Refactor PowerManager and RequiresPower to use conditions

Instead of Actor.IsDisabled.
Added INotifyPowerLevelChanged interface to do so as efficiently as possible.

OpenRA.Game/Player.cs

@@ -24,7 +24,14 @@ using OpenRA.Widgets;
 
 namespace OpenRA
 {
-	public enum PowerState { Normal, Low, Critical }
+	[Flags]
+	public enum PowerState
+	{
+		Normal = 1,
+		Low = 2,
+		Critical = 4
+	}
+
 	public enum WinState { Undefined, Won, Lost }
 
 	public class Player : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -403,7 +403,7 @@
     <Compile Include="Traits\Power\CanPowerDown.cs" />
     <Compile Include="Traits\Power\Player\PowerManager.cs" />
     <Compile Include="Traits\Power\Power.cs" />
-    <Compile Include="Traits\Power\RequiresPower.cs" />
+    <Compile Include="Traits\Conditions\GrantConditionOnPowerState.cs" />
     <Compile Include="Traits\Power\ScalePowerWithHealth.cs" />
     <Compile Include="Traits\Production.cs" />
     <Compile Include="Traits\ProductionFromMapEdge.cs" />

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPowerState.cs

@@ -0,0 +1,88 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you 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. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Grants condition as long as a valid power state is maintained.")]
+	public class GrantConditionOnPowerStateInfo : ConditionalTraitInfo
+	{
+		[FieldLoader.Require]
+		[GrantedConditionReference]
+		[Desc("Condition to grant.")]
+		public readonly string Condition = null;
+
+		[FieldLoader.Require]
+		[Desc("PowerStates at which the condition is granted. Options are Normal, Low and Critical.")]
+		public readonly PowerState ValidPowerStates = PowerState.Low | PowerState.Critical;
+
+		public override object Create(ActorInitializer init) { return new GrantConditionOnPowerState(init.Self, this); }
+	}
+
+	public class GrantConditionOnPowerState : ConditionalTrait<GrantConditionOnPowerStateInfo>, INotifyOwnerChanged, INotifyPowerLevelChanged
+	{
+		PowerManager playerPower;
+		ConditionManager conditionManager;
+		int conditionToken = ConditionManager.InvalidConditionToken;
+
+		bool validPowerState;
+
+		public GrantConditionOnPowerState(Actor self, GrantConditionOnPowerStateInfo info)
+			: base(info)
+		{
+			playerPower = self.Owner.PlayerActor.Trait<PowerManager>();
+		}
+
+		protected override void Created(Actor self)
+		{
+			base.Created(self);
+
+			conditionManager = self.TraitOrDefault<ConditionManager>();
+
+			Update(self);
+		}
+
+		protected override void TraitEnabled(Actor self)
+		{
+			Update(self);
+		}
+
+		protected override void TraitDisabled(Actor self)
+		{
+			Update(self);
+		}
+
+		void Update(Actor self)
+		{
+			if (conditionManager == null)
+				return;
+
+			validPowerState = !IsTraitDisabled && Info.ValidPowerStates.HasFlag(playerPower.PowerState);
+
+			if (validPowerState && conditionToken == ConditionManager.InvalidConditionToken)
+				conditionToken = conditionManager.GrantCondition(self, Info.Condition);
+			else if (!validPowerState && conditionToken != ConditionManager.InvalidConditionToken)
+				conditionToken = conditionManager.RevokeCondition(self, conditionToken);
+		}
+
+		void INotifyPowerLevelChanged.PowerLevelChanged(Actor self)
+		{
+			Update(self);
+		}
+
+		void INotifyOwnerChanged.OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			playerPower = newOwner.PlayerActor.Trait<PowerManager>();
+			Update(self);
+		}
+	}
+}

OpenRA.Mods.Common/Traits/Power/Player/PowerManager.cs

@@ -32,6 +32,7 @@ namespace OpenRA.Mods.Common.Traits
 		readonly DeveloperMode devMode;
 
 		readonly Dictionary<Actor, int> powerDrain = new Dictionary<Actor, int>();
+
 		[Sync] int totalProvided;
 		public int PowerProvided { get { return totalProvided; } }
 
