Make Tick return bool

OpenRA.Game/Activities/Activity.cs

@@ -21,8 +21,7 @@ namespace OpenRA.Activities
 	/*
 	 * Things to be aware of when writing activities:
 	 *
-	 * - Use "return NextActivity" at least once somewhere in the tick method.
-	 * - Do not use "return new SomeActivity()" as that will break the queue. Queue the new activity and use "return NextActivity" instead.
+	 * - Use "return true" at least once somewhere in the tick method.
 	 * - Do not "reuse" (with "SequenceActivities", for example) activity objects that have already started running.
 	 *   Queue a new instance instead.
 	 * - Avoid calling actor.CancelActivity(). It is almost always a bug. Call activity.Cancel() instead.
@@ -32,11 +31,13 @@ namespace OpenRA.Activities
 		public ActivityState State { get; private set; }
 
 		protected Activity ChildActivity { get; private set; }
-		public Activity NextActivity { get; protected set; }
+		public Activity NextActivity { get; private set; }
 
 		public bool IsInterruptible { get; protected set; }
 		public bool ChildHasPriority { get; protected set; }
 		public bool IsCanceling { get { return State == ActivityState.Canceling; } }
+		bool finishing;
+		bool lastRun;
 
 		public Activity()
 		{
@@ -55,33 +56,60 @@ namespace OpenRA.Activities
 				State = ActivityState.Active;
 			}
 
+			// Only run the parent tick when the child is done.
+			// We must always let the child finish on its own before continuing.
 			if (ChildHasPriority)
 			{
-				ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
-				if (ChildActivity != null)
-					return this;
+				lastRun = TickChild(self) && (finishing || Tick(self));
+				finishing |= lastRun;
 			}
 
-			var ret = Tick(self);
+			// The parent determines whether the child gets a chance at ticking.
+			else
+				lastRun = Tick(self);
 
+			// Avoid a single tick delay if the childactivity was just queued.
 			if (ChildActivity != null && ChildActivity.State == ActivityState.Queued)
-				ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
+			{
+				if (ChildHasPriority)
+					lastRun = TickChild(self) && finishing;
+				else
+					TickChild(self);
+			}
 
-			if (ret != this)
+			if (lastRun)
 			{
 				State = ActivityState.Done;
 				OnLastRun(self);
+				return NextActivity;
 			}
 
-			return ret;
+			return this;
+		}
+
+		protected bool TickChild(Actor self)
+		{
+			ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
+			return ChildActivity == null;
 		}
 
 		/// <summary>
-		/// Runs every timestep as long as this activity is active.
+		/// Called every tick to run activity logic. Returns false if the activity should
+		/// remain active, or true if it is complete. Cancelled activities must ensure they
+		/// return the actor to a consistent state before returning true.
+		///
+		/// Child activities can be queued using QueueChild, and these will be ticked
+		/// instead of the parent while they are active. Activities that need to run logic
+		/// in parallel with child activities should set ChildHasPriority to false and
+		/// manually call TickChildren.
+		///
+		/// Queuing one or more child activities and returning true is valid, and causes
+		/// the activity to be completed immediately (without ticking again) once the
+		/// children have completed.
 		/// </summary>
-		public virtual Activity Tick(Actor self)
+		public virtual bool Tick(Actor self)
 		{
-			return NextActivity;
+			return true;
 		}
 
 		/// <summary>

OpenRA.Game/Activities/CallFunc.cs

@@ -24,10 +24,10 @@ namespace OpenRA.Activities
 
 		Action a;
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (a != null) a();
-			return NextActivity;
+			return true;
 		}
 	}
 }

OpenRA.Mods.Cnc/Activities/LayMines.cs

@@ -37,10 +37,10 @@ namespace OpenRA.Mods.Cnc.Activities
 			this.minefield = minefield;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			if (rearmableInfo != null && ammoPools.Any(p => p.Info.Name == info.AmmoPoolName && !p.HasAmmo()))
 			{
@@ -50,20 +50,20 @@ namespace OpenRA.Mods.Cnc.Activities
 					.ClosestTo(self);
 
 				if (rearmTarget == null)
-					return NextActivity;
+					return true;
 
 				// Add a CloseEnough range of 512 to the Rearm/Repair activities in order to ensure that we're at the host actor
 				QueueChild(new MoveAdjacentTo(self, Target.FromActor(rearmTarget)));
 				QueueChild(movement.MoveTo(self.World.Map.CellContaining(rearmTarget.CenterPosition), rearmTarget));
 				QueueChild(new Resupply(self, rearmTarget, new WDist(512)));
-				return this;
+				return false;
 			}
 
 			if ((minefield == null || minefield.Contains(self.Location)) && ShouldLayMine(self, self.Location))
 			{
 				LayMine(self);
 				QueueChild(new Wait(20)); // A little wait after placing each mine, for show
-				return this;
+				return false;
 			}
 
 			if (minefield != null && minefield.Length > 0)
@@ -75,13 +75,13 @@ namespace OpenRA.Mods.Cnc.Activities
 					if (ShouldLayMine(self, p))
 					{
 						QueueChild(movement.MoveTo(p, 0));
-						return this;
+						return false;
 					}
 				}
 			}
 
 			// TODO: Return somewhere likely to be safe (near rearm building) so we're not sitting out in the minefield.
-			return NextActivity;
+			return true;
 		}
 
 		static bool ShouldLayMine(Actor self, CPos p)

OpenRA.Mods.Cnc/Activities/Leap.cs

@@ -70,11 +70,11 @@ namespace OpenRA.Mods.Cnc.Activities
 			attack.GrantLeapCondition(self);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Correct the visual position after we jumped
 			if (canceled || jumpComplete)
-				return NextActivity;
+				return true;
 
 			if (target.Type != TargetType.Invalid)
 				targetPosition = target.CenterPosition;
@@ -100,7 +100,7 @@ namespace OpenRA.Mods.Cnc.Activities
 				QueueChild(mobile.VisualMove(self, position, self.World.Map.CenterOfSubCell(destinationCell, destinationSubCell)));
 			}
 
-			return this;
+			return false;
 		}
 
 		protected override void OnLastRun(Actor self)

OpenRA.Mods.Cnc/Activities/LeapAttack.cs

@@ -72,10 +72,10 @@ namespace OpenRA.Mods.Cnc.Activities
 			attack.IsAiming = true;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			bool targetIsHiddenActor;
 			target = target.Recalculate(self.Owner, out targetIsHiddenActor);
@@ -97,7 +97,7 @@ namespace OpenRA.Mods.Cnc.Activities
 
 			// Target is hidden or dead, and we don't have a fallback position to move towards
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
-				return NextActivity;
+				return true;
 
 			var pos = self.CenterPosition;
 			var checkTarget = useLastVisibleTarget ? lastVisibleTarget : target;
@@ -105,27 +105,27 @@ namespace OpenRA.Mods.Cnc.Activities
 			if (!checkTarget.IsInRange(pos, lastVisibleMaxRange) || checkTarget.IsInRange(pos, lastVisibleMinRange))
 			{
 				if (!allowMovement || lastVisibleMaxRange == WDist.Zero || lastVisibleMaxRange < lastVisibleMinRange)
-					return NextActivity;
+					return true;
 
 				QueueChild(mobile.MoveWithinRange(target, lastVisibleMinRange, lastVisibleMaxRange, checkTarget.CenterPosition, Color.Red));
-				return this;
+				return false;
 			}
 
 			// Ready to leap, but target isn't visible
 			if (targetIsHiddenActor || target.Type != TargetType.Actor)
-				return NextActivity;
+				return true;
 
 			// Target is not valid
 			if (!target.IsValidFor(self) || !attack.HasAnyValidWeapons(target))
-				return NextActivity;
+				return true;
 
 			var edible = target.Actor.TraitOrDefault<EdibleByLeap>();
 			if (edible == null || !edible.CanLeap(self))
-				return NextActivity;
+				return true;
 
 			// Can't leap yet
 			if (attack.Armaments.All(a => a.IsReloading))
-				return this;
+				return false;
 
