/// <summary>
/// This event is fired when an item is dropped
/// onto this slot. Will accept the item
/// into the slot OR swap the item. If the item is
/// `Stackable`, will attempt to stack it
/// </summary>
/// <param name="eventData">The `PointerEventData` of the event</param>
public virtual void OnDrop(PointerEventData eventData)
{
if (eventData.used || Draggable.DraggedItem == null)
{
return;
}
// if this slot doesn't have an item,
// add this one
if (Item == null)
{
AddItem(Draggable.DraggedItem);
}
else
{
Stackable stackableItem = Draggable.DraggedItem.GetComponent <Items.Stackable>();
Stackable slotStackableItem = Item.GetComponent <Items.Stackable>();
// the dropped item is stackable, as is
// the item in this slot. Attempt to stack.
// will return if successful.
if (stackableItem != null && slotStackableItem != null)
{
try {
slotStackableItem.Add(stackableItem);
Draggable.DraggedItem.OnEndDrag(eventData);
Draggable.DraggedItem = null;
// manually spawn the tooltip as the
// `OnPointerEnter` event won't trigger
// automatically
TooltipTrigger tooltipTrigger = Item.GetComponent <TooltipTrigger>();
if (tooltipTrigger != null)
{
tooltipTrigger.OnPointerEnter(
new PointerEventData(EventSystem.current)
);
}
// if the item isn't stackable, swap items
} catch (NotStackableException e) {
Slot otherSlot = Draggable.DraggedItem.OldSlot;
otherSlot.AddItem(RemoveItem());
AddItem(Draggable.DraggedItem);
Draggable.DraggedItem.OnEndDrag(eventData);
Draggable.DraggedItem = null;
}
}
else
{
// swap the item with the item
// that was dropped
Draggable otherItem = Draggable.DraggedItem;
Slot otherSlot = otherItem.OldSlot;
// if other slot is currently occupied,
// the draggable item will need to be
// dropped before it can be swapped
if (otherSlot.Item != null)
{
return;
}
// try to swap items- will only fail
// if one slot requires a specific
// `ItemType`
try {
// don't remove the item from
// this slot until it successfully
// gets added to the other slot
Draggable itemInThisSlot = Item;
otherSlot.AddItem(itemInThisSlot);
RemoveItem();
AddItem(otherItem);
} catch (CannotAddItemException e) {
Debug.LogWarning(e);
return;
}
}
}
Item.OnEndDrag(eventData);
eventData.Use();
}