@@ -43,6 +44,11 @@ namespace OpenRA.Mods.Common.Traits
 		public int PowerOutageRemainingTicks { get; private set; }
 		public int PowerOutageTotalTicks { get; private set; }
 
+		int nextPowerAdviceTime = 0;
+		bool lowPower = false;
+		bool wasLowPower = false;
+		bool wasHackEnabled;
+
 		public PowerManager(Actor self, PowerManagerInfo info)
 		{
 			this.self = self;
@@ -86,10 +92,6 @@ namespace OpenRA.Mods.Common.Traits
 				totalDrained += amount;
 		}
 
-		int nextPowerAdviceTime = 0;
-		bool wasLowPower = false;
-		bool wasHackEnabled;
-
 		void ITick.Tick(Actor self)
 		{
 			if (wasHackEnabled != devMode.UnlimitedPower)
@@ -107,15 +109,21 @@ namespace OpenRA.Mods.Common.Traits
 				wasHackEnabled = devMode.UnlimitedPower;
 			}
 
-			var lowPower = totalProvided < totalDrained;
+			lowPower = ExcessPower < 0;
+
+			if (lowPower != wasLowPower)
+				UpdateRequiresPowerActors();
+
 			if (lowPower && !wasLowPower)
 				nextPowerAdviceTime = 0;
+
 			wasLowPower = lowPower;
 
 			if (--nextPowerAdviceTime <= 0)
 			{
 				if (lowPower)
 					Game.Sound.PlayNotification(self.World.Map.Rules, self.Owner, "Speech", info.SpeechNotification, self.Owner.Faction.InternalName);
+
 				nextPowerAdviceTime = info.AdviceInterval;
 			}
 
@@ -148,6 +156,15 @@ namespace OpenRA.Mods.Common.Traits
 				p.Trait.UpdateStatus(p.Actor);
 		}
 
+		void UpdateRequiresPowerActors()
+		{
+			var traitPairs = self.World.ActorsWithTrait<INotifyPowerLevelChanged>()
+				.Where(p => !p.Actor.IsDead && p.Actor.IsInWorld && p.Actor.Owner == self.Owner);
+
+			foreach (var p in traitPairs)
+				p.Trait.PowerLevelChanged(p.Actor);
+		}
+
 		void IResolveOrder.ResolveOrder(Actor self, Order order)
 		{
 			if (devMode.Enabled && order.OrderString == "PowerOutage")

OpenRA.Mods.Common/Traits/Power/RequiresPower.cs

@@ -1,42 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
- * This file is part of OpenRA, which is free software. It is made
- * available to you 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. For more
- * information, see COPYING.
- */
-#endregion
-
-using OpenRA.Traits;
-
-namespace OpenRA.Mods.Common.Traits
-{
-	[Desc("Needs power to operate.")]
-	class RequiresPowerInfo : ConditionalTraitInfo, ITraitInfo
-	{
-		public override object Create(ActorInitializer init) { return new RequiresPower(init.Self, this); }
-	}
-
-	class RequiresPower : ConditionalTrait<RequiresPowerInfo>, IDisable, INotifyOwnerChanged
-	{
-		PowerManager playerPower;
-
-		public RequiresPower(Actor self, RequiresPowerInfo info)
-			: base(info)
-		{
-			playerPower = self.Owner.PlayerActor.Trait<PowerManager>();
-		}
-
-		public bool Disabled
-		{
-			get { return playerPower.PowerProvided < playerPower.PowerDrained && !IsTraitDisabled; }
-		}
-
-		public void OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
-		{
-			playerPower = newOwner.PlayerActor.Trait<PowerManager>();
-		}
-	}
-}

OpenRA.Mods.Common/TraitsInterfaces.cs

@@ -95,6 +95,9 @@ namespace OpenRA.Mods.Common.Traits
 		void AfterRepair(Actor self, Actor target);
 	}
 
+	[RequireExplicitImplementation]
+	public interface INotifyPowerLevelChanged { void PowerLevelChanged(Actor self); }
+
 	public interface INotifyBuildingPlaced { void BuildingPlaced(Actor self); }
 	public interface INotifyNuke { void Launching(Actor self); }
 	public interface INotifyBurstComplete { void FiredBurst(Actor self, Target target, Armament a); }