Cleans up some shield code, adds grid checks (#12621)

closes https://github.com/space-wizards/space-station-14/issues/11196

Content.Shared/Blocking/BlockingSystem.cs

@@ -1,6 +1,6 @@
 using Content.Shared.Actions;
 using Content.Shared.Actions.ActionTypes;
-using Content.Shared.Buckle.Components;
+using Content.Shared.Buckle;
 using Content.Shared.Doors.Components;
 using Content.Shared.Hands;
 using Content.Shared.Hands.EntitySystems;
@@ -33,6 +33,7 @@ public sealed class BlockingSystem : EntitySystem
     [Dependency] private readonly SharedContainerSystem _containerSystem = default!;
     [Dependency] private readonly EntityLookupSystem _lookup = default!;
     [Dependency] private readonly SharedPhysicsSystem _physics = default!;
+    [Dependency] private readonly SharedBuckleSystem _buckleSystem = default!;
 
     public override void Initialize()
     {
@@ -117,13 +118,14 @@ public sealed class BlockingSystem : EntitySystem
     /// Creates a new hard fixture to bodyblock
     /// Also makes the user static to prevent prediction issues
     /// </summary>
-    /// <param name="uid"> The entity with the blocking component</param>
+    /// <param name="item"> The entity with the blocking component</param>
     /// <param name="component"> The <see cref="BlockingComponent"/></param>
     /// <param name="user"> The entity who's using the item to block</param>
     /// <returns></returns>
     public bool StartBlocking(EntityUid item, BlockingComponent component, EntityUid user)
     {
-        if (component.IsBlocking) return false;
+        if (component.IsBlocking)
+            return false;
 
         var xform = Transform(user);
 
@@ -135,8 +137,8 @@ public sealed class BlockingSystem : EntitySystem
 
         if (component.BlockingToggleAction != null)
         {
-            //Don't allow someone to block if they're in a container.
+            //Don't allow someone to block if they're not parented to a grid
-            if (_containerSystem.IsEntityInContainer(user) || !_mapManager.TryFindGridAt(xform.MapPosition, out var grid))
+            if (xform.GridUid != xform.ParentUid)
             {
                 CantBlockError(user);
                 return false;

Content.Shared/Blocking/BlockingUserSystem.cs

@@ -1,9 +1,7 @@
-using Content.Shared.Audio;
+using Content.Shared.Damage;
-using Content.Shared.Damage;
 using Content.Shared.Damage.Prototypes;
 using Robust.Shared.Audio;
 using Robust.Shared.Containers;
-using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 
 namespace Content.Shared.Blocking;
@@ -30,17 +28,13 @@ public sealed class BlockingUserSystem : EntitySystem
     private void OnParentChanged(EntityUid uid, BlockingUserComponent component, ref EntParentChangedMessage args)
     {
         if (TryComp<BlockingComponent>(component.BlockingItem, out var blockComp) && blockComp.IsBlocking)
-        {
             _blockingSystem.StopBlocking(component.BlockingItem.Value, blockComp, uid);
-        }
     }
 
     private void OnInsertAttempt(EntityUid uid, BlockingUserComponent component, ContainerGettingInsertedAttemptEvent args)
     {
         if (TryComp<BlockingComponent>(component.BlockingItem, out var blockComp) && blockComp.IsBlocking)
-        {
             _blockingSystem.StopBlocking(component.BlockingItem.Value, blockComp, uid);
-        }
     }
 
     private void OnAnchorChanged(EntityUid uid, BlockingUserComponent component, ref AnchorStateChangedEvent args)
@@ -49,17 +43,13 @@ public sealed class BlockingUserSystem : EntitySystem
             return;
 
         if (TryComp<BlockingComponent>(component.BlockingItem, out var blockComp) && blockComp.IsBlocking)
-        {
             _blockingSystem.StopBlocking(component.BlockingItem.Value, blockComp, uid);
-        }
     }
 
     private void OnDamageChanged(EntityUid uid, BlockingUserComponent component, DamageChangedEvent args)
     {
         if (args.DamageDelta != null && args.DamageIncreased)
-        {
             _damageable.TryChangeDamage(component.BlockingItem, args.DamageDelta, origin: args.Origin);
-        }
     }
 
     private void OnUserDamageModified(EntityUid uid, BlockingUserComponent component, DamageModifyEvent args)