public class

DropTarget

extends Object
implements DropTargetListener Serializable
java.lang.Object
   ↳ java.awt.dnd.DropTarget

Class Overview

The DropTarget is associated with a Component when that Component wishes to accept drops during Drag and Drop operations.

Each DropTarget is associated with a FlavorMap. The default FlavorMap hereafter designates the FlavorMap returned by SystemFlavorMap.getDefaultFlavorMap().

Summary

Nested Classes
class DropTarget.DropTargetAutoScroller this protected nested class implements autoscrolling  
Public Constructors
DropTarget(Component c, int ops, DropTargetListener dtl, boolean act, FlavorMap fm)
Creates a new DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, a DropTargetListener to handle event processing, a boolean indicating if the DropTarget is currently accepting drops, and a FlavorMap to use (or null for the default FlavorMap).
DropTarget(Component c, int ops, DropTargetListener dtl, boolean act)
Creates a DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, a DropTargetListener to handle event processing, and a boolean indicating if the DropTarget is currently accepting drops.
DropTarget()
Creates a DropTarget.
DropTarget(Component c, DropTargetListener dtl)
Creates a DropTarget given the Component to associate itself with, and the DropTargetListener to handle event processing.
DropTarget(Component c, int ops, DropTargetListener dtl)
Creates a DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, and a DropTargetListener to handle event processing.
Public Methods
synchronized void addDropTargetListener(DropTargetListener dtl)
Adds a new DropTargetListener (UNICAST SOURCE).
void addNotify(ComponentPeer peer)
Notify the DropTarget that it has been associated with a Component This method is usually called from java.awt.Component.addNotify() of the Component associated with this DropTarget to notify the DropTarget that a ComponentPeer has been associated with that Component.
synchronized void dragEnter(DropTargetDragEvent dtde)
Calls dragEnter on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
synchronized void dragExit(DropTargetEvent dte)
Calls dragExit on the registered DropTargetListener and passes it the specified DropTargetEvent.
synchronized void dragOver(DropTargetDragEvent dtde)
Calls dragOver on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
synchronized void drop(DropTargetDropEvent dtde)
Calls drop on the registered DropTargetListener and passes it the specified DropTargetDropEvent if this DropTarget is active.
synchronized void dropActionChanged(DropTargetDragEvent dtde)
Calls dropActionChanged on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
synchronized Component getComponent()
Gets the Component associated with this DropTarget.
int getDefaultActions()
Gets an int representing the current action(s) supported by this DropTarget.
DropTargetContext getDropTargetContext()
Gets the DropTargetContext associated with this DropTarget.
FlavorMap getFlavorMap()
Gets the FlavorMap associated with this DropTarget.
boolean isActive()
Reports whether or not this DropTarget is currently active (ready to accept drops).
synchronized void removeDropTargetListener(DropTargetListener dtl)
Removes the current DropTargetListener (UNICAST SOURCE).
void removeNotify(ComponentPeer peer)
Notify the DropTarget that it has been disassociated from a Component This method is usually called from java.awt.Component.removeNotify() of the Component associated with this DropTarget to notify the DropTarget that a ComponentPeer has been disassociated with that Component.
synchronized void setActive(boolean isActive)
Sets the DropTarget active if true, inactive if false.
synchronized void setComponent(Component c)
Note: this interface is required to permit the safe association of a DropTarget with a Component in one of two ways, either: component.setDropTarget(droptarget); or droptarget.setComponent(component);

The Component will receive drops only if it is enabled.

void setDefaultActions(int ops)
Sets the default acceptable actions for this DropTarget

void setFlavorMap(FlavorMap fm)
Sets the FlavorMap associated with this DropTarget.
Protected Methods
void clearAutoscroll()
clear autoscrolling
DropTarget.DropTargetAutoScroller createDropTargetAutoScroller(Component c, Point p)
create an embedded autoscroller