 			// Use CenterOfSubCell with ToSubCell instead of target.Centerposition
 			// to avoid continuous facing adjustments as the target moves
@@ -138,13 +138,13 @@ namespace OpenRA.Mods.Cnc.Activities
 			if (mobile.Facing != desiredFacing)
 			{
 				QueueChild(new Turn(self, desiredFacing));
-				return this;
+				return false;
 			}
 
 			QueueChild(new Leap(self, target, mobile, targetMobile, info.Speed.Length, attack, edible));
 
 			// Re-queue the child activities to kill the target if it didn't die in one go
-			return this;
+			return false;
 		}
 
 		protected override void OnLastRun(Actor self)

OpenRA.Mods.Cnc/Activities/Teleport.cs

@@ -52,7 +52,7 @@ namespace OpenRA.Mods.Cnc.Activities
 				IsInterruptible = false;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			var pc = self.TraitOrDefault<PortableChrono>();
 			if (teleporter == self && pc != null && (!pc.CanTeleport || IsCanceling))
@@ -60,7 +60,7 @@ namespace OpenRA.Mods.Cnc.Activities
 				if (killOnFailure)
 					self.Kill(teleporter, killDamageTypes);
 
-				return NextActivity;
+				return true;
 			}
 
 			var bestCell = ChooseBestDestinationCell(self, destination);
@@ -69,7 +69,7 @@ namespace OpenRA.Mods.Cnc.Activities
 				if (killOnFailure)
 					self.Kill(teleporter, killDamageTypes);
 
-				return NextActivity;
+				return true;
 			}
 
 			destination = bestCell.Value;
@@ -112,7 +112,7 @@ namespace OpenRA.Mods.Cnc.Activities
 					building.PlayCustomAnimation(teleporter, "active");
 			}
 
-			return NextActivity;
+			return true;
 		}
 
 		CPos? ChooseBestDestinationCell(Actor self, CPos destination)

OpenRA.Mods.Cnc/Activities/VoxelHarvesterDockSequence.cs

@@ -27,7 +27,7 @@ namespace OpenRA.Mods.Cnc.Activities
 			spriteOverlay = refinery.TraitOrDefault<WithDockingOverlay>();
 		}
 
-		public override Activity OnStateDock(Actor self)
+		public override void OnStateDock(Actor self)
 		{
 			body.Docked = true;
 
@@ -42,11 +42,9 @@ namespace OpenRA.Mods.Cnc.Activities
 			}
 			else
 				dockingState = DockingState.Loop;
-
-			return this;
 		}
 
-		public override Activity OnStateUndock(Actor self)
+		public override void OnStateUndock(Actor self)
 		{
 			dockingState = DockingState.Wait;
 
@@ -65,8 +63,6 @@ namespace OpenRA.Mods.Cnc.Activities
 				dockingState = DockingState.Complete;
 				body.Docked = false;
 			}
-
-			return this;
 		}
 	}
 }

OpenRA.Mods.Cnc/Traits/Attack/AttackTDGunboatTurreted.cs

@@ -46,13 +46,13 @@ namespace OpenRA.Mods.Cnc.Traits
 				this.forceAttack = forceAttack;
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				if (IsCanceling || !target.IsValidFor(self))
-					return NextActivity;
+					return true;
 
 				if (attack.IsTraitDisabled)
-					return this;
+					return false;
 
 				var weapon = attack.ChooseArmamentsForTarget(target, forceAttack).FirstOrDefault();
 				if (weapon != null)
@@ -60,13 +60,13 @@ namespace OpenRA.Mods.Cnc.Traits
 					// Check that AttackTDGunboatTurreted hasn't cancelled the target by modifying attack.Target
 					// Having both this and AttackTDGunboatTurreted modify that field is a horrible hack.
 					if (hasTicked && attack.RequestedTarget.Type == TargetType.Invalid)
-						return NextActivity;
+						return true;
 
 					attack.SetRequestedTarget(self, target);
 					hasTicked = true;
 				}
 
-				return NextActivity;
+				return true;
 			}
 		}
 	}

OpenRA.Mods.Cnc/Traits/Attack/AttackTesla.cs

@@ -94,13 +94,13 @@ namespace OpenRA.Mods.Cnc.Traits
 				this.forceAttack = forceAttack;
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				if (IsCanceling || !attack.CanAttack(self, target))
-					return NextActivity;
+					return true;
 
 				if (attack.charges == 0)
-					return this;
+					return false;
 
 				foreach (var notify in self.TraitsImplementing<INotifyTeslaCharging>())
 					notify.Charging(self, target);
@@ -110,7 +110,7 @@ namespace OpenRA.Mods.Cnc.Traits
 
 				QueueChild(new Wait(attack.info.InitialChargeDelay));
 				QueueChild(new ChargeFire(attack, target));
-				return this;
+				return false;
 			}
 
 			void IActivityNotifyStanceChanged.StanceChanged(Actor self, AutoTarget autoTarget, UnitStance oldStance, UnitStance newStance)
@@ -145,18 +145,18 @@ namespace OpenRA.Mods.Cnc.Traits
 				this.target = target;
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				if (IsCanceling || !attack.CanAttack(self, target))
-					return NextActivity;
+					return true;
 
 				if (attack.charges == 0)
-					return NextActivity;
+					return true;
 
 				attack.DoAttack(self, target);
 
 				QueueChild(new Wait(attack.info.ChargeDelay));
-				return this;
+				return false;
 			}
 		}
 	}

OpenRA.Mods.Common/Activities/Air/FallToEarth.cs

@@ -32,7 +32,7 @@ namespace OpenRA.Mods.Common.Activities
 				acceleration = self.World.SharedRandom.Next(2) * 2 - 1;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (self.World.Map.DistanceAboveTerrain(self.CenterPosition).Length <= 0)
 			{
@@ -43,7 +43,8 @@ namespace OpenRA.Mods.Common.Activities
 				}
 
 				self.Kill(self);
-				return null;
+				Cancel(self);
+				return true;
 			}
 
 			if (info.Spins)
@@ -56,7 +57,7 @@ namespace OpenRA.Mods.Common.Activities
 			move -= new WVec(WDist.Zero, WDist.Zero, info.Velocity);
 			aircraft.SetPosition(self, aircraft.CenterPosition + move);
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/Fly.cs

@@ -100,7 +100,7 @@ namespace OpenRA.Mods.Common.Activities
 			return true;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
@@ -122,15 +122,15 @@ namespace OpenRA.Mods.Common.Activities
 					else
 						VerticalTakeOffOrLandTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
 
-					return this;
+					return false;
 				}
 
-				return NextActivity;
+				return true;
 			}
 			else if (dat <= aircraft.LandAltitude)
 			{
 				QueueChild(new TakeOff(self, target));
-				return this;
+				return false;
 			}
 
 			bool targetIsHiddenActor;
@@ -147,7 +147,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			// Target is hidden or dead, and we don't have a fallback position to move towards
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
-				return NextActivity;
+				return true;
 
 			var checkTarget = useLastVisibleTarget ? lastVisibleTarget : target;
 			var pos = aircraft.GetPosition();
@@ -158,7 +158,7 @@ namespace OpenRA.Mods.Common.Activities
 			var insideMaxRange = maxRange.Length > 0 && checkTarget.IsInRange(pos, maxRange);
 			var insideMinRange = minRange.Length > 0 && checkTarget.IsInRange(pos, minRange);
 			if (insideMaxRange && !insideMinRange)
-				return NextActivity;
+				return true;
 
 			var move = aircraft.Info.CanHover ? aircraft.FlyStep(desiredFacing) : aircraft.FlyStep(aircraft.Facing);
 
@@ -166,7 +166,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (aircraft.Info.CanHover && insideMinRange)
 			{
 				FlyTick(self, aircraft, desiredFacing, aircraft.Info.CruiseAltitude, -move);
-				return this;
+				return false;
 			}
 
 			// The next move would overshoot, so consider it close enough or set final position if CanHover
@@ -186,11 +186,11 @@ namespace OpenRA.Mods.Common.Activities
 					if (dat != aircraft.Info.CruiseAltitude)
 					{
 						Fly.VerticalTakeOffOrLandTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
-						return this;
+						return false;
 					}
 				}
 
