SetExpression (JavaFX 17)

Module javafx.base
Package javafx.beans.binding

## Class SetExpression<E>

- java.lang.Object
- - javafx.beans.binding.SetExpression<E>

- Type Parameters:
    `E` - the type of the `Set` elements
  All Implemented Interfaces:
    `Iterable<E>`, `Collection<E>`, `Set<E>`, `Observable`, `ObservableObjectValue<ObservableSet<E>>`, `ObservableSetValue<E>`, `ObservableValue<ObservableSet<E>>`, `ObservableSet<E>`
  Direct Known Subclasses:
    `ReadOnlySetProperty`, `SetBinding`

      public abstract class SetExpression<E>
      extends Object
      implements ObservableSetValue<E>

  `SetExpression` is an `ObservableSetValue` plus additional convenience methods to generate bindings in a fluent style.

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

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

  Since:
    JavaFX 2.1

- - ### Property Summary

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

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `SetExpression()` | Creates a default `SetExpression`.

  - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `StringBinding` | `asString()` | Creates a `StringBinding` that holds the value of the `SetExpression` turned into a `String`.
    `abstract ReadOnlyBooleanProperty` | `emptyProperty()` | A boolean property that is `true`, if the set is empty.
    `int` | `getSize()` | The size of the set
    `BooleanBinding` | `isEqualTo​(ObservableSet<?> other)` | Creates a new `BooleanBinding` that holds `true` if this set is equal to another `ObservableSet`.
    `BooleanBinding` | `isNotEqualTo​(ObservableSet<?> other)` | Creates a new `BooleanBinding` that holds `true` if this set is not equal to another `ObservableSet`.
    `BooleanBinding` | `isNotNull()` | Creates a new `BooleanBinding` that holds `true` if the wrapped set is not `null`.
    `BooleanBinding` | `isNull()` | Creates a new `BooleanBinding` that holds `true` if the wrapped set is `null`.
    `static <E> SetExpression<E>` | `setExpression​(ObservableSetValue<E> value)` | Returns a `SetExpression` that wraps a `ObservableSetValue`.
    `abstract ReadOnlyIntegerProperty` | `sizeProperty()` | An integer property that represents the size of the set.

    - ### Methods declared in class java.lang.Object

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

    - ### Methods declared in interface java.util.Collection

      `parallelStream, removeIf, stream, toArray`

    - ### Methods declared in interface java.lang.Iterable

      `forEach`

    - ### Methods declared in interface javafx.beans.Observable

      `addListener, removeListener`

    - ### Methods declared in interface javafx.beans.value.ObservableObjectValue

      `get`

    - ### Methods declared in interface javafx.collections.ObservableSet

      `addListener, removeListener`

    - ### Methods declared in interface javafx.beans.value.ObservableValue

      `addListener, getValue, removeListener`

    - ### Methods declared in interface java.util.Set

      `add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, spliterator, toArray, toArray`

- - ### Property Detail

    - #### size

          public abstract ReadOnlyIntegerProperty sizeProperty

      An integer property that represents the size of the set.
      See Also:
        `getSize()`

    - #### empty

          public abstract ReadOnlyBooleanProperty emptyProperty

      A boolean property that is `true`, if the set is empty.
      See Also:
        `Set.isEmpty()`

  - ### Constructor Detail

    - #### SetExpression

          public SetExpression()

      Creates a default `SetExpression`.

  - ### Method Detail

    - #### setExpression

          public static <E> SetExpression<E> setExpression​(ObservableSetValue<E> value)

      Returns a `SetExpression` that wraps a `ObservableSetValue`. If the `ObservableSetValue` is already a `SetExpression`, it will be returned. Otherwise a new `SetBinding` is created that is bound to the `ObservableSetValue`.
      Type Parameters:
        `E` - the type of the `Set` elements
      Parameters:
        `value` - The source `ObservableSetValue`
      Returns:
        A `SetExpression` that wraps the `ObservableSetValue` if necessary
      Throws:
        `NullPointerException` - if `value` is `null`

    - #### getSize

          public int getSize()

      The size of the set
      Returns:
        the size

    - #### sizeProperty

          public abstract ReadOnlyIntegerProperty sizeProperty()

      An integer property that represents the size of the set.
      See Also:
        `getSize()`

    - #### emptyProperty

          public abstract ReadOnlyBooleanProperty emptyProperty()

      A boolean property that is `true`, if the set is empty.
      See Also:
        `Set.isEmpty()`

    - #### isEqualTo

          public BooleanBinding isEqualTo​(ObservableSet<?> other)

      Creates a new `BooleanBinding` that holds `true` if this set is equal to another `ObservableSet`.
      Parameters:
        `other` - the other `ObservableSet`
      Returns:
        the new `BooleanBinding`
      Throws:
        `NullPointerException` - if `other` is `null`

    - #### isNotEqualTo

          public BooleanBinding isNotEqualTo​(ObservableSet<?> other)

      Creates a new `BooleanBinding` that holds `true` if this set is not equal to another `ObservableSet`.
      Parameters:
        `other` - the other `ObservableSet`
      Returns:
        the new `BooleanBinding`
      Throws:
        `NullPointerException` - if `other` is `null`

    - #### isNull

          public BooleanBinding isNull()

      Creates a new `BooleanBinding` that holds `true` if the wrapped set is `null`.
      Returns:
        the new `BooleanBinding`

    - #### isNotNull

          public BooleanBinding isNotNull()

      Creates a new `BooleanBinding` that holds `true` if the wrapped set is not `null`.
      Returns:
        the new `BooleanBinding`

    - #### asString

          public StringBinding asString()

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