Address feedback.

If `IJavaPeerable.PeerReference` isn't valid, return null.

Author: jonpryor

src/Java.Interop/Java.Interop/JavaObject.cs

@@ -8,7 +8,8 @@ namespace Java.Interop
 	[JniTypeSignature ("java/lang/Object", GenerateJavaPeer=false)]
 	unsafe public class JavaObject : IJavaPeerable
 	{
-		internal const DynamicallyAccessedMemberTypes ConstructorsAndInterfaces = DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors | DynamicallyAccessedMemberTypes.Interfaces;
+		internal const DynamicallyAccessedMemberTypes Constructors = DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors;
+		internal const DynamicallyAccessedMemberTypes ConstructorsAndInterfaces = Constructors | DynamicallyAccessedMemberTypes.Interfaces;
 
 		readonly static JniPeerMembers _members = new JniPeerMembers ("java/lang/Object", typeof (JavaObject));
 

src/Java.Interop/Java.Interop/JavaPeerableExtensions.cs

@@ -24,23 +24,19 @@ public static bool TryJavaCast<
 		}
 
 		public static TResult? JavaAs<
-				[DynamicallyAccessedMembers (JavaObject.ConstructorsAndInterfaces)]
+				[DynamicallyAccessedMembers (JavaObject.Constructors)]
 				TResult
 		> (this IJavaPeerable? self)
 			where TResult : class, IJavaPeerable
 		{
-			if (self == null) {
+			if (self == null || !self.PeerReference.IsValid) {
 				return null;
 			}
 
 			if (self is TResult result) {
 				return result;
 			}
 
-			if (!self.PeerReference.IsValid) {
-				throw new ObjectDisposedException (self.GetType ().FullName);
-			}
-
 			var r = self.PeerReference;
 			return JniEnvironment.Runtime.ValueManager.CreatePeer (
 					ref r, JniObjectReferenceOptions.Copy,

src/Java.Interop/Java.Interop/ManagedPeer.cs

@@ -18,7 +18,6 @@ namespace Java.Interop {
 	/* static */ sealed class ManagedPeer : JavaObject {
 
 		internal const string JniTypeName = "net/dot/jni/ManagedPeer";
-		internal const DynamicallyAccessedMemberTypes Constructors = DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors;
 		internal const DynamicallyAccessedMemberTypes ConstructorsMethodsNestedTypes = Constructors | DynamicallyAccessedMemberTypes.PublicMethods | DynamicallyAccessedMemberTypes.NonPublicMethods | DynamicallyAccessedMemberTypes.NonPublicNestedTypes;
 
 

tests/Java.Interop-Tests/Java.Interop/JavaPeerableExtensionsTests.cs

@@ -35,6 +35,13 @@ public void JavaAs_NullSelfReturnsNull ()
 		Assert.AreEqual (null, JavaPeerableExtensions.JavaAs<IAndroidInterface> (null));
 	}
 
+	public void JavaAs_InvalidPeerRefReturnsNull ()
+	{
+		var v   = new MyJavaInterfaceImpl ();
+		v.Dispose ();
+		Assert.AreEqual (null, JavaPeerableExtensions.JavaAs<IJavaInterface> (v));
+	}
+
 	[Test]
 	public void JavaAs_InstanceThatDoesNotImplementInterfaceReturnsNull ()
 	{
@@ -83,6 +90,7 @@ public string Value {
 	}
 }
 
+[JniTypeSignature (IJavaInterface.JniTypeName, GenerateJavaPeer=false)]
 internal class IJavaInterfaceInvoker : JavaObject, IJavaInterface {
 
 	internal    static  readonly    JniPeerMembers  _members    = new JniPeerMembers (IJavaInterface.JniTypeName, typeof (IJavaInterfaceInvoker));