Add GrantConditionOnFaction.

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

@@ -511,6 +511,7 @@
     <Compile Include="Traits\Conditions\ProximityExternalCondition.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnAttack.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnDamageState.cs" />
+    <Compile Include="Traits\Conditions\GrantConditionOnFaction.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnTerrain.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnMovement.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnPrerequisite.cs" />

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

@@ -0,0 +1,79 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2018 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 System.Collections.Generic;
+using System.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Grants a condition while the trait is active.")]
+	class GrantConditionOnFactionInfo : ConditionalTraitInfo
+	{
+		[FieldLoader.Require]
+		[GrantedConditionReference]
+		[Desc("Condition to grant.")]
+		public readonly string Condition = null;
+
+		[Desc("Only grant this condition for certain factions.")]
+		public readonly HashSet<string> Factions = new HashSet<string>();
+
+		[Desc("Should it recheck everything when it is captured?")]
+		public readonly bool ResetOnOwnerChange = false;
+
+		public override object Create(ActorInitializer init) { return new GrantConditionOnFaction(init, this); }
+	}
+
+	class GrantConditionOnFaction : ConditionalTrait<GrantConditionOnFactionInfo>, INotifyOwnerChanged
+	{
+		ConditionManager conditionManager;
+		int conditionToken = ConditionManager.InvalidConditionToken;
+		string faction;
+
+		public GrantConditionOnFaction(ActorInitializer init, GrantConditionOnFactionInfo info)
+			: base(info)
+		{
+			faction = init.Contains<FactionInit>() ? init.Get<FactionInit, string>() : init.Self.Owner.Faction.InternalName;
+		}
+
+		protected override void Created(Actor self)
+		{
+			conditionManager = self.Trait<ConditionManager>();
+
+			base.Created(self);
+		}
+
+		public void OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			if (Info.ResetOnOwnerChange && faction != newOwner.Faction.InternalName)
+			{
+				faction = newOwner.Faction.InternalName;
+
+				TraitDisabled(self);
+				TraitEnabled(self);
+			}
+		}
+
+		protected override void TraitEnabled(Actor self)
+		{
+			if (conditionToken == ConditionManager.InvalidConditionToken && Info.Factions.Contains(faction))
+				conditionToken = conditionManager.GrantCondition(self, Info.Condition);
+		}
+
+		protected override void TraitDisabled(Actor self)
+		{
+			if (conditionToken == ConditionManager.InvalidConditionToken)
+				return;
+
+			conditionToken = conditionManager.RevokeCondition(self, conditionToken);
+		}
+	}
+}