java.awt.dnd
Class DropTargetDragEvent

java.lang.Object
  java.util.EventObject
      java.awt.dnd.DropTargetEvent
          java.awt.dnd.DropTargetDragEvent

All Implemented Interfaces:

Serializable

public class DropTargetDragEvent

extends DropTargetEvent

The DropTargetDragEvent is delivered to a DropTargetListener via its dragEnter() and dragOver() methods.

The DropTargetDragEvent reports the source drop actions and the user drop action that reflect the current state of the drag operation.

Source drop actions is a bitwise mask of DnDConstants that represents the set of drop actions supported by the drag source for this drag operation.

User drop action depends on the drop actions supported by the drag source and the drop action selected by the user. The user can select a drop action by pressing modifier keys during the drag operation:

 
   Ctrl + Shift -> ACTION_LINK
   Ctrl         -> ACTION_COPY
   Shift        -> ACTION_MOVE
 

If the user selects a drop action, the user drop action is one of DnDConstants that represents the selected drop action if this drop action is supported by the drag source or DnDConstants.ACTION_NONE if this drop action is not supported by the drag source.

If the user doesn't select a drop action, the set of DnDConstants that represents the set of drop actions supported by the drag source is searched for DnDConstants.ACTION_MOVE, then for DnDConstants.ACTION_COPY, then for DnDConstants.ACTION_LINK and the user drop action is the first constant found. If no constant is found the user drop action is DnDConstants.ACTION_NONE.

Since:

1.2

See Also:

Serialized Form

Field Summary

private int	actions The source drop actions.
private int	dropAction The user drop action.
private Point	location The location of the drag cursor's hotspot in Component coordinates.
private static long	serialVersionUID

Fields inherited from class java.awt.dnd.DropTargetEvent

context

Fields inherited from class java.util.EventObject

source

Constructor Summary

DropTargetDragEvent(DropTargetContext dtc, Point cursorLocn, int dropAction, int srcActions)
Construct a DropTargetDragEvent given the DropTargetContext for this operation, the location of the "Drag" Cursor's hotspot in the Component's coordinates, the user drop action, and the source drop actions.

Method Summary

void	acceptDrag(int dragOperation) Accepts the drag.
DataFlavor[]	getCurrentDataFlavors() This method returns the current DataFlavors from the DropTargetContext.
List	getCurrentDataFlavorsAsList() This method returns the current DataFlavors as a java.util.List
int	getDropAction() This method returns the user drop action.
Point	getLocation() This method returns a Point indicating the Cursor's current location within the Component's coordinates.
int	getSourceActions() This method returns the source drop actions.
boolean	isDataFlavorSupported(DataFlavor df) This method returns a boolean indicating if the specified DataFlavor is supported.
void	rejectDrag() Rejects the drag as a result of examining either the dropAction or the available DataFlavor types.

Methods inherited from class java.awt.dnd.DropTargetEvent

getDropTargetContext

Methods inherited from class java.util.EventObject

getSource, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

location

private Point location

The location of the drag cursor's hotspot in Component coordinates.

actions

private int actions

The source drop actions.

dropAction

private int dropAction

The user drop action.

Constructor Detail

DropTargetDragEvent

public DropTargetDragEvent(DropTargetContext dtc,
                           Point cursorLocn,
                           int dropAction,
                           int srcActions)

Construct a DropTargetDragEvent given the DropTargetContext for this operation, the location of the "Drag" Cursor's hotspot in the Component's coordinates, the user drop action, and the source drop actions.

Parameters:

dtc - The DropTargetContext for this operation

cursorLocn - The location of the "Drag" Cursor's hotspot in Component coordinates

dropAction - The user drop action

srcActions - The source drop actions

Throws:

NullPointerException - if cursorLocn is null

IllegalArgumentException - if dropAction is not one of DnDConstants.

IllegalArgumentException - if srcActions is not a bitwise mask of DnDConstants.

IllegalArgumentException - if dtc is null.

Method Detail

getLocation

public Point getLocation()

This method returns a Point indicating the Cursor's current location within the Component's coordinates.

Returns:

the current cursor location in Component's coords.

getCurrentDataFlavors

public DataFlavor[] getCurrentDataFlavors()

This method returns the current DataFlavors from the DropTargetContext.

Returns:

current DataFlavors from the DropTargetContext

getCurrentDataFlavorsAsList

public List getCurrentDataFlavorsAsList()

This method returns the current DataFlavors as a java.util.List

Returns:

a java.util.List of the Current DataFlavors

isDataFlavorSupported

public boolean isDataFlavorSupported(DataFlavor df)

This method returns a boolean indicating if the specified DataFlavor is supported.

Parameters:

df - the DataFlavor to test

Returns:

if a particular DataFlavor is supported

getSourceActions

public int getSourceActions()

This method returns the source drop actions.

Returns:

the source drop actions

getDropAction

public int getDropAction()

This method returns the user drop action.

Returns:

the user drop action

acceptDrag

public void acceptDrag(int dragOperation)

Accepts the drag. This method should be called from a DropTargetListeners dragEnter, dragOver, and dropActionChanged methods if the implementation wishes to accept an operation from the srcActions other than the one selected by the user as represented by the dropAction.

Parameters:

dragOperation - the operation accepted by the target

rejectDrag

public void rejectDrag()

Rejects the drag as a result of examining either the dropAction or the available DataFlavor types.