Class PropertyHelper<S,V>

java.lang.Object
org.jdesktop.beansbinding.Property<S,V>
org.jdesktop.beansbinding.PropertyHelper<S,V>
Type Parameters:
S - the type of source object that this Property operates on
V - the type of value that this Property represents
Direct Known Subclasses:
BeanProperty, ELProperty
public abstract class PropertyHelper<S,V> extends Property<S,V>
An abstract subclass of Property that helps with the management of PropertyStateListeners by implementing the methods for adding, removing, and getting listeners. PropertyHelper can be constructed to manage listeners for multiple source objects, or to ignore the source object argument when dealing with listeners and associate them directly with the PropertyHelper instance itself. This makes PropertyHelper useful as a base for both property types described in the documentation for Property.

PropertyHelper also provides, by way of the protected methods listeningStarted(S) and listeningStopped(S) a hook for subclasses to know when it's time to start tracking changes to a particular source object.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PropertyHelper()
    Create a PropertyHelper that manages listeners for multiple source objects.
    PropertyHelper(boolean ignoresSource)
    Create a PropertyHelper, specifying whether it manages listeners for multiple source objects, or ignores the source object argument when dealing with listeners

  • Method Summary

    Modifier and Type
    Method
    Description
    final void
    addPropertyStateListener(S source, PropertyStateListener listener)
    Adds a PropertyStateListener to be notified when the state of the Property changes with respect to the given source.
    protected final void
    firePropertyStateChange(PropertyStateEvent pse)
    Notify listeners that the state of this property has changed, as characterized by the given PropertyStateEvent.
    final PropertyStateListener[]
    getPropertyStateListeners(S source)
    Returns an arry