TreeView in custom editor drag and drop to Inspector

Unity Engine
,
1

Hello!

I’m working on an editor that list all assets from a certain type in my project.
It look like that:

5932703--634589--Screenshot_1.png
5932703--634589--Screenshot_1.png718×300 9.56 KB

I would like to be able to drag the asset in the left tree view to a corresponding variable exposed in the inspector, but I can’t find a way to do that… The thing is I don’t really know if I’m using the tree view correctly… when dragging in the tree view, should I be dragging rows? dragging a reference to the asset itself? What should I put in the DragAndDrop.SetGenericData?
It make a perfect transition to a second question, do you know a good ressource on tree view usage and best practice? I couldn’t find any ='(

Thank you for your help!!

2

Hi,
I hope it is not to late, but have you seen the TreeView Example Project? For your specific case you can look for the TreeViewWithTreeModel class:

        protected override void SetupDragAndDrop(SetupDragAndDropArgs args)
        {
            if (hasSearch)
                return;

            DragAndDrop.PrepareStartDrag();
            var draggedRows = GetRows().Where(item => args.draggedItemIDs.Contains(item.id)).ToList();
            DragAndDrop.SetGenericData(k_GenericDragID, draggedRows);
            DragAndDrop.objectReferences = new UnityEngine.Object[] { }; // this IS required for dragging to work
            string title = draggedRows.Count == 1 ? draggedRows[0].displayName : "< Multiple >";
            DragAndDrop.StartDrag (title);
        }
3

geate. the answer above is what I need. well done

4

What did you use for k_GenericDragID? Anything special that needs to go there? Asking because the link no longer works.

5

k_GenericDragId is a string, and you can name it anything. For example, the tree control in the Timeline package has it set as:

const string k_GenericDragId = "TimelineDragging";