DropTargetContext createDropTargetContext()
Creates the DropTargetContext associated with this DropTarget.
void initializeAutoscrolling(Point p)
initialize autoscrolling

void updateAutoscroll(Point dragCursorLocn)
update autoscrolling with current cursor locn

[Expand]
Inherited Methods
From class java.lang.Object
From interface java.awt.dnd.DropTargetListener

Public Constructors

public DropTarget (Component c, int ops, DropTargetListener dtl, boolean act, FlavorMap fm)

Creates a new DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, a DropTargetListener to handle event processing, a boolean indicating if the DropTarget is currently accepting drops, and a FlavorMap to use (or null for the default FlavorMap).

The Component will receive drops only if it is enabled.

Parameters
c The Component with which this DropTarget is associated
ops The default acceptable actions for this DropTarget
dtl The DropTargetListener for this DropTarget
act Is the DropTarget accepting drops.
fm The FlavorMap to use, or null for the default FlavorMap
Throws
HeadlessException if GraphicsEnvironment.isHeadless() returns true
See Also

public DropTarget (Component c, int ops, DropTargetListener dtl, boolean act)

Creates a DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, a DropTargetListener to handle event processing, and a boolean indicating if the DropTarget is currently accepting drops.

The Component will receive drops only if it is enabled.

Parameters
c The Component with which this DropTarget is associated
ops The default acceptable actions for this DropTarget
dtl The DropTargetListener for this DropTarget
act Is the DropTarget accepting drops.
Throws
HeadlessException if GraphicsEnvironment.isHeadless() returns true
See Also

public DropTarget ()

Creates a DropTarget.

Throws
HeadlessException if GraphicsEnvironment.isHeadless() returns true
See Also

public DropTarget (Component c, DropTargetListener dtl)

Creates a DropTarget given the Component to associate itself with, and the DropTargetListener to handle event processing.

The Component will receive drops only if it is enabled.

Parameters
c The Component with which this DropTarget is associated
dtl The DropTargetListener for this DropTarget
Throws
HeadlessException if GraphicsEnvironment.isHeadless() returns true
See Also

public DropTarget (Component c, int ops, DropTargetListener dtl)

Creates a DropTarget given the Component to associate itself with, an int representing the default acceptable action(s) to support, and a DropTargetListener to handle event processing.

The Component will receive drops only if it is enabled.

Parameters
c The Component with which this DropTarget is associated
ops The default acceptable actions for this DropTarget
dtl The DropTargetListener for this DropTarget
Throws
HeadlessException if GraphicsEnvironment.isHeadless() returns true
See Also

Public Methods

public synchronized void addDropTargetListener (DropTargetListener dtl)

Adds a new DropTargetListener (UNICAST SOURCE).

Parameters
dtl The new DropTargetListener

Throws
if a DropTargetListener is already added to this DropTarget.
TooManyListenersException

public void addNotify (ComponentPeer peer)

Notify the DropTarget that it has been associated with a Component This method is usually called from java.awt.Component.addNotify() of the Component associated with this DropTarget to notify the DropTarget that a ComponentPeer has been associated with that Component. Calling this method, other than to notify this DropTarget of the association of the ComponentPeer with the Component may result in a malfunction of the DnD system.

Parameters
peer The Peer of the Component we are associated with!

public synchronized void dragEnter (DropTargetDragEvent dtde)

Calls dragEnter on the registered DropTargetListener and passes it the specified DropTargetDragEvent. Has no effect if this DropTarget is not active.

Parameters
dtde the DropTargetDragEvent
Throws
NullPointerException if this DropTarget is active and dtde is null
See Also

public synchronized void dragExit (DropTargetEvent dte)

Calls dragExit on the registered DropTargetListener and passes it the specified DropTargetEvent. Has no effect if this DropTarget is not active.

This method itself does not throw any exception for null parameter but for exceptions thrown by the respective method of the listener.

