ListExpression (JavaFX 27)
Description: declaration: module: javafx.base, package: javafx.beans.binding, class: ListExpression

# Class ListExpression<E>

java.lang.Object
javafx.beans.binding.ListExpression<E>

Type Parameters:
  `E` - the type of the `List` elements.

All Implemented Interfaces:
  `Iterable<E>, Collection<E>, List<E>, SequencedCollection<E>, Observable, ObservableListValue<E>, ObservableObjectValue<ObservableList<E>>, ObservableValue<ObservableList<E>>, ObservableList<E>`

Direct Known Subclasses:
  `ListBinding, ReadOnlyListProperty`

public abstract class ListExpression<E> extends Object implements ObservableListValue<E>
`ListExpression` is an `ObservableListValue` plus additional convenience methods to generate bindings in a fluent style.

A concrete sub-class of `ListExpression` has to implement the method `ObservableObjectValue.get()`, which provides the actual value of this expression.

If the wrapped list of a `ListExpression` is `null`, all methods implementing the `List` interface will behave as if they were applied to an immutable empty list.

Since:
  JavaFX 2.1

- ## Property Summary

  Properties
  Type
  Property
  Description
  `abstract ReadOnlyBooleanProperty`
  `empty`
  A boolean property that is `true`, if the list is empty.
  `abstract ReadOnlyIntegerProperty`
  `size`
  An integer property that represents the size of the list.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ListExpression()`
  Creates a default `ListExpression`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `add(int i, E element)`
  `boolean`
  `add(E element)`
  `boolean`
  `addAll(int i, Collection<? extends E> elements)`
  `boolean`
  `addAll(E... elements)`
  A convenience method for var-arg addition of elements.
  `boolean`
  `addAll(Collection<? extends E> elements)`
  `StringBinding`
  `asString()`
  Creates a `StringBinding` that holds the value of the `ListExpression` turned into a `String`.
  `void`
  `clear()`
  `boolean`
  `contains(Object obj)`
  `boolean`
  `containsAll(Collection<?> objects)`
  `abstract ReadOnlyBooleanProperty`
  `emptyProperty()`
  A boolean property that is `true`, if the list is empty.
  `E`
  `get(int i)`
  `int`
  `getSize()`
  The size of the list
  `ObservableList<E>`
  `getValue()`
  Returns the current value of this `ObservableValue`
  `int`
  `indexOf(Object obj)`
  `boolean`
  `isEmpty()`
  Gets the value of the `empty` property.
  `BooleanBinding`
  `isEqualTo(ObservableList<?> other)`
  Creates a new `BooleanBinding` that holds `true` if this list is equal to another `ObservableList`.
  `BooleanBinding`
  `isNotEqualTo(ObservableList<?> other)`
  Creates a new `BooleanBinding` that holds `true` if this list is not equal to another `ObservableList`.
  `BooleanBinding`
  `isNotNull()`
  Creates a new `BooleanBinding` that holds `true` if the wrapped list is not `null`.
  `BooleanBinding`
  `isNull()`
  Creates a new `BooleanBinding` that holds `true` if the wrapped list is `null`.
  `Iterator<E>`
  `iterator()`
  `int`
  `lastIndexOf(Object obj)`
  `static <E> ListExpression<E>`
  `listExpression(ObservableListValue<E> value)`
  Returns a `ListExpression` that wraps a `ObservableListValue`.
  `ListIterator<E>`
  `listIterator()`
  `ListIterator<E>`
  `listIterator(int i)`
  `E`
  `remove(int i)`
  `void`
  `remove(int from, int to)`
  A simplified way of calling `sublist(from, to).clear()`.
  `boolean`
  `remove(Object obj)`
  `boolean`
  `removeAll(E... elements)`
  A convenience method for var-arg usage of the `removeAll` method.
  `boolean`
  `removeAll(Collection<?> objects)`
  `boolean`
  `retainAll(E... elements)`
  A convenience method for var-arg usage of the `retainAll` method.
  `boolean`
  `retainAll(Collection<?> objects)`
  `E`
  `set(int i, E element)`
  `boolean`
  `setAll(E... elements)`
  Clears the ObservableList and adds all the elements passed as var-args.
  `boolean`
  `setAll(Collection<? extends E> elements)`
  Clears the ObservableList and adds all elements from the collection.
  `int`
  `size()`
  `abstract ReadOnlyIntegerProperty`
  `sizeProperty()`
  An integer property that represents the size of the list.
  `List<E>`
  `subList(int from, int to)`
  `Object[]`
  `toArray()`
  `<T> T[]`
  `toArray(T[] array)`
  `ObjectBinding<E>`
  `valueAt(int index)`
  Creates a new `ObjectBinding` that contains the element at the specified position.
  `ObjectBinding<E>`
  `valueAt(ObservableIntegerValue index)`
  Creates a new `ObjectBinding` that contains the element at the specified position.

