move aircraft code into Mods.RA/Air/

OpenRA.Mods.RA/Air/TargetableAircraft.cs

@@ -0,0 +1,39 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2010 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 LICENSE.
+ */
+#endregion
+
+using System.Drawing;
+using OpenRA.Graphics;
+using System.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Air
+{
+    public class TargetableAircraftInfo : TargetableUnitInfo, ITraitPrerequisite<AircraftInfo>
+    {
+        public readonly string[] GroundedTargetTypes = { };
+        public override object Create(ActorInitializer init) { return new TargetableAircraft(init.self, this); }
+    }
+
+    public class TargetableAircraft : TargetableUnit<TargetableAircraftInfo>
+    {
+        Aircraft Aircraft;
+        public TargetableAircraft(Actor self, TargetableAircraftInfo info)
+            : base(info)
+        {
+            Aircraft = self.Trait<Aircraft>();
+        }
+
+        public override string[] TargetTypes
+        {
+            get { return (Aircraft.Altitude > 0) ? info.TargetTypes 
+                                                 : info.GroundedTargetTypes; }
+        }
+    }
+}