java.awt.dnd

## 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:
    `DropTargetEvent`, `DropTargetListener`

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `DropTargetAdapter()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and 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 inherited from class java.lang.Object

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

    - ### Methods inherited from interface java.awt.dnd.DropTargetListener

      `drop`

- - ### Constructor Detail

    - #### DropTargetAdapter

          public DropTargetAdapter()

  - ### Method Detail

    - #### 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`

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