1.onBeforeDrag (before dragging)
2.onStartDrag (start dragging)
(Placed before) 2.1.onBeforeDrop
2.2.onDrop (put)
3.onDragEnter (drag when entering a node)
4.onDragOver (after entering the node drag)
5.onDragLeave (drag after entering a node, and left again)
6.onStopDrag (stop dragging)
*for reference only