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DropTargetContext (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档

JavaTM 2 Platform
Std. Ed. v1.4.1

java.awt.dnd
Class DropTargetContext

java.lang.Object
  |
  +--java.awt.dnd.DropTargetContext
All Implemented Interfaces:
Serializable

public class DropTargetContext
extends Object
implements Serializable

A DropTargetContext is created whenever the logical cursor associated with a Drag and Drop operation coincides with the visible geometry of a Component associated with a DropTarget. The DropTargetContext provides the mechanism for a potential receiver of a drop operation to both provide the end user with the appropriate drag under feedback, but also to effect the subsequent data transfer if appropriate.

Since:
1.2
See Also:
Serialized Form

Nested Class Summary
protected  class DropTargetContext.TransferableProxy
          TransferableProxy is a helper inner class that implements Transferable interface and serves as a proxy for another Transferable object which represents data transfer for a particular drag-n-drop operation.
 
Method Summary
protected  void acceptDrag(int dragOperation)
          accept the Drag.
protected  void acceptDrop(int dropOperation)
          called to signal that the drop is acceptable using the specified operation.
 void addNotify(java.awt.dnd.peer.DropTargetContextPeer dtcp)
          Called when associated with the DropTargetContextPeer.
protected  Transferable createTransferableProxy(Transferable t, boolean local)
          Creates a TransferableProxy to proxy for the specified Transferable.
 void dropComplete(boolean success)
          This method signals that the drop is completed and if it was successful or not.
 Component getComponent()
          This method returns the Component associated with this DropTargetContext.
protected  DataFlavor[] getCurrentDataFlavors()
          get the available DataFlavors of the Transferable operand of this operation.
protected  List getCurrentDataFlavorsAsList()
          This method returns a the currently available DataFlavors of the Transferable operand as a java.util.List.
 DropTarget getDropTarget()
          This method returns the DropTarget associated with this DropTargetContext.
protected  int getTargetActions()
          This method returns an int representing the current actions this DropTarget will accept.
protected  Transferable getTransferable()
          get the Transferable (proxy) operand of this operation
protected  boolean isDataFlavorSupported(DataFlavor df)
          This method returns a boolean indicating if the given DataFlavor is supported by this DropTargetContext.
protected  void rejectDrag()
          reject the Drag.
protected  void rejectDrop()
          called to signal that the drop is unacceptable.
 void removeNotify()
          Called when disassociated with the DropTargetContextPeer.
protected  void setTargetActions(int actions)
          This method sets the current actions acceptable to this DropTarget.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getDropTarget

public DropTarget getDropTarget()
This method returns the DropTarget associated with this DropTargetContext.

Returns:
the DropTarget associated with this DropTargetContext

getComponent

public Component getComponent()
This method returns the Component associated with this DropTargetContext.

Returns:
the Component associated with this Context

addNotify

public void addNotify(java.awt.dnd.peer.DropTargetContextPeer dtcp)
Called when associated with the DropTargetContextPeer.

Parameters:
dtcp - the DropTargetContextPeer

removeNotify

public void removeNotify()
Called when disassociated with the DropTargetContextPeer.


setTargetActions

protected void setTargetActions(int actions)
This method sets the current actions acceptable to this DropTarget.

Parameters:
actions - an int representing the supported action(s)

getTargetActions

protected int getTargetActions()
This method returns an int representing the current actions this DropTarget will accept.

Returns:
the current actions acceptable to this DropTarget

dropComplete

public void dropComplete(boolean success)
                  throws InvalidDnDOperationException
This method signals that the drop is completed and if it was successful or not.

Parameters:
success - true for success, false if not

Throws:
InvalidDnDOperationException - if a drop is not outstanding/extant

acceptDrag

protected void acceptDrag(int dragOperation)
accept the Drag.

Parameters:
dragOperation - the supported action(s)

rejectDrag

protected void rejectDrag()
reject the Drag.


acceptDrop

protected void acceptDrop(int dropOperation)
called to signal that the drop is acceptable using the specified operation. must be called during DropTargetListener.drop method invocation.

Parameters:
dropOperation - the supported action(s)

rejectDrop

protected void rejectDrop()
called to signal that the drop is unacceptable. must be called during DropTargetListener.drop method invocation.


getCurrentDataFlavors

protected DataFlavor[] getCurrentDataFlavors()
get the available DataFlavors of the Transferable operand of this operation.

Returns:
a DataFlavor[] containing the supported DataFlavors of the Transferable operand.

getCurrentDataFlavorsAsList

protected List getCurrentDataFlavorsAsList()
This method returns a the currently available DataFlavors of the Transferable operand as a java.util.List.

Returns:
the currently available DataFlavors as a java.util.List

isDataFlavorSupported

protected boolean isDataFlavorSupported(DataFlavor df)
This method returns a boolean indicating if the given DataFlavor is supported by this DropTargetContext.

Parameters:
df - the DataFlavor

Returns:
if the DataFlavor specified is supported

getTransferable

protected Transferable getTransferable()
                                throws InvalidDnDOperationException
get the Transferable (proxy) operand of this operation

Returns:
the Transferable
Throws:
InvalidDnDOperationException - if a drag is not outstanding/extant


createTransferableProxy

protected Transferable createTransferableProxy(Transferable t,
                                               boolean local)
Creates a TransferableProxy to proxy for the specified Transferable.

Parameters:
t - the Transferable to be proxied
local - true if t represents the result of a local drag-n-drop operation.
Returns:
the new TransferableProxy instance.

JavaTM 2 Platform
Std. Ed. v1.4.1

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.