Package org.apache.cayenne.util

Class IndexPropertyList

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList

org.apache.cayenne.util.IndexPropertyList

All Implemented Interfaces:

Serializable, Iterable, Collection, List, ValueHolder

public class IndexPropertyList
extends AbstractList
implements ValueHolder

A List implementation that would maintain its internal ordering based on some object numeric "index" property. When objects are added to the list at a certain index, an "index" property is modified to reflect list order, when objects are removed, their index property is set to the negative number.

For performance reasons this implementation does not guarantee that there is no gaps in the integer ordering sequence (i.e. generally object.getIndexProperty() != list.indexOf(object)). However it guarantees the right ordering based on index property.

Since:

1.2

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected String	indexProperty
protected List	list	A list used for the actual objects storage.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
IndexPropertyList(String indexProperty)	Creates an empty NumericPropertyOrderedList.
IndexPropertyList(String indexProperty, List objects, boolean sortNeeded)	Creates a NumericPropertyOrderedList that decorates another list.

Method Summary

Modifier and Type	Method	Description
void	add(int index, Object element)
protected int	calculateIndexValue(int listIndex)	Calculates an index value at the specified list index.
Object	get(int index)
protected int	getIndexValue(Object object)
Object	getValue()	Returns an object stored by this ValueHolder.
Object	getValueDirectly()	Retrieves ValueHolder value without triggering fault resolution.
void	invalidate()	Turns a ValueHolder into a fault.
boolean	isFault()	Returns true if the internal value is not yet resolved.
Object	remove(int index)
Object	set(int index, Object element)
protected void	setIndexValue(Object object, int index)
Object	setValue(Object value)	Sets an object stored by this ValueHolder.
Object	setValueDirectly(Object value)	Sets ValueHolder vaue without triggering fault resolution.
protected void	shift(int startIndex, int afterIndexValue)
int	size()
protected void	sort()	Sorts internal list.
void	touch()	Changes list state to "dirty" forcing reordering on next access.

Methods inherited from class java.util.AbstractList

add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

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

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

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Field Detail

list

protected List list

A list used for the actual objects storage.

indexProperty

protected String indexProperty

Constructor Detail

IndexPropertyList

public IndexPropertyList(String indexProperty)

Creates an empty NumericPropertyOrderedList.

IndexPropertyList

public IndexPropertyList(String indexProperty,
                         List objects,
                         boolean sortNeeded)

Creates a NumericPropertyOrderedList that decorates another list. If the list is not known to be properly sorted, caller must set sortNeeded to true. This will result in sorting the original list on first access attempt.

Method Detail

isFault

public boolean isFault()

Description copied from interface: ValueHolder

Returns true if the internal value is not yet resolved.

Specified by:

isFault in interface ValueHolder

setValueDirectly

public Object setValueDirectly(Object value)
                        throws CayenneRuntimeException

Description copied from interface: ValueHolder

Sets ValueHolder vaue without triggering fault resolution.

Specified by:

setValueDirectly in interface ValueHolder

Throws:

CayenneRuntimeException

setValue

public Object setValue(Object value)
                throws CayenneRuntimeException

Description copied from interface: ValueHolder

Sets an object stored by this ValueHolder.

Specified by:

setValue in interface ValueHolder

Parameters:

value - a new value of the ValueHolder.

Returns:

a previous value saved in the ValueHolder.

Throws:

CayenneRuntimeException

getValue

public Object getValue()
                throws CayenneRuntimeException

Description copied from interface: ValueHolder

Returns an object stored by this ValueHolder.

Specified by:

getValue in interface ValueHolder

Throws:

CayenneRuntimeException

getValueDirectly

public Object getValueDirectly()
                        throws CayenneRuntimeException

Description copied from interface: ValueHolder

Retrieves ValueHolder value without triggering fault resolution.

Specified by:

getValueDirectly in interface ValueHolder

Throws:

CayenneRuntimeException

invalidate

public void invalidate()

Description copied from interface: ValueHolder

Turns a ValueHolder into a fault.

Specified by:

invalidate in interface ValueHolder

touch

public void touch()

Changes list state to "dirty" forcing reordering on next access.

get

public Object get(int index)

Specified by:

get in interface List

Specified by:

get in class AbstractList

size

public int size()

Specified by:

size in interface Collection

Specified by:

size in interface List

Specified by:

size in class AbstractCollection

set

public Object set(int index,
                  Object element)

Specified by:

set in interface List

Overrides:

set in class AbstractList

add

public void add(int index,
                Object element)

Specified by:

add in interface List

Overrides:

add in class AbstractList

remove

public Object remove(int index)

Specified by:

remove in interface List

Overrides:

remove in class AbstractList

calculateIndexValue

protected int calculateIndexValue(int listIndex)

Calculates an index value at the specified list index. Note that using this value may require a shift of the objects following this index.

getIndexValue

protected int getIndexValue(Object object)

setIndexValue

protected void setIndexValue(Object object,
                             int index)

shift

protected void shift(int startIndex,
                     int afterIndexValue)

sort

protected void sort()

Sorts internal list.