Crawling Part 1: The Knockdownening (#36881)

Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>
Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>
Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>
Co-authored-by: Princess Cheeseballs <66055347+Pronana@users.noreply.github.com>
Co-authored-by: ScarKy0 <scarky0@onet.eu>

Content.Shared/Hands/EntitySystems/SharedHandsSystem.cs

@@ -36,6 +36,7 @@ public abstract partial class SharedHandsSystem
         InitializeDrop();
         InitializePickup();
         InitializeRelay();
+        InitializeEventListeners();
 
         SubscribeLocalEvent<HandsComponent, ComponentInit>(OnInit);
         SubscribeLocalEvent<HandsComponent, MapInitEvent>(OnMapInit);
@@ -166,6 +167,26 @@ public abstract partial class SharedHandsSystem
         return false;
     }
 
+    /// <summary>
+    ///     Does this entity have any empty hands, and how many?
+    /// </summary>
+    public int GetEmptyHandCount(Entity<HandsComponent?> entity)
+    {
+        if (!Resolve(entity, ref entity.Comp, false) || entity.Comp.Count == 0)
+            return 0;
+
+        var hands = 0;
+
+        foreach (var hand in EnumerateHands(entity))
+        {
+            if (!HandIsEmpty(entity, hand))
+                continue;
+            hands++;
+        }
+
+        return hands;
+    }
+
     /// <summary>
     /// Attempts to retrieve the item held in the entity's active hand.
     /// </summary>