  ### Methods declared in class Object

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

  ### Methods declared in interface Collection

  `parallelStream, removeIf, stream, toArray`

  ### Methods declared in interface Iterable

  `forEach`

  ### Methods declared in interface List

  `addFirst, addLast, equals, getFirst, getLast, hashCode, removeFirst, removeLast, replaceAll, reversed, sort, spliterator`

  ### Methods declared in interface Observable

  `addListener, removeListener, subscribe`

  ### Methods declared in interface ObservableList

  `addListener, filtered, removeListener, replaceRange, sorted, sorted`

  ### Methods declared in interface ObservableObjectValue

  `get`

  ### Methods declared in interface ObservableValue

  `addListener, flatMap, map, orElse, removeListener, subscribe, subscribe, when`

- ## Property Details

  - ### size

    public abstract ReadOnlyIntegerProperty sizeProperty
    An integer property that represents the size of the list.
    See Also:
      - `getSize()`
      - `sizeProperty()`

  - ### empty

    public abstract ReadOnlyBooleanProperty emptyProperty
    A boolean property that is `true`, if the list is empty.
    See Also:
      - `isEmpty()`
      - `emptyProperty()`

- ## Constructor Details

  - ### ListExpression

    public ListExpression()
    Creates a default `ListExpression`.

- ## Method Details

  - ### getValue

    public ObservableList<E> getValue()
    Description copied from interface: `ObservableValue`
    Returns the current value of this `ObservableValue`
    Specified by:
      `getValue` in interface `ObservableValue<E>`
    Returns:
      The current value

  - ### listExpression

    public static <E> ListExpression<E> listExpression(ObservableListValue<E> value)
    Returns a `ListExpression` that wraps a `ObservableListValue`. If the `ObservableListValue` is already a `ListExpression`, it will be returned. Otherwise a new `ListBinding` is created that is bound to the `ObservableListValue`.
    Type Parameters:
      `E` - the type of the wrapped `List`
    Parameters:
      `value` - The source `ObservableListValue`
    Returns:
      A `ListExpression` that wraps the `ObservableListValue` if necessary
    Throws:
      `NullPointerException` - if `value` is `null`

  - ### getSize

    public int getSize()
    The size of the list
    Returns:
      the size

  - ### sizeProperty

    public abstract ReadOnlyIntegerProperty sizeProperty()
    An integer property that represents the size of the list.
    Returns:
      the property
    See Also:
      - `getSize()`

  - ### emptyProperty

    public abstract ReadOnlyBooleanProperty emptyProperty()
    A boolean property that is `true`, if the list is empty.
    Returns:
      the `ReadOnlyBooleanProperty`
    See Also:
      - `isEmpty()`

