Add CanPutInPack property of IItem

scripts/item/IItem.cs

@@ -26,6 +26,14 @@ public interface IItem
     /// <para>当前项目的描述</para>
     /// </summary>
     string? Description { get; }
+    /// <summary>
+    /// <para>
+    ///     Whether the current item can be put into item containers like packsack.<br/>
+    ///     This attribute is usually set to false for items of the backpack class to avoid pack nesting.
+    /// </para>
+    /// <para>当前物品是否可以放入背包类的容器中。一般将背包类物品的该属性设为false来避免背包嵌套。</para>
+    /// </summary>
+    bool CanPutInPack { get; }
 
     /// <summary>
     /// <para>Execute when current item is used <br/> e.g. when player clicks left mouse button with current item in hand</para>

scripts/item/Packsack.cs

@@ -1,6 +1,7 @@
 using ColdMint.scripts.inventory;
 using ColdMint.scripts.pickable;
 using ColdMint.scripts.utils;
+
 using Godot;
 
 namespace ColdMint.scripts.item;
@@ -14,6 +15,8 @@ public partial class Packsack : PickAbleTemplate
     private PackedScene? _packedScene;
     private PacksackUi? _packsackUi;
 
+    public override bool CanPutInPack => false;
+
     public override void Destroy()
     {
         if (ItemContainer == null) return;
@@ -31,10 +34,12 @@ public partial class Packsack : PickAbleTemplate
         {
             return;
         }
+
         if (_packsackUi == null)
         {
-            _packsackUi = NodeUtils.InstantiatePackedScene<PacksackUi>(_packedScene,this);
+            _packsackUi = NodeUtils.InstantiatePackedScene<PacksackUi>(_packedScene, this);
         }
+
         _packsackUi?.Show();
     }
 
@@ -45,6 +50,5 @@ public partial class Packsack : PickAbleTemplate
         base._Ready();
         ItemContainer = new UniversalItemContainer();
         _packedScene = GD.Load<PackedScene>("res://prefab/ui/packsackUI.tscn");
-        
     }
 }

scripts/item/itemStacks/PacksackStack.cs

@@ -17,17 +17,16 @@ public class PacksackStack(Packsack packsack) : IItemStack
     public Texture2D Icon => packsack.Icon;
     public string Name => packsack.Name;
     public string? Description => packsack.Description;
-
+    
-    //todo: 只拒绝是背包的物品是权宜之计，应该为物品加入一个“是否可以放入背包”的属性来实现这个判断。
     public bool CanAddItem(IItem item)
     {
-        if (item is Packsack) return false;
+        if (!item.CanPutInPack) return false;
         return packsack.ItemContainer?.CanAddItem(item) ?? false;
     }
 
     public bool AddItem(IItem item)
     {
-        if (item is Packsack) return false;
+        if (!item.CanPutInPack) return false;
         return packsack.ItemContainer?.AddItem(item) ?? false;
     }
 

scripts/pickable/PickAbleTemplate.cs

@@ -21,6 +21,7 @@ public partial class PickAbleTemplate : RigidBody2D, IItem
     [Export] protected string? UniqueName { get; set; }
     public new string Name => UniqueName ?? ItemTypeManager.DefaultNameOf(Id);
     [Export] protected string? UniqueDescription { get; set; }
+    public virtual bool CanPutInPack => true;
 
     /// <summary>
     /// <para>Owner</para>