-				return NextActivity;
+				return true;
 			}
 
 			if (!aircraft.Info.CanHover)
@@ -216,7 +216,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			FlyTick(self, aircraft, desiredFacing, aircraft.Info.CruiseAltitude);
 
-			return this;
+			return false;
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)

OpenRA.Mods.Common/Activities/Air/FlyAttack.cs

@@ -63,7 +63,7 @@ namespace OpenRA.Mods.Common.Activities
 			}
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
@@ -73,16 +73,16 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				// Cancel the requested target, but keep firing on it while in range
 				attackAircraft.ClearRequestedTarget();
-				return NextActivity;
+				return true;
 			}
 
 			// Check that AttackFollow hasn't cancelled the target by modifying attack.Target
 			// Having both this and AttackFollow modify that field is a horrible hack.
 			if (hasTicked && attackAircraft.RequestedTarget.Type == TargetType.Invalid)
-				return NextActivity;
+				return true;
 
 			if (attackAircraft.IsTraitPaused)
-				return this;
+				return false;
 
 			bool targetIsHiddenActor;
 			target = target.Recalculate(self.Owner, out targetIsHiddenActor);
@@ -108,14 +108,14 @@ namespace OpenRA.Mods.Common.Activities
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
 			{
 				attackAircraft.ClearRequestedTarget();
-				return NextActivity;
+				return true;
 			}
 
 			// If all valid weapons have depleted their ammo and Rearmable trait exists, return to RearmActor to reload and then resume the activity
 			if (rearmable != null && !useLastVisibleTarget && attackAircraft.Armaments.All(x => x.IsTraitPaused || !x.Weapon.IsValidAgainst(target, self.World, self)))
 			{
 				QueueChild(new ReturnToBase(self, aircraft.Info.AbortOnResupply));
-				return this;
+				return false;
 			}
 
 			var pos = self.CenterPosition;
@@ -128,12 +128,12 @@ namespace OpenRA.Mods.Common.Activities
 				if (checkTarget.IsInRange(pos, lastVisibleMaximumRange))
 				{
 					attackAircraft.ClearRequestedTarget();
-					return NextActivity;
+					return true;
 				}
 
 				// Fly towards the last known position
 				QueueChild(new Fly(self, target, WDist.Zero, lastVisibleMaximumRange, checkTarget.CenterPosition, Color.Red));
-				return this;
+				return false;
 			}
 
 			var delta = attackAircraft.GetTargetPosition(pos, target) - pos;
@@ -160,7 +160,7 @@ namespace OpenRA.Mods.Common.Activities
 					Fly.VerticalTakeOffOrLandTick(self, aircraft, desiredFacing, aircraft.Info.CruiseAltitude);
 			}
 
-			return this;
+			return false;
 		}
 
 		void IActivityNotifyStanceChanged.StanceChanged(Actor self, AutoTarget autoTarget, UnitStance oldStance, UnitStance newStance)

OpenRA.Mods.Common/Activities/Air/FlyCircle.cs

@@ -27,20 +27,20 @@ namespace OpenRA.Mods.Common.Activities
 			this.turnSpeedOverride = turnSpeedOverride;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (remainingTicks == 0 || (NextActivity != null && remainingTicks < 0))
-				return NextActivity;
+				return true;
 
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
 			{
 				Cancel(self);
-				return NextActivity;
+				return true;
 			}
 
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			if (remainingTicks > 0)
 				remainingTicks--;
@@ -53,7 +53,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			Fly.FlyTick(self, aircraft, desiredFacing, aircraft.Info.CruiseAltitude, move, turnSpeedOverride);
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/FlyFollow.cs

@@ -45,14 +45,14 @@ namespace OpenRA.Mods.Common.Activities
 				lastVisibleTarget = Target.FromPos(initialTargetPosition.Value);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
 				Cancel(self);
 
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			bool targetIsHiddenActor;
 			target = target.Recalculate(self.Owner, out targetIsHiddenActor);
@@ -65,7 +65,7 @@ namespace OpenRA.Mods.Common.Activities
 			// If we are ticking again after previously sequencing a MoveWithRange then that move must have completed
 			// Either we are in range and can see the target, or we've lost track of it and should give up
 			if (wasMovingWithinRange && targetIsHiddenActor)
-				return NextActivity;
+				return true;
 
 			wasMovingWithinRange = false;
 
@@ -75,7 +75,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			// Target is hidden or dead, and we don't have a fallback position to move towards
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
-				return NextActivity;
+				return true;
 
 			var pos = self.CenterPosition;
 			var checkTarget = useLastVisibleTarget ? lastVisibleTarget : target;
@@ -85,12 +85,12 @@ namespace OpenRA.Mods.Common.Activities
 			if (checkTarget.IsInRange(pos, maxRange) && !checkTarget.IsInRange(pos, minRange))
 			{
 				Fly.FlyTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
-				return useLastVisibleTarget ? NextActivity : this;
+				return useLastVisibleTarget;
 			}
 
 			wasMovingWithinRange = true;
 			QueueChild(aircraft.MoveWithinRange(target, minRange, maxRange, checkTarget.CenterPosition, targetLineColor));
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/FlyOffMap.cs

@@ -23,20 +23,20 @@ namespace OpenRA.Mods.Common.Activities
 			aircraft = self.Trait<Aircraft>();
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
 			{
 				Cancel(self);
-				return NextActivity;
+				return true;
 			}
 
 			if (IsCanceling || !self.World.Map.Contains(self.Location))
-				return NextActivity;
+				return true;
 
 			Fly.FlyTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/FlyTimed.cs

@@ -27,21 +27,21 @@ namespace OpenRA.Mods.Common.Activities
 			cruiseAltitude = aircraft.Info.CruiseAltitude;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
 			{
 				Cancel(self);
-				return NextActivity;
+				return true;
 			}
 
 			if (IsCanceling || remainingTicks-- == 0)
-				return NextActivity;
+				return true;
 
 			Fly.FlyTick(self, aircraft, aircraft.Facing, cruiseAltitude);
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/Land.cs

@@ -71,7 +71,7 @@ namespace OpenRA.Mods.Common.Activities
 				target = Target.FromCell(self.World, self.Location);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || target.Type == TargetType.Invalid)
 			{
@@ -88,15 +88,15 @@ namespace OpenRA.Mods.Common.Activities
 						if (dat > aircraft.LandAltitude && dat < aircraft.Info.CruiseAltitude)
 						{
 							QueueChild(new TakeOff(self));
-							return this;
+							return false;
 						}
 
 						aircraft.RemoveInfluence();
-						return NextActivity;
+						return true;
 					}
 				}
 				else
-					return NextActivity;
+					return true;
 			}
 
 			var pos = aircraft.GetPosition();
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			// We are already at the landing location.
 			if ((targetPosition - pos).LengthSquared == 0)
-				return NextActivity;
+				return true;
 
 			// Look for free landing cell
 			if (target.Type == TargetType.Terrain && !landingInitiated)
@@ -119,7 +119,7 @@ namespace OpenRA.Mods.Common.Activities
 				{
 					Cancel(self, true);
 					QueueChild(aircraft.MoveTo(landingCell, 0));
-					return this;
+					return false;
 				}
 
 				if (newLocation.Value != landingCell)
@@ -138,7 +138,7 @@ namespace OpenRA.Mods.Common.Activities
 				if (desiredFacing != -1)
 					QueueChild(new Turn(self, desiredFacing));
 
-				return this;
+				return false;
 			}
 
 			if (!aircraft.Info.VTOL && !finishedApproach)
@@ -198,7 +198,7 @@ namespace OpenRA.Mods.Common.Activities
 				// Fix a problem when the airplane is sent to land near the landing cell
 				QueueChild(new Fly(self, Target.FromPos(w3), WDist.Zero, new WDist(turnRadius / 2)));
 				finishedApproach = true;
-				return this;
+				return false;
 			}
 
 			if (!landingInitiated)
@@ -215,7 +215,7 @@ namespace OpenRA.Mods.Common.Activities
 
 					self.NotifyBlocker(blockingCells);
 					finishedApproach = false;
-					return this;
+					return false;
 				}
 
 				if (aircraft.Info.LandingSounds.Length > 0)
@@ -231,9 +231,9 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				var landAltitude = self.World.Map.DistanceAboveTerrain(targetPosition) + aircraft.LandAltitude;
 				if (Fly.VerticalTakeOffOrLandTick(self, aircraft, aircraft.Facing, landAltitude))
-					return this;
+					return false;
 
