Package com.google.common.collect

Class AbstractMapBasedMultimap.WrappedCollection

java.lang.Object

java.util.AbstractCollection<V>

com.google.common.collect.AbstractMapBasedMultimap.WrappedCollection

All Implemented Interfaces:

java.lang.Iterable<V>, java.util.Collection<V>

Direct Known Subclasses:

AbstractMapBasedMultimap.WrappedList, AbstractMapBasedMultimap.WrappedSet, AbstractMapBasedMultimap.WrappedSortedSet

Enclosing class:

AbstractMapBasedMultimap<K,V>

class AbstractMapBasedMultimap.WrappedCollection
extends java.util.AbstractCollection<V>

Collection decorator that stays in sync with the multimap values for a key. There are two kinds of wrapped collections: full and subcollections. Both have a delegate pointing to the underlying collection class.

Full collections, identified by a null ancestor field, contain all multimap values for a given key. Its delegate is a value in AbstractMapBasedMultimap.map whenever the delegate is non-empty. The refreshIfEmpty, removeIfEmpty, and addToMap methods ensure that the WrappedCollection and map remain consistent.

A subcollection, such as a sublist, contains some of the values for a given key. Its ancestor field points to the full wrapped collection with all values for the key. The subcollection refreshIfEmpty, removeIfEmpty, and addToMap methods call the corresponding methods of the full wrapped collection.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	AbstractMapBasedMultimap.WrappedCollection.WrappedIterator	Collection iterator for WrappedCollection.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) AbstractMapBasedMultimap.WrappedCollection	ancestor
(package private) java.util.Collection<V>	ancestorDelegate
(package private) java.util.Collection<V>	delegate
(package private) K	key

Constructor Summary

Constructors

Constructor	Description
WrappedCollection(K key, java.util.Collection<V> delegate, AbstractMapBasedMultimap.WrappedCollection ancestor)

Method Summary

Modifier and Type	Method	Description
boolean	add(V value)
boolean	addAll(java.util.Collection<? extends V> collection)
(package private) void	addToMap()	Add the delegate to the map.
void	clear()
boolean	contains(java.lang.Object o)
boolean	containsAll(java.util.Collection<?> c)
boolean	equals(java.lang.Object object)
(package private) AbstractMapBasedMultimap.WrappedCollection	getAncestor()
(package private) java.util.Collection<V>	getDelegate()
(package private) K	getKey()
int	hashCode()
java.util.Iterator<V>	iterator()
(package private) void	refreshIfEmpty()	If the delegate collection is empty, but the multimap has values for the key, replace the delegate with the new collection for the key.
boolean	remove(java.lang.Object o)
boolean	removeAll(java.util.Collection<?> c)
(package private) void	removeIfEmpty()	If collection is empty, remove it from AbstractMapBasedMultimap.this.map.
boolean	retainAll(java.util.Collection<?> c)
int	size()
java.util.Spliterator<V>	spliterator()
java.lang.String	toString()

Methods inherited from class java.util.AbstractCollection

isEmpty, toArray, toArray

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

key

final K key

delegate

java.util.Collection<V> delegate

ancestor

final AbstractMapBasedMultimap.WrappedCollection ancestor

ancestorDelegate

final java.util.Collection<V> ancestorDelegate

Constructor Detail

WrappedCollection

WrappedCollection(K key,
                  java.util.Collection<V> delegate,
                  AbstractMapBasedMultimap.WrappedCollection ancestor)

Method Detail

refreshIfEmpty

void refreshIfEmpty()

If the delegate collection is empty, but the multimap has values for the key, replace the delegate with the new collection for the key.

For a subcollection, refresh its ancestor and validate that the ancestor delegate hasn't changed.

removeIfEmpty

void removeIfEmpty()

If collection is empty, remove it from AbstractMapBasedMultimap.this.map. For subcollections, check whether the ancestor collection is empty.

getKey

K getKey()

addToMap

void addToMap()

Add the delegate to the map. Other WrappedCollection methods should call this method after adding elements to a previously empty collection.

Subcollection add the ancestor's delegate instead.

size

public int size()

Specified by:

size in interface java.util.Collection<V>

Specified by:

size in class java.util.AbstractCollection<V>

equals

public boolean equals(java.lang.Object object)

Specified by:

equals in interface java.util.Collection<V>

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Collection<V>

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractCollection<V>

getDelegate

java.util.Collection<V> getDelegate()

iterator

public java.util.Iterator<V> iterator()

Specified by:

iterator in interface java.util.Collection<V>

Specified by:

iterator in interface java.lang.Iterable<V>

Specified by:

iterator in class java.util.AbstractCollection<V>

spliterator

public java.util.Spliterator<V> spliterator()

add

public boolean add(V value)

Specified by:

add in interface java.util.Collection<V>

Overrides:

add in class java.util.AbstractCollection<V>

getAncestor

AbstractMapBasedMultimap.WrappedCollection getAncestor()

addAll

public boolean addAll(java.util.Collection<? extends V> collection)

Specified by:

addAll in interface java.util.Collection<V>

Overrides:

addAll in class java.util.AbstractCollection<V>

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection<V>

Overrides:

contains in class java.util.AbstractCollection<V>

containsAll

public boolean containsAll(java.util.Collection<?> c)

Specified by:

containsAll in interface java.util.Collection<V>

Overrides:

containsAll in class java.util.AbstractCollection<V>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<V>

Overrides:

clear in class java.util.AbstractCollection<V>

remove

public boolean remove(java.lang.Object o)

Specified by:

remove in interface java.util.Collection<V>

Overrides:

remove in class java.util.AbstractCollection<V>

removeAll

public boolean removeAll(java.util.Collection<?> c)

Specified by:

removeAll in interface java.util.Collection<V>

Overrides:

removeAll in class java.util.AbstractCollection<V>

retainAll

public boolean retainAll(java.util.Collection<?> c)

Specified by:

retainAll in interface java.util.Collection<V>

Overrides:

retainAll in class java.util.AbstractCollection<V>