Moves Attack, Armament, Move, Air traits and activities as well as anything required by them to Mods.Common.

Extracts Exit from Production into its own trait.

OpenRA.Mods.Common/Activities/Move/Follow.cs

@@ -0,0 +1,50 @@
+#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 OpenRA.Activities;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Follow : Activity
+	{
+		readonly Target target;
+		readonly WRange minRange;
+		readonly WRange maxRange;
+		readonly IMove move;
+
+		public Follow(Actor self, Target target, WRange minRange, WRange maxRange)
+		{
+			this.target = target;
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+
+			move = self.Trait<IMove>();
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			var cachedPosition = target.CenterPosition;
+			var path = move.MoveWithinRange(target, minRange, maxRange);
+
+			// We are already in range, so wait until the target moves before doing anything
+			if (target.IsInRange(self.CenterPosition, maxRange) && !target.IsInRange(self.CenterPosition, minRange))
+			{
+				var wait = new WaitFor(() => !target.IsValidFor(self) || target.CenterPosition != cachedPosition);
+				return Util.SequenceActivities(wait, path, this);
+			}
+
+			return Util.SequenceActivities(path, this);
+		}
+	}
+}