  - ### valueAt

    public ObjectBinding<E> valueAt(int index)
    Creates a new `ObjectBinding` that contains the element at the specified position. If `index` points behind the list, the `ObjectBinding` contains `null`.
    Parameters:
      `index` - the index of the element
    Returns:
      the `ObjectBinding`
    Throws:
      `IllegalArgumentException` - if `index < 0`

  - ### valueAt

    public ObjectBinding<E> valueAt(ObservableIntegerValue index)
    Creates a new `ObjectBinding` that contains the element at the specified position. If `index` points outside of the list, the `ObjectBinding` contains `null`.
    Parameters:
      `index` - the index of the element
    Returns:
      the `ObjectBinding`
    Throws:
      `NullPointerException` - if `index` is `null`

  - ### isEqualTo

    public BooleanBinding isEqualTo(ObservableList<?> other)
    Creates a new `BooleanBinding` that holds `true` if this list is equal to another `ObservableList`.
    Parameters:
      `other` - the other `ObservableList`
    Returns:
      the new `BooleanBinding`
    Throws:
      `NullPointerException` - if `other` is `null`

  - ### isNotEqualTo

    public BooleanBinding isNotEqualTo(ObservableList<?> other)
    Creates a new `BooleanBinding` that holds `true` if this list is not equal to another `ObservableList`.
    Parameters:
      `other` - the other `ObservableList`
    Returns:
      the new `BooleanBinding`
    Throws:
      `NullPointerException` - if `other` is `null`

  - ### isNull

    public BooleanBinding isNull()
    Creates a new `BooleanBinding` that holds `true` if the wrapped list is `null`.
    Returns:
      the new `BooleanBinding`

  - ### isNotNull

    public BooleanBinding isNotNull()
    Creates a new `BooleanBinding` that holds `true` if the wrapped list is not `null`.
    Returns:
      the new `BooleanBinding`

  - ### asString

    public StringBinding asString()
    Creates a `StringBinding` that holds the value of the `ListExpression` turned into a `String`. If the value of this `ListExpression` changes, the value of the `StringBinding` will be updated automatically.
    Returns:
      the new `StringBinding`

  - ### size

    public int size()
    Specified by:
      `size` in interface `Collection<E>`
    Specified by:
      `size` in interface `List<E>`

  - ### isEmpty

    public boolean isEmpty()
    Gets the value of the `empty` property.
    Specified by:
      `isEmpty` in interface `Collection<E>`
    Specified by:
      `isEmpty` in interface `List<E>`
    Property description:
      A boolean property that is `true`, if the list is empty.
    Returns:
      the value of the `empty` property
    See Also:
      - `emptyProperty()`

  - ### contains

    public boolean contains(Object obj)
    Specified by:
      `contains` in interface `Collection<E>`
    Specified by:
      `contains` in interface `List<E>`

  - ### iterator

    public Iterator<E> iterator()
    Specified by:
      `iterator` in interface `Collection<E>`
    Specified by:
      `iterator` in interface `Iterable<E>`
    Specified by:
      `iterator` in interface `List<E>`

  - ### toArray

    public Object[] toArray()
    Specified by:
      `toArray` in interface `Collection<E>`
    Specified by:
      `toArray` in interface `List<E>`

  - ### toArray

    public <T> T[] toArray(T[] array)
    Specified by:
      `toArray` in interface `Collection<E>`
    Specified by:
      `toArray` in interface `List<E>`

  - ### add

    public boolean add(E element)
    Specified by:
      `add` in interface `Collection<E>`
    Specified by:
      `add` in interface `List<E>`

  - ### remove

    public boolean remove(Object obj)
    Specified by:
      `remove` in interface `Collection<E>`
    Specified by:
      `remove` in interface `List<E>`

  - ### containsAll

    public boolean containsAll(Collection<?> objects)
    Specified by:
      `containsAll` in interface `Collection<E>`
    Specified by:
      `containsAll` in interface `List<E>`

  - ### addAll

    public boolean addAll(Collection<? extends E> elements)
    Specified by:
      `addAll` in interface `Collection<E>`
    Specified by:
      `addAll` in interface `List<E>`

