Class DropTargetAdapter

java.lang.Object
java.awt.dnd.DropTargetAdapter
All Implemented Interfaces:
DropTargetListener, EventListener
public abstract class DropTargetAdapter extends Object implements DropTargetListener
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.

Since:
1.4
See Also:

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    DropTargetAdapter()
    Constructs a DropTargetAdapter.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    dragEnter(DropTargetDragEvent dtde)
    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.
    void
    dragExit(DropTargetEvent dte)
    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.
    void
    dragOver(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.
    void
    dropActionChanged(DropTargetDragEvent dtde)
    Called if the user has modified the current drop gesture.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

    Methods declared in interface DropTargetListener

    drop
    Modifier and Type
    Method
    Description
    void
    drop(DropTargetDropEvent dtde)
    Called when the drag operation has terminated with a drop on the operable part of the drop site for the DropTarget registered with this listener.

  • Constructor Details

    • DropTargetAdapter

      protected DropTargetAdapter()
      Constructs a DropTargetAdapter.

  • Method Details

    • dragEnter

      public void dragEnter(DropTargetDragEvent dtde)
      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.
      Specified by:
      dragEnter in interface DropTargetListener
      Parameters:
      dtde - the DropTargetDragEvent

    • dragOver

      public void dragOver(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.
      Specified by:
      dragOver in interface DropTargetListener
      Parameters:
      dtde - the DropTargetDragEvent

    • dropActionChanged

      public void dropActionChanged(DropTargetDragEvent dtde)
      Called if the user has modified the current drop gesture.
      Specified by:
      dropActionChanged in interface DropTargetListener
      Parameters:
      dtde - the DropTargetDragEvent

    • dragExit

      public void dragExit(DropTargetEvent dte)
      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.
      Specified by:
      dragExit in interface DropTargetListener
      Parameters:
      dte - the DropTargetEvent