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

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and 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.List

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

    - ### Methods inherited from interface java.util.Collection

      `parallelStream, removeIf, stream`

    - ### Methods inherited from interface java.lang.Iterable

      `forEach`

- - ### 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.

Copyright © 2001–2021 Apache Cayenne. All rights reserved.