Activity.Cancel returns void instead of bool.

OpenRA.Game/Activities/Activity.cs

@@ -25,11 +25,6 @@ namespace OpenRA.Activities
 	 * optionally child activities, and usually a next activity. An actor's CurrentActivity is a pointer into that graph
 	 * and moves through it as activities run.
 	 *
-	 * There are two kinds of activities, the base activity and composite activities. They differ in the way their children
-	 * are run: while a base activity is responsible for running its children itself, a composite activity relies on the actor's
-	 * activity-running code. Therefore, the actor's CurrentActivity stays on the base activity while it runs its children. With
-	 * composite activities however, the CurrentActivity moves through the list of children as they run.
-	 *
 	 *
 	 * Things to be aware of when writing activities:
 	 *
@@ -38,23 +33,12 @@ namespace OpenRA.Activities
 	 * - Do not "reuse" (with "SequenceActivities", for example) activity objects that have already finished running.
 	 *   Queue a new instance instead.
 	 * - Avoid calling actor.CancelActivity(). It is almost always a bug. Call activity.Cancel() instead.
-	 * - A composite activity will run at least twice. The first time when it returns its children,
-	 *   the second time when its last child returns its Parent.
 	 * - Do not return the Parent explicitly unless you have an extremly good reason. "return NextActivity"
 	 *   will do the right thing in all circumstances.
 	 * - You do not need to care about the ChildActivity pointer advancing through the list of children,
 	 *   the activity code already takes care of that.
 	 * - If you want to check whether there are any follow-up activities queued, check against "NextInQueue"
 	 *   in favour of "NextActivity" to avoid checking against the Parent activity.
-	 *
-	 *
-	 * Guide when to use which kind of activity:
-	 *
-	 * - The activity does not have any children -> base activity
-	 * - The activity needs to run preparatory steps during each tick before its children can be run -> base activity
-	 * - The activity or the actor is left in a bogus state when one of the child activities is canceled -> base activity
-	 * - The activity's children are self-contained and can run independently of the parent -> composite activity
-	 * - The activity does not have any or little logic of its own, but is just composed of sub-steps -> composite activity
 	 */
 	public abstract class Activity
 	{
@@ -217,20 +201,18 @@ namespace OpenRA.Activities
 			OnActorDispose(self);
 		}
 
-		public virtual bool Cancel(Actor self, bool keepQueue = false)
+		public virtual void Cancel(Actor self, bool keepQueue = false)
 		{
 			if (!keepQueue)
 				NextInQueue = null;
 
 			if (!IsInterruptible)
-				return false;
+				return;
 
 			if (ChildActivity != null)
 				ChildActivity.Cancel(self);
 
 			State = ActivityState.Canceling;
-
-			return true;
 		}
 
 		public virtual void Queue(Actor self, Activity activity, bool pretick = false)

OpenRA.Game/Actor.cs

@@ -225,12 +225,10 @@ namespace OpenRA
 				CurrentActivity.RootActivity.Queue(this, nextActivity);
 		}
 
-		public bool CancelActivity()
+		public void CancelActivity()
 		{
 			if (CurrentActivity != null)
-				return CurrentActivity.RootActivity.Cancel(this);
-
-			return true;
+				CurrentActivity.RootActivity.Cancel(this);
 		}
 
 		public override int GetHashCode()

OpenRA.Mods.Common/Activities/DeliverUnit.cs

@@ -206,12 +206,12 @@ namespace OpenRA.Mods.Common.Activities
 			});
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			if (!IsCanceling && innerActivity != null)
 				innerActivity.Cancel(self);
 
-			return base.Cancel(self);
+			base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Enter.cs

@@ -160,14 +160,14 @@ namespace OpenRA.Mods.Common.Activities
 			return this;
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			OnCancel(self);
 
 			if (!IsCanceling && moveActivity != null)
 				moveActivity.Cancel(self);
 
-			return base.Cancel(self, keepQueue);
+			base.Cancel(self, keepQueue);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/EnterTransport.cs

@@ -133,12 +133,12 @@ namespace OpenRA.Mods.Common.Activities
 			return NextActivity;
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			if (!IsCanceling && enterTransport != null)
 				enterTransport.Cancel(self);
 
-			return base.Cancel(self, keepQueue);
+			base.Cancel(self, keepQueue);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/HarvesterDockSequence.cs

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

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

@@ -167,12 +167,12 @@ namespace OpenRA.Mods.Common.Activities
 			return Target.None;
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			if (!IsCanceling && inner != null)
 				inner.Cancel(self);
 
-			return base.Cancel(self);
+			base.Cancel(self);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/PickupUnit.cs

@@ -159,12 +159,12 @@ namespace OpenRA.Mods.Common.Activities
 			});
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			if (!IsCanceling && innerActivity != null)
 				innerActivity.Cancel(self);
 
-			return base.Cancel(self, keepQueue);
+			base.Cancel(self, keepQueue);
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Wait.cs

@@ -27,17 +27,11 @@ namespace OpenRA.Mods.Common.Activities
 
 		public override Activity Tick(Actor self)
 		{
+			if (IsCanceling)
+				return NextActivity;
+
 			return (remainingTicks-- == 0) ? NextActivity : this;
 		}
-
-		public override bool Cancel(Actor self, bool keepQueue = false)
-		{
-			if (!base.Cancel(self, keepQueue))
-				return false;
-
-			remainingTicks = 0;
-			return true;
-		}
 	}
 
 	public class WaitFor : Activity
@@ -53,16 +47,10 @@ namespace OpenRA.Mods.Common.Activities
 
 		public override Activity Tick(Actor self)
 		{
+			if (IsCanceling)
+				return NextActivity;
+
 			return (f == null || f()) ? NextActivity : this;
 		}
-
-		public override bool Cancel(Actor self, bool keepQueue = false)
-		{
-			if (!base.Cancel(self, keepQueue))
-				return false;
-
-			f = null;
-			return true;
-		}
 	}
 }

OpenRA.Mods.Common/Activities/WaitForTransport.cs

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

OpenRA.Mods.Common/Scripting/CallLuaFunc.cs

@@ -43,11 +43,11 @@ namespace OpenRA.Mods.Common.Activities
 			return NextActivity;
 		}
 
-		public override bool Cancel(Actor self, bool keepQueue = false)
+		public override void Cancel(Actor self, bool keepQueue = false)
 		{
 			base.Cancel(self, keepQueue);
 			Dispose();
-			return true;
+			return;
 		}
 
 		public void Dispose()

OpenRA.Mods.Common/Traits/TransformCrusherOnCrush.cs

@@ -51,7 +51,7 @@ namespace OpenRA.Mods.Common.Traits
 				transform.Facing = facing.Facing;
 
 			transform.SkipMakeAnims = info.SkipMakeAnims;
-			if (crusher.CancelActivity())
+			crusher.CancelActivity();
 			crusher.QueueActivity(transform);
 		}
 	}