This package defines the classes and interfaces necessary to perform Drag and Drop operations in Java. It defines classes for the drag-source and the drop-target, as well as events for transferring the data being dragged. This package also provides a means for giving visual feedback to the user throughout the duration of the Drag and Drop operation.
A typical Drag and Drop operation can be decomposed into the following states (not entirely sequentially):
DragSource
comes into existence, associated with some presentation element (Component
) in the GUI, to initiate a Drag and Drop of some potentially Transferable
data.DropTarget
(s) come into/go out of existence, associated with presentation elements in the GUI (Components), potentially capable of consuming Transferable
data types.DragGestureRecognizer
is obtained from the DragSource
and is associated with a Component
in order to track and identify any Drag initiating gesture by the user over the Component
.Component
, which the registered DragGestureRecognizer
detects, and notifies its DragGestureListener
of. Note: Although this API consistently refers to the stimulus for a drag and drop operation being a physical gesture by a human user, this does not preclude a programmatically driven DnD operation given the appropriate implementation of a DragSource
. This package contains the abstract class MouseDragGestureRecognizer
for recognizing mouse device gestures. Other abstract subclasses may be provided by the platform to support other input devices or particular Component
class semantics.
DragGestureListener
causes the DragSource
to initiate the Drag and Drop operation on behalf of the user, perhaps animating the GUI Cursor and/or rendering an Image
of the item(s) that are the subject of the operation.Component
(s) in the GUI with associated DropTarget
(s), the DragSource
receives notifications in order to provide "Drag Over" feedback effects, and the DropTarget
(s) receive notifications in order to provide "Drag Under" feedback effects based upon the operation(s) supported and the data type(s) involved. The gesture itself moves a logical cursor across the GUI hierarchy, intersecting the geometry of GUI Component(s), possibly resulting in the logical "Drag" cursor entering, crossing, and subsequently leaving Component
(s) and associated DropTarget
(s).
The DragSource
object manifests "Drag Over" feedback to the user, in the typical case by animating the GUI Cursor
associated with the logical cursor.
DropTarget
objects manifest "Drag Under" feedback to the user, in the typical case, by rendering animations into their associated GUI Component
(s) under the GUI Cursor.
The determination of the feedback effects, and the ultimate success or failure of the data transfer, should one occur, is parameterized as follows:
DragSource
and DropTarget
: Copy, Move or Reference(link).DragSource
and the set of data types comprehensible by the DropTarget
.DragSource
and DropTarget
receive notifications that include, and result in the type negotiation and transfer of, the information associated with the DragSource
via a Transferable
object.Class | Description |
---|---|
Autoscroll | During DnD operations it is possible that a user may wish to drop the subject of the operation on a region of a scrollable GUI control that is not currently visible to the user. |
DnDConstants | This class contains constant values representing the type of action(s) to be performed by a Drag and Drop operation. |
DragGestureEvent | A DragGestureEvent is passed to DragGestureListener 's dragGestureRecognized() method when a particular DragGestureRecognizer detects that a platform dependent drag initiating gesture has occurred on the Component that it is tracking. |
DragGestureListener | The listener interface for receiving drag gesture events. |
DragGestureRecognizer | The DragGestureRecognizer is an abstract base class for the specification of a platform-dependent listener that can be associated with a particular Component in order to identify platform-dependent drag initiating gestures. |
DragSource | The DragSource is the entity responsible for the initiation of the Drag and Drop operation, and may be used in a number of scenarios: 1 default instance per JVM for the lifetime of that JVM. |
DragSourceAdapter | An abstract adapter class for receiving drag source events. |
DragSourceContext | The DragSourceContext class is responsible for managing the initiator side of the Drag and Drop protocol. |
DragSourceDragEvent | The DragSourceDragEvent is delivered from the DragSourceContextPeer , via the DragSourceContext , to the DragSourceListener registered with that DragSourceContext and with its associated DragSource . |
DragSourceDropEvent | The DragSourceDropEvent is delivered from the DragSourceContextPeer , via the DragSourceContext , to the dragDropEnd method of DragSourceListener s registered with that DragSourceContext and with its associated DragSource . |
DragSourceEvent | This class is the base class for DragSourceDragEvent and DragSourceDropEvent . |
DragSourceListener | The DragSourceListener defines the event interface for originators of Drag and Drop operations to track the state of the user's gesture, and to provide appropriate "drag over" feedback to the user throughout the Drag and Drop operation. |
DragSourceMotionListener | A listener interface for receiving mouse motion events during a drag operation. |
DropTarget | The DropTarget is associated with a Component when that Component wishes to accept drops during Drag and Drop operations. |
DropTarget.DropTargetAutoScroller | this protected nested class implements autoscrolling |
DropTargetAdapter | An abstract adapter class for receiving drop target events. |
DropTargetContext | 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 . |
DropTargetDragEvent | The DropTargetDragEvent is delivered to a DropTargetListener via its dragEnter() and dragOver() methods. |
DropTargetDropEvent | The DropTargetDropEvent is delivered via the DropTargetListener drop() method. |
DropTargetEvent | The DropTargetEvent is the base class for both the DropTargetDragEvent and the DropTargetDropEvent . |
DropTargetListener | The DropTargetListener interface is the callback interface used by the DropTarget class to provide notification of DnD operations that involve the subject DropTarget . |
InvalidDnDOperationException | This exception is thrown by various methods in the java.awt.dnd package. |
MouseDragGestureRecognizer | This abstract subclass of DragGestureRecognizer defines a DragGestureRecognizer for mouse-based gestures. |
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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