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
Modifier and Type | Class | Description |
---|---|---|
protected static class | DropTarget.DropTargetAutoScroller | this protected nested class implements autoscrolling |
Constructor Summary
Constructor | Description |
---|---|
DropTarget() | Creates a |
DropTarget(Component c,
int ops,
DropTargetListener dtl) | Creates a |
DropTarget(Component c,
int ops,
DropTargetListener dtl,
boolean act) | Creates a |
DropTarget(Component c,
int ops,
DropTargetListener dtl,
boolean act,
FlavorMap fm) | Creates a new DropTarget given the |
DropTarget(Component c,
DropTargetListener dtl) | Creates a |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
void | addDropTargetListener(DropTargetListener dtl) | Adds a new |
void | addNotify() | 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 |
void | dragExit(DropTargetEvent dte) | Calls |
void | dragOver(DropTargetDragEvent dtde) | Calls |
void | drop(DropTargetDropEvent dtde) | Calls |
void | dropActionChanged(DropTargetDragEvent dtde) | Calls |
Component | getComponent() | Gets the |
int | getDefaultActions() | Gets an |
DropTargetContext | getDropTargetContext() | Gets the |
FlavorMap | getFlavorMap() | Gets the |
protected void | initializeAutoscrolling(Point p) | initialize autoscrolling |
boolean | isActive() | Reports whether or not this |
void | removeDropTargetListener(DropTargetListener dtl) | Removes the current |
void | removeNotify() | 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 |
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: |
void | setDefaultActions(int ops) | Sets the default acceptable actions for this |
void | setFlavorMap(FlavorMap fm) | Sets the |
protected void | updateAutoscroll(Point dragCursorLocn) | update autoscrolling with current cursor location |
Methods declared in 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
- TheComponent
with which thisDropTarget
is associated -
ops
- The default acceptable actions for thisDropTarget
-
dtl
- TheDropTargetListener
for thisDropTarget
-
act
- Is theDropTarget
accepting drops. -
fm
- TheFlavorMap
to use, or null for the defaultFlavorMap
- 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
- TheComponent
with which thisDropTarget
is associated -
ops
- The default acceptable actions for thisDropTarget
-
dtl
- TheDropTargetListener
for thisDropTarget
-
act
- Is theDropTarget
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
- TheComponent
with which thisDropTarget
is associated -
dtl
- TheDropTargetListener
for thisDropTarget
- 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
- TheComponent
with which thisDropTarget
is associated -
ops
- The default acceptable actions for thisDropTarget
-
dtl
- TheDropTargetListener
for thisDropTarget
- 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 newComponent
thisDropTarget
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 theDropTarget
(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 newDropTargetListener
- Throws:
-
TooManyListenersException
- if aDropTargetListener
is already added to thisDropTarget
.
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 interfaceDropTargetListener
- Parameters:
-
dtde
- theDropTargetDragEvent
- Throws:
-
NullPointerException
- if thisDropTarget
is active anddtde
isnull
- 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 interfaceDropTargetListener
- Parameters:
-
dtde
- theDropTargetDragEvent
- Throws:
-
NullPointerException
- if thisDropTarget
is active anddtde
isnull
- 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 interfaceDropTargetListener
- Parameters:
-
dtde
- theDropTargetDragEvent
- Throws:
-
NullPointerException
- if thisDropTarget
is active anddtde
isnull
- 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 interfaceDropTargetListener
- Parameters:
-
dte
- theDropTargetEvent
- 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 interfaceDropTargetListener
- Parameters:
-
dtde
- theDropTargetDropEvent
- Throws:
-
NullPointerException
- ifdtde
is null and at least one of the following is true: thisDropTarget
is not active, or there is no aDropTargetListener
registered. - See Also:
isActive()
getFlavorMap
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
setFlavorMap
public void setFlavorMap(FlavorMap fm)
Sets the FlavorMap
associated with this DropTarget
.
- Parameters:
-
fm
- the newFlavorMap
, or null to associate the default FlavorMap with this DropTarget.
addNotify
public void addNotify()
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.
removeNotify
public void removeNotify()
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.
getDropTargetContext
public DropTargetContext getDropTargetContext()
Gets the DropTargetContext
associated with this DropTarget
.
- Returns:
- the
DropTargetContext
associated with thisDropTarget
.
createDropTargetContext
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.
- Returns:
- the DropTargetContext associated with this DropTarget
createDropTargetAutoScroller
protected DropTarget.DropTargetAutoScroller createDropTargetAutoScroller(Component c, Point p)
create an embedded autoscroller
- Parameters:
-
c
- theComponent
-
p
- thePoint
- Returns:
- an embedded autoscroller
initializeAutoscrolling
protected void initializeAutoscrolling(Point p)
initialize autoscrolling
- Parameters:
-
p
- thePoint
updateAutoscroll
protected void updateAutoscroll(Point dragCursorLocn)
update autoscrolling with current cursor location
- Parameters:
-
dragCursorLocn
- thePoint
clearAutoscroll
protected void clearAutoscroll()
clear autoscrolling