Add native support for uninterruptible activities

This pattern occurs a few times throughout the code, so it makes sense to bake it into the Activity class itself.

OpenRA.Game/Activities/Activity.cs

@@ -18,14 +18,25 @@ namespace OpenRA.Activities
 	public abstract class Activity
 	{
 		public Activity NextActivity { get; set; }
+		public bool IsInterruptible { get; protected set; }
 		protected bool IsCanceled { get; private set; }
 
+		public Activity()
+		{
+			IsInterruptible = true;
+		}
+
 		public abstract Activity Tick(Actor self);
 
-		public virtual void Cancel(Actor self)
+		public virtual bool Cancel(Actor self)
 		{
+			if (!IsInterruptible)
+				return false;
+
 			IsCanceled = true;
 			NextActivity = null;
+
+			return true;
 		}
 
 		public virtual void Queue(Activity activity)

OpenRA.Game/Activities/CallFunc.cs

@@ -19,22 +19,15 @@ namespace OpenRA.Activities
 		public CallFunc(Action a, bool interruptable)
 		{
 			this.a = a;
-			this.interruptable = interruptable;
+			IsInterruptible = interruptable;
 		}
 
 		Action a;
-		bool interruptable;
 
 		public override Activity Tick(Actor self)
 		{
 			if (a != null) a();
 			return NextActivity;
 		}
-
-		public override void Cancel(Actor self)
-		{
-			if (interruptable)
-				base.Cancel(self);
-		}
 	}
 }

OpenRA.Game/Actor.cs

@@ -206,10 +206,12 @@ namespace OpenRA
 				CurrentActivity.Queue(nextActivity);
 		}
 
-		public void CancelActivity()
+		public bool CancelActivity()
 		{
 			if (CurrentActivity != null)
-				CurrentActivity.Cancel(this);
+				return CurrentActivity.Cancel(this);
+
+			return true;
 		}
 
 		public override int GetHashCode()

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

@@ -26,6 +26,7 @@ namespace OpenRA.Mods.Common.Activities
 		public FallToEarth(Actor self, FallsToEarthInfo info)
 		{
 			this.info = info;
+			IsInterruptible = false;
 			aircraft = self.Trait<Aircraft>();
 			if (info.Spins)
 				acceleration = self.World.SharedRandom.Next(2) * 2 - 1;
@@ -57,8 +58,5 @@ namespace OpenRA.Mods.Common.Activities
 
 			return this;
 		}
-
-		// Cannot be cancelled
-		public override void Cancel(Actor self) { }
 	}
 }

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

@@ -68,13 +68,13 @@ namespace OpenRA.Mods.Common.Activities
 			return this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (!IsCanceled && inner != null)
+			if (!IsCanceled && inner != null && !inner.Cancel(self))
-				inner.Cancel(self);
+				return false;
 
 			// NextActivity must always be set to null:
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 	}
 }

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

@@ -63,12 +63,12 @@ namespace OpenRA.Mods.Common.Activities
 			return inner == null || inner == NextActivity ? NextActivity : this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (!IsCanceled && inner != null)
+			if (!IsCanceled && inner != null && !inner.Cancel(self))
-				inner.Cancel(self);
+				return false;
 
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/DeliverResources.cs

@@ -30,6 +30,7 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			movement = self.Trait<IMove>();
 			harv = self.Trait<Harvester>();
+			IsInterruptible = false;
 		}
 
 		public override Activity Tick(Actor self)
@@ -79,8 +80,5 @@ namespace OpenRA.Mods.Common.Activities
 
 			return ActivityUtils.SequenceActivities(new Wait(10), this);
 		}
-
-		// Cannot be cancelled
-		public override void Cancel(Actor self) { }
 	}
 }

OpenRA.Mods.Common/Activities/DeliverUnit.cs

@@ -207,12 +207,12 @@ namespace OpenRA.Mods.Common.Activities
 			});
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (innerActivity != null)
+			if (!IsCanceled && innerActivity != null && !innerActivity.Cancel(self))
-				innerActivity.Cancel(self);
+				return false;
 
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Enter.cs

@@ -112,13 +112,15 @@ namespace OpenRA.Mods.Common.Activities
 				inner.Cancel(self);
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
 			AbortOrExit(self);
 			if (nextState < State.Exiting)
-				base.Cancel(self);
+				return base.Cancel(self);
 			else
 				NextActivity = null;
+
+			return true;
 		}
 
 		ReserveStatus TryReserveElseTryAlternateReserve(Actor self)

OpenRA.Mods.Common/Activities/HarvesterDockSequence.cs

@@ -81,10 +81,10 @@ namespace OpenRA.Mods.Common.Activities
 			throw new InvalidOperationException("Invalid harvester dock state");
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
 			dockingState = State.Undock;
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)

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

@@ -46,12 +46,12 @@ namespace OpenRA.Mods.Common.Activities
 			return this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (inner != null)
+			if (!IsCanceled && inner != null && !inner.Cancel(self))
-				inner.Cancel(self);
+				return false;
 
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)

