draggable items

Assets/Scripts/Inventory.cs

@@ -7,7 +7,17 @@ public class Inventory : MonoBehaviour
 
   public bool isPlayerInventory = false;
   public int maxSlots = 20; // maximum number of slots in the inventory
-  public List<InventoryItem> items = new List<InventoryItem>(); // list of items in the inventory
+  public InventoryItem[] items; // list of items in the inventory
+
+
+  private void Awake()
+  {
+    items = new InventoryItem[maxSlots];
+    for (int i = 0; i < maxSlots; i++)
+    {
+      items[i] = null;
+    }
+  }
 
   // adds an item to the inventory, returns the quantity of items which could not be added
   public int Add(Item item, int count)
@@ -17,10 +27,12 @@ public class Inventory : MonoBehaviour
     // check if the item is stackable
     if (item.stackable)
     {
+
       // look for an existing stack of the same item in the inventory
-      foreach (InventoryItem invItem in items)
+      for (int i = 0; i < items.Length; i++)
       {
-        if (invItem.item == item && invItem.count < item.maxStackSize)
+        InventoryItem invItem = items[i];
+        if (invItem != null && invItem.item == item && invItem.count < item.maxStackSize)
         {
           // add as many items as possible to the stack
           int space = item.maxStackSize - invItem.count;
@@ -43,11 +55,30 @@ public class Inventory : MonoBehaviour
     }
 
     // if there is still remaining count, add new stacks of the item
-    while (remainingCount > 0 && items.Count < maxSlots)
+    for (int i = 0; i < items.Length; i++)
+
     {
-      int toAdd = Mathf.Min(item.maxStackSize, remainingCount);
-      items.Add(new InventoryItem(item, toAdd));
-      remainingCount -= toAdd;
+      InventoryItem invItem = items[i];
+      Debug.Log(invItem);
+      if (invItem.item == null)
+      {
+
+        int toAdd = Mathf.Min(item.maxStackSize, remainingCount);
+        items[i] = new InventoryItem(item, toAdd);
+        remainingCount -= toAdd;
+
+        // exit the loop if all items have been added
+        if (remainingCount == 0)
+        {
+
+          if (isPlayerInventory)
+          {
+            OnPlayerInventoryChanged?.Invoke();
+          }
+
+          return 0;
+        }
+      }
     }
 
     // return the quantity of items which could not be added
@@ -55,6 +86,7 @@ public class Inventory : MonoBehaviour
     {
       OnPlayerInventoryChanged?.Invoke();
     }
+
     return remainingCount;
   }
 
@@ -65,10 +97,10 @@ public class Inventory : MonoBehaviour
     int remainingCount = count;
 
     // look for an existing stack of the item in the inventory
-    for (int i = 0; i < items.Count; i++)
+    for (int i = 0; i < items.Length; i++)
     {
       InventoryItem invItem = items[i];
-      if (invItem.item == item)
+      if (invItem != null && invItem.item == item)
       {
         // remove as many items as possible from the stack
         int toRemove = Mathf.Min(invItem.count, remainingCount);
@@ -78,7 +110,7 @@ public class Inventory : MonoBehaviour
         // remove the stack if it's now empty
         if (invItem.count == 0)
         {
-          items.RemoveAt(i);
+          items[i] = null;
         }
 
         // exit the loop if all items have been removed
@@ -100,6 +132,17 @@ public class Inventory : MonoBehaviour
     }
     return remainingCount;
   }
+
+  public void SwapItems(int index1, int index2)
+  {
+    InventoryItem temp = items[index1];
+    items[index1] = items[index2];
+    items[index2] = temp;
+    if (isPlayerInventory)
+    {
+      OnPlayerInventoryChanged?.Invoke();
+    }
+  }
 }
 
 

