added ItemStorage.cs, ItemStorageSlot.cs, ItemStorageUI.cs

* Inventory, InventorySlot, InventoryUI, Shop, ShopSlot, ShopUI are extending them

Assets/Scripts/ItemStorageSlot.cs

@@ -0,0 +1,68 @@
+using System.Collections;
+using System.Collections.Generic;
+using TMPro;
+using UnityEngine;
+using UnityEngine.EventSystems;
+using UnityEngine.UI;
+
+public class ItemStorageSlot : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler {
+    public Image icon;
+    public TextMeshProUGUI amountText;
+    
+    public Item Item => _item;
+    
+    private Item _item;
+    
+    #region DescriptionHover
+
+    public float timeToWait;
+
+    public void OnPointerEnter(PointerEventData eventData) {
+        StopAllCoroutines();
+        StartCoroutine(StartTimer());
+    }
+
+    public void OnPointerExit(PointerEventData eventData) {
+        StopAllCoroutines();
+        HoverManager.onMouseExit();
+    }
+
+    private void ShowMessage() {
+        if(_item){
+            HoverManager.onMouseHover(_item.description, Input.mousePosition);
+        }
+    }
+
+    private IEnumerator StartTimer() {
+        yield return new WaitForSeconds(timeToWait);
+
+        ShowMessage();
+    }
+
+    #endregion
+    
+    /**
+     * Sets the Item of the Item Storage Slot
+     */
+    public void AddItem(Item newItem) {
+        _item = newItem;
+
+        icon.sprite = _item.defaultSprite;
+        icon.enabled = true;
+    }
+    
+    /**
+     * Clears the Item Storage Slot
+     */
+    public virtual void ClearSlot() {
+        _item = null;
+        icon.sprite = null;
+        icon.enabled = false;
+    }
+    
+    /**
+     * Gets called when the Item Storage Slot is clicked
+     */
+    public virtual void UseItem() {
+    }
+}