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package java.awt.dnd;


An abstract adapter class for receiving drop target events. The methods in
this class are empty. This class exists only as a convenience for creating
listener objects.

 Extend this class to create a DropTargetEvent listener and override the methods for the events of interest. (If you implement the DropTargetListener interface, you have to define all of the methods in it. This abstract class defines a null implementation for every method except drop(DropTargetDropEvent), so you only have to define methods for events you care about.) You must provide an implementation for at least drop(DropTargetDropEvent). This method cannot have a null implementation because its specification requires that you either accept or reject the drop, and, if accepted, indicate whether the drop was successful. 
 Create a listener object using the extended class 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. 
Author:David Mendenhall
See Also:
Since:1.4
/**
 * An abstract adapter class for receiving drop target events. The methods in
 * this class are empty. This class exists only as a convenience for creating
 * listener objects.
 * <p>
 * Extend this class to create a {@code DropTargetEvent} listener
 * and override the methods for the events of interest. (If you implement the
 * {@code DropTargetListener} interface, you have to define all of
 * the methods in it. This abstract class defines a null implementation for
 * every method except {@code drop(DropTargetDropEvent)}, so you only have
 * to define methods for events you care about.) You must provide an
 * implementation for at least {@code drop(DropTargetDropEvent)}. This
 * method cannot have a null implementation because its specification requires
 * that you either accept or reject the drop, and, if accepted, indicate
 * whether the drop was successful.
 * <p>
 * Create a listener object using the extended class and then register it with
 * a {@code DropTarget}. When the drag enters, moves over, or exits
 * the operable part of the drop site for that {@code DropTarget}, when
 * the drop action changes, and when the drop occurs, the relevant method in
 * the listener object is invoked, and the {@code DropTargetEvent} is
 * passed to it.
 * <p>
 * The operable part of the drop site for the {@code DropTarget} is
 * the part of the associated {@code Component}'s geometry that is not
 * obscured by an overlapping top-level window or by another
 * {@code Component} higher in the Z-order that has an associated active
 * {@code DropTarget}.
 * <p>
 * During the drag, the data associated with the current drag operation can be
 * retrieved by calling {@code getTransferable()} on
 * {@code DropTargetDragEvent} instances passed to the listener's
 * methods.
 * <p>
 * Note that {@code getTransferable()} on the
 * {@code DropTargetDragEvent} instance should only be called within the
 * respective listener's method and all the necessary data should be retrieved
 * from the returned {@code Transferable} before that method returns.
 *
 * @see DropTargetEvent
 * @see DropTargetListener
 *
 * @author David Mendenhall
 * @since 1.4
 */
public abstract class DropTargetAdapter implements DropTargetListener {

    
Called while a drag operation is ongoing, when the mouse pointer enters the operable part of the drop site for the DropTarget registered with this listener. 
Params:
  • dtde – the DropTargetDragEvent
/**
     * Called while a drag operation is ongoing, when the mouse pointer enters
     * the operable part of the drop site for the {@code DropTarget}
     * registered with this listener.
     *
     * @param dtde the {@code DropTargetDragEvent}
     */
    public void dragEnter(DropTargetDragEvent dtde) {}

    
Called when a drag operation is ongoing, while the mouse pointer is still over the operable part of the drop site for the DropTarget registered with this listener. 
Params:
  • dtde – the DropTargetDragEvent
/**
     * Called when a drag operation is ongoing, while the mouse pointer is still
     * over the operable part of the drop site for the {@code DropTarget}
     * registered with this listener.
     *
     * @param dtde the {@code DropTargetDragEvent}
     */
    public void dragOver(DropTargetDragEvent dtde) {}

    
Called if the user has modified
the current drop gesture.

Params:
  • dtde – the DropTargetDragEvent
/**
     * Called if the user has modified
     * the current drop gesture.
     *
     * @param dtde the {@code DropTargetDragEvent}
     */
    public void dropActionChanged(DropTargetDragEvent dtde) {}

    
Called while a drag operation is ongoing, when the mouse pointer has exited the operable part of the drop site for the DropTarget registered with this listener. 
Params:
  • dte – the DropTargetEvent
/**
     * Called while a drag operation is ongoing, when the mouse pointer has
     * exited the operable part of the drop site for the
     * {@code DropTarget} registered with this listener.
     *
     * @param dte the {@code DropTargetEvent}
     */
    public void dragExit(DropTargetEvent dte) {}
}