com.vaadin.data.util
Class DefaultItemSorter

java.lang.Object
  com.vaadin.data.util.DefaultItemSorter

All Implemented Interfaces:

ItemSorter, Serializable, Cloneable, Comparator<Object>

public class DefaultItemSorter
extends Object
implements ItemSorter

Provides a default implementation of an ItemSorter. The DefaultItemSorter adheres to the Container.Sortable.sort(Object[], boolean[]) rules and sorts the container according to the properties given using #setSortProperties(Sortable, Object[], boolean[]).

A Comparator is used for comparing the individual Property values. The comparator can be set using the constructor. If no comparator is provided a default comparator is used.

See Also:

Serialized Form

Nested Class Summary

static class

DefaultItemSorter.DefaultPropertyValueComparator Provides a default comparator used for comparing Property values.

Constructor Summary

DefaultItemSorter()
Constructs a DefaultItemSorter using the default Comparator for comparing Propertyvalues.

DefaultItemSorter(Comparator<Object> propertyValueComparator)
Constructs a DefaultItemSorter which uses the Comparator indicated by the propertyValueComparator parameter for comparing Propertyvalues.

Method Summary

int	compare(Object o1, Object o2) Compares its two arguments for order.
protected int	compareProperty(Object propertyId, boolean sortDirection, Item item1, Item item2) Compares the property indicated by propertyId in the items indicated by item1 and item2 for order.
void	setSortProperties(Container.Sortable container, Object[] propertyId, boolean[] ascending) Sets the parameters for an upcoming sort operation.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

DefaultItemSorter

public DefaultItemSorter()

Constructs a DefaultItemSorter using the default Comparator for comparing Propertyvalues.

DefaultItemSorter

public DefaultItemSorter(Comparator<Object> propertyValueComparator)

Constructs a DefaultItemSorter which uses the Comparator indicated by the propertyValueComparator parameter for comparing Propertyvalues.

Parameters:

propertyValueComparator - The comparator to use when comparing individual Property values

Method Detail

compare

public int compare(Object o1,
                   Object o2)

Description copied from interface: ItemSorter

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

The parameters for the ItemSorter compare() method must always be item ids which exist in the container set using #setSortProperties(Sortable, Object[], boolean[]).

Specified by:

compare in interface ItemSorter

Specified by:

compare in interface Comparator<Object>

See Also:

Comparator.compare(Object, Object)

compareProperty

protected int compareProperty(Object propertyId,
                              boolean sortDirection,
                              Item item1,
                              Item item2)

Compares the property indicated by propertyId in the items indicated by item1 and item2 for order. Returns a negative integer, zero, or a positive integer as the property value in the first item is less than, equal to, or greater than the property value in the second item. If the sortDirection is false the returned value is negated.

The comparator set for this DefaultItemSorter is used for comparing the two property values.

Parameters:

propertyId - The property id for the property that is used for comparison.

sortDirection - The direction of the sort. A false value negates the result.

item1 - The first item to compare.

item2 - The second item to compare.

Returns:

a negative, zero, or positive integer if the property value in the first item is less than, equal to, or greater than the property value in the second item. Negated if sortDirection is false.

setSortProperties

public void setSortProperties(Container.Sortable container,
                              Object[] propertyId,
                              boolean[] ascending)

Description copied from interface: ItemSorter

Sets the parameters for an upcoming sort operation. The parameters determine what container to sort and how the ItemSorter sorts the container.

Specified by:

setSortProperties in interface ItemSorter

Parameters:

container - The container that will be sorted. The container must contain the propertyIds given in the propertyId parameter.

propertyId - The property ids used for sorting. The property ids must exist in the container and should only be used if they are also sortable, i.e include in the collection returned by container.getSortableContainerPropertyIds(). See Container.Sortable.sort(Object[], boolean[]) for more information.

ascending - Sorting order flags for each property id. See Container.Sortable.sort(Object[], boolean[]) for more information.