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

@@ -32,6 +32,7 @@ namespace OpenRA.Mods.Common.Activities
 			this.start = start;
 			this.end = end;
 			this.length = length;
+			IsInterruptible = false;
 		}
 
 		public override Activity Tick(Actor self)
@@ -62,8 +63,5 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			yield return Target.FromPos(end);
 		}
-
-		// Cannot be cancelled
-		public override void Cancel(Actor self) { }
 	}
 }

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

@@ -272,10 +272,10 @@ namespace OpenRA.Mods.Common.Activities
 			return Pair.New(nextCell, subCell);
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
 			path = NoPath;
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 
 		public override IEnumerable<Target> GetTargets(Actor self)
@@ -331,10 +331,10 @@ namespace OpenRA.Mods.Common.Activities
 				}
 			}
 
-			public override void Cancel(Actor self)
+			public override bool Cancel(Actor self)
 			{
 				Move.Cancel(self);
-				base.Cancel(self);
+				return base.Cancel(self);
 			}
 
 			public override void Queue(Activity activity)

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

@@ -161,12 +161,12 @@ namespace OpenRA.Mods.Common.Activities
 			return Target.None;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (inner != null)
+			if (!IsCanceled && inner != null && !inner.Cancel(self))
-				inner.Cancel(self);
+				return false;
 
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Parachute.cs

@@ -37,6 +37,7 @@ namespace OpenRA.Mods.Common.Activities
 			para = self.Info.TraitInfo<ParachutableInfo>();
 			fallVector = new WVec(0, 0, para.FallRate);
 			this.dropPosition = dropPosition;
+			IsInterruptible = false;
 		}
 
 		Activity FirstTick(Actor self)
@@ -91,8 +92,5 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			NextActivity = activity;
 		}
-
-		// Cannot be cancelled
-		public override void Cancel(Actor self) { }
 	}
 }

OpenRA.Mods.Common/Activities/PickupUnit.cs

@@ -157,12 +157,12 @@ namespace OpenRA.Mods.Common.Activities
 			});
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (innerActivity != null)
+			if (!IsCanceled && innerActivity != null && !innerActivity.Cancel(self))
-				innerActivity.Cancel(self);
+				return false;
 
-			base.Cancel(self);
+			return base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Sell.cs

@@ -27,6 +27,7 @@ namespace OpenRA.Mods.Common.Activities
 			health = self.TraitOrDefault<Health>();
 			sellableInfo = self.Info.TraitInfo<SellableInfo>();
 			playerResources = self.Owner.PlayerActor.Trait<PlayerResources>();
+			IsInterruptible = false;
 		}
 
 		public override Activity Tick(Actor self)
@@ -45,8 +46,5 @@ namespace OpenRA.Mods.Common.Activities
 			self.Dispose();
 			return this;
 		}
-
-		// Cannot be cancelled
-		public override void Cancel(Actor self) { }
 	}
 }

OpenRA.Mods.Common/Activities/Wait.cs

@@ -17,13 +17,12 @@ namespace OpenRA.Mods.Common.Activities
 	public class Wait : Activity
 	{
 		int remainingTicks;
-		bool interruptable = true;
 
 		public Wait(int period) { remainingTicks = period; }
 		public Wait(int period, bool interruptable)
 		{
 			remainingTicks = period;
-			this.interruptable = interruptable;
+			IsInterruptible = interruptable;
 		}
 
 		public override Activity Tick(Actor self)
@@ -31,26 +30,25 @@ namespace OpenRA.Mods.Common.Activities
 			return (remainingTicks-- == 0) ? NextActivity : this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (!interruptable)
+			if (!base.Cancel(self))
-				return;
+				return false;
 
 			remainingTicks = 0;
-			base.Cancel(self);
+			return true;
 		}
 	}
 
 	public class WaitFor : Activity
 	{
 		Func<bool> f;
-		bool interruptable = true;
 
 		public WaitFor(Func<bool> f) { this.f = f; }
 		public WaitFor(Func<bool> f, bool interruptable)
 		{
 			this.f = f;
-			this.interruptable = interruptable;
+			IsInterruptible = interruptable;
 		}
 
 		public override Activity Tick(Actor self)
@@ -58,13 +56,13 @@ namespace OpenRA.Mods.Common.Activities
 			return (f == null || f()) ? NextActivity : this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (!interruptable)
+			if (!base.Cancel(self))
-				return;
+				return false;
 
 			f = null;
-			base.Cancel(self);
+			return true;
 		}
 	}
 }

OpenRA.Mods.Common/Activities/WaitForTransport.cs

@@ -41,10 +41,12 @@ namespace OpenRA.Mods.Common.Activities
 			return this;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
-			if (inner != null)
+			if (!IsCanceled && inner != null && !inner.Cancel(self))
-				inner.Cancel(self);
+				return false;
+
+			return base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Scripting/CallLuaFunc.cs

@@ -43,10 +43,13 @@ namespace OpenRA.Mods.Common.Activities
 			return NextActivity;
 		}
 
-		public override void Cancel(Actor self)
+		public override bool Cancel(Actor self)
 		{
+			if (!base.Cancel(self))
+				return false;
+
 			Dispose();
-			base.Cancel(self);
+			return true;
 		}
 
 		public void Dispose()