Port Demolish to the new Enter activity.

OpenRA.Mods.Common/Activities/Demolish.cs

@@ -9,55 +9,79 @@
  */
 #endregion
 
+using System;
 using System.Drawing;
 using System.Linq;
 using OpenRA.Mods.Common.Effects;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	class Demolish : LegacyEnter
+	class Demolish : Enter
 	{
-		readonly Actor target;
-		readonly IDemolishable[] demolishables;
 		readonly int delay;
 		readonly int flashes;
 		readonly int flashesDelay;
 		readonly int flashInterval;
 		readonly INotifyDemolition[] notifiers;
+		readonly EnterBehaviour enterBehaviour;
 
-		public Demolish(Actor self, Actor target, EnterBehaviour enterBehaviour, int delay,
+		Actor enterActor;
+		IDemolishable[] enterDemolishables;
+
+		public Demolish(Actor self, Target target, EnterBehaviour enterBehaviour, int delay,
 			int flashes, int flashesDelay, int flashInterval)
-			: base(self, target, enterBehaviour, targetLineColor: Color.Red)
+			: base(self, target, Color.Red)
 		{
-			this.target = target;
-			demolishables = target.TraitsImplementing<IDemolishable>().ToArray();
 			notifiers = self.TraitsImplementing<INotifyDemolition>().ToArray();
 			this.delay = delay;
 			this.flashes = flashes;
 			this.flashesDelay = flashesDelay;
 			this.flashInterval = flashInterval;
+			this.enterBehaviour = enterBehaviour;
 		}
 
-		protected override bool CanReserve(Actor self)
+		protected override bool TryStartEnter(Actor self, Actor targetActor)
 		{
-			return demolishables.Any(i => i.IsValidTarget(target, self));
+			enterActor = targetActor;
+			enterDemolishables = targetActor.TraitsImplementing<IDemolishable>().ToArray();
+
+			// Make sure we can still demolish the target before entering
+			// (but not before, because this may stop the actor in the middle of nowhere)
+			if (!enterDemolishables.Any(i => i.IsValidTarget(enterActor, self)))
+			{
+				Cancel(self, true);
+				return false;
+			}
+
+			return true;
 		}
 
-		protected override void OnInside(Actor self)
+		protected override void OnEnterComplete(Actor self, Actor targetActor)
 		{
 			self.World.AddFrameEndTask(w =>
 			{
-				if (target.IsDead)
+				// Make sure the target hasn't changed while entering
+				// OnEnterComplete is only called if targetActor is alive
+				if (targetActor != enterActor)
 					return;
 
-				w.Add(new FlashTarget(target, count: flashes, delay: flashesDelay, interval: flashInterval));
+				if (!enterDemolishables.Any(i => i.IsValidTarget(enterActor, self)))
+					return;
+
+				w.Add(new FlashTarget(enterActor, count: flashes, delay: flashesDelay, interval: flashInterval));
 
 				foreach (var ind in notifiers)
 					ind.Demolishing(self);
 
-				foreach (var d in demolishables)
-					d.Demolish(target, self, delay);
+				foreach (var d in enterDemolishables)
+					d.Demolish(enterActor, self, delay);
+
+				if (enterBehaviour == EnterBehaviour.Dispose)
+					self.Dispose();
+				else if (enterBehaviour == EnterBehaviour.Suicide)
+					self.Kill(self);
 			});
 		}
 	}