Renamed Upgrades directory to Conditions.

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

@@ -0,0 +1,101 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2016 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.Support;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	/// <summary>Use as base class for *Info to subclass of UpgradableTrait. (See UpgradableTrait.)</summary>
+	public abstract class ConditionalTraitInfo : IConditionConsumerInfo, IRulesetLoaded
+	{
+		static readonly IReadOnlyDictionary<string, bool> NoConditions = new ReadOnlyDictionary<string, bool>(new Dictionary<string, bool>());
+
+		[ConsumedConditionReference]
+		[Desc("Boolean expression defining the condition to enable this trait.")]
+		public readonly BooleanExpression RequiresCondition = null;
+
+		public abstract object Create(ActorInitializer init);
+
+		// HACK: A shim for all the ActorPreview code that used to query UpgradeMinEnabledLevel directly
+		// This can go away after we introduce an InitialConditions ActorInit and have the traits query the
+		// condition directly
+		public bool EnabledByDefault { get; private set; }
+
+		public virtual void RulesetLoaded(Ruleset rules, ActorInfo ai)
+		{
+			EnabledByDefault = RequiresCondition != null ? RequiresCondition.Evaluate(NoConditions) : true;
+		}
+	}
+
+	/// <summary>
+	/// Abstract base for enabling and disabling trait using conditions.
+	/// Requires basing *Info on UpgradableTraitInfo and using base(info) constructor.
+	/// TraitEnabled will be called at creation if the trait starts enabled or does not use conditions.
+	/// </summary>
+	public abstract class ConditionalTrait<InfoType> : IConditionConsumer, IDisabledTrait, INotifyCreated, ISync where InfoType : ConditionalTraitInfo
+	{
+		public readonly InfoType Info;
+
+		IEnumerable<string> IConditionConsumer.Conditions
+		{
+			get
+			{
+				if (Info.RequiresCondition != null)
+					return Info.RequiresCondition.Variables;
+
+				return Enumerable.Empty<string>();
+			}
+		}
+
+		[Sync] public bool IsTraitDisabled { get; private set; }
+
+		public ConditionalTrait(InfoType info)
+		{
+			Info = info;
+
+			// Conditional traits will be enabled (if appropriate) by the ConditionManager
+			// calling IConditionConsumer.ConditionsChanged at the end of INotifyCreated.
+			IsTraitDisabled = Info.RequiresCondition != null;
+		}
+
+		protected virtual void Created(Actor self)
+		{
+			if (Info.RequiresCondition == null)
+				TraitEnabled(self);
+		}
+
+		void INotifyCreated.Created(Actor self) { Created(self); }
+
+		void IConditionConsumer.ConditionsChanged(Actor self, IReadOnlyDictionary<string, bool> conditions)
+		{
+			if (Info.RequiresCondition == null)
+				return;
+
+			var wasDisabled = IsTraitDisabled;
+			IsTraitDisabled = !Info.RequiresCondition.Evaluate(conditions);
+
+			if (IsTraitDisabled != wasDisabled)
+			{
+				if (wasDisabled)
+					TraitEnabled(self);
+				else
+					TraitDisabled(self);
+			}
+		}
+
+		// Subclasses can add condition support by querying IsTraitDisabled and/or overriding these methods.
+		protected virtual void TraitEnabled(Actor self) { }
+		protected virtual void TraitDisabled(Actor self) { }
+	}
+}