From 80842fd4b855f71bea8a0c7585ca827212132036 Mon Sep 17 00:00:00 2001
From: Paul Chote <pchote@users.noreply.github.com>
Date: Sun, 18 Nov 2018 16:01:58 +0000
Subject: [PATCH] Add GrantConditionOnPlayerResources trait.

---
 OpenRA.Mods.Common/OpenRA.Mods.Common.csproj  |  1 +
 .../GrantConditionOnPlayerResources.cs        | 72 +++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPlayerResources.cs

diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index bb30a78172..658208b07b 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -314,6 +314,7 @@
     <Compile Include="Traits\CapturableProgressBar.cs" />
     <Compile Include="Traits\CaptureProgressBar.cs" />
     <Compile Include="Traits\CaptureProgressBlink.cs" />
+    <Compile Include="Traits\Conditions\GrantConditionOnPlayerResources.cs" />
     <Compile Include="Traits\Multipliers\CreatesShroudMultiplier.cs" />
     <Compile Include="Traits\Multipliers\RevealsShroudMultiplier.cs" />
     <Compile Include="Traits\RepairsUnits.cs" />
diff --git a/OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPlayerResources.cs b/OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPlayerResources.cs
new file mode 100644
index 0000000000..45a7263fbb
--- /dev/null
+++ b/OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPlayerResources.cs
@@ -0,0 +1,72 @@
+#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.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Grants a condition to this actor when the player has stored resources.")]
+	public class GrantConditionOnPlayerResourcesInfo : ITraitInfo
+	{
+		[FieldLoader.Require]
+		[GrantedConditionReference]
+		[Desc("Condition to grant.")]
+		public readonly string Condition = null;
+
+		[Desc("Enable condition when the amount of stored resources is greater than this.")]
+		public readonly int Threshold = 0;
+
+		public object Create(ActorInitializer init) { return new GrantConditionOnPlayerResources(this); }
+	}
+
+	public class GrantConditionOnPlayerResources : INotifyCreated, INotifyOwnerChanged, ITick
+	{
+		readonly GrantConditionOnPlayerResourcesInfo info;
+		PlayerResources playerResources;
+
+		ConditionManager conditionManager;
+		int conditionToken = ConditionManager.InvalidConditionToken;
+
+		public GrantConditionOnPlayerResources(GrantConditionOnPlayerResourcesInfo info)
+		{
+			this.info = info;
+		}
+
+		void INotifyCreated.Created(Actor self)
+		{
+			// Special case handling is required for the Player actor.
+			// Created is called before Player.PlayerActor is assigned,
+			// so we must query other player traits from self, knowing that
+			// it refers to the same actor as self.Owner.PlayerActor
+			var playerActor = self.Info.Name == "player" ? self : self.Owner.PlayerActor;
+			playerResources = playerActor.Trait<PlayerResources>();
+			conditionManager = self.TraitOrDefault<ConditionManager>();
+		}
+
+		void INotifyOwnerChanged.OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			playerResources = newOwner.PlayerActor.Trait<PlayerResources>();
+		}
+
+		void ITick.Tick(Actor self)
+		{
+			if (string.IsNullOrEmpty(info.Condition) || conditionManager == null)
+				return;
+
+			var enabled = playerResources.Resources > info.Threshold;
+			if (enabled && conditionToken == ConditionManager.InvalidConditionToken)
+				conditionToken = conditionManager.GrantCondition(self, info.Condition);
+			else if (!enabled && conditionToken != ConditionManager.InvalidConditionToken)
+				conditionToken = conditionManager.RevokeCondition(self, conditionToken);
+		}
+	}
+}