-				return NextActivity;
+				return true;
 			}
 
 			var d = targetPosition - pos;
@@ -244,13 +244,13 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				var landingAltVec = new WVec(WDist.Zero, WDist.Zero, aircraft.LandAltitude);
 				aircraft.SetPosition(self, targetPosition + landingAltVec);
-				return NextActivity;
+				return true;
 			}
 
 			var landingAlt = self.World.Map.DistanceAboveTerrain(targetPosition) + aircraft.LandAltitude;
 			Fly.FlyTick(self, aircraft, d.Yaw.Facing, landingAlt);
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/ReturnToBase.cs

@@ -66,12 +66,12 @@ namespace OpenRA.Mods.Common.Activities
 					&& rearmable.RearmableAmmoPools.Any(p => !p.FullAmmo());
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			// Special case: Don't kill other deploy hotkey activities.
 			if (aircraft.ForceLanding)
-				return NextActivity;
+				return true;
 
 			// If a Cancel was triggered at this point, it's unlikely that previously queued child activities finished,
 			// so 'resupplied' needs to be set to false, else it + abortOnResupply might cause another Cancel
@@ -84,7 +84,7 @@ namespace OpenRA.Mods.Common.Activities
 				self.CancelActivity();
 
 			if (resupplied || IsCanceling || self.IsDead)
-				return NextActivity;
+				return true;
 
 			if (dest == null || dest.IsDead || !Reservable.IsAvailableFor(dest, self))
 				dest = ChooseResupplier(self, true);
@@ -109,17 +109,17 @@ namespace OpenRA.Mods.Common.Activities
 							QueueChild(new Fly(self, target, WDist.Zero, aircraft.Info.WaitDistanceFromResupplyBase, targetLineColor: Color.Green));
 						}
 
-						return this;
+						return false;
 					}
 
 					QueueChild(new Fly(self, Target.FromActor(nearestResupplier), WDist.Zero, aircraft.Info.WaitDistanceFromResupplyBase, targetLineColor: Color.Green));
 					QueueChild(new FlyCircle(self, aircraft.Info.NumberOfTicksToVerifyAvailableAirport));
-					return this;
+					return false;
 				}
 
 				// Prevent an infinite loop in case we'd return to the activity that called ReturnToBase in the first place. Go idle instead.
 				self.CancelActivity();
-				return NextActivity;
+				return true;
 			}
 
 			if (ShouldLandAtBuilding(self, dest))
@@ -141,7 +141,7 @@ namespace OpenRA.Mods.Common.Activities
 				QueueChild(new Fly(self, Target.FromActor(dest)));
 
 			resupplied = true;
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/TakeOff.cs

@@ -62,13 +62,13 @@ namespace OpenRA.Mods.Common.Activities
 				Game.Sound.Play(SoundType.World, aircraft.Info.TakeoffSounds, self.World, aircraft.CenterPosition);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Refuse to take off if it would land immediately again.
 			if (aircraft.ForceLanding)
 			{
 				Cancel(self);
-				return NextActivity;
+				return true;
 			}
 
 			var dat = self.World.Map.DistanceAboveTerrain(aircraft.CenterPosition);
@@ -78,12 +78,12 @@ namespace OpenRA.Mods.Common.Activities
 				if (aircraft.Info.VTOL)
 				{
 					Fly.VerticalTakeOffOrLandTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
-					return this;
+					return false;
 				}
 				else
 				{
 					Fly.FlyTick(self, aircraft, aircraft.Facing, aircraft.Info.CruiseAltitude);
-					return this;
+					return false;
 				}
 			}
 
@@ -91,14 +91,14 @@ namespace OpenRA.Mods.Common.Activities
 			if (moveToRallyPoint && NextActivity == null)
 			{
 				if (!aircraft.Info.VTOL && assignTargetOnFirstRun)
-					return NextActivity;
+					return true;
 
 				QueueChild(new AttackMoveActivity(self, () => move.MoveToTarget(self, target)));
 				moveToRallyPoint = false;
-				return this;
+				return false;
 			}
 
-			return NextActivity;
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Attack.cs

@@ -83,10 +83,10 @@ namespace OpenRA.Mods.Common.Activities
 			return target.Recalculate(self.Owner, out targetIsHiddenActor);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			bool targetIsHiddenActor;
 			target = RecalculateTarget(self, out targetIsHiddenActor);
@@ -106,7 +106,7 @@ namespace OpenRA.Mods.Common.Activities
 			// If we are ticking again after previously sequencing a MoveWithRange then that move must have completed
 			// Either we are in range and can see the target, or we've lost track of it and should give up
 			if (wasMovingWithinRange && targetIsHiddenActor)
-				return NextActivity;
+				return true;
 
 			// Update target lines if required
 			if (useLastVisibleTarget != oldUseLastVisibleTarget)
@@ -114,7 +114,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			// Target is hidden or dead, and we don't have a fallback position to move towards
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
-				return NextActivity;
+				return true;
 
 			wasMovingWithinRange = false;
 			var pos = self.CenterPosition;
@@ -125,12 +125,12 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				// We've reached the assumed position but it is not there or we can't move any further - give up
 				if (checkTarget.IsInRange(pos, lastVisibleMaximumRange) || move == null || lastVisibleMaximumRange == WDist.Zero)
-					return NextActivity;
+					return true;
 
 				// Move towards the last known position
 				wasMovingWithinRange = true;
 				QueueChild(move.MoveWithinRange(target, WDist.Zero, lastVisibleMaximumRange, checkTarget.CenterPosition, Color.Red));
-				return this;
+				return false;
 			}
 
 			attackStatus = AttackStatus.UnableToAttack;
@@ -145,9 +145,9 @@ namespace OpenRA.Mods.Common.Activities
 				wasMovingWithinRange = true;
 
 			if (attackStatus >= AttackStatus.NeedsToTurn)
-				return this;
+				return false;
 
-			return NextActivity;
+			return true;
 		}
 
 		protected virtual AttackStatus TickAttack(Actor self, AttackFrontal attack)

OpenRA.Mods.Common/Activities/DeliverResources.cs

@@ -37,10 +37,10 @@ namespace OpenRA.Mods.Common.Activities
 				harv.LinkProc(self, targetActor);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || isDocking)
-				return NextActivity;
+				return true;
 
 			// Find the nearest best refinery if not explicitly ordered to a specific refinery:
 			if (harv.LinkedProc == null || !harv.LinkedProc.IsInWorld)
@@ -50,7 +50,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (harv.LinkedProc == null)
 			{
 				QueueChild(new Wait(harv.Info.SearchForDeliveryBuildingDelay));
-				return this;
+				return false;
 			}
 
 			var proc = harv.LinkedProc;
@@ -63,7 +63,7 @@ namespace OpenRA.Mods.Common.Activities
 					n.MovingToRefinery(self, proc, new FindAndDeliverResources(self));
 
 				QueueChild(movement.MoveTo(proc.Location + iao.DeliveryOffset, 0));
-				return this;
+				return false;
 			}
 
 			if (!isDocking)
@@ -71,10 +71,10 @@ namespace OpenRA.Mods.Common.Activities
 				QueueChild(new Wait(10));
 				isDocking = true;
 				iao.OnDock(self, this);
-				return this;
+				return false;
 			}
 
-			return NextActivity;
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/DeployForGrantedCondition.cs

@@ -36,15 +36,15 @@ namespace OpenRA.Mods.Common.Activities
 				QueueChild(new Turn(self, deploy.Info.Facing));
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || initiated || (deploy.DeployState != DeployState.Deployed && moving))
-				return NextActivity;
+				return true;
 
