplicationModel.DataTransfer
 {
 	public partial class DataTransferManager
 	{
+		private static Lazy<DataTransferManager> _instance = new Lazy<DataTransferManager>(() => new DataTransferManager());
+
 		private DataTransferManager()
 		{
 		}
 
-		public event TypedEventHandler<DataTransferManager, DataRequestedEventArgs> DataRequested;
+		public event TypedEventHandler<DataTransferManager, DataRequestedEventArgs>? DataRequested;
+
+		public static DataTransferManager GetForCurrentView() => _instance.Value;
+
+		public static void ShowShareUI() => ShowShareUI(new ShareUIOptions());
+
+		public static async void ShowShareUI(ShareUIOptions options)
+		{
+			var dataTransferManager = _instance.Value;
+			var args = new DataRequestedEventArgs();
+			dataTransferManager.DataRequested?.Invoke(dataTransferManager, args);
+			var dataPackage = args.Request.Data;
+			try
+			{
+				// Because showing the Share UI is a fire-and-forget operation
+				// and retrieving data from DataPackage requires async-await,
+				// this method must be async void.
+				await ShowShareUIAsync(options, dataPackage);
+			}
+			catch (Exception ex)
+			{
+				if (dataTransferManager.Log().IsEnabled(LogLevel.Error))
+				{
+					dataTransferManager.Log().LogError($"Exception occurred trying to show share UI: {ex}");
+				}
+			}
+		}
+
+		private static async Task<Uri?> GetSharedUriAsync(DataPackageView view)
+		{
+			if (view.Contains(StandardDataFormats.Uri))
+			{
+				return await view.GetUriAsync();
+			}
+			else if (view.Contains(StandardDataFormats.WebLink))
+			{
+				return await view.GetWebLinkAsync();
+			}
+			else if (view.Contains(StandardDataFormats.ApplicationLink))
+			{
+				return await view.GetApplicationLinkAsync();
+			}
+
+			return null;
+		}
 	}
 }
 #endif

src/Uno.UWP/ApplicationModel/DataTransfer/DataTransferManager.iOS.cs

@@ -0,0 +1,114 @@
+#nullable enable
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using CoreGraphics;
+using Foundation;
+using Microsoft.Extensions.Logging;
+using UIKit;
+using Uno.Extensions;
+using Uno.Helpers.Theming;
+using Windows.ApplicationModel.Core;
+using Windows.Foundation;
+
+namespace Windows.ApplicationModel.DataTransfer
+{
+	public partial class DataTransferManager
+	{
+		public static bool IsSupported() => true;
+
+		private static async Task ShowShareUIAsync(ShareUIOptions options, DataPackage dataPackage)
+		{
+			var rootViewController = UIApplication.SharedApplication?.KeyWindow?.RootViewController;
+			if (rootViewController == null)
+			{
+				if (_instance.Value.Log().IsEnabled(LogLevel.Error))
+				{
+					_instance.Value.Log().LogError("The Share API was called too early in the application lifecycle");
+				}
+				return;
+			}
+
+			var dataPackageView = dataPackage.GetView();
+
+			var sharedData = new List<NSObject>();
+
+			var title = dataPackage.Properties.Title ?? string.Empty;
+
+			if (dataPackageView.Contains(StandardDataFormats.Text))
+			{
+				var text = await dataPackageView.GetTextAsync();
+				sharedData.Add(new DataActivityItemSource(new NSString(text), title));
+			}
+
+			var uri = await GetSharedUriAsync(dataPackageView);
+			if (uri != null)
+			{
+				sharedData.Add(new DataActivityItemSource(NSUrl.FromString(uri.ToString()), title));
+			}
+
+			var activityViewController = new UIActivityViewController(sharedData.ToArray(), null);
+
+			if (activityViewController.PopoverPresentationController != null && rootViewController.View != null)
+			{				
+				activityViewController.PopoverPresentationController.SourceView = rootViewController.View;
+
+				if (options.SelectionRect != null)
+				{
+					activityViewController.PopoverPresentationController.SourceRect = options.SelectionRect.Value.ToCGRect();
+				}
+				else
+				{
+					activityViewController.PopoverPresentationController.SourceRect = new CGRect(rootViewController.View.Bounds.Width / 2, rootViewController.View.Bounds.Height / 2, 0, 0);				
+					activityViewController.PopoverPresentationController.PermittedArrowDirections = 0;
+				}
+			}
+
+			if (options.Theme != ShareUITheme.Default)
+			{
+				activityViewController.OverrideUserInterfaceStyle = options.Theme == ShareUITheme.Light ? UIUserInterfaceStyle.Light : UIUserInterfaceStyle.Dark;
+			}
+			else
+			{
+				// Theme should match the application theme
+				activityViewController.OverrideUserInterfaceStyle = CoreApplication.RequestedTheme == SystemTheme.Light ? UIUserInterfaceStyle.Light : UIUserInterfaceStyle.Dark;
+			}
+
+			var completionSource = new TaskCompletionSource<bool>();
+
+			activityViewController.CompletionWithItemsHandler = (NSString activityType, bool completed, NSExtensionItem[] returnedItems, NSError error) =>
+			{
+				completionSource.SetResult(completed);
+			};
+
+			await rootViewController.PresentViewControllerAsync(activityViewController, true);
+
+			var result = await completionSource.Task;
+
+			if (result)
+			{
+				dataPackage.OnShareCompleted();
+			}
+			else
+			{
+				dataPackage.OnShareCanceled();
+			}
+		}
+
+		internal class DataActivityItemSource : UIActivityItemSource
+		{
+			private NSObject _data;
+			private string _title;
+
+			internal DataActivityItemSource(NSObject data, string title) =>
+				(_data, _title) = (data, title);
+
+			public override NSObject GetItemForActivity(UIActivityViewController activityViewController, NSString? activityType) => _data;
+
+			public override string GetSubjectForActivity(UIActivityViewController activityViewController, NSString? activityType) => _title;
+
+			public override NSObject GetPlaceholderData(UIActivityViewController activityViewController) => _data;
+		}
+	}
+}

