Remove legacy NET preprocessor paths

Make modern .NET code paths unconditional and remove obsolete non-NET/generated compatibility branches now that Java.Interop targets current .NET or netstandard2.0 only.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: simonrozsival

Documentation/Motivation.md

@@ -11,10 +11,9 @@ intended to fix some of the shortcomings and design mistakes I've made over the
 
 In particular, it attempts to fix the following issues: 
 
-* Split out the core invocation logic so that the containing assembly is in the
-  `xbuild-frameworks\MonoAndroid\v1.0` directory, allowing low-level JNI use
-  without taking an API-level constraint.
-* Make the assembly a PCL lib.
+* Split out the core invocation logic so it can be used without taking an
+  API-level constraint.
+* Make the assembly a reusable .NET library.
 * Support use of the lib on "desktop" Java VMs. This would allow more testing
   without an Android device, could allow using Xamarin.Android Views to be shown
   in the GUI designer, etc.
@@ -28,4 +27,3 @@ which returns a global reference while most other methods return a local ref.
 
 The `JNIEnv` API is also huge, unwieldy, and terrible.
 
-

src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs

@@ -186,20 +186,12 @@ public static string ToJniName (Type type)
 			}, _ => false);
 		}
 
-#if !NETSTANDARD2_0
 		static readonly Lazy<Type> IJavaPeerableType = new Lazy<Type> (() =>
 			Type.GetType ("Java.Interop.IJavaPeerable, Java.Interop", throwOnError: true)!
 		);
-#endif
 
-		// NOTE: NETSTANDARD2_0 could be running in an MSBuild context where Java.Interop.dll is not available.
-		// Trimming warnings are not enabled for netstandard2.0 in this project.
 		static bool ShouldCheckSpecialExportJniType (Type type) =>
-#if NETSTANDARD2_0
-			!type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable");
-#else
 			!IJavaPeerableType.Value.IsAssignableFrom (type);
-#endif
 
 		public static string ToJniName (string jniType, int rank)
 		{
@@ -788,4 +780,3 @@ static string ToLowerCase (string value)
 	}
 }
 
-

src/Java.Interop/Java.Interop/JavaArray.cs

@@ -31,7 +31,7 @@ public int Length {
 
 		[MaybeNull]
 		public abstract T this [int index] {
-			// I think this will be fixable in .NET5+ with support for "T?"
+			// Keep this until nullable annotations can fully express this indexer contract.
 #pragma warning disable CS8766 // Nullability of reference types in return type doesn't match implicitly implemented member (possibly because of nullability attributes).
 			get;
 #pragma warning restore CS8766
@@ -422,4 +422,3 @@ internal static T[] ToArray (IEnumerable<T> value)
 		}
 	}
 }
-

src/Java.Interop/Java.Interop/JavaTypeParametersAttribute.cs

@@ -1,6 +1,5 @@
 using System;
 
-#if NET
 
 namespace Java.Interop
 {
@@ -16,5 +15,3 @@ public JavaTypeParametersAttribute (string [] typeParameters)
 		public string [] TypeParameters { get; }
 	}
 }
-
-#endif  // NET

src/Java.Interop/Java.Interop/JniConstructorSignatureAttribute.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 
-#if NET
 
 namespace Java.Interop
 {
@@ -16,5 +15,3 @@ public JniConstructorSignatureAttribute (string memberSignature)
 		}
 	}
 }
-
-#endif  // NET

src/Java.Interop/Java.Interop/JniEnvironment.Types.cs

@@ -197,7 +197,6 @@ static IntPtr RawCallStaticObjectMethodA (IntPtr env, out IntPtr thrown, IntPtr
 #endif  // FEATURE_JNIENVIRONMENT_JI_FUNCTION_POINTERS
 			}
 
-#if NET
 			public static bool TryFindClass (string classname, out JniObjectReference instance)
 			{
 				if (classname == null)
@@ -208,7 +207,6 @@ public static bool TryFindClass (string classname, out JniObjectReference instan
 				instance = TryFindClass (classname, throwOnError: false);
 				return instance.IsValid;
 			}
-#endif  // NET
 
 			public static JniType? GetTypeFromInstance (JniObjectReference instance)
 			{
@@ -265,7 +263,7 @@ public static void RegisterNatives (JniObjectReference type, JniNativeMethodRegi
 					throw new ArgumentOutOfRangeException (nameof (numMethods), numMethods,
 							$"`numMethods` must be between 0 and `methods.Length` ({methods?.Length ?? 0})!");
 				}
-#if DEBUG && NETCOREAPP
+#if DEBUG
 				for (int i = 0; methods != null && i < numMethods; ++i) {
 					var m   = methods [i];
 					if (m.Marshaler != null && m.Marshaler.GetType ().GenericTypeArguments.Length != 0) {
@@ -275,7 +273,7 @@ public static void RegisterNatives (JniObjectReference type, JniNativeMethodRegi
 						Debug.WriteLine ($"  Marshaler Type={m.Marshaler.GetType ().FullName} Method={method.DeclaringType?.FullName}.{method.Name}");
 					}
 				}
-#endif  // DEBUG && NETCOREAPP
+#endif  // DEBUG
 
 				int r   = _RegisterNatives (type, methods ?? Array.Empty<JniNativeMethodRegistration>(), numMethods);
 

src/Java.Interop/Java.Interop/JniMemberSignature.cs

@@ -1,7 +1,5 @@
 #nullable enable
 
-#if NET
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Collections.Generic;
@@ -146,5 +144,3 @@ public override string ToString ()
 		public static bool operator!= (JniMemberSignature a, JniMemberSignature b) => !a.Equals (b);
 	}
 }
-
-#endif  // NET

src/Java.Interop/Java.Interop/JniMemberSignatureAttribute.cs

@@ -2,7 +2,6 @@
 
 using System;
 
-#if NET
 
 namespace Java.Interop
 {
@@ -23,5 +22,3 @@ internal JniMemberSignatureAttribute (string memberName, string memberSignature)
 		public      string      MemberSignature     {get;}
 	}
 }
-
-#endif  // NET

src/Java.Interop/Java.Interop/JniMethodInfo.cs

@@ -10,10 +10,8 @@ public sealed class JniMethodInfo
 
 		public      bool    IsStatic    {get; private set;}
 
-#if NET
 		internal    JniType?    StaticRedirect;
 		internal    int?        ParameterCount;
-#endif  //NET
 
 		internal    bool    IsValid {
 			get {return ID != IntPtr.Zero;}

src/Java.Interop/Java.Interop/JniMethodSignatureAttribute.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 
-#if NET
 
 namespace Java.Interop
 {
@@ -16,5 +15,3 @@ public JniMethodSignatureAttribute (string memberName, string memberSignature)
 		}
 	}
 }
-
-#endif  // NET