Make Tick return bool

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;
 		}
 	}
 }