Added Callbacks and Forwards on pressing the Exit and Back buttons in the item panel (in the menu).

[IL0co]

Added forwards: Shop_OnItemPanelExitButton Shop_OnItemPanelBackButton

As well as callbacks that are registered when registering an item (Shop_SetCallbacks)

[TiBarification]

Each addition into Shop_SetCallbacks is a pain. Need to think about another registration callbacks.

enum SHOP_CB_TYPE {
  ItemRegistration = 1,
  ItemToggle = 2,
  OtherThing = 3
}
Like `Shop_SetCallbackHandler(type: SHOP_CB_TYPE, handler: FuncPrototype);` and each row extend it like subscribing for individual events instead of having them at this complex function

[IL0co]

Each addition into Shop_SetCallbacks is a pain. Need to think about another registration callbacks.

enum SHOP_CB_TYPE {
  ItemRegistration = 1,
  ItemToggle = 2,
  OtherThing = 3
}
Like `Shop_SetCallbackHandler(type: SHOP_CB_TYPE, handler: FuncPrototype);` and each row extend it like subscribing for individual events instead of having them at this complex function

Yes, I think it will be very useful to use a system like sdkhooks. But how to do this in the current situation, when we already register everything in one native in a row?

This is what I do with my plugin, one native for registration and enum with a list of all types, as well as typeset MCS_ItemCallBack - where all function references are indicated.

enum MCS_ItemCallBackType {
    ItemCB_OnDisplay,           // Callback to the display name of an item
    ItemCB_OnPreview,           // Callback for the preview display request
    ItemCB_OnSwitching,         // Callback when switching an item.
    ItemCB_OnUsing,             // Callback when the item is used.
    ItemCB_Length,              // The number of elements in the enum.
};

native void MCS_RegItemCallBack(MCS_ItemCallBackType type, MCS_ItemCallBack callback, any data = 0);