Method arguments for the HandleDragAndDrop virtual method.
| dragAndDropPosition | When dragging items the current drag can have the following 3 positions relative to the items: Upon an item, Between two items or Outside items. |
| insertAtIndex | This index refers to the index in the children list of the parentItem where the current drag is positioned. |
| parentItem | The parent item is set if the drag is either upon this item or between two of its children. |
| performDrop | This value is false as long as the mouse button is down, when the mouse button is released it is true. |