 			QueueChild(new DeployInner(self, deploy));
 
 			initiated = true;
-			return this;
+			return false;
 		}
 	}
 
@@ -61,14 +61,14 @@ namespace OpenRA.Mods.Common.Activities
 			IsInterruptible = false;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Wait for deployment
 			if (deployment.DeployState == DeployState.Deploying || deployment.DeployState == DeployState.Undeploying)
-				return this;
+				return false;
 
 			if (initiated)
-				return NextActivity;
+				return true;
 
 			if (deployment.DeployState == DeployState.Undeployed)
 				deployment.Deploy();
@@ -76,7 +76,7 @@ namespace OpenRA.Mods.Common.Activities
 				deployment.Undeploy();
 
 			initiated = true;
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Enter.cs

@@ -58,7 +58,7 @@ namespace OpenRA.Mods.Common.Activities
 		/// </summary>
 		protected virtual void OnEnterComplete(Actor self, Actor targetActor) { }
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// Update our view of the target
 			bool targetIsHiddenActor;
@@ -81,9 +81,8 @@ namespace OpenRA.Mods.Common.Activities
 
 			// We need to wait for movement to finish before transitioning to
 			// the next state or next activity
-			ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
-			if (ChildActivity != null)
-				return this;
+			if (!TickChild(self))
+				return false;
 
 			// Note that lastState refers to what we have just *finished* doing
 			switch (lastState)
@@ -93,11 +92,11 @@ namespace OpenRA.Mods.Common.Activities
 					// NOTE: We can safely cancel in this case because we know the
 					// actor has finished any in-progress move activities
 					if (IsCanceling)
-						return NextActivity;
+						return true;
 
 					// Lost track of the target
 					if (useLastVisibleTarget && lastVisibleTarget.Type == TargetType.Invalid)
-						return NextActivity;
+						return true;
 
 					// We are not next to the target - lets fix that
 					if (target.Type != TargetType.Invalid && !move.CanEnterTargetNow(self, target))
@@ -105,28 +104,28 @@ namespace OpenRA.Mods.Common.Activities
 						// Target lines are managed by this trait, so we do not pass targetLineColor
 						var initialTargetPosition = (useLastVisibleTarget ? lastVisibleTarget : target).CenterPosition;
 						QueueChild(move.MoveToTarget(self, target, initialTargetPosition));
-						return this;
+						return false;
 					}
 
 					// We are next to where we thought the target should be, but it isn't here
 					// There's not much more we can do here
 					if (useLastVisibleTarget || target.Type != TargetType.Actor)
-						return NextActivity;
+						return true;
 
 					// Are we ready to move into the target?
 					if (TryStartEnter(self, target.Actor))
 					{
 						lastState = EnterState.Entering;
 						QueueChild(move.MoveIntoTarget(self, target));
-						return this;
+						return false;
 					}
 
 					// Subclasses can cancel the activity during TryStartEnter
 					// Return immediately to avoid an extra tick's delay
 					if (IsCanceling)
-						return NextActivity;
+						return true;
 
-					return this;
+					return false;
 				}
 
 				case EnterState.Entering:
@@ -138,14 +137,14 @@ namespace OpenRA.Mods.Common.Activities
 
 					lastState = EnterState.Exiting;
 					QueueChild(move.MoveIntoWorld(self, self.Location));
-					return this;
+					return false;
 				}
 
 				case EnterState.Exiting:
-					return NextActivity;
+					return true;
 			}
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs

@@ -76,20 +76,20 @@ namespace OpenRA.Mods.Common.Activities
 			}
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			if (NextActivity != null)
 			{
 				// Interrupt automated harvesting after clearing the first cell.
 				if (!harvInfo.QueueFullLoad && (hasHarvestedCell || harv.LastSearchFailed))
-					return NextActivity;
+					return true;
 
 				// Interrupt automated harvesting after first complete harvest cycle.
 				if (hasDeliveredLoad || harv.IsFull)
-					return NextActivity;
+					return true;
 			}
 
 			// Are we full or have nothing more to gather? Deliver resources.
@@ -97,7 +97,7 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				QueueChild(new DeliverResources(self));
 				hasDeliveredLoad = true;
-				return this;
+				return false;
 			}
 
 			// After a failed search, wait and sit still for a bit before searching again.
@@ -105,7 +105,7 @@ namespace OpenRA.Mods.Common.Activities
 			{
 				QueueChild(new Wait(harv.Info.WaitDuration));
 				hasWaited = true;
-				return this;
+				return false;
 			}
 
 			hasWaited = false;
@@ -144,14 +144,14 @@ namespace OpenRA.Mods.Common.Activities
 					}
 				}
 
-				return this;
+				return false;
 			}
 
 			// If we get here, our search for resources was successful. Commence harvesting.
 			QueueChild(new HarvestResource(self, closestHarvestableCell.Value));
 			lastHarvestedCell = closestHarvestableCell.Value;
 			hasHarvestedCell = true;
-			return this;
+			return false;
 		}
 
 		/// <summary>

OpenRA.Mods.Common/Activities/HarvestResource.cs

@@ -47,10 +47,10 @@ namespace OpenRA.Mods.Common.Activities
 			claimLayer.TryClaimCell(self, targetCell);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || harv.IsFull)
-				return NextActivity;
+				return true;
 
 			// Move towards the target cell
 			if (self.Location != targetCell)
@@ -60,11 +60,11 @@ namespace OpenRA.Mods.Common.Activities
 
 				self.SetTargetLine(Target.FromCell(self.World, targetCell), Color.Red, false);
 				QueueChild(move.MoveTo(targetCell, 2));
-				return this;
+				return false;
 			}
 
 			if (!harv.CanHarvestCell(self, self.Location))
-				return NextActivity;
+				return true;
 
 			// Turn to one of the harvestable facings
 			if (harvInfo.HarvestFacings != 0)
@@ -74,13 +74,13 @@ namespace OpenRA.Mods.Common.Activities
 				if (desired != current)
 				{
 					QueueChild(new Turn(self, desired));
-					return this;
+					return false;
 				}
 			}
 
 			var resource = resLayer.Harvest(self.Location);
 			if (resource == null)
-				return NextActivity;
+				return true;
 
 			harv.AcceptResource(self, resource);
 
@@ -88,7 +88,7 @@ namespace OpenRA.Mods.Common.Activities
 				t.Harvested(self, resource);
 
 			QueueChild(new Wait(harvInfo.BaleLoadDelay));
-			return this;
+			return false;
 		}
 
 		protected override void OnLastRun(Actor self)

OpenRA.Mods.Common/Activities/HarvesterDockSequence.cs

@@ -19,7 +19,7 @@ namespace OpenRA.Mods.Common.Activities
 {
 	public abstract class HarvesterDockSequence : Activity
 	{
-		protected enum DockingState { Wait, Turn, Dock, Loop, Undock, Complete, Finished }
+		protected enum DockingState { Wait, Turn, Dock, Loop, Undock, Complete }
 
 		protected readonly Actor Refinery;
 		protected readonly Harvester Harv;
@@ -45,35 +45,37 @@ namespace OpenRA.Mods.Common.Activities
 			EndDrag = refinery.CenterPosition + DragOffset;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			switch (dockingState)
 			{
 				case DockingState.Wait:
-					return this;
+					return false;
 
 				case DockingState.Turn:
 					dockingState = DockingState.Dock;
 					QueueChild(new Turn(self, DockAngle));
 					if (IsDragRequired)
 						QueueChild(new Drag(self, StartDrag, EndDrag, DragLength));
-					return this;
+					return false;
 
 				case DockingState.Dock:
 					if (Refinery.IsInWorld && !Refinery.IsDead)
 						foreach (var nd in Refinery.TraitsImplementing<INotifyDocking>())
 							nd.Docked(Refinery, self);
 
-					return OnStateDock(self);
+					OnStateDock(self);
+					return false;
 
 				case DockingState.Loop:
 					if (!Refinery.IsInWorld || Refinery.IsDead || Harv.TickUnload(self, Refinery))
 						dockingState = DockingState.Undock;
 
