Add a new native-lua implementation.

OpenRA.Game/Scripting/ScriptMemberWrapper.cs

@@ -0,0 +1,127 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Eluant;
+using Eluant.ObjectBinding;
+using OpenRA.FileFormats;
+using OpenRA.Traits;
+
+namespace OpenRA.Scripting
+{
+	public class ScriptMemberWrapper
+	{
+		readonly ScriptContext context;
+		public readonly object Target;
+		public readonly MemberInfo Member;
+
+		public readonly bool IsMethod;
+		public readonly bool IsGetProperty;
+		public readonly bool IsSetProperty;
+
+		public ScriptMemberWrapper(ScriptContext context, object target, MemberInfo mi)
+		{
+			this.context = context;
+			Target = target;
+			Member = mi;
+
+			var property = mi as PropertyInfo;
+			if (property != null)
+			{
+				IsGetProperty = property.GetGetMethod() != null;
+				IsSetProperty = property.GetSetMethod() != null;
+			}
+			else
+				IsMethod = true;
+		}
+
+		LuaValue Invoke(LuaVararg args)
+		{
+			if (!IsMethod)
+				throw new LuaException("Trying to invoke a ScriptMemberWrapper that isn't a method!");
+
+			var mi = Member as MethodInfo;
+			var pi = mi.GetParameters();
+
+			object[] clrArgs = new object[pi.Length];
+			var argCount = args.Count;
+			for (var i = 0; i < pi.Length; i++)
+			{
+				if (i >= argCount)
+				{
+					if (!pi[i].IsOptional)
+						throw new LuaException("Argument '{0}' of '{1}' is not optional.".F(pi[i].LuaDocString(), Member.LuaDocString()));
+
+					clrArgs[i] = pi[i].DefaultValue;
+					continue;
+				}
+
+				if (!args[i].TryGetClrValue(pi[i].ParameterType, out clrArgs[i]))
+					throw new LuaException("Unable to convert parameter {0} to {1}".F(i, pi[i].ParameterType.Name));
+			}
+
+			var ret = (Member as MethodInfo).Invoke(Target, clrArgs);
+			return ret.ToLuaValue(context);
+		}
+
+		public LuaValue Get(LuaRuntime runtime)
+		{
+			if (IsMethod)
+				return runtime.CreateFunctionFromDelegate((Func<LuaVararg, LuaValue>)Invoke);
+
+			if (IsGetProperty)
+			{
+				var pi = Member as PropertyInfo;
+				return pi.GetValue(Target, null).ToLuaValue(context);
+			}
+
+			throw new LuaException("The property '{0}' is write-only".F(Member.Name));
+		}
+
+		public void Set(LuaRuntime runtime, LuaValue value)
+		{
+			if (IsSetProperty)
+			{
+				var pi = Member as PropertyInfo;
+				object clrValue;
+				if (!value.TryGetClrValue(pi.PropertyType, out clrValue))
+					throw new LuaException("Unable to convert '{0}' to Clr type '{1}'".F(value.WrappedClrType().Name, pi.PropertyType));
+
+				pi.SetValue(Target, clrValue, null);
+			}
+			else
+				throw new LuaException("The property '{0}' is read-only".F(Member.Name));
+		}
+
+		public static IEnumerable<MemberInfo> WrappableMembers(Type t)
+		{
+			// Only expose defined public non-static methods that were explicitly declared by the author
+			var flags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly;
+			return t.GetMembers(flags).Where(mi =>
+			{
+				// Properties are always wrappable
+				if (mi is PropertyInfo)
+					return true;
+
+				// Methods are allowed if they aren't generic, and aren't generated by the compiler
+				var method = mi as MethodInfo;
+				if (method != null && !method.IsGenericMethodDefinition && !method.IsSpecialName)
+					return true;
+
+				// Fields aren't allowed
+				return false;
+			});
+		}
+	}
+}