TDropContainer represent an area where TDraggable controls can be dropped. When a TDraggable is dropped, a callback request is initiated. The OnCallback event is raised during a callback request and it is raised after the OnDrop event.
TDraggable will make its child controls 'draggable'. When a TDraggable is dropped, a callback request is initiated. The OnCallback event is raised during a callback request and it is raised after the OnDrop event.