Module javafx.base
Package javafx.beans.property

Class DoubleProperty

java.lang.Object
javafx.beans.binding.NumberExpressionBase
javafx.beans.binding.DoubleExpression
javafx.beans.property.ReadOnlyDoubleProperty
javafx.beans.property.DoubleProperty
All Implemented Interfaces:
NumberExpression, Observable, Property<Number>, ReadOnlyProperty<Number>, ObservableDoubleValue, ObservableNumberValue, ObservableValue<Number>, WritableDoubleValue, WritableNumberValue, WritableValue<Number>
Direct Known Subclasses:
DoublePropertyBase, JavaBeanDoubleProperty
public abstract class DoubleProperty
extends ReadOnlyDoubleProperty
implements Property<Number>, WritableDoubleValue
This class defines a Property wrapping a double value.

The value of a DoubleProperty can be get and set with ObservableDoubleValue.get(), DoubleExpression.getValue(), WritableDoubleValue.set(double), and setValue(Number).

A property can be bound and unbound unidirectional with Property.bind(ObservableValue) and Property.unbind(). Bidirectional bindings can be created and removed with bindBidirectional(Property) and unbindBidirectional(Property).

The context of a DoubleProperty can be read with ReadOnlyProperty.getBean() and ReadOnlyProperty.getName().

Note: setting or binding this property to a null value will set the property to "0.0". See setValue(java.lang.Number).

Since:
JavaFX 2.0
See Also:
ObservableDoubleValue, WritableDoubleValue, ReadOnlyDoubleProperty, Property

  • Constructor Details

  • Method Details

    • setValue

      public void setValue​(Number v)
      Set the wrapped value.
      Specified by:
      setValue in interface WritableDoubleValue
      Specified by:
      setValue in interface WritableValue<Number>
      Parameters:
      v - The new value

    • bindBidirectional

      public void bindBidirectional​(Property<Number> other)
      Create a bidirectional binding between this Property and another one. Bidirectional bindings exists independently of unidirectional bindings. So it is possible to add unidirectional binding to a property with bidirectional binding and vice-versa. However, this practice is discouraged.

      It is possible to have multiple bidirectional bindings of one Property.

      JavaFX bidirectional binding implementation use weak listeners. This means bidirectional binding does not prevent properties from being garbage collected.

      Specified by:
      bindBidirectional in interface Property<Number>
      Parameters:
      other - the other Property

    • unbindBidirectional

      public void unbindBidirectional​(Property<Number> other)
      Remove a bidirectional binding between this Property and another one. If no bidirectional binding between the properties exists, calling this method has no effect. It is possible to unbind by a call on the second property. This code will work: 
           property1.bindBirectional(property2);
     property2.unbindBidirectional(property1);
      Specified by:
      unbindBidirectional in interface Property<Number>
      Parameters:
      other - the other Property

    • toString

      public String toString()
      Returns a string representation of this DoubleProperty object.
      Overrides:
      toString in class ReadOnlyDoubleProperty
      Returns:
      a string representation of this DoubleProperty object.

    • doubleProperty

      public static DoubleProperty doubleProperty​(Property<Double> property)
      Returns a DoubleProperty that wraps a Property and is bidirectionally bound to it. Changing this property will result in a change of the original property.

      This is very useful when bidirectionally binding an ObjectProperty<Double> and a DoubleProperty. 

         DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0);
   ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0);

   // Need to keep the reference as bidirectional binding uses weak references
   DoubleProperty objectAsDouble = DoubleProperty.doubleProperty(objectProperty);

   doubleProperty.bindBidirectional(objectAsDouble);
      Another approach is to convert the DoubleProperty to ObjectProperty using asObject() method.

      Note: null values in the source property will be interpreted as 0.0

      Parameters:
      property - The source Property
      Returns:
      A DoubleProperty that wraps the Property
      Throws:
      NullPointerException - if property is null
      Since:
      JavaFX 8.0
      See Also:
      asObject()

    • asObject

      public ObjectProperty<Double> asObject()
      Creates an ObjectProperty that bidirectionally bound to this DoubleProperty. If the value of this DoubleProperty changes, the value of the ObjectProperty will be updated automatically and vice-versa.

      Can be used for binding an ObjectProperty to DoubleProperty. 

         DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0);
   ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0);

   objectProperty.bind(doubleProperty.asObject());
      Overrides:
      asObject in class ReadOnlyDoubleProperty
      Returns:
      the new ObjectProperty
      Since:
      JavaFX 8.0