refactor activity queueing

OpenRA.Game/Actor.cs

@@ -151,16 +151,9 @@ namespace OpenRA
 		public void QueueActivity( IActivity nextActivity )
 		{
 			if( currentActivity == null )
-			{
 				currentActivity = nextActivity;
-				return;
-			}
-			var act = currentActivity;
-			while( act.NextActivity != null )
-			{
-				act = act.NextActivity;
-			}
-			act.NextActivity = nextActivity;
+			else
+				currentActivity.Queue( nextActivity );
 		}
 
 		public void CancelActivity()

OpenRA.Game/Traits/Activities/Drag.cs

@@ -14,7 +14,7 @@ namespace OpenRA.Traits.Activities
 {
 	public class Drag : IActivity
 	{
-		public IActivity NextActivity { get; set; }
+		IActivity NextActivity { get; set; }
 
 		float2 endLocation;
 		float2 startLocation;
@@ -40,5 +40,13 @@ namespace OpenRA.Traits.Activities
 		}
 
 		public void Cancel(Actor self) {	}
+
+		public void Queue( IActivity activity )
+		{
+			if( NextActivity != null )
+				NextActivity.Queue( activity );
+			else
+				NextActivity = activity;
+		}
 	}
 }

OpenRA.Game/Traits/Activities/Idle.cs

@@ -12,9 +12,17 @@ namespace OpenRA.Traits.Activities
 {
 	class Idle : IActivity
 	{
-		public IActivity NextActivity { get; set; }
+		IActivity NextActivity { get; set; }
 
 		public IActivity Tick(Actor self) { return NextActivity; }
 		public void Cancel(Actor self) {}
+
+		public void Queue( IActivity activity )
+		{
+			if( NextActivity != null )
+				NextActivity.Queue( activity );
+			else
+				NextActivity = activity;
+		}
 	}
 }

OpenRA.Game/Traits/Activities/Move.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Traits.Activities
 {
 	public class Move : IActivity
 	{
-		public IActivity NextActivity { get; set; }
+		IActivity NextActivity { get; set; }
 
 		int2? destination;
 		int nearEnough;
@@ -164,9 +164,7 @@ namespace OpenRA.Traits.Activities
 				Log.Write("debug", "Turn: #{0} from {1} to {2}",
 					self.ActorID, mobile.Facing, firstFacing);
 
-				return new Turn( firstFacing )
-					{ NextActivity = this }
-					.Tick( self );
+				return Util.SequenceActivities( new Turn( firstFacing ), this ).Tick( self );
 			}
 			else
 			{
@@ -261,6 +259,14 @@ namespace OpenRA.Traits.Activities
 			NextActivity = null;
 		}
 
+		public void Queue( IActivity activity )
+		{
+			if( NextActivity != null )
+				NextActivity.Queue( activity );
+			else
+				NextActivity = activity;
+		}
+
 		abstract class MovePart : IActivity
 		{
 			public readonly Move move;
@@ -280,11 +286,14 @@ namespace OpenRA.Traits.Activities
 				this.moveFractionTotal = (int)(( to - from ).Length*3);
 			}
 
-			public IActivity NextActivity { get { return move; } set { move.NextActivity = value; } }
-
 			public void Cancel( Actor self )
 			{
-				NextActivity.Cancel( self );
+				move.Cancel( self );
+			}
+
+			public void Queue( IActivity activity )
+			{
+				move.Queue( activity );
 			}
 
 			public IActivity Tick( Actor self )

OpenRA.Game/Traits/Activities/RemoveSelf.cs

@@ -10,18 +10,13 @@
 
 namespace OpenRA.Traits.Activities
 {
-	public class RemoveSelf : IActivity
+	public class RemoveSelf : CancelableActivity
 	{
-		bool isCanceled;
-		public IActivity NextActivity { get; set; }
-
-		public IActivity Tick(Actor self)
+		public override IActivity Tick(Actor self)
 		{
-			if (isCanceled) return NextActivity;
+			if (IsCanceled) return NextActivity;
 			self.Destroy();
 			return null;
 		}
-
-		public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
 	}
 }

OpenRA.Game/Traits/Activities/Sell.cs

@@ -12,7 +12,7 @@ namespace OpenRA.Traits.Activities
 {
 	class Sell : IActivity
 	{
-		public IActivity NextActivity { get; set; }
+		IActivity NextActivity { get; set; }
 
 		bool started;
 
@@ -55,5 +55,13 @@ namespace OpenRA.Traits.Activities
 		}
 
 		public void Cancel(Actor self) { /* never gonna give you up.. */ }
+
+		public void Queue( IActivity activity )
+		{
+			if( NextActivity != null )
+				NextActivity.Queue( activity );
+			else
+				NextActivity = activity;
+		}
 	}
 }

OpenRA.Game/Traits/Activities/Turn.cs

@@ -12,9 +12,8 @@ using System.Linq;
 
 namespace OpenRA.Traits.Activities
 {
-	public class Turn : IActivity
+	public class Turn : CancelableActivity
 	{
-		public IActivity NextActivity { get; set; }
 		int desiredFacing;
 
 		public Turn( int desiredFacing )
@@ -22,8 +21,9 @@ namespace OpenRA.Traits.Activities
 			this.desiredFacing = desiredFacing;
 		}
 
-		public IActivity Tick( Actor self )
+		public override IActivity Tick( Actor self )
 		{
+			if (IsCanceled) return NextActivity;
 			var facing = self.Trait<IFacing>();
 
 			if( desiredFacing == facing.Facing )
@@ -32,11 +32,5 @@ namespace OpenRA.Traits.Activities
 
 			return this;
 		}
-
-		public void Cancel( Actor self )
-		{
-			desiredFacing = self.Trait<IFacing>().Facing;
-			NextActivity = null;
-		}
 	}
 }

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -170,9 +170,33 @@ namespace OpenRA.Traits
 	
 	public interface IActivity
 	{
-		IActivity NextActivity { get; set; }
 		IActivity Tick(Actor self);
 		void Cancel(Actor self);
+		void Queue(IActivity activity);
+	}
+
+	public abstract class CancelableActivity : IActivity
+	{
+		protected IActivity NextActivity { get; private set; }
+		protected bool IsCanceled { get; private set; }
+
+		public abstract IActivity Tick( Actor self );
+		protected virtual void OnCancel() {}
+
+		public void Cancel( Actor self )
+		{
+			IsCanceled = true;
+			NextActivity = null;
+			OnCancel();
+		}
+
+		public void Queue( IActivity activity )
+		{
+			if( NextActivity != null )
+				NextActivity.Queue( activity );
+			else
+				NextActivity = activity;
+		}
 	}
 
 	public interface IRenderOverlay { void Render(); }

OpenRA.Game/Traits/Util.cs

@@ -113,7 +113,7 @@ namespace OpenRA.Traits
 		public static IActivity SequenceActivities(params IActivity[] acts)
 		{
 			return acts.Reverse().Aggregate(
-				(next, a) => { a.NextActivity = next; return a; });
+				(next, a) => { a.Queue( next ); return a; });
 		}
 
 		public static Color ArrayToColor(int[] x) { return Color.FromArgb(x[0], x[1], x[2]); }