Interface DropTargetListener
- All Superinterfaces:
- EventListener
- All Known Implementing Classes:
- DropTarget,- DropTargetAdapter
DropTargetListener interface
 is the callback interface used by the
 DropTarget class to provide
 notification of DnD operations that involve
 the subject DropTarget. Methods of
 this interface may be implemented to provide
 "drag under" visual feedback to the user throughout
 the Drag and Drop operation.
 
 Create a listener object by implementing the interface and then register it
 with a DropTarget. When the drag enters, moves over, or exits
 the operable part of the drop site for that DropTarget, when
 the drop action changes, and when the drop occurs, the relevant method in
 the listener object is invoked, and the DropTargetEvent is
 passed to it.
 
 The operable part of the drop site for the DropTarget is
 the part of the associated Component's geometry that is not
 obscured by an overlapping top-level window or by another
 Component higher in the Z-order that has an associated active
 DropTarget.
 
 During the drag, the data associated with the current drag operation can be
 retrieved by calling getTransferable() on
 DropTargetDragEvent instances passed to the listener's
 methods.
 
 Note that getTransferable() on the
 DropTargetDragEvent instance should only be called within the
 respective listener's method and all the necessary data should be retrieved
 from the returned Transferable before that method returns.
- Since:
- 1.2
- 
Method SummaryModifier and TypeMethodDescriptionvoiddragEnter(DropTargetDragEvent dtde) Called while a drag operation is ongoing, when the mouse pointer enters the operable part of the drop site for theDropTargetregistered with this listener.voiddragExit(DropTargetEvent dte) Called while a drag operation is ongoing, when the mouse pointer has exited the operable part of the drop site for theDropTargetregistered with this listener.voiddragOver(DropTargetDragEvent dtde) Called when a drag operation is ongoing, while the mouse pointer is still over the operable part of the drop site for theDropTargetregistered with this listener.voiddrop(DropTargetDropEvent dtde) Called when the drag operation has terminated with a drop on the operable part of the drop site for theDropTargetregistered with this listener.voidCalled if the user has modified the current drop gesture.
- 
Method Details- 
dragEnterCalled while a drag operation is ongoing, when the mouse pointer enters the operable part of the drop site for theDropTargetregistered with this listener.- Parameters:
- dtde- the- DropTargetDragEvent
 
- 
dragOverCalled when a drag operation is ongoing, while the mouse pointer is still over the operable part of the drop site for theDropTargetregistered with this listener.- Parameters:
- dtde- the- DropTargetDragEvent
 
- 
dropActionChangedCalled if the user has modified the current drop gesture.- Parameters:
- dtde- the- DropTargetDragEvent
 
- 
dragExitCalled while a drag operation is ongoing, when the mouse pointer has exited the operable part of the drop site for theDropTargetregistered with this listener.- Parameters:
- dte- the- DropTargetEvent
 
- 
dropCalled when the drag operation has terminated with a drop on the operable part of the drop site for theDropTargetregistered with this listener.This method is responsible for undertaking the transfer of the data associated with the gesture. The DropTargetDropEventprovides a means to obtain aTransferableobject that represents the data object(s) to be transferred.From this method, the DropTargetListenershall accept or reject the drop via the acceptDrop(int dropAction) or rejectDrop() methods of theDropTargetDropEventparameter.Subsequent to acceptDrop(), but not before, DropTargetDropEvent's getTransferable() method may be invoked, and data transfer may be performed via the returnedTransferable's getTransferData() method.At the completion of a drop, an implementation of this method is required to signal the success/failure of the drop by passing an appropriate booleanto theDropTargetDropEvent's dropComplete(boolean success) method.Note: The data transfer should be completed before the call to the DropTargetDropEvent's dropComplete(boolean success) method. After that, a call to the getTransferData() method of theTransferablereturned byDropTargetDropEvent.getTransferable()is guaranteed to succeed only if the data transfer is local; that is, only ifDropTargetDropEvent.isLocalTransfer()returnstrue. Otherwise, the behavior of the call is implementation-dependent.- Parameters:
- dtde- the- DropTargetDropEvent
 
 
-