Module javafx.base
Package javafx.beans.binding

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>, 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 Details

  • Constructor Details

    • ListExpression

      public ListExpression()
      Creates a default ListExpression.

  • Method Details

    • 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.
      See Also:
      getSize()

    • emptyProperty

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