com.vaadin.ui.


Class Table.TableDropCriterion

java.lang.Object
  com.vaadin.event.dd.acceptcriteria.ServerSideCriterion
      com.vaadin.ui.Table.TableDropCriterion

All Implemented Interfaces:

AcceptCriterion, Serializable

Enclosing class:

Table

public abstract static class Table.TableDropCriterion
extends ServerSideCriterion

Lazy loading accept criterion for Table. Accepted target rows are loaded from server once per drag and drop operation. Developer must override one method that decides on which rows the currently dragged data can be dropped.

Initially pretty much no data is sent to client. On first required criterion check (per drag request) the client side data structure is initialized from server and no subsequent requests requests are needed during that drag and drop operation.

See Also:

Serialized Form

Constructor Summary
Table.TableDropCriterion()
           
 
Method Summary
 boolean accept(DragAndDropEvent dragEvent)
          Validates the data in event to be appropriate for the DropHandler.drop(DragAndDropEvent) method.
protected abstract  Set<Object> getAllowedItemIds(DragAndDropEvent dragEvent, Table table, Collection<Object> visibleItemIds)
           
protected  String getIdentifier()
           
 void paintResponse(PaintTarget target)
          This needs to be implemented iff criterion does some lazy server side initialization.
 
Methods inherited from class com.vaadin.event.dd.acceptcriteria.ServerSideCriterion
isClientSideVerifiable, paint, paintContent
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Table.TableDropCriterion

public Table.TableDropCriterion()
Method Detail

getIdentifier

protected String getIdentifier()

Overrides:
getIdentifier in class ServerSideCriterion

accept

public boolean accept(DragAndDropEvent dragEvent)

Description copied from interface: AcceptCriterion

Validates the data in event to be appropriate for the DropHandler.drop(DragAndDropEvent) method.

Note that even if your criterion is validated on client side, you should always validate the data on server side too.

Returns:

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
Overrides:
paintResponse in class ServerSideCriterion

Throws:
PaintException

getAllowedItemIds

protected abstract Set<Object> getAllowedItemIds(DragAndDropEvent dragEvent,
                                                 Table table,
                                                 Collection<Object> visibleItemIds)

Parameters:
dragEvent -
table - the table for which the allowed item identifiers are defined
visibleItemIds - the list of currently rendered item identifiers, accepted item id's need to be detected only for these visible items
Returns:
the set of identifiers for items on which the dragEvent will be accepted