java.awt.dnd
Class DragSource

java.lang.Object
  java.awt.dnd.DragSource

All Implemented Interfaces:

Serializable

public class DragSource

extends Object

implements Serializable

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.
• 1 instance per class of potential Drag Initiator object (e.g TextField). [implementation dependent]
• 1 per instance of a particular Component, or application specific object associated with a Component instance in the GUI. [implementation dependent]
• Some other arbitrary association. [implementation dependent]

The initial interpretation of the user's gesture, and the subsequent starting of the drag operation are the responsibility of the implementing Component, which is usually implemented by a DragGestureRecognizer.

When a drag gesture occurs, the DragSource's startDrag() method shall be invoked in order to cause processing of the user's navigational gestures and delivery of Drag and Drop protocol notifications. A DragSource shall only permit a single Drag and Drop operation to be current at any one time, and shall reject any further startDrag() requests by throwing an IllegalDnDOperationException until such time as the extant operation is complete.

The startDrag() method invokes the createDragSourceContext() method to instantiate an appropriate DragSourceContext and associate the DragSourceContextPeer with that.

If the Drag and Drop System is unable to initiate a drag operation for some reason, the startDrag() method throws a java.awt.dnd.InvalidDnDOperationException to signal such a condition. Typically this exception is thrown when the underlying platform system is either not in a state to initiate a drag, or the parameters specified are invalid.

Note that during the drag, the set of operations exposed by the source at the start of the drag operation may not change until the operation is complete. The operation(s) are constant for the duration of the operation with respect to the DragSource.

Since:

1.2

See Also:

Serialized Form

Field Summary
static Cursor	DefaultCopyDrop           The default Cursor to use with a copy operation indicating that a drop is currently allowed.
static Cursor	DefaultCopyNoDrop           The default Cursor to use with a copy operation indicating that a drop is currently not allowed.
static Cursor	DefaultLinkDrop           The default Cursor to use with a link operation indicating that a drop is currently allowed.
static Cursor	DefaultLinkNoDrop           The default Cursor to use with a link operation indicating that a drop is currently not allowed.
static Cursor	DefaultMoveDrop           The default Cursor to use with a move operation indicating that a drop is currently allowed.
static Cursor	DefaultMoveNoDrop           The default Cursor to use with a move operation indicating that a drop is currently not allowed.

 

Constructor Summary

DragSource()           Creates a new DragSource.

 

Method Summary
void	addDragSourceListener(DragSourceListener dsl)           Adds the specified DragSourceListener to this DragSource to receive drag source events during drag operations intiated with this DragSource.
void	addDragSourceMotionListener(DragSourceMotionListener dsml)           Adds the specified DragSourceMotionListener to this DragSource to receive drag motion events during drag operations intiated with this DragSource.
DragGestureRecognizer	createDefaultDragGestureRecognizer(Component c, int actions, DragGestureListener dgl)           Creates a new DragGestureRecognizer that implements the default abstract subclass of DragGestureRecognizer for this DragSource, and sets the specified Component and DragGestureListener on the newly created object.
DragGestureRecognizer	createDragGestureRecognizer(Class recognizerAbstractClass, Component c, int actions, DragGestureListener dgl)           Creates a new DragGestureRecognizer that implements the specified abstract subclass of DragGestureRecognizer, and sets the specified Component and DragGestureListener on the newly created object.
protected  DragSourceContext	createDragSourceContext(java.awt.dnd.peer.DragSourceContextPeer dscp, DragGestureEvent dgl, Cursor dragCursor, Image dragImage, Point imageOffset, Transferable t, DragSourceListener dsl)           Creates the DragSourceContext to handle this drag.
static DragSource	getDefaultDragSource()           Gets the DragSource object associated with the underlying platform.
DragSourceListener[]	getDragSourceListeners()           Gets all the DragSourceListeners registered with this DragSource.
DragSourceMotionListener[]	getDragSourceMotionListeners()           Gets all of the DragSourceMotionListeners registered with this DragSource.
FlavorMap	getFlavorMap()           This method returns the FlavorMap for this DragSource.
EventListener[]	getListeners(Class listenerType)           Gets all the objects currently registered as FooListeners upon this DragSource.
static boolean	isDragImageSupported()           Reports whether or not drag Image support is available on the underlying platform.
void	removeDragSourceListener(DragSourceListener dsl)           Removes the specified DragSourceListener from this DragSource.
void	removeDragSourceMotionListener(DragSourceMotionListener dsml)           Removes the specified DragSourceMotionListener from this DragSource.
void	startDrag(DragGestureEvent trigger, Cursor dragCursor, Image dragImage, Point dragOffset, Transferable transferable, DragSourceListener dsl)           Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Image to drag, the offset of the Image origin from the hotspot of the Cursor at the instant of the trigger, the subject data of the drag, and the DragSourceListener.
void	startDrag(DragGestureEvent trigger, Cursor dragCursor, Image dragImage, Point imageOffset, Transferable transferable, DragSourceListener dsl, FlavorMap flavorMap)           Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Image to drag, the offset of the Image origin from the hotspot of the Cursor at the instant of the trigger, the Transferable subject data of the drag, the DragSourceListener, and the FlavorMap.
void	startDrag(DragGestureEvent trigger, Cursor dragCursor, Transferable transferable, DragSourceListener dsl)           Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Transferable subject data of the drag, and the DragSourceListener.
void	startDrag(DragGestureEvent trigger, Cursor dragCursor, Transferable transferable, DragSourceListener dsl, FlavorMap flavorMap)           Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Transferable subject data of the drag, the DragSourceListener, and the FlavorMap.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

