Implement human pockets and ID card slot correctly.

Pockets & ID need uniform equipped. Pockets accept any sufficiently small item.

Content.Server/GameObjects/Components/GUI/HumanInventoryControllerComponent.cs

@@ -0,0 +1,87 @@
+using Robust.Server.GameObjects.Components.Container;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Network;
+using Robust.Shared.Timers;
+using static Content.Shared.GameObjects.Components.Inventory.EquipmentSlotDefines;
+
+namespace Content.Server.GameObjects
+{
+    // Handles the special behavior of pockets/ID card slot and their relation to uniforms.
+    [RegisterComponent]
+    [ComponentReference(typeof(IInventoryController))]
+    public class HumanInventoryControllerComponent : Component, IInventoryController
+    {
+        public override string Name => "HumanInventoryController";
+
+        private InventoryComponent _inventory;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            _inventory = Owner.GetComponent<InventoryComponent>();
+        }
+
+        bool IInventoryController.CanEquip(Slots slot, IEntity entity, bool flagsCheck)
+        {
+            var slotMask = SlotMasks[slot];
+
+            if ((slotMask & (SlotFlags.POCKET | SlotFlags.IDCARD)) != SlotFlags.NONE)
+            {
+                // Can't wear stuff in ID card or pockets unless you have a uniform.
+                if (_inventory.GetSlotItem(Slots.INNERCLOTHING) == null)
+                {
+                    return false;
+                }
+
+                if (slotMask == SlotFlags.POCKET)
+                {
+                    var itemComponent = entity.GetComponent<ItemComponent>();
+
+                    // If this item is small enough then it always fits in pockets.
+                    if (itemComponent.ObjectSize <= (int) ReferenceSizes.Pocket)
+                    {
+                        return true;
+                    }
+                }
+            }
+
+            // Standard flag check.
+            return flagsCheck;
+        }
+
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case ContainerContentsModifiedMessage contentsModified:
+                    Timer.Spawn(0, DropIdAndPocketsIfWeNoLongerHaveAUniform);
+                    break;
+            }
+        }
+
+        // Hey, it's descriptive.
+        private void DropIdAndPocketsIfWeNoLongerHaveAUniform()
+        {
+            if (_inventory.GetSlotItem(Slots.INNERCLOTHING) != null)
+            {
+                return;
+            }
+
+            void DropMaybe(Slots slot)
+            {
+                if (_inventory.GetSlotItem(slot) != null)
+                {
+                    _inventory.Unequip(slot);
+                }
+            }
+
+            DropMaybe(Slots.POCKET1);
+            DropMaybe(Slots.POCKET2);
+            DropMaybe(Slots.IDCARD);
+        }
+    }
+}

Content.Server/GameObjects/Components/GUI/IInventoryController.cs

@@ -0,0 +1,20 @@
+using Robust.Shared.Interfaces.GameObjects;
+using static Content.Shared.GameObjects.Components.Inventory.EquipmentSlotDefines;
+
+namespace Content.Server.GameObjects
+{
+    /// <summary>
+    ///     Allows for overriding inventory-related behavior on an entity.
+    /// </summary>
+    public interface IInventoryController
+    {
+        /// <summary>
+        ///     Can be implemented to override "can this item be equipped" behavior.
+        /// </summary>
+        /// <param name="slot">The slot to be equipped into.</param>
+        /// <param name="entity">The entity to equip.</param>
+        /// <param name="flagsCheck">Whether the entity passes default slot masks & flags checks.</param>
+        /// <returns>True if the entity can be equipped, false otherwise</returns>
+        bool CanEquip(Slots slot, IEntity entity, bool flagsCheck) => flagsCheck;
+    }
+}