Assets/Scripts/UI/DraggableSlotContentUI.cs

@@ -0,0 +1,34 @@
+using UnityEngine;
+using UnityEngine.EventSystems;
+using UnityEngine.UI;
+public class DraggableSlotContentUI : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
+{
+  public int slotIndex;
+  [HideInInspector] public Transform parentAfterDrag;
+  public Image image;
+  public void OnBeginDrag(PointerEventData eventData)
+  {
+    Debug.Log("Start Drag");
+
+    parentAfterDrag = transform.parent;
+    transform.SetParent(transform.root);
+    transform.SetAsLastSibling();
+    image.raycastTarget = false;
+  }
+
+  public void OnDrag(PointerEventData eventData)
+  {
+    Debug.Log("Dragging");
+    transform.position = Input.mousePosition;
+
+  }
+
+  public void OnEndDrag(PointerEventData eventData)
+  {
+    Debug.Log("End drag");
+    transform.SetParent(parentAfterDrag);
+    image.raycastTarget = true;
+    // invoke
+    Inventory.OnPlayerInventoryChanged?.Invoke();
+  }
+}

Assets/Scripts/UI/DraggableSlotContentUI.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 4b88f5aa1c0fe8349953801d1f513200
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Scripts/UI/InventoryUI.cs

@@ -25,7 +25,9 @@ public class InventoryUI : MonoBehaviour
 
     for (int i = 0; i < playerInventory.maxSlots; i++)
     {
-      slotUIList.Add(Instantiate(slotPrefab, Vector3.zero, Quaternion.identity, slotListObj.transform).GetComponent<SlotUI>());
+      SlotUI newSlot = Instantiate(slotPrefab, Vector3.zero, Quaternion.identity, slotListObj.transform).GetComponent<SlotUI>();
+      newSlot.slotIndex = i;
+      slotUIList.Add(newSlot);
     }
   }
   private void UpdateSlots()
@@ -34,14 +36,9 @@ public class InventoryUI : MonoBehaviour
     int i = 0;
     foreach (SlotUI slotUi in slotUIList)
     {
-      if (i < playerInventory.items.Count)
-      {
-        slotUi.SetInventoryItem(playerInventory.items[i]);
-      }
-      else
-      {
-        slotUi.SetInventoryItem(null);
-      }
+
+      slotUi.SetInventoryItem(playerInventory.items[i]);
+
 
       i++;
     }

Assets/Scripts/UI/SlotUI.cs

@@ -2,16 +2,21 @@ using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
-
-public class SlotUI : MonoBehaviour
+using UnityEngine.EventSystems;
+public class SlotUI : MonoBehaviour, IDropHandler
 {
+  public int slotIndex;
+  [SerializeField] private GameObject contentObject;
   [SerializeField] private InventoryItem inventoryItem;
   [SerializeField] private Image itemSpriteImage;
   [SerializeField] private TMPro.TextMeshProUGUI quantityText;
 
+  private Inventory playerInventory;
   private void Start()
   {
     UpdateSlot();
+    contentObject.GetComponent<DraggableSlotContentUI>().slotIndex = slotIndex;
+    playerInventory = GameObject.FindGameObjectWithTag("Player").GetComponent<Inventory>();
   }
   public void SetInventoryItem(InventoryItem newInventoryItem)
   {
@@ -24,11 +29,14 @@ public class SlotUI : MonoBehaviour
     if (inventoryItem != null)
     {
       itemSpriteImage.sprite = inventoryItem?.item?.sprite ?? null;
-      Debug.Log(itemSpriteImage.sprite);
       if (itemSpriteImage.sprite == null)
       {
         itemSpriteImage.color = new Color(0, 0, 0, 0);
       }
+      else
+      {
+        itemSpriteImage.color = new Color(255, 255, 255, 1);
+      }
 
       quantityText.SetText(inventoryItem.count != 0 ? inventoryItem.count.ToString() : "");
     }
@@ -41,4 +49,13 @@ public class SlotUI : MonoBehaviour
 
   }
 
+
+
+  public void OnDrop(PointerEventData eventData)
+  {
+    Debug.Log("DROP");
+    DraggableSlotContentUI dropped = eventData.pointerDrag.GetComponent<DraggableSlotContentUI>();
+    playerInventory.SwapItems(dropped.slotIndex, slotIndex);
+  }
+
 }