com.vaadin.client.ui.dd

Class VDragAndDropManager

java.lang.Object

com.vaadin.client.ui.dd.VDragAndDropManager

Deprecated.

Replaced in 8.1 with DropTargetExtensionConnector and DragSourceExtensionConnector

@Deprecated
public class VDragAndDropManager
extends Object

Helper class to manage the state of drag and drop event on Vaadin client side. Can be used to implement most of the drag and drop operation automatically via cross-browser event preview method or just as a helper when implementing own low level drag and drop operation (like with HTML5 api).

Singleton. Only one drag and drop operation can be active anyways. Use get() to get instance. TODO cancel drag and drop if more than one touches !?

Author:

Vaadin Ltd

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	VDragAndDropManager.DDManagerMediator Deprecated. Implementation if this interface is provided as a parameter to DDEventHandleStrategy methods.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ACTIVE_DRAG_SOURCE_STYLENAME Deprecated. Style name for the active drag source.
static int	MINIMUM_DISTANCE_TO_START_DRAG Deprecated. #13381, #14796.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	VDragAndDropManager() Deprecated. Singleton.

Method Summary

Modifier and Type	Method and Description
void	endDrag() Deprecated. Drag is ended (drop happened) on current drop handler.
void	executeWhenReady(com.google.gwt.user.client.Command command) Deprecated. Method to execute commands when all existing dd related tasks are completed (some may require server visit).
protected VDropHandler	findDragTarget(com.google.gwt.dom.client.Element element) Deprecated. First seeks the widget from this element, then iterates widgets until one implement HasDropHandler.
static VDragAndDropManager	get() Deprecated. Returns the current drag and drop manager instance.
protected ApplicationConnection	getCurrentDragApplicationConnection() Deprecated. Returns the application connection for the current drag source.
VDropHandler	getCurrentDropHandler() Deprecated. Returns the current drop handler.
protected DDEventHandleStrategy	getEventHandleStrategy() Deprecated. Returns DnD strategy to handle native preview events used by the manager.
void	handleServerResponse(ValueMap valueMap) Deprecated. Handle the server response for drag and drop.
void	interruptDrag() Deprecated. The drag and drop operation is ended, but drop did not happen.
void	setCurrentDropHandler(VDropHandler currentDropHandler) Deprecated. If drag and drop operation is not handled by VDragAndDropManagers internal handler, this can be used to update current VDropHandler .
VDragEvent	startDrag(VTransferable transferable, com.google.gwt.dom.client.NativeEvent startEvent, boolean handleDragEvents) Deprecated. This method is used to start Vaadin client side drag and drop operation.
protected void	updateDragImagePosition(com.google.gwt.dom.client.NativeEvent gwtEvent, com.google.gwt.dom.client.Element dragImage) Deprecated. Updates drag image position.
void	visitServer(VDragEventServerCallback acceptCallback) Deprecated. Visits server during drag and drop procedure.

Methods inherited from class java.lang.Object

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

Field Detail

ACTIVE_DRAG_SOURCE_STYLENAME

public static final String ACTIVE_DRAG_SOURCE_STYLENAME

Deprecated.

Style name for the active drag source.

See Also:

Constant Field Values

MINIMUM_DISTANCE_TO_START_DRAG

public static final int MINIMUM_DISTANCE_TO_START_DRAG

Deprecated.

#13381, #14796. The drag only actually starts when the mouse move or touch move event is more than 3 pixel away.

See Also:

Constant Field Values

Constructor Detail

VDragAndDropManager

protected VDragAndDropManager()

Deprecated.

Singleton.

Method Detail

getCurrentDropHandler

public VDropHandler getCurrentDropHandler()

Deprecated.

Returns the current drop handler.

Returns:

current drop handler, or null if one doesn't exist

setCurrentDropHandler

public void setCurrentDropHandler(VDropHandler currentDropHandler)

Deprecated.

If drag and drop operation is not handled by VDragAndDropManagers internal handler, this can be used to update current VDropHandler .

Parameters:

currentDropHandler - the current drop handler

get

public static VDragAndDropManager get()

Deprecated.

Returns the current drag and drop manager instance. If one doesn't exist yet, it's created.

Returns:

the current drag and drop manager

startDrag

public VDragEvent startDrag(VTransferable transferable,
                            com.google.gwt.dom.client.NativeEvent startEvent,
                            boolean handleDragEvents)

Deprecated.

This method is used to start Vaadin client side drag and drop operation. Operation may be started by virtually any Widget.

Cancels possible existing drag. TODO figure out if this is always a bug if one is active. Maybe a good and cheap lifesaver thought.

If possible, method automatically detects current VDropHandler and fires VDropHandler.dragEnter(VDragEvent) event on it.

May also be used to control the drag and drop operation. If this option is used, VDropHandler is searched on mouse events and appropriate methods on it called automatically.

Parameters:

transferable - the VTransferable instance that represents the original dragged element

startEvent - the native event that starts the drag

handleDragEvents - if true, VDragAndDropManager handles the drag and drop operation GWT event preview.

Returns:

the drag event

updateDragImagePosition

protected void updateDragImagePosition(com.google.gwt.dom.client.NativeEvent gwtEvent,
                                       com.google.gwt.dom.client.Element dragImage)

Deprecated.

Updates drag image position.

Parameters:

gwtEvent - the event whose coordinates should be used

dragImage - the image to position

findDragTarget

protected VDropHandler findDragTarget(com.google.gwt.dom.client.Element element)

Deprecated.

First seeks the widget from this element, then iterates widgets until one implement HasDropHandler. Returns DropHandler from that.

Parameters:

element - the topmost element that is a potential drag target

Returns:

the drop handler from the given element or its closest ancestor that has one, or null if there is no such thing

endDrag

public void endDrag()

Deprecated.

Drag is ended (drop happened) on current drop handler. Calls drop method on current drop handler and does appropriate cleanup.

interruptDrag

public void interruptDrag()

Deprecated.

The drag and drop operation is ended, but drop did not happen. If operation is currently on a drop handler, its dragLeave method is called and appropriate cleanup happens.

visitServer

public void visitServer(VDragEventServerCallback acceptCallback)

Deprecated.

Visits server during drag and drop procedure. Transferable and event type is given to server side counterpart of DropHandler. If another server visit is started before the current is received, the current is just dropped. TODO consider if callback should have interrupted() method for cleanup.

Parameters:

acceptCallback - the callback that should handle the matching server response when it arrives

handleServerResponse

public void handleServerResponse(ValueMap valueMap)

Deprecated.

Handle the server response for drag and drop.

Parameters:

valueMap - DnD value map from the response

getEventHandleStrategy

protected DDEventHandleStrategy getEventHandleStrategy()

Deprecated.

Returns DnD strategy to handle native preview events used by the manager. Subclasses can override this method to return custom strategy or use GWT deferred binding.

Returns:

internal DnD native preview event handler

getCurrentDragApplicationConnection

protected ApplicationConnection getCurrentDragApplicationConnection()

Deprecated.

Returns the application connection for the current drag source. If there is no current drag source, returns null instead.

Returns:

the application connection, or null if not found

executeWhenReady

public void executeWhenReady(com.google.gwt.user.client.Command command)

Deprecated.

Method to execute commands when all existing dd related tasks are completed (some may require server visit).

Using this method may be handy if criterion that uses lazy initialization are used. Check

TODO Optimization: consider if we actually only need to keep the last command in queue here.

Parameters:

command - the command to execute