Parameters
dte the DropTargetEvent
See Also

public synchronized void dragOver (DropTargetDragEvent dtde)

Calls dragOver on the registered DropTargetListener and passes it the specified DropTargetDragEvent. Has no effect if this DropTarget is not active.

Parameters
dtde the DropTargetDragEvent
Throws
NullPointerException if this DropTarget is active and dtde is null
See Also

public synchronized void drop (DropTargetDropEvent dtde)

Calls drop on the registered DropTargetListener and passes it the specified DropTargetDropEvent if this DropTarget is active.

Parameters
dtde the DropTargetDropEvent
Throws
NullPointerException if dtde is null and at least one of the following is true: this DropTarget is not active, or there is no a DropTargetListener registered.
See Also

public synchronized void dropActionChanged (DropTargetDragEvent dtde)

Calls dropActionChanged on the registered DropTargetListener and passes it the specified DropTargetDragEvent. Has no effect if this DropTarget is not active.

Parameters
dtde the DropTargetDragEvent
Throws
NullPointerException if this DropTarget is active and dtde is null
See Also

public synchronized Component getComponent ()

Gets the Component associated with this DropTarget.

Returns
  • the current Component

public int getDefaultActions ()

Gets an int representing the current action(s) supported by this DropTarget.

Returns
  • the current default actions

public DropTargetContext getDropTargetContext ()

Gets the DropTargetContext associated with this DropTarget.

Returns
  • the DropTargetContext associated with this DropTarget.

public FlavorMap getFlavorMap ()

Gets the FlavorMap associated with this DropTarget. If no FlavorMap has been set for this DropTarget, it is associated with the default FlavorMap.

Returns
  • the FlavorMap for this DropTarget

public boolean isActive ()

Reports whether or not this DropTarget is currently active (ready to accept drops).

Returns
  • true if active, false if not

public synchronized void removeDropTargetListener (DropTargetListener dtl)

Removes the current DropTargetListener (UNICAST SOURCE).

Parameters
dtl the DropTargetListener to deregister.

public void removeNotify (ComponentPeer peer)

Notify the DropTarget that it has been disassociated from a Component This method is usually called from java.awt.Component.removeNotify() of the Component associated with this DropTarget to notify the DropTarget that a ComponentPeer has been disassociated with that Component. Calling this method, other than to notify this DropTarget of the disassociation of the ComponentPeer from the Component may result in a malfunction of the DnD system.

Parameters
peer The Peer of the Component we are being disassociated from!

public synchronized void setActive (boolean isActive)

Sets the DropTarget active if true, inactive if false.

Parameters
isActive sets the DropTarget (in)active.

public synchronized void setComponent (Component c)

Note: this interface is required to permit the safe association of a DropTarget with a Component in one of two ways, either: component.setDropTarget(droptarget); or droptarget.setComponent(component);

The Component will receive drops only if it is enabled.

Parameters
c The new Component this DropTarget is to be associated with.

public void setDefaultActions (int ops)

Sets the default acceptable actions for this DropTarget

Parameters
ops the default actions

See Also

public void setFlavorMap (FlavorMap fm)

Sets the FlavorMap associated with this DropTarget.

Parameters
fm the new FlavorMap, or null to associate the default FlavorMap with this DropTarget.

Protected Methods

protected void clearAutoscroll ()

clear autoscrolling

protected DropTarget.DropTargetAutoScroller createDropTargetAutoScroller (Component c, Point p)

create an embedded autoscroller

Parameters
c the Component
p the Point

protected DropTargetContext createDropTargetContext ()

Creates the DropTargetContext associated with this DropTarget. Subclasses may override this method to instantiate their own DropTargetContext subclass. This call is typically *only* called by the platform's DropTargetContextPeer as a drag operation encounters this DropTarget. Accessing the Context while no Drag is current has undefined results.

protected void initializeAutoscrolling (Point p)

initialize autoscrolling

Parameters
p the Point

protected void updateAutoscroll (Point dragCursorLocn)

update autoscrolling with current cursor locn

Parameters
dragCursorLocn the Point