java.awt.dnd
Class DropTarget

java.lang.Object   
  java.awt.dnd.DropTarget

All Implemented Interfaces:

DropTargetListener , Serializable , EventListener

public class DropTarget
extends Object   
implements DropTargetListener   , Serializable   

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().

Since:

1.2

See Also:

Serialized Form

Nested Class Summary

protected static class

DropTarget.DropTargetAutoScroller this protected nested class implements autoscrolling

Constructor Summary

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.

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 (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).

Method Summary

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.
protected void	clearAutoscroll () clear autoscrolling
protected DropTarget.DropTargetAutoScroller	createDropTargetAutoScroller (Component c, Point p) create an embedded autoscroller
protected DropTargetContext	createDropTargetContext () Creates the DropTargetContext associated with this DropTarget.
void	dragEnter (DropTargetDragEvent dtde) Calls dragEnter on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
void	dragExit (DropTargetEvent dte) Calls dragExit on the registered DropTargetListener and passes it the specified DropTargetEvent.
void	dragOver (DropTargetDragEvent dtde) Calls dragOver on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
void	drop (DropTargetDropEvent dtde) Calls drop on the registered DropTargetListener and passes it the specified DropTargetDropEvent if this DropTarget is active.
void	dropActionChanged (DropTargetDragEvent dtde) Calls dropActionChanged on the registered DropTargetListener and passes it the specified DropTargetDragEvent.
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.
protected void	initializeAutoscrolling (Point p) initialize autoscrolling
boolean	isActive () Reports whether or not this DropTarget is currently active (ready to accept drops).
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.
void	setActive (boolean isActive) Sets the DropTarget active if true, inactive if false.
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);
void	setDefaultActions (int ops) Sets the default acceptable actions for this DropTarget
void	setFlavorMap (FlavorMap fm) Sets the FlavorMap associated with this DropTarget.
protected void	updateAutoscroll (Point dragCursorLocn) update autoscrolling with current cursor locn

Methods inherited from class java.lang.Object

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

Constructor Detail

DropTarget

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

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:

GraphicsEnvironment.isHeadless()

DropTarget

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

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:

GraphicsEnvironment.isHeadless()

DropTarget

public DropTarget()
           throws HeadlessException   

Creates a DropTarget.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

See Also:

GraphicsEnvironment.isHeadless()

DropTarget

public DropTarget(Component    c,
                  DropTargetListener    dtl)
           throws HeadlessException   

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:

GraphicsEnvironment.isHeadless()

DropTarget

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

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:

GraphicsEnvironment.isHeadless()

Method Detail

setComponent

public 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.

getComponent

public Component    getComponent()

Gets the Component associated with this DropTarget.

Returns:

the current Component

setDefaultActions

public void setDefaultActions(int ops)

Sets the default acceptable actions for this DropTarget

Parameters:

ops - the default actions

See Also:

DnDConstants

getDefaultActions

public int getDefaultActions()

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

Returns:

the current default actions

setActive

public void setActive(boolean isActive)

Sets the DropTarget active if true, inactive if false.

Parameters:

isActive - sets the DropTarget (in)active.

isActive

public boolean isActive()

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

Returns:

true if active, false if not

addDropTargetListener

public void addDropTargetListener(DropTargetListener    dtl)
                           throws TooManyListenersException   

Adds a new DropTargetListener (UNICAST SOURCE).

Parameters:

dtl - The new DropTargetListener

Throws:

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

TooManyListenersException

removeDropTargetListener

public void removeDropTargetListener(DropTargetListener    dtl)

Removes the current DropTargetListener (UNICAST SOURCE).

Parameters:

dtl - the DropTargetListener to deregister.

dragEnter

public 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.

Specified by:

dragEnter in interface DropTargetListener

Parameters:

dtde - the DropTargetDragEvent

Throws:

NullPointerException - if this DropTarget is active and dtde is null

See Also:

isActive()

dragOver

public 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.

Specified by:

dragOver in interface DropTargetListener

Parameters:

dtde - the DropTargetDragEvent

Throws:

NullPointerException - if this DropTarget is active and dtde is null

See Also:

isActive()

dropActionChanged

public 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.

Specified by:

dropActionChanged in interface DropTargetListener

Parameters:

dtde - the DropTargetDragEvent

Throws:

NullPointerException - if this DropTarget is active and dtde is null

See Also:

isActive()

dragExit

public 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.

Specified by:

dragExit in interface DropTargetListener

Parameters:

dte - the DropTargetEvent

See Also:

isActive()

drop

public void drop(DropTargetDropEvent    dtde)

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

Specified by:

drop in interface DropTargetListener