Information about a drag-and-drop operation that just started. You can use it to store generic data for the rest of the drag. See BaseVerticalCollectionView.setupDragAndDrop.
| draggedElement | The element on which the drag operation started. |
| selectedIds | The selected IDs in the source. |
| startDragArgs | Provides entry points to initialize data and visual of the new drag-and-drop operation. |