Unrevert #10934

Content.Shared/Inventory/InventorySystem.Relay.cs

@@ -5,6 +5,7 @@ using Content.Shared.IdentityManagement.Components;
 using Content.Shared.Movement.Systems;
 using Content.Shared.Slippery;
 using Content.Shared.Strip.Components;
+using Content.Shared.Temperature;
 
 namespace Content.Shared.Inventory;
 
@@ -19,19 +20,43 @@ public partial class InventorySystem
         SubscribeLocalEvent<InventoryComponent, GetExplosionResistanceEvent>(RelayInventoryEvent);
         SubscribeLocalEvent<InventoryComponent, BeforeStripEvent>(RelayInventoryEvent);
         SubscribeLocalEvent<InventoryComponent, SeeIdentityAttemptEvent>(RelayInventoryEvent);
+        SubscribeLocalEvent<InventoryComponent, ModifyChangedTemperatureEvent>(RelayInventoryEvent);
     }
 
     protected void RelayInventoryEvent<T>(EntityUid uid, InventoryComponent component, T args) where T : EntityEventArgs, IInventoryRelayEvent
     {
+        if (args.TargetSlots == SlotFlags.NONE)
+            return;
+
         var containerEnumerator = new ContainerSlotEnumerator(uid, component.TemplateId, _prototypeManager, this, args.TargetSlots);
-        while(containerEnumerator.MoveNext(out var container))
+        var ev = new InventoryRelayedEvent<T>(args);
+        while (containerEnumerator.MoveNext(out var container))
         {
-            if(!container.ContainedEntity.HasValue) continue;
-            RaiseLocalEvent(container.ContainedEntity.Value, args, false);
+            if (!container.ContainedEntity.HasValue) continue;
+            RaiseLocalEvent(container.ContainedEntity.Value, ev, false);
         }
     }
 }
 
+/// <summary>
+///     Event wrapper for relayed events.
+/// </summary>
+/// <remarks>
+///      This avoids nested inventory relays, and makes it easy to have certain events only handled by the initial
+///      target entity. E.g. health based movement speed modifiers should not be handled by a hat, even if that hat
+///      happens to be a dead mouse. Clothing that wishes to modify movement speed must subscribe to
+///      InventoryRelayedEvent<RefreshMovementSpeedModifiersEvent>
+/// </remarks>
+public sealed class InventoryRelayedEvent<TEvent> : EntityEventArgs where TEvent : EntityEventArgs, IInventoryRelayEvent
+{
+    public readonly TEvent Args;
+
+    public InventoryRelayedEvent(TEvent args)
+    {
+        Args = args;
+    }
+}
+
 /// <summary>
 ///     Events that should be relayed to inventory slots should implement this interface.
 /// </summary>