https://docs.oracle.com/javase/jp/6/api/java/awt/dnd/DropTargetListener.html
DropTargetListener (Java Platform SE 6)
java platformse
https://download.eclipse.org/rt/rap/doc/3.1/guide/reference/api/org/eclipse/swt/dnd/DropTargetListener.html
DropTargetListener (Eclipse RAP 3.1.0-SNAPSHOT API Reference)
eclipse rapsnapshot apireference