  - ### addAll

    public boolean addAll(int i, Collection<? extends E> elements)
    Specified by:
      `addAll` in interface `List<E>`

  - ### removeAll

    public boolean removeAll(Collection<?> objects)
    Specified by:
      `removeAll` in interface `Collection<E>`
    Specified by:
      `removeAll` in interface `List<E>`

  - ### retainAll

    public boolean retainAll(Collection<?> objects)
    Specified by:
      `retainAll` in interface `Collection<E>`
    Specified by:
      `retainAll` in interface `List<E>`

  - ### clear

    public void clear()
    Specified by:
      `clear` in interface `Collection<E>`
    Specified by:
      `clear` in interface `List<E>`

  - ### get

    public E get(int i)
    Specified by:
      `get` in interface `List<E>`

  - ### set

    public E set(int i, E element)
    Specified by:
      `set` in interface `List<E>`

  - ### add

    public void add(int i, E element)
    Specified by:
      `add` in interface `List<E>`

  - ### remove

    public E remove(int i)
    Specified by:
      `remove` in interface `List<E>`

  - ### indexOf

    public int indexOf(Object obj)
    Specified by:
      `indexOf` in interface `List<E>`

  - ### lastIndexOf

    public int lastIndexOf(Object obj)
    Specified by:
      `lastIndexOf` in interface `List<E>`

  - ### listIterator

    public ListIterator<E> listIterator()
    Specified by:
      `listIterator` in interface `List<E>`

  - ### listIterator

    public ListIterator<E> listIterator(int i)
    Specified by:
      `listIterator` in interface `List<E>`

  - ### subList

    public List<E> subList(int from, int to)
    Specified by:
      `subList` in interface `List<E>`

  - ### addAll

    public boolean addAll(E... elements)
    Description copied from interface: `ObservableList`
    A convenience method for var-arg addition of elements.
    Specified by:
      `addAll` in interface `ObservableList<E>`
    Parameters:
      `elements` - the elements to add
    Returns:
      true (as specified by Collection.add(E))

  - ### setAll

    public boolean setAll(E... elements)
    Description copied from interface: `ObservableList`
    Clears the ObservableList and adds all the elements passed as var-args.
    Specified by:
      `setAll` in interface `ObservableList<E>`
    Parameters:
      `elements` - the elements to set
    Returns:
      true (as specified by Collection.add(E))

  - ### setAll

    public boolean setAll(Collection<? extends E> elements)
    Description copied from interface: `ObservableList`
    Clears the ObservableList and adds all elements from the collection.
    Specified by:
      `setAll` in interface `ObservableList<E>`
    Parameters:
      `elements` - the collection with elements that will be added to this observableArrayList
    Returns:
      true (as specified by Collection.add(E))

  - ### removeAll

    public boolean removeAll(E... elements)
    Description copied from interface: `ObservableList`
    A convenience method for var-arg usage of the `removeAll` method.
    Specified by:
      `removeAll` in interface `ObservableList<E>`
    Parameters:
      `elements` - the elements to be removed
    Returns:
      true if list changed as a result of this call

  - ### retainAll

    public boolean retainAll(E... elements)
    Description copied from interface: `ObservableList`
    A convenience method for var-arg usage of the `retainAll` method.
    Specified by:
      `retainAll` in interface `ObservableList<E>`
    Parameters:
      `elements` - the elements to be retained
    Returns:
      true if list changed as a result of this call

  - ### remove

    public void remove(int from, int to)
    Description copied from interface: `ObservableList`
    A simplified way of calling `sublist(from, to).clear()`. As this is a common operation, ObservableList has this method for convenient usage.
    Specified by:
      `remove` in interface `ObservableList<E>`
    Parameters:
      `from` - the start of the range to remove (inclusive)
      `to` - the end of the range to remove (exclusive)