XmDropTransferAdd man page
XmDropTransferAdd — A Drag and Drop function that enables additional drop transfer entries to be processed after initiating a drop transfer
#include <Xm/DragDrop.h> void XmDropTransferAdd( Widget drop_transfer, XmDropTransferEntryRec *transfers, Cardinal num_transfers);
XmDropTransferAdd identifies a list of additional drop transfer entries to be processed after a drop transfer is started.
Specifies the ID of the DropTransfer widget returned by XmDropTransferStart
Specifies the additional drop transfer entries that the receiver wants processed
Specifies the number of items in the transfers array
For a complete definition of DropTransfer and its associated resources, see XmDropTransfer(3).
XmDragContext(3), XmDropTransfer(3), and XmDropTransferStart(3).