put enter transport order targeters into respective files

OpenRA.Mods.Common/Orders/EnterTransportsTargeter.cs

@@ -0,0 +1,50 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 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.Generic;
+using System.Drawing;
+using OpenRA.Mods.Common.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Orders
+{
+	public class EnterTransportsTargeter : EnterAlliedActorTargeter<CargoInfo>
+	{
+		readonly AlternateTransportsMode mode;
+
+		public EnterTransportsTargeter(string order, int priority,
+			Func<Actor, bool> canTarget, Func<Actor, bool> useEnterCursor,
+			AlternateTransportsMode mode)
+			: base(order, priority, canTarget, useEnterCursor) { this.mode = mode; }
+
+		public override bool CanTargetActor(Actor self, Actor target, TargetModifiers modifiers, ref string cursor)
+		{
+			switch (mode)
+			{
+				case AlternateTransportsMode.None:
+					return false;
+				case AlternateTransportsMode.Force:
+					if (!modifiers.HasModifier(TargetModifiers.ForceMove))
+						return false;
+					break;
+				case AlternateTransportsMode.Default:
+					if (modifiers.HasModifier(TargetModifiers.ForceMove))
+						return false;
+					break;
+				case AlternateTransportsMode.Always:
+					break;
+			}
+
+			return base.CanTargetActor(self, target, modifiers, ref cursor);
+		}
+	}
+}