Support power prepare check.

Author: darkademic

OpenRA.Mods.Common/Traits/SupportPowers/SupportPower.cs

@@ -204,6 +204,11 @@ public virtual void SelectTarget(Actor self, string order, SupportPowerManager m
 			self.World.OrderGenerator = new SelectGenericPowerTarget(order, manager, info.Cursor, MouseButton.Left);
 		}
 
+		public virtual bool Prepare(Actor self, Order order, SupportPowerManager manager)
+		{
+			return true;
+		}
+
 		public virtual void Activate(Actor self, Order order, SupportPowerManager manager)
 		{
 			if (Info.DisplayRadarPing && manager.RadarPings != null)

OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs

@@ -258,6 +258,9 @@ public virtual void Activate(Order order)
 			if (!HasSufficientFunds(power, true))
 				return;
 
+			if (!power.Prepare(power.Self, order, Manager))
+				return;
+
 			// Note: order.Subject is the *player* actor
 			power.Activate(power.Self, order, Manager);
 			remainingSubTicks = TotalTicks * 100;