fix: Uses client bug to make addon containers work (#776)

* Fixes tooltip for container furniture so it works. This doesn't work on ClassicUO.
* Fixes double click opening container furniture by double clicking the addon component.
* Fixes the context menu not showing up sometimes on the addon piece.

Note: You cannot drop anything into the addon component since it might be far away and it is not a real container. There is no easy fix for this without building an entire custom container class for addons or changing how items drag/drop entirely. Requires closing/opening container gumps as it switches from one component to another that shares the same content. Also requires sharing tooltips, invalidated properties, process delta changes, etc.
Not worth the effort.

<img width="444" alt="Screen_Shot_2021-09-12_at_4 27 28_PM" src="https://user-images.githubusercontent.com/3953314/133011752-c5b54cf2-2c7b-45c0-882d-0365ef62e686.png">

Projects/UOContent/Items/Addons/AddonComponent.cs

@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+using Server.ContextMenus;
 using Server.Engines.Craft;
 
 namespace Server.Items
@@ -141,10 +143,7 @@ namespace Server.Items
             }
         }
 
-        public override void OnDoubleClick(Mobile from)
-        {
-            _addon?.OnComponentUsed(this, from);
-        }
+        public override void OnDoubleClick(Mobile from) => _addon?.OnComponentUsed(this, from);
 
         public override void OnLocationChange(Point3D old)
         {
@@ -162,6 +161,11 @@ namespace Server.Items
             }
         }
 
+        public override void GetProperties(ObjectPropertyList list) => _addon?.GetProperties(list);
+
+        public override void GetContextMenuEntries(Mobile from, List<ContextMenuEntry> list) =>
+            _addon?.GetContextMenuEntries(from, list);
+
         public override void OnAfterDelete()
         {
             base.OnAfterDelete();

Projects/UOContent/Items/Addons/AddonContainerComponent.cs

@@ -1,5 +1,8 @@
+using System;
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using Server.ContextMenus;
+using Server.Network;
 
 namespace Server.Items
 {
@@ -19,11 +22,11 @@ namespace Server.Items
 
         [SerializableField(0)]
         [SerializableFieldAttr("[CommandProperty(AccessLevel.GameMaster)]")]
-        public BaseAddonContainer _addon;
+        private BaseAddonContainer _addon;
 
         [SerializableField(1)]
         [SerializableFieldAttr("[CommandProperty(AccessLevel.GameMaster)]")]
-        public Point3D _offset;
+        private Point3D _offset;
 
         [Hue]
         [CommandProperty(AccessLevel.GameMaster)]
@@ -65,9 +68,6 @@ namespace Server.Items
             }
         }
 
-        public override void GetContextMenuEntries(Mobile from, List<ContextMenuEntry> list) =>
-            _addon?.GetContextMenuEntries(from, list);
-
         public override void OnMapChange()
         {
             if (_addon != null)
@@ -76,6 +76,11 @@ namespace Server.Items
             }
         }
 
+        public override void GetProperties(ObjectPropertyList list) => _addon?.GetProperties(list);
+
+        public override void GetContextMenuEntries(Mobile from, List<ContextMenuEntry> list) =>
+            _addon?.GetContextMenuEntries(from, list);
+
         public override void OnAfterDelete()
         {
             base.OnAfterDelete();
@@ -83,6 +88,17 @@ namespace Server.Items
             _addon?.Delete();
         }
 
+        public override void SendWorldPacketTo(NetState ns, ReadOnlySpan<byte> world = default)
+        {
+            Span<byte> buffer = stackalloc byte[OutgoingEntityPackets.MaxWorldEntityPacketLength].InitializePacket();
+            var length = OutgoingItemPackets.CreateWorldItem(buffer, this);
+            // Use an itemid of a real container
+            BinaryPrimitives.WriteUInt16BigEndian(buffer[7..9], (ushort)(_addon?.ItemID ?? 0x9AB));
+            ns.Send(buffer[..length]);
+
+            base.SendWorldPacketTo(ns, world);
+        }
+
         [AfterDeserialization]
         private void AfterDeserialization()
         {

Projects/UOContent/Items/Addons/ArcaneBookshelfEastAddon.cs

@@ -1,27 +1,29 @@
 namespace Server.Items
 {
     [Serializable(0)]
-    public partial class ArcaneBookshelfEastAddon : BaseAddon
+    public partial class ArcaneBookshelfEastAddon : BaseAddonContainer
     {
         [Constructible]
-        public ArcaneBookshelfEastAddon()
+        public ArcaneBookshelfEastAddon() : base(0x3084)
         {
-            AddComponent(new AddonComponent(0x3084), 0, 0, 0);
-            AddComponent(new AddonComponent(0x3085), -1, 0, 0);
+            AddComponent(new AddonContainerComponent(0x3085), -1, 0, 0);
         }
 
-        public override BaseAddonDeed Deed => new ArcaneBookshelfEastDeed();
+        public override BaseAddonContainerDeed Deed => new ArcaneBookshelfEastDeed();
+        public override bool RetainDeedHue => true;
+        public override int DefaultGumpID => 0x107;
+        public override int DefaultDropSound => 0x42;
     }
 
     [Serializable(0)]
-    public partial class ArcaneBookshelfEastDeed : BaseAddonDeed
+    public partial class ArcaneBookshelfEastDeed : BaseAddonContainerDeed
     {
         [Constructible]
         public ArcaneBookshelfEastDeed()
         {
         }
 
-        public override BaseAddon Addon => new ArcaneBookshelfEastAddon();
+        public override BaseAddonContainer Addon => new ArcaneBookshelfEastAddon();
         public override int LabelNumber => 1073371; // arcane bookshelf (east)
     }
 }

Projects/UOContent/Items/Addons/BaseAddonContainer.cs

@@ -187,6 +187,19 @@ namespace Server.Items
             }
         }
 
+        public override void InvalidateProperties()
+        {
+            base.InvalidateProperties();
+
+            if (_components != null)
+            {
+                foreach (var component in _components)
+                {
+                    component.InvalidateProperties();
+                }
+            }
+        }
+
         // Handles v0 with old Enum -> Int casting
         private void Deserialize(IGenericReader reader, int version)
         {
@@ -332,6 +345,10 @@ namespace Server.Items
 
         public virtual void OnComponentUsed(AddonContainerComponent c, Mobile from)
         {
+            if (!Deleted)
+            {
+                OnDoubleClick(from);
+            }
         }
     }
 }