Add a possible operation.


   operation STRING )
  1. operation is the name of a drag & drop operation.


Drag & drop actions can be of different kinds; you can do a copy of the dragged object, or move the dragged object from the source to the destination.

The default drag & drop operation is defined by a call to setOperation() method in ON DRAG_START. Use the addPossibleOperation() method to define additional operations that are allowed.

See setOperation() for possible values.