src/Uno.UWP/ApplicationModel/DataTransfer/DataTransferManager.other.cs

@@ -1,9 +1,13 @@
-#if !__WASM__
+#if !__WASM__ && !__IOS__
 
 namespace Windows.ApplicationModel.DataTransfer
 {
 	public partial class DataTransferManager
     {
+		private DataTransferManager()
+		{
+		}
+
 		public static bool IsSupported() => false;
 
 		public static DataTransferManager GetForCurrentView() => throw new NotSupportedException("DataTransferManager is not yet supported on this platform.");

src/Uno.UWP/ApplicationModel/DataTransfer/DataTransferManager.wasm.cs

@@ -1,27 +1,20 @@
 #nullable enable
 
 using System;
+using System.Threading.Tasks;
 using Uno.Foundation;
 
 namespace Windows.ApplicationModel.DataTransfer
 {
 	public partial class DataTransferManager
 	{
 		private const string JsType = "Windows.ApplicationModel.DataTransfer.DataTransferManager";
-
-		private static Lazy<DataTransferManager> _instance = new Lazy<DataTransferManager>(() => new DataTransferManager());
-
+
 		public static bool IsSupported() => bool.TryParse(WebAssemblyRuntime.InvokeJS($"{JsType}.isSupported()"), out var result) && result;
 
-		public static DataTransferManager GetForCurrentView() => _instance.Value;
-
-		public static async void ShowShareUI()
+		private static async Task ShowShareUIAsync(ShareUIOptions options, DataPackage dataPackage)
 		{
-			var dataTransferManager = _instance.Value;
-			var args = new DataRequestedEventArgs();
-			dataTransferManager.DataRequested?.Invoke(dataTransferManager, args);
-			var dataPackage = args.Request.Data;
-			var dataPackageView = args.Request.Data.GetView();
+			var dataPackageView = dataPackage.GetView();
 
 			var title = dataPackage.Properties.Title != null ? $"\"{WebAssemblyRuntime.EscapeJs(dataPackage.Properties.Title)}\"" : null;
 
@@ -36,19 +29,7 @@ public static async void ShowShareUI()
 			}
 			text = text != null ? $"\"{WebAssemblyRuntime.EscapeJs(text)}\"" : null;
 
-			Uri? uri = null;
-			if (dataPackageView.Contains(StandardDataFormats.Uri))
-			{
-				uri = await dataPackageView.GetUriAsync();
-			}
-			else if (dataPackageView.Contains(StandardDataFormats.WebLink))
-			{
-				uri = await dataPackageView.GetWebLinkAsync();
-			}
-			else if (dataPackageView.Contains(StandardDataFormats.ApplicationLink))
-			{
-				uri = await dataPackageView.GetApplicationLinkAsync();
-			}
+			var uri = await GetSharedUriAsync(dataPackageView);
 
 			var uriText = uri != null ? $"\"{WebAssemblyRuntime.EscapeJs(uri.ToString())}\"" : null;
 

src/Uno.UWP/ApplicationModel/DataTransfer/ShareUIOptions.cs

@@ -0,0 +1,18 @@
+using Windows.Foundation;
+
+namespace Windows.ApplicationModel.DataTransfer
+{
+	public partial class ShareUIOptions
+	{
+		public ShareUIOptions()
+		{		
+		}
+
+#if __IOS__
+
+		public ShareUITheme Theme { get; set; }
+
+		public Rect? SelectionRect { get; set; }
+#endif
+	}
+}

src/Uno.UWP/ApplicationModel/DataTransfer/ShareUITheme.cs

@@ -0,0 +1,9 @@
+namespace Windows.ApplicationModel.DataTransfer
+{
+	public enum ShareUITheme
+	{
+		Default,
+		Light,
+		Dark,
+	}
+}