saner planes, part 1

OpenRA.Game/Actor.cs

@@ -65,11 +65,20 @@ namespace OpenRA
 
 		public void Tick()
 		{
-			while (currentActivity != null)
+			while (currentActivity != null && !(currentActivity is Idle))
 			{
 				var a = currentActivity;
 				currentActivity = a.Tick(this) ?? new Idle();
-				if (a == currentActivity || currentActivity is Idle) break;
+
+				if (a == currentActivity) break;
+
+				if (currentActivity is Idle)
+				{
+					foreach (var ni in traits.WithInterface<INotifyIdle>())
+						ni.Idle(this);
+
+					break;
+				}
 			}
 		}
 

OpenRA.Game/OpenRA.Game.csproj

@@ -75,6 +75,7 @@
   <ItemGroup>
     <Compile Include="Chat.cs" />
     <Compile Include="Chrome.cs" />
+    <Compile Include="Traits\AI\ReturnOnIdle.cs" />
     <Compile Include="Widgets\Delegates\ConnectionDialogsDelegate.cs" />
     <Compile Include="Widgets\Delegates\CreateServerMenuDelegate.cs" />
     <Compile Include="Widgets\Delegates\MainMenuButtonsDelegate.cs" />

OpenRA.Game/Traits/AI/ReturnOnIdle.cs

@@ -0,0 +1,41 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
+ * This file is part of OpenRA.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System;
+using OpenRA.Traits.Activities;
+
+namespace OpenRA.Traits.AI
+{
+	class ReturnOnIdleInfo : StatelessTraitInfo<ReturnOnIdle> { }
+
+	// fly home or fly-off-map behavior for idle planes
+
+	class ReturnOnIdle : INotifyIdle
+	{
+		public void Idle(Actor self)
+		{
+			var altitude = self.traits.Get<Unit>().Altitude;
+			if (altitude == 0) return;	// we're on the ground, let's stay there.
+
+			self.QueueActivity(new ReturnToBase(self, null));
+			self.QueueActivity(new Rearm());
+		}
+	}
+}

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -137,4 +137,5 @@ namespace OpenRA.Traits
 	}
 
 	public interface IRenderOverlay { void Render(); }
+	public interface INotifyIdle { void Idle(Actor self); }
 }