-					return this;
+					return false;
 
 				case DockingState.Undock:
-					return OnStateUndock(self);
+					OnStateUndock(self);
+					return false;
 
 				case DockingState.Complete:
 					if (Refinery.IsInWorld && !Refinery.IsDead)
@@ -85,11 +87,7 @@ namespace OpenRA.Mods.Common.Activities
 					if (IsDragRequired)
 						QueueChild(new Drag(self, EndDrag, StartDrag, DragLength));
 
-					dockingState = DockingState.Finished;
-					return this;
-
-				case DockingState.Finished:
-					return NextActivity;
+					return true;
 			}
 
 			throw new InvalidOperationException("Invalid harvester dock state");
@@ -106,8 +104,8 @@ namespace OpenRA.Mods.Common.Activities
 			yield return Target.FromActor(Refinery);
 		}
 
-		public abstract Activity OnStateDock(Actor self);
+		public abstract void OnStateDock(Actor self);
 
-		public abstract Activity OnStateUndock(Actor self);
+		public abstract void OnStateUndock(Actor self);
 	}
 }

OpenRA.Mods.Common/Activities/Hunt.cs

@@ -31,18 +31,18 @@ namespace OpenRA.Mods.Common.Activities
 				&& a.IsTargetableBy(self) && attack.HasAnyValidWeapons(Target.FromActor(a)));
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			var target = targets.ClosestTo(self);
 			if (target == null)
-				return this;
+				return false;
 
 			QueueChild(new AttackMoveActivity(self, () => move.MoveTo(target.Location, 2)));
 			QueueChild(new Wait(25));
-			return this;
+			return false;
 		}
 	}
 }

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

@@ -50,7 +50,7 @@ namespace OpenRA.Mods.Common.Activities
 				token = conditionManager.GrantCondition(self, attackMove.Info.AssaultMoveCondition);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// We are not currently attacking a target, so scan for new targets.
 			if (!IsCanceling && ChildActivity != null && ChildActivity.NextActivity == null && autoTarget != null)
@@ -74,13 +74,9 @@ namespace OpenRA.Mods.Common.Activities
 				}
 			}
 
-			ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
-			if (ChildActivity != null)
-				return this;
-
-			// The last queued childactivity is guaranteed to be the inner move, so if we get here it means
-			// we have reached our destination and there are no more enemies on our path.
-			return NextActivity;
+			// The last queued childactivity is guaranteed to be the inner move, so if the childactivity
+			// queue is empty it means we have reached our destination and there are no more enemies on our path.
+			return TickChild(self);
 		}
 
 		protected override void OnLastRun(Actor self)

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

@@ -34,10 +34,10 @@ namespace OpenRA.Mods.Common.Activities
 			IsInterruptible = false;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (disableable != null && disableable.IsTraitDisabled)
-				return this;
+				return false;
 
 			var pos = length > 1
 				? WPos.Lerp(start, end, ticks, length - 1)
@@ -45,9 +45,9 @@ namespace OpenRA.Mods.Common.Activities
 
 			positionable.SetVisualPosition(self, pos);
 			if (++ticks >= length)
-				return NextActivity;
+				return true;
 
-			return this;
+			return false;
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)

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

@@ -45,10 +45,10 @@ namespace OpenRA.Mods.Common.Activities
 				lastVisibleTarget = Target.FromPos(initialTargetPosition.Value);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			bool targetIsHiddenActor;
 			target = target.Recalculate(self.Owner, out targetIsHiddenActor);
@@ -61,7 +61,7 @@ namespace OpenRA.Mods.Common.Activities
 			// If we are ticking again after previously sequencing a MoveWithRange then that move must have completed
 			// Either we are in range and can see the target, or we've lost track of it and should give up
 			if (wasMovingWithinRange && targetIsHiddenActor)
-				return NextActivity;
+				return true;
 
 			wasMovingWithinRange = false;
 
@@ -71,7 +71,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			// Target is hidden or dead, and we don't have a fallback position to move towards
 			if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
-				return NextActivity;
+				return true;
 
 			var pos = self.CenterPosition;
 			var checkTarget = useLastVisibleTarget ? lastVisibleTarget : target;
@@ -79,12 +79,12 @@ namespace OpenRA.Mods.Common.Activities
 			// We've reached the required range - if the target is visible and valid then we wait
 			// otherwise if it is hidden or dead we give up
 			if (checkTarget.IsInRange(pos, maxRange) && !checkTarget.IsInRange(pos, minRange))
-				return useLastVisibleTarget ? NextActivity : this;
+				return useLastVisibleTarget;
 
 			// Move into range
 			wasMovingWithinRange = true;
 			QueueChild(move.MoveWithinRange(target, minRange, maxRange, checkTarget.CenterPosition, targetLineColor));
-			return this;
+			return false;
 		}
 	}
 }

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

@@ -144,18 +144,18 @@ namespace OpenRA.Mods.Common.Activities
 			}
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// If the actor is inside a tunnel then we must let them move
 			// all the way through before moving to the next activity
 			if (IsCanceling && self.Location.Layer != CustomMovementLayerType.Tunnel)
-				return NextActivity;
+				return true;
 
 			if (mobile.IsTraitDisabled || mobile.IsTraitPaused)
-				return this;
+				return false;
 
 			if (destination == mobile.ToCell)
-				return NextActivity;
+				return true;
 
 			if (path == null)
 				path = EvalPath();
@@ -163,22 +163,21 @@ namespace OpenRA.Mods.Common.Activities
 			if (path.Count == 0)
 			{
 				destination = mobile.ToCell;
-				return this;
+				return false;
 			}
 
 			destination = path[0];
 
 			var nextCell = PopPath(self);
 			if (nextCell == null)
-				return this;
+				return false;
 
 			var firstFacing = self.World.Map.FacingBetween(mobile.FromCell, nextCell.Value.First, mobile.Facing);
 			if (firstFacing != mobile.Facing)
 			{
 				path.Add(nextCell.Value.First);
-
 				QueueChild(new Turn(self, firstFacing));
-				return this;
+				return false;
 			}
 
 			mobile.SetLocation(mobile.FromCell, mobile.FromSubCell, nextCell.Value.First, nextCell.Value.Second);
@@ -192,7 +191,7 @@ namespace OpenRA.Mods.Common.Activities
 				(map.Grid.OffsetOfSubCell(mobile.FromSubCell) + map.Grid.OffsetOfSubCell(mobile.ToSubCell)) / 2;
 
 			QueueChild(new MoveFirstHalf(this, from, to, mobile.Facing, mobile.Facing, 0));
-			return this;
+			return false;
 		}
 
 		Pair<CPos, SubCell>? PopPath(Actor self)
@@ -309,10 +308,10 @@ namespace OpenRA.Mods.Common.Activities
 				}
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				if (Move.mobile.IsTraitDisabled)
-					return this;
+					return false;
 
 				var ret = InnerTick(self, Move.mobile);
 
@@ -322,10 +321,10 @@ namespace OpenRA.Mods.Common.Activities
 				UpdateCenterLocation(self, Move.mobile);
 
 				if (ret == this)
-					return ret;
+					return false;
 
 				Queue(ret);
-				return NextActivity;
+				return true;
 			}
 
 			Activity InnerTick(Actor self, Mobile mobile)

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

@@ -85,7 +85,7 @@ namespace OpenRA.Mods.Common.Activities
 			QueueChild(Mobile.MoveTo(() => CalculatePathToTarget(self)));
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			bool targetIsHiddenActor;
 			var oldTargetLocation = lastVisibleTargetLocation;
@@ -119,11 +119,9 @@ namespace OpenRA.Mods.Common.Activities
 			if (!IsCanceling && shouldRepath)
 				QueueChild(Mobile.MoveTo(() => CalculatePathToTarget(self)));
 
-			ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
-			if (ChildActivity != null)
-				return this;
-
-			return NextActivity;
+			// The last queued childactivity is guaranteed to be the inner move, so if the childactivity
+			// queue is empty it means we have reached our destination.
+			return TickChild(self);
 		}
 
 		List<CPos> CalculatePathToTarget(Actor self)

