Drag and Drop in 5.3

The page at http://docs.unity3d.com/ScriptReference/EventSystems.IDragHandler.html shows a script that doesn't not function (at least for me) in Unity 5.3. I could not find a fixed version anywhere so I fixed it as best as I can figure out and I thought I should share it here. If not correct, it at least functions for now.

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.EventSystems;
3. using UnityEngine.UI;
4.  
5. [RequireComponent(typeof(Image))]
6. public class InventoryDragController : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
7. {
8.     public bool dragOnSurfaces = true;
9.  
10.     private GameObject m_DraggingIcon;
11.     private RectTransform m_DraggingPlane;
12.  
13.     public void OnBeginDrag(PointerEventData eventData)
14.     {
15.         var canvas = FindInParents<Canvas>(gameObject);
16.         if (canvas == null)
17.             return;
18.  
19.         // We have clicked something that can be dragged.
20.         // What we want to do is create an icon for this.
21.         m_DraggingIcon = new GameObject("icon");
22.  
23.         m_DraggingIcon.transform.SetParent(canvas.transform, false);
24.         m_DraggingIcon.transform.SetAsLastSibling();
25.  
26.         var image = m_DraggingIcon.AddComponent<Image>();
27.         // The icon will be under the cursor.
28.         // We want it to be ignored by the event system.
29.         //m_DraggingIcon.AddComponent<IgnoreRaycast>();
30.         image.raycastTarget = false;
31.  
32.         image.sprite = GetComponent<Image>().sprite;
33.         image.SetNativeSize();
34.  
35.         if (dragOnSurfaces)
36.             m_DraggingPlane = transform as RectTransform;
37.         else
38.             m_DraggingPlane = canvas.transform as RectTransform;
39.  
40.         SetDraggedPosition(eventData);
41.     }
42.  
43.     public void OnDrag(PointerEventData data)
44.     {
45.         if (m_DraggingIcon != null)
46.             SetDraggedPosition(data);
47.     }
48.  
49.     private void SetDraggedPosition(PointerEventData data)
50.     {
51.         if (dragOnSurfaces && data.pointerEnter != null && data.pointerEnter.transform as RectTransform != null)
52.             m_DraggingPlane = data.pointerEnter.transform as RectTransform;
53.  
54.         var rt = m_DraggingIcon.GetComponent<RectTransform>();
55.         Vector3 globalMousePos;
56.         if (RectTransformUtility.ScreenPointToWorldPointInRectangle(m_DraggingPlane, data.position, data.pressEventCamera, out globalMousePos))
57.         {
58.             rt.position = globalMousePos;
59.             rt.rotation = m_DraggingPlane.rotation;
60.         }
61.     }
62.  
63.     public void OnEndDrag(PointerEventData eventData)
64.     {
65.         if (m_DraggingIcon != null)
66.             Destroy(m_DraggingIcon);
67.     }
68.  
69.     static public T FindInParents<T>(GameObject go) where T : Component
70.     {
71.         if (go == null) return null;
72.         var comp = go.GetComponent<T>();
73.  
74.         if (comp != null)
75.             return comp;
76.  
77.         Transform t = go.transform.parent;
78.         while (t != null && comp == null)
79.         {
80.             comp = t.gameObject.GetComponent<T>();
81.             t = t.parent;
82.         }
83.         return comp;
84.     }
85. }
86.  

If someone else has already done this (probably) sorry. Hopefully it helps someone

 

I tried figuring out how to do that on the site but I couldn't figure out how to post a bug. Odd that I never even considered trying to do it from within Unity. Makes sense now I suppose. Thanks, learn something new every day

I expect you already submitted one or should I still do it?

 

Sure no problem.