com.vaadin.event.dd.acceptcriteria

Class ServerSideCriterion

java.lang.Object

com.vaadin.event.dd.acceptcriteria.ServerSideCriterion

All Implemented Interfaces:

AcceptCriterion, Serializable

public abstract class ServerSideCriterion
extends Object
implements Serializable, AcceptCriterion

Parent class for criteria which are verified on the server side during a drag operation to accept/discard dragged content (presented by Transferable).

Subclasses should implement the AcceptCriterion.accept(com.vaadin.event.dd.DragAndDropEvent) method.

As all server side state can be used to make a decision, this is more flexible than ClientSideCriterion. However, this does require additional requests from the browser to the server during a drag operation.

Since:

6.3

See Also:

AcceptCriterion, ClientSideCriterion, Serialized Form

Constructor Summary

Constructors

Constructor and Description
ServerSideCriterion()

Method Summary

Modifier and Type	Method and Description
protected String	getIdentifier()
boolean	isClientSideVerifiable() Returns whether the criteria can be checked on the client or whether a server request is needed to check the criteria.
void	paint(PaintTarget target)
void	paintContent(PaintTarget target)
void	paintResponse(PaintTarget target) This needs to be implemented iff criterion does some lazy server side initialization.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.event.dd.acceptcriteria.AcceptCriterion

accept

Constructor Detail

ServerSideCriterion

public ServerSideCriterion()

Method Detail

isClientSideVerifiable

public final boolean isClientSideVerifiable()

Description copied from interface: AcceptCriterion

Returns whether the criteria can be checked on the client or whether a server request is needed to check the criteria. This requirement may depend on the state of the criterion (e.g. logical operations between criteria), so this cannot be based on a marker interface.

Specified by:

isClientSideVerifiable in interface AcceptCriterion

paint

public void paint(PaintTarget target)
           throws PaintException

Specified by:

paint in interface AcceptCriterion

Throws:

PaintException

paintContent

public void paintContent(PaintTarget target)

paintResponse

public void paintResponse(PaintTarget target)
                   throws PaintException

Description copied from interface: AcceptCriterion

This needs to be implemented iff criterion does some lazy server side initialization. The UIDL painted in this method will be passed to client side drop handler implementation. Implementation can assume that AcceptCriterion.accept(DragAndDropEvent) is called before this method.

Specified by:

paintResponse in interface AcceptCriterion

Throws:

PaintException

getIdentifier

protected String getIdentifier()