The public API of Common Widgets drag and drop includes the following classes, along with some methods in CwWidget and in callback data classes.
CwDragDropObject hierarchy
The CwDragDropObject class implements drag and drop
objects. CwDragDropObject is an abstract class that provides
resource and proc methods to its subclasses. The hierarchy looks like
the following:
CwDragDropObject
CwDragContext
CwDropSite
CwDropTransfer
CwDropTransferEntry
The CwDropTransferEntry class is used in the data transfer process. Instances of CwDropTransferEntry contain a targetType and a transferClientData object.