psdi.webclient.applet.wfcanvas.diagram.dnd

Class DnDHandler

java.lang.Object

psdi.webclient.applet.wfcanvas.diagram.dnd.DnDHandler

All Implemented Interfaces:

java.awt.dnd.peer.DragSourceContextPeer, java.awt.event.MouseListener, java.awt.event.MouseMotionListener, java.util.EventListener

public class DnDHandler
extends java.lang.Object
implements java.awt.dnd.peer.DragSourceContextPeer, java.awt.event.MouseListener, java.awt.event.MouseMotionListener

This class is written to substitue for the native system drag and drop handler. The native version doesn't work within the Java plugin. This version add a listener to the component starting the drag and then generates the correct drag and drop events for the the listeners. The class is created in the class WorkflowDragSource which is a subclass of DragSource with a new startDrag call which creates this a the peer for the DragSourceContext

Constructor Summary

Constructors

Constructor and Description
DnDHandler(java.awt.dnd.DragGestureEvent trigger) Constructs a DnDHandler using the drag gesture trigger

Method Summary

Modifier and Type	Method and Description
static java.awt.dnd.DragSource	createDragSource() This creates the appropriate drag source.
static java.awt.dnd.DropTarget	createDropTarget(java.awt.Component c, java.awt.dnd.DropTargetListener dtl) This creates the appropriate drop target.
java.awt.Cursor	getCursor() Returns the current cursor
void	mouseClicked(java.awt.event.MouseEvent e) Called when the mouse has been pressed and released
void	mouseDragged(java.awt.event.MouseEvent e) Called when the mouse is being dragged
void	mouseEntered(java.awt.event.MouseEvent e) Called when the mouse has entered the component
void	mouseExited(java.awt.event.MouseEvent e) Called when the mouse leaves the component
void	mouseMoved(java.awt.event.MouseEvent e) Called when the mouse has moved
void	mousePressed(java.awt.event.MouseEvent e) Called when the mouse is pressed.
void	mouseReleased(java.awt.event.MouseEvent e) Called when the mouse is released.
void	setCursor(java.awt.Cursor cursor) Sets the current cursor
void	startDrag(java.awt.dnd.DragSourceContext dsc, java.awt.Cursor cursor, java.awt.Image dragImage, java.awt.Point imageOffset) Starts the drag operation for a drag context
void	transferablesFlavorsChanged() Called if the transferable data flavors change

Methods inherited from class java.lang.Object

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

Constructor Detail

DnDHandler

public DnDHandler(java.awt.dnd.DragGestureEvent trigger)

Constructs a DnDHandler using the drag gesture trigger

Parameters:

trigger - The DragGestureEvent

Method Detail

startDrag

public void startDrag(java.awt.dnd.DragSourceContext dsc,
                      java.awt.Cursor cursor,
                      java.awt.Image dragImage,
                      java.awt.Point imageOffset)
               throws java.awt.dnd.InvalidDnDOperationException

Starts the drag operation for a drag context

Specified by:

startDrag in interface java.awt.dnd.peer.DragSourceContextPeer

Parameters:

dsc - The DragSourceContext

cursor - The initial cursor

dragImage - The image to be show during dragging

imageOffset - The offset of the image from the cursor

Throws:

java.awt.dnd.InvalidDnDOperationException

getCursor

public java.awt.Cursor getCursor()

Returns the current cursor

Specified by:

getCursor in interface java.awt.dnd.peer.DragSourceContextPeer

Returns:

The cursor

setCursor

public void setCursor(java.awt.Cursor cursor)
               throws java.awt.dnd.InvalidDnDOperationException

Sets the current cursor

Specified by:

setCursor in interface java.awt.dnd.peer.DragSourceContextPeer

Parameters:

cursor - The current cursor

Throws:

java.awt.dnd.InvalidDnDOperationException

transferablesFlavorsChanged

public void transferablesFlavorsChanged()

Called if the transferable data flavors change

Specified by:

transferablesFlavorsChanged in interface java.awt.dnd.peer.DragSourceContextPeer

mouseClicked

public void mouseClicked(java.awt.event.MouseEvent e)

Called when the mouse has been pressed and released

Specified by:

mouseClicked in interface java.awt.event.MouseListener

Parameters:

e - The mouse event

mouseEntered

public void mouseEntered(java.awt.event.MouseEvent e)

Called when the mouse has entered the component

Specified by:

mouseEntered in interface java.awt.event.MouseListener

Parameters:

e - The mouse event

mouseExited

public void mouseExited(java.awt.event.MouseEvent e)

Called when the mouse leaves the component

Specified by:

mouseExited in interface java.awt.event.MouseListener

Parameters:

e - The mouse event

mousePressed

public void mousePressed(java.awt.event.MouseEvent e)

Called when the mouse is pressed.

Specified by:

mousePressed in interface java.awt.event.MouseListener

Parameters:

e - The mouse event

mouseReleased

public void mouseReleased(java.awt.event.MouseEvent e)

Called when the mouse is released.

Specified by:

mouseReleased in interface java.awt.event.MouseListener

Parameters:

e - The mouse event

mouseDragged

public void mouseDragged(java.awt.event.MouseEvent e)

Called when the mouse is being dragged

Specified by:

mouseDragged in interface java.awt.event.MouseMotionListener

Parameters:

e - The mouse event

mouseMoved

public void mouseMoved(java.awt.event.MouseEvent e)

Called when the mouse has moved

Specified by:

mouseMoved in interface java.awt.event.MouseMotionListener

Parameters:

e - The mouse event

createDragSource

public static java.awt.dnd.DragSource createDragSource()

This creates the appropriate drag source. If the native DnD works ok then it is a standard DragSource otherwise it is our own version

createDropTarget

public static java.awt.dnd.DropTarget createDropTarget(java.awt.Component c,
                                                       java.awt.dnd.DropTargetListener dtl)

This creates the appropriate drop target. If the native DnD works ok then it is a standard DropTarget otherwise it is our own version

Parameters:

c - the component which is the drop target

dtl - The drop raget listener