DefaultCopyDrop

public static final Cursor DefaultCopyDrop

The default Cursor to use with a copy operation indicating that a drop is currently allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DefaultMoveDrop

public static final Cursor DefaultMoveDrop

The default Cursor to use with a move operation indicating that a drop is currently allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DefaultLinkDrop

public static final Cursor DefaultLinkDrop

The default Cursor to use with a link operation indicating that a drop is currently allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DefaultCopyNoDrop

public static final Cursor DefaultCopyNoDrop

The default Cursor to use with a copy operation indicating that a drop is currently not allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DefaultMoveNoDrop

public static final Cursor DefaultMoveNoDrop

The default Cursor to use with a move operation indicating that a drop is currently not allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DefaultLinkNoDrop

public static final Cursor DefaultLinkNoDrop

The default Cursor to use with a link operation indicating that a drop is currently not allowed. null if GraphicsEnvironment.isHeadless() returns true.

See Also:

GraphicsEnvironment.isHeadless()

DragSource

public DragSource()
           throws HeadlessException

Creates a new DragSource.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

See Also:

GraphicsEnvironment.isHeadless()

getDefaultDragSource

public static DragSource getDefaultDragSource()

Gets the DragSource object associated with the underlying platform.

Returns:

the platform DragSource

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

See Also:

GraphicsEnvironment.isHeadless()

isDragImageSupported

public static boolean isDragImageSupported()

Reports whether or not drag Image support is available on the underlying platform.

Returns:

if the Drag Image support is available on this platform

startDrag

public void startDrag(DragGestureEvent trigger,
                      Cursor dragCursor,
                      Image dragImage,
                      Point imageOffset,
                      Transferable transferable,
                      DragSourceListener dsl,
                      FlavorMap flavorMap)
               throws InvalidDnDOperationException

Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Image to drag, the offset of the Image origin from the hotspot of the Cursor at the instant of the trigger, the Transferable subject data of the drag, the DragSourceListener, and the FlavorMap.

Parameters:

trigger - the DragGestureEvent that initiated the drag

dragCursor - the initial Cursor or null for defaults

dragImage - the image to drag or null,

imageOffset - the offset of the Image origin from the hotspot of the Cursor at the instant of the trigger

transferable - the subject data of the drag

dsl - the DragSourceListener

flavorMap - the FlavorMap to use, or null

Throws:

java.awt.dnd.InvalidDnDOperationException - if the Drag and Drop system is unable to initiate a drag operation, or if the user attempts to start a drag while an existing drag operation is still executing

InvalidDnDOperationException

startDrag

public void startDrag(DragGestureEvent trigger,
                      Cursor dragCursor,
                      Transferable transferable,
                      DragSourceListener dsl,
                      FlavorMap flavorMap)
               throws InvalidDnDOperationException

Start a drag, given the DragGestureEvent that initiated the drag, the initial Cursor to use, the Transferable subject data of the drag, the DragSourceListener, and the FlavorMap.

Parameters:

trigger - the DragGestureEvent that initiated the drag

dragCursor - the initial Cursor or null for defaults

transferable - the subject data of the drag

dsl - the DragSourceListener

flavorMap - the FlavorMap to use or null

Throws:

java.awt.dnd.InvalidDnDOperationException - if the Drag and Drop system is unable to initiate a drag operation, or if the user attempts to start a drag while an existing drag operation is still executing

InvalidDnDOperationException

public void startDrag(DragGestureEvent trigger,
                      Cursor dragCursor,
                      Image dragImage,
                      Point dragOffset,
                      Transferable transferable,
                      DragSourceListener dsl)
               throws InvalidDnDOperationException

public void startDrag(DragGestureEvent trigger,
                      Cursor dragCursor,
                      Transferable transferable,
                      DragSourceListener dsl)
               throws InvalidDnDOperationException

protected DragSourceContext createDragSourceContext(java.awt.dnd.peer.DragSourceContextPeer dscp,
                                                    DragGestureEvent dgl,
                                                    Cursor dragCursor,
                                                    Image dragImage,
                                                    Point imageOffset,
                                                    Transferable t,
                                                    DragSourceListener dsl)

public FlavorMap getFlavorMap()

public DragGestureRecognizer createDragGestureRecognizer(Class recognizerAbstractClass,
                                                         Component c,
                                                         int actions,
                                                         DragGestureListener dgl)

public DragGestureRecognizer createDefaultDragGestureRecognizer(Component c,
                                                                int actions,
                                                                DragGestureListener dgl)

public void addDragSourceListener(DragSourceListener dsl)

public void removeDragSourceListener(DragSourceListener dsl)

public DragSourceListener[] getDragSourceListeners()

public void addDragSourceMotionListener(DragSourceMotionListener dsml)

public void removeDragSourceMotionListener(DragSourceMotionListener dsml)

public DragSourceMotionListener[] getDragSourceMotionListeners()

public EventListener[] getListeners(Class listenerType)