Content.Server/GameObjects/Components/GUI/InventoryComponent.cs

@@ -1,13 +1,9 @@
-// Only unused on .NET Core due to KeyValuePair.Deconstruct
+using System;
-// ReSharper disable once RedundantUsingDirective
-using Robust.Shared.Utility;
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using Content.Server.GameObjects.EntitySystems;
 using Content.Shared.GameObjects;
 using Robust.Server.GameObjects.Components.Container;
-using Robust.Server.Interfaces.GameObjects;
 using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
@@ -92,30 +88,43 @@ namespace Content.Server.GameObjects
         ///     This will fail if there is already an item in the specified slot.
         /// </remarks>
         /// <param name="slot">The slot to put the item in.</param>
-        /// <param name="clothing">The item to insert into the slot.</param>
+        /// <param name="item">The item to insert into the slot.</param>
         /// <returns>True if the item was successfully inserted, false otherwise.</returns>
-        public bool Equip(Slots slot, ClothingComponent clothing)
+        public bool Equip(Slots slot, ItemComponent item)
         {
-            if (clothing == null)
+            if (item == null)
             {
-                throw new ArgumentNullException(nameof(clothing),
+                throw new ArgumentNullException(nameof(item),
                     "Clothing must be passed here. To remove some clothing from a slot, use Unequip()");
             }
 
-            if (clothing.SlotFlags == SlotFlags.PREVENTEQUIP //Flag to prevent equipping at all
+            var pass = false;
-                || (clothing.SlotFlags & SlotMasks[slot]) == 0
+
-            ) //Does the clothing flag have any of our requested slot flags
+            if (item is ClothingComponent clothing)
+            {
+                if (clothing.SlotFlags != SlotFlags.PREVENTEQUIP && (clothing.SlotFlags & SlotMasks[slot]) != 0)
+                {
+                    pass = true;
+                }
+            }
+
+            if (Owner.TryGetComponent(out IInventoryController controller))
+            {
+                pass = controller.CanEquip(slot, item.Owner, pass);
+            }
+
+            if (!pass)
             {
                 return false;
             }
 
             var inventorySlot = SlotContainers[slot];
-            if (!inventorySlot.Insert(clothing.Owner))
+            if (!inventorySlot.Insert(item.Owner))
             {
                 return false;
             }
 
-            clothing.EquippedToSlot();
+            item.EquippedToSlot();
 
             Dirty();
             return true;
@@ -256,7 +265,7 @@ namespace Content.Server.GameObjects
                 {
                     var hands = Owner.GetComponent<HandsComponent>();
                     var activeHand = hands.GetActiveHand;
-                    if (activeHand != null && activeHand.Owner.TryGetComponent(out ClothingComponent clothing))
+                    if (activeHand != null && activeHand.Owner.TryGetComponent(out ItemComponent clothing))
                     {
                         hands.Drop(hands.ActiveIndex);
                         if (!Equip(msg.Inventoryslot, clothing))

Content.Shared/GameObjects/Components/Inventory/InventoryTemplates.cs

@@ -28,6 +28,8 @@ namespace Content.Shared.GameObjects
 
         private static readonly Dictionary<Slots, int> _slotDrawingOrder = new Dictionary<Slots, int>
         {
+            {Slots.POCKET1, 12},
+            {Slots.POCKET2, 11},
             {Slots.HEAD, 10},
             {Slots.MASK, 9},
             {Slots.EARS, 8},
@@ -46,7 +48,7 @@ namespace Content.Shared.GameObjects
             Slots.EYES, Slots.HEAD, Slots.EARS,
             Slots.OUTERCLOTHING, Slots.MASK, Slots.INNERCLOTHING,
             Slots.BACKPACK, Slots.BELT, Slots.GLOVES,
-            Slots.NONE, Slots.SHOES, Slots.IDCARD
+            Slots.NONE, Slots.SHOES, Slots.IDCARD, Slots.POCKET1, Slots.POCKET2
         };
 
         public override int SlotDrawingOrder(Slots slot)

Resources/Prototypes/Entities/mobs/human.yml

@@ -84,6 +84,7 @@
   - type: CharacterInfo
   - type: FootstepSound
   - type: HumanoidAppearance
+  - type: HumanInventoryController
 
 - type: entity
   save: false