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

@@ -35,31 +35,28 @@ namespace OpenRA.Mods.Common.Activities
 			targetStartPos = target.Positions.PositionClosestTo(self.CenterPosition);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || target.Type == TargetType.Invalid)
-				return NextActivity;
+				return true;
 
 			if (mobile.IsTraitDisabled || mobile.IsTraitPaused)
-				return this;
+				return false;
 
 			var currentPos = self.CenterPosition;
 			var targetPos = target.Positions.PositionClosestTo(currentPos);
 
 			// Give up if the target has moved too far
 			if (targetMovementThreshold > WDist.Zero && (targetPos - targetStartPos).LengthSquared > targetMovementThreshold.LengthSquared)
-				return NextActivity;
+				return true;
 
 			// Turn if required
 			var delta = targetPos - currentPos;
 			var facing = delta.HorizontalLengthSquared != 0 ? delta.Yaw.Facing : mobile.Facing;
 			if (facing != mobile.Facing)
 			{
-				var turn = ActivityUtils.RunActivity(self, new Turn(self, facing));
-				if (turn != null)
-					QueueChild(turn);
-
-				return this;
+				QueueChild(new Turn(self, facing));
+				return false;
 			}
 
 			// Can complete the move in this step
@@ -67,13 +64,12 @@ namespace OpenRA.Mods.Common.Activities
 			if (delta.LengthSquared <= speed * speed)
 			{
 				mobile.SetVisualPosition(self, targetPos);
-				return NextActivity;
+				return true;
 			}
 
 			// Move towards the target
 			mobile.SetVisualPosition(self, currentPos + delta * speed / delta.Length);
-
-			return this;
+			return false;
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)

OpenRA.Mods.Common/Activities/Parachute.cs

@@ -39,15 +39,15 @@ namespace OpenRA.Mods.Common.Activities
 				np.OnParachute(self);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			var nextPosition = self.CenterPosition - fallVector;
 			if (nextPosition.Z < groundLevel)
-				return NextActivity;
+				return true;
 
 			pos.SetVisualPosition(self, nextPosition);
 
-			return this;
+			return false;
 		}
 
 		protected override void OnLastRun(Actor self)

OpenRA.Mods.Common/Activities/PickupUnit.cs

@@ -54,41 +54,41 @@ namespace OpenRA.Mods.Common.Activities
 			carryall.ReserveCarryable(self, cargo);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (cargo != carryall.Carryable)
-				return NextActivity;
+				return true;
 
 			if (IsCanceling)
 			{
 				if (carryall.State == Carryall.CarryallState.Reserved)
 					carryall.UnreserveCarryable(self);
 
-				return NextActivity;
+				return true;
 			}
 
 			if (cargo.IsDead || carryable.IsTraitDisabled || !cargo.AppearsFriendlyTo(self))
 			{
 				carryall.UnreserveCarryable(self);
-				return NextActivity;
+				return true;
 			}
 
 			if (carryall.State != Carryall.CarryallState.Reserved)
-				return NextActivity;
+				return true;
 
 			switch (state)
 			{
 				case PickupState.Intercept:
 					QueueChild(movement.MoveWithinRange(Target.FromActor(cargo), WDist.FromCells(4), targetLineColor: Color.Yellow));
 					state = PickupState.LockCarryable;
-					return this;
+					return false;
 
 				case PickupState.LockCarryable:
 					if (!carryable.LockForPickup(cargo, self))
 						Cancel(self);
 
 					state = PickupState.Pickup;
-					return this;
+					return false;
 
 				case PickupState.Pickup:
 				{
@@ -103,11 +103,11 @@ namespace OpenRA.Mods.Common.Activities
 					// Remove our carryable from world
 					QueueChild(new CallFunc(() => Attach(self)));
 					QueueChild(new TakeOff(self));
-					return this;
+					return false;
 				}
 			}
 
-			return NextActivity;
+			return true;
 		}
 
 		void Attach(Actor self)

OpenRA.Mods.Common/Activities/RemoveSelf.cs

@@ -15,11 +15,12 @@ namespace OpenRA.Mods.Common.Activities
 {
 	public class RemoveSelf : Activity
 	{
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
-			if (IsCanceling) return NextActivity;
+			if (IsCanceling) return true;
 			self.Dispose();
-			return null;
+			Cancel(self);
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Resupply.cs

@@ -73,7 +73,7 @@ namespace OpenRA.Mods.Common.Activities
 					pool.RemainingTicks = pool.Info.ReloadDelay;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			// HACK: If the activity is cancelled while we're already resupplying (or about to start resupplying),
 			// move actor outside the resupplier footprint
@@ -84,7 +84,7 @@ namespace OpenRA.Mods.Common.Activities
 				foreach (var notifyResupply in notifyResupplies)
 					notifyResupply.ResupplyTick(host.Actor, self, ResupplyType.None);
 
-				return this;
+				return false;
 			}
 
 			if (IsCanceling || host.Type == TargetType.Invalid
@@ -94,7 +94,7 @@ namespace OpenRA.Mods.Common.Activities
 				foreach (var notifyResupply in notifyResupplies)
 					notifyResupply.ResupplyTick(host.Actor, self, ResupplyType.None);
 
-				return NextActivity;
+				return true;
 			}
 
 			if (activeResupplyTypes.HasFlag(ResupplyType.Repair))
@@ -112,10 +112,10 @@ namespace OpenRA.Mods.Common.Activities
 				if (aircraft != null)
 					aircraft.AllowYieldingReservation();
 
-				return NextActivity;
+				return true;
 			}
 
-			return this;
+			return false;
 		}
 
 		public override void Cancel(Actor self, bool keepQueue = false)

OpenRA.Mods.Common/Activities/Sell.cs

@@ -32,7 +32,7 @@ namespace OpenRA.Mods.Common.Activities
 			IsInterruptible = false;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			var sellValue = self.GetSellValue();
 
@@ -49,7 +49,7 @@ namespace OpenRA.Mods.Common.Activities
 				self.World.AddFrameEndTask(w => w.Add(new FloatingText(self.CenterPosition, self.Owner.Color, FloatingText.FormatCashTick(refund), 30)));
 
 			self.Dispose();
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/SimpleTeleport.cs

@@ -20,11 +20,11 @@ namespace OpenRA.Mods.Common.Activities
 
 		public SimpleTeleport(CPos destination) { this.destination = destination; }
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			self.Trait<IPositionable>().SetPosition(self, destination);
 			self.Generation++;
-			return NextActivity;
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/SpriteHarvesterDockSequence.cs

@@ -27,17 +27,16 @@ namespace OpenRA.Mods.Common.Activities
 			wda = self.Info.TraitInfo<WithDockingAnimationInfo>();
 		}
 
-		public override Activity OnStateDock(Actor self)
+		public override void OnStateDock(Actor self)
 		{
 			foreach (var trait in self.TraitsImplementing<INotifyHarvesterAction>())
 				trait.Docked();
 
 			wsb.PlayCustomAnimation(self, wda.DockSequence, () => wsb.PlayCustomAnimationRepeating(self, wda.DockLoopSequence));
 			dockingState = DockingState.Loop;
-			return this;
 		}
 
-		public override Activity OnStateUndock(Actor self)
+		public override void OnStateUndock(Actor self)
 		{
 			wsb.PlayCustomAnimationBackwards(self, wda.DockSequence,
 				() =>
@@ -47,8 +46,6 @@ namespace OpenRA.Mods.Common.Activities
 						trait.Undocked();
 				});
 			dockingState = DockingState.Wait;
-
-			return this;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Transform.cs

@@ -43,17 +43,17 @@ namespace OpenRA.Mods.Common.Activities
 				QueueChild(new Land(self));
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			// Prevent deployment in bogus locations
 			var transforms = self.TraitOrDefault<Transforms>();
 			if (transforms != null && !transforms.CanDeploy())
 			{
 				Cancel(self, true);
-				return NextActivity;
+				return true;
 			}
 
 			foreach (var nt in self.TraitsImplementing<INotifyTransform>())
@@ -68,10 +68,10 @@ namespace OpenRA.Mods.Common.Activities
 				// Wait forever
 				QueueChild(new WaitFor(() => false));
 				makeAnimation.Reverse(self, () => DoTransform(self));
-				return this;
+				return false;
 			}
 
-			return NextActivity;
+			return true;
 		}
 
 		protected override void OnLastRun(Actor self)

OpenRA.Mods.Common/Activities/Turn.cs

@@ -28,20 +28,20 @@ namespace OpenRA.Mods.Common.Activities
 			this.desiredFacing = desiredFacing;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
 			if (mobile != null && (mobile.IsTraitDisabled || mobile.IsTraitPaused))
-				return this;
+				return false;
 
 			if (desiredFacing == facing.Facing)
-				return NextActivity;
+				return true;
 
 			facing.Facing = Util.TickFacing(facing.Facing, desiredFacing, facing.TurnSpeed);
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/UnloadCargo.cs

@@ -89,10 +89,10 @@ namespace OpenRA.Mods.Common.Activities
 			QueueChild(new Wait(cargo.Info.BeforeUnloadDelay));
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling || cargo.IsEmpty(self))
-				return NextActivity;
+				return true;
 
 			if (cargo.CanUnload())
 			{
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.Common.Activities
 				{
 					self.NotifyBlocker(BlockedExitCells(actor));
 					QueueChild(new Wait(10));
-					return this;
+					return false;
 				}
 
 				cargo.Unload(self);
@@ -130,6 +130,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (!unloadAll || !cargo.CanUnload())
 			{
 				Cancel(self, true);
+
 				if (cargo.Info.AfterUnloadDelay > 0)
 					QueueChild(new Wait(cargo.Info.AfterUnloadDelay, false));
 
@@ -137,7 +138,7 @@ namespace OpenRA.Mods.Common.Activities
 					QueueChild(new TakeOff(self));
 			}
 
-			return this;
+			return false;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Wait.cs

@@ -25,12 +25,12 @@ namespace OpenRA.Mods.Common.Activities
 			IsInterruptible = interruptible;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
-			return (remainingTicks-- == 0) ? NextActivity : this;
+			return remainingTicks-- == 0;
 		}
 	}
 
@@ -45,12 +45,12 @@ namespace OpenRA.Mods.Common.Activities
 			IsInterruptible = interruptible;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)
-				return NextActivity;
+				return true;
 
-			return (f == null || f()) ? NextActivity : this;
+			return f == null || f();
 		}
 	}
 }

OpenRA.Mods.Common/Activities/WaitForTransport.cs

@@ -30,12 +30,12 @@ namespace OpenRA.Mods.Common.Activities
 			QueueChild(inner);
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			if (transportable != null)
 				transportable.MovementCancelled(self);
 
-			return NextActivity;
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Scripting/CallLuaFunc.cs

@@ -27,7 +27,7 @@ namespace OpenRA.Mods.Common.Activities
 			this.context = context;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			try
 			{
@@ -40,7 +40,7 @@ namespace OpenRA.Mods.Common.Activities
 			}
 
 			Dispose();
-			return NextActivity;
+			return true;
 		}
 
 		public override void Cancel(Actor self, bool keepQueue = false)

OpenRA.Mods.Common/Traits/Attack/AttackFollow.cs

@@ -255,22 +255,22 @@ namespace OpenRA.Mods.Common.Traits
 				}
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				if (IsCanceling)
 				{
 					// Cancel the requested target, but keep firing on it while in range
 					attack.ClearRequestedTarget();
-					return NextActivity;
+					return true;
 				}
 
 				// Check that AttackFollow hasn't cancelled the target by modifying attack.Target
 				// Having both this and AttackFollow modify that field is a horrible hack.
 				if (hasTicked && attack.RequestedTarget.Type == TargetType.Invalid)
-					return NextActivity;
+					return true;
 
 				if (attack.IsTraitPaused)
-					return this;
+					return false;
 
 				bool targetIsHiddenActor;
 				target = target.Recalculate(self.Owner, out targetIsHiddenActor);
@@ -317,7 +317,7 @@ namespace OpenRA.Mods.Common.Traits
 				if (wasMovingWithinRange && targetIsHiddenActor)
 				{
 					attack.ClearRequestedTarget();
-					return NextActivity;
+					return true;
 				}
 
 				// Update target lines if required
@@ -328,7 +328,7 @@ namespace OpenRA.Mods.Common.Traits
 				if (useLastVisibleTarget && !lastVisibleTarget.IsValidFor(self))
 				{
 					attack.ClearRequestedTarget();
-					return NextActivity;
+					return true;
 				}
 
 				var pos = self.CenterPosition;
@@ -341,22 +341,22 @@ namespace OpenRA.Mods.Common.Traits
 					if (useLastVisibleTarget)
 					{
 						attack.ClearRequestedTarget();
-						return NextActivity;
+						return true;
 					}
 
-					return this;
+					return false;
 				}
 
 				// We can't move into range, so give up
 				if (move == null || maxRange == WDist.Zero || maxRange < minRange)
 				{
 					attack.ClearRequestedTarget();
-					return NextActivity;
+					return true;
 				}
 
 				wasMovingWithinRange = true;
 				QueueChild(move.MoveWithinRange(target, minRange, maxRange, checkTarget.CenterPosition, Color.Red));
-				return this;
+				return false;
 			}
 
 			void IActivityNotifyStanceChanged.StanceChanged(Actor self, AutoTarget autoTarget, UnitStance oldStance, UnitStance newStance)

OpenRA.Mods.Common/Traits/Attack/AttackOmni.cs

@@ -46,16 +46,16 @@ namespace OpenRA.Mods.Common.Traits
 				this.forceAttack = forceAttack;
 			}
 
-			public override Activity Tick(Actor self)
+			public override bool Tick(Actor self)
 			{
 				// This activity can't move to reacquire hidden targets, so use the
 				// Recalculate overload that invalidates hidden targets.
 				target = target.RecalculateInvalidatingHiddenTargets(self.Owner);
 				if (IsCanceling || !target.IsValidFor(self) || !attack.IsReachableTarget(target, allowMove))
-					return NextActivity;
+					return true;
 
 				attack.DoAttack(self, target);
-				return this;
+				return false;
 			}
 
 			void IActivityNotifyStanceChanged.StanceChanged(Actor self, AutoTarget autoTarget, UnitStance oldStance, UnitStance newStance)

OpenRA.Mods.D2k/Activities/SwallowActor.cs

@@ -95,7 +95,7 @@ namespace OpenRA.Mods.D2k.Activities
 			return true;
 		}
 
-		public override Activity Tick(Actor self)
+		public override bool Tick(Actor self)
 		{
 			switch (stance)
 			{
@@ -109,7 +109,7 @@ namespace OpenRA.Mods.D2k.Activities
 					break;
 				case AttackState.Burrowed:
 					if (--countdown > 0)
-						return this;
+						return false;
 
 					var targetLocation = target.Actor.Location;
 
@@ -117,14 +117,14 @@ namespace OpenRA.Mods.D2k.Activities
 					if ((burrowLocation - targetLocation).Length > NearEnough)
 					{
 						RevokeCondition(self);
-						return NextActivity;
+						return true;
 					}
 
 					// The target reached solid ground
 					if (!positionable.CanEnterCell(targetLocation, null, false))
 					{
 						RevokeCondition(self);
-						return NextActivity;
+						return true;
 					}
 
 					var targets = self.World.ActorMap.GetActorsAt(targetLocation)
@@ -133,7 +133,7 @@ namespace OpenRA.Mods.D2k.Activities
 					if (!targets.Any())
 					{
 						RevokeCondition(self);
-						return NextActivity;
+						return true;
 					}
 
 					stance = AttackState.Attacking;
@@ -144,7 +144,7 @@ namespace OpenRA.Mods.D2k.Activities
 					break;
 				case AttackState.Attacking:
 					if (--countdown > 0)
-						return this;
+						return false;
 
 					sandworm.IsAttacking = false;
 
@@ -156,10 +156,10 @@ namespace OpenRA.Mods.D2k.Activities
 					}
 
 					RevokeCondition(self);
-					return NextActivity;
+					return true;
 			}
 
-			return this;
+			return false;
 		}
 
 		void RevokeCondition(Actor self)