Question Get AssetReference object in a custom Editor Window script using DragAndDrop.objectReferences.

Hello. I have created a custom editor window script in which I am trying to implement a Drag-and-Drop interface to drag multiple addressable objects from addessable group window and create ScriptableObject assets which has a reference to these dragged objects as AssetReference.

[Custom Editor Window with drag and drop box]

[Addressable assets to drag and drop]

This is my code which I have implemented for drag-and-drop:

Code (CSharp):

1. Rect rect = GUILayoutUtility.GetRect(100f, 100f);
2. GUI.Box(rect, "Drag Objects");
3. if (rect.Contains(Event.current.mousePosition))
4. {
5.     if (Event.current.type == EventType.DragUpdated ||
6.         Event.current.type == EventType.DragPerform)
7.     {
8.         DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
9.         if (Event.current.type == EventType.DragPerform)
10.         {
11.             DragAndDrop.AcceptDrag();
12.             this.presetCount = DragAndDrop.objectReferences.Length;
13.             foreach(var obj in DragAndDrop.objectReferences)
14.             {
15.                 Debug.Log("Dragged Object: " + obj);
16.             }
17.         }
18.     }
19. }

But the DragAndDrop.objectReferences array is empty. I understand that AssetReference object does not fall under UnityEngine.Object type. But is there any way I can access AssetReference objects in my editor script when dragging it from the addressable groups window?

 

I solved the problem for now. I checked the source code for AssetReferenceDrawer.cs script located under Addressables/Editor/GUI and implemented the same technique used to drag and drop addressable files from group window to AssetReference fields in inspector.

I imported addressables package as a local package and changed AssetEntryTreeViewItem class to public. Then I changed my custom editor drag-and-drop code as following:

Code (CSharp):

1.  
2. Rect newRect = GUILayoutUtility.GetRect(100f, 100f);
3. GUI.Box(newRect, "Drag Addressable assets");
4. if (newRect.Contains(Event.current.mousePosition))
5. {
6.     if (Event.current.type == EventType.DragUpdated ||
7.         Event.current.type == EventType.DragPerform)
8.     {
9.         DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
10.         if (Event.current.type == EventType.DragPerform)
11.         {
12.             DragAndDrop.AcceptDrag();
13.             List<AssetEntryTreeViewItem> draggedItems = DragAndDrop.GetGenericData("AssetEntryTreeViewItem") as List<AssetEntryTreeViewItem>;
14.             foreach (AssetEntryTreeViewItem item in draggedItems)
15.             {
16.                 string path = AssetDatabase.GetAssetPath(item.entry.TargetAsset);
17.                 AssetReference reference = new AssetReference();
18.                 reference.SetEditorAsset(AssetDatabase.LoadAssetAtPath<UnityEngine.Object>(path));
19.                 /// Do something with the AssetReference object
20.             }
21.         }
22.     }
23. }
24.  

 

Here's chunk of my old code, it's still working.

Code (CSharp):

1. SerializedObject so;
2. SerializedProperty charCards;
3.  
4. void OnEnable()
5. {
6.     InitProperty();
7. }
8.  
9. void InitProperty()
10. {
11.     so = new SerializedObject(Object-ThatContainsClassName);
12.     charCards = so.FindProperty(nameof(ClassName.charCards));
13. }
14.  
15. void OnGUI()
16. {
17.     so.Update();
18.     EditorGUILayout.PropertyField(charCards, new GUIContent { text = "Character Cards" });
19.     so.ApplyModifiedProperties();
20. }