com.vaadin.terminal.gwt.client.ui.dd
Class VDragEvent

java.lang.Object
  com.vaadin.terminal.gwt.client.ui.dd.VDragEvent

public class VDragEvent
extends Object

DragEvent used by Vaadin client side engine. Supports components, items, properties and custom payload (HTML5 style).

Method Summary

void	createDragImage(com.google.gwt.user.client.Element element, boolean alignImageToEvent) Automatically tries to create a proxy image from given element.
com.google.gwt.dom.client.NativeEvent	getCurrentGwtEvent() Returns the the latest NativeEvent that relates to this drag and drop operation.
com.google.gwt.user.client.Element	getDragImage()
Map<String,Object>	getDropDetails() TODO consider using similar smaller (than map) api as in Transferable TODO clean up when drop handler changes
com.google.gwt.user.client.Element	getElementOver() Detecting the element on which the the event is happening may be problematic during drag and drop operation.
VTransferable	getTransferable()
void	setCurrentGwtEvent(com.google.gwt.dom.client.NativeEvent event)
void	setDragImage(com.google.gwt.user.client.Element node) Sets the drag image used for current drag and drop operation.
void	setDragImage(com.google.gwt.user.client.Element element, int offsetX, int offsetY) Sets the drag image used for current drag and drop operation.
void	setElementOver(com.google.gwt.user.client.Element targetElement)

Methods inherited from class java.lang.Object

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

Method Detail

getTransferable

public VTransferable getTransferable()

getCurrentGwtEvent

public com.google.gwt.dom.client.NativeEvent getCurrentGwtEvent()

Returns the the latest NativeEvent that relates to this drag and drop operation. For example on VDropHandler.dragEnter(VDragEvent) this is commonly a MouseOverEvent.

Returns:

setCurrentGwtEvent

public void setCurrentGwtEvent(com.google.gwt.dom.client.NativeEvent event)

getElementOver

public com.google.gwt.user.client.Element getElementOver()

Detecting the element on which the the event is happening may be problematic during drag and drop operation. This is especially the case if a drag image (often called also drag proxy) is kept under the mouse cursor (see createDragImage(Element, boolean). Drag and drop event handlers (like the one provided by VDragAndDropManager ) should set elmentOver field to reflect the the actual element on which the pointer currently is (drag image excluded). VDropHandlers can then more easily react properly on drag events by reading the element via this method.

Returns:

the element in VDropHandler on which mouse cursor is on

setElementOver

public void setElementOver(com.google.gwt.user.client.Element targetElement)

setDragImage

public void setDragImage(com.google.gwt.user.client.Element node)

Sets the drag image used for current drag and drop operation. Drag image is displayed next to mouse cursor during drag and drop.

The element to be used as drag image will automatically get CSS style name "v-drag-element". TODO decide if this method should be here or in VTransferable (in HTML5 it is in DataTransfer) or VDragAndDropManager TODO should be possible to override behavior. Like to proxy the element to HTML5 DataTransfer

Parameters:

node -

getDropDetails

public Map<String,Object> getDropDetails()

TODO consider using similar smaller (than map) api as in Transferable TODO clean up when drop handler changes

Returns:

setDragImage

public void setDragImage(com.google.gwt.user.client.Element element,
                         int offsetX,
                         int offsetY)

Sets the drag image used for current drag and drop operation. Drag image is displayed next to mouse cursor during drag and drop.

The element to be used as drag image will automatically get CSS style name "v-drag-element".

Parameters:

element - the dom element to be positioned next to mouse cursor

offsetX - the horizontal offset of drag image from mouse cursor

offsetY - the vertical offset of drag image from mouse cursor

getDragImage

public com.google.gwt.user.client.Element getDragImage()

Returns:

the current Element used as a drag image (aka drag proxy) or null if drag image is not currently set for this drag operation.

createDragImage

public void createDragImage(com.google.gwt.user.client.Element element,
                            boolean alignImageToEvent)

Automatically tries to create a proxy image from given element.

Parameters:

element -

alignImageToEvent - if true, proxy image is aligned to start event, else next to mouse cursor