[uikit] Fix method names in UIDropSession & UIDragDropSession (#2314)

- Fixes bug #58079: UIDropSession loadObjects: is called Completion
  (https://bugzilla.xamarin.com/show_bug.cgi?id=58079)
- Fixes bug #58081: IUIDropSession.Completion first arg should be a Class
  (https://bugzilla.xamarin.com/show_bug.cgi?id=58081)
- Similar to `CanLoadObjects`, use `itemProviderReadingClass` as the param name in `LoadObjects`.
- Provide `Type` overloads so customers don't have to do `new ObjCRuntime.Class (typeof (UIImage))` but can just do `typeof (UIImage)` instead.

src/UIKit/UIDragDropSessionExtensions.cs

@@ -0,0 +1,32 @@
+//
+// UIDragDropSessionExtensions.cs
+//
+// Authors:
+//   Vincent Dondain  <vidondai@microsoft.com>
+//
+// Copyright 2017 Microsoft
+//
+
+#if !TVOS && !WATCH
+
+using System;
+using XamCore.ObjCRuntime;
+using XamCore.Foundation;
+
+namespace XamCore.UIKit {
+
+	public static class UIDragDropSessionExtensions {
+
+		public static NSProgress LoadObjects (this IUIDropSession session, Type type, Action<INSItemProviderReading []> completion)
+		{
+			return session.LoadObjects (new Class (type), completion);
+		}
+
+		public static bool CanLoadObjects (this IUIDragDropSession session, Type type)
+		{
+			return session.CanLoadObjects (new Class (type));
+		}
+	}
+}
+
+#endif

src/frameworks.sources

@@ -1320,6 +1320,7 @@ UIKIT_SOURCES = \
 	UIKit/UIDocumentInteractionController.cs \
 	UIKit/UIDocumentMenuViewController.cs \
 	UIKit/UIDocumentPickerViewController.cs \
+	UIKit/UIDragDropSessionExtensions.cs \
 	UIKit/UIDynamicAnimator.cs \
 	UIKit/UIEnumsExtensions.cs \
 	UIKit/UIEvent.cs \

src/uikit.cs

@@ -16204,7 +16204,7 @@ namespace XamCore.UIKit {
 	
 		[Abstract]
 		[Export ("canLoadObjectsOfClass:")]
-		bool CanLoadObjectsOfClass (Class itemProviderReadingClass);
+		bool CanLoadObjects (Class itemProviderReadingClass);
 	}
 	
 	[NoWatch, NoTV, iOS (11,0)]
@@ -16374,7 +16374,7 @@ namespace XamCore.UIKit {
 	
 		[Abstract]
 		[Export ("loadObjectsOfClass:completion:")]
-		NSProgress Completion (INSItemProviderReading aClass, Action<INSItemProviderReading []> completion);
+		NSProgress LoadObjects (Class itemProviderReadingClass, Action<INSItemProviderReading []> completion);
 	}
 	
 	[NoWatch, NoTV, iOS (11,0)]

tests/monotouch-test/UIKit/UIDragDropSessionExtensionsTest.cs

@@ -0,0 +1,79 @@
+//
+// Unit tests for UIDragDropSessionExtensionsTest
+//
+// Authors:
+//	Vincent Dondain <vidondai@microsoft.com>
+//	
+//
+// Copyright 2017 Microsoft.
+//
+
+#if !__TVOS__ && !__WATCHOS__
+
+using System;
+#if XAMCORE_2_0
+using CoreGraphics;
+using Foundation;
+using ObjCRuntime;
+using UIKit;
+#else
+using MonoTouch.CoreGraphics;
+using MonoTouch.Foundation;
+using MonoTouch.ObjCRuntime;
+using MonoTouch.UIKit;
+#endif
+using NUnit.Framework;
+
+namespace MonoTouchFixtures.UIKit {
+	[TestFixture]
+	[Preserve (AllMembers = true)]
+	public class UIDragDropSessionExtensionsTest {
+
+		[Test]
+		public void LoadObjectsTest ()
+		{
+			if (!TestRuntime.CheckXcodeVersion (9,0))
+				Assert.Ignore ("Ignoring tests: Requires iOS11+");
+
+			var test = new DropSession ();
+			test.CanLoadObjects (typeof (UIImage));
+			test.LoadObjects (typeof (UIImage), null);
+		}
+	}
+
+	class DropSession : NSObject, IUIDropSession {
+		public IUIDragSession LocalDragSession => throw new NotImplementedException ();
+
+		public UIDropSessionProgressIndicatorStyle ProgressIndicatorStyle { get => throw new NotImplementedException (); set => throw new NotImplementedException (); }
+
+		public UIDragItem [] Items => throw new NotImplementedException ();
+
+		public bool AllowsMoveOperation => throw new NotImplementedException ();
+
+		public bool RestrictedToDraggingApplication => throw new NotImplementedException ();
+
+		public bool CanLoadObjects (Class itemProviderReadingClass)
+		{
+			Assert.That (itemProviderReadingClass.Handle, Is.EqualTo (new Class (typeof (UIImage)).Handle), "UIDragDropSessionExtensionsTest did not convert the type properly for 'CanLoadObjects'.");
+			return true;
+		}
+
+		public bool HasConformingItems (string [] typeIdentifiers)
+		{
+			throw new NotImplementedException ();
+		}
+
+		public NSProgress LoadObjects (Class itemProviderReadingClass, Action<INSItemProviderReading []> completion)
+		{
+			Assert.That (itemProviderReadingClass.Handle, Is.EqualTo (new Class (typeof (UIImage)).Handle), "UIDragDropSessionExtensionsTest did not convert the type properly for 'LoadObjects'.");
+			return new NSProgress ();
+		}
+
+		public CGPoint LocationInView (UIView view)
+		{
+			throw new NotImplementedException ();
+		}
+	}
+}
+
+#endif // !__TVOS__ && !__WATCHOS__

tests/monotouch-test/monotouch-test.csproj

@@ -656,6 +656,7 @@
     <Compile Include="HomeKit\HMMutableSignificantTimeEventTest.cs" />
     <Compile Include="HomeKit\HMPresenceEventTest.cs" />
     <Compile Include="HomeKit\HMSignificantTimeEventTest.cs" />
+    <Compile Include="UIKit\UIDragDropSessionExtensionsTest.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
   <ItemGroup>