org.eclipse.emf.validation.util
Class FilteredCollection<E>

java.lang.Object
  java.util.AbstractCollection<E>
      org.eclipse.emf.validation.util.FilteredCollection<E>

Type Parameters:

E - the collection element type

All Implemented Interfaces:

Iterable<E>, Collection<E>

public class FilteredCollection<E>
extends AbstractCollection<E>

Wrapper for a Java 2 Collection that provides a filtered view of its contents according to a client-specified filter algorithm.

Nested Class Summary

static interface

FilteredCollection.Filter<E> Interface for the algorithm that determines which elements are in and which are out of the filtered collection.

Constructor Summary

FilteredCollection(Collection<? extends E> collection, FilteredCollection.Filter<? super E> filter)
Initializes me to filter the specified collection, obtained independently.

Method Summary

FilteredCollection.Filter<? super E>	getFilter() Retrieves the filter with which I was initialized.
Iterator<E>	iterator() Obtains an iterator that dynamically filters out unwanted items using my filter algorithm.
int	size() Computes the size of the filtered view, i.e.

Methods inherited from class java.util.AbstractCollection

add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

FilteredCollection

public FilteredCollection(Collection<? extends E> collection,
                          FilteredCollection.Filter<? super E> filter)

Initializes me to filter the specified collection, obtained independently.

Note that it is a very bad idea to modify the wrapped collection after creating this filtered view on it. The results are undefined, but probably not what you want.

Parameters:

collection - the collection that I am to filter

filter - the filter algorithm to apply

Method Detail

getFilter

public final FilteredCollection.Filter<? super E> getFilter()

Retrieves the filter with which I was initialized. Note that the result of modifying this filter's algorithm while I am using it is undefined, but not likely to be what you want.

Returns:

my filter

iterator

public Iterator<E> iterator()

Obtains an iterator that dynamically filters out unwanted items using my filter algorithm.

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in class AbstractCollection<E>

Returns:

an iterator the exposes only the elements of my wrapped collection that match my filter

size

public int size()

Computes the size of the filtered view, i.e. the number of elements in the original collection that match my filter, by iterating myself.

Note that my size is recounted every time that it is requested, in case my filter's algorithm is changed or the contents of the underlying collection are changed.

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>

Returns:

the number of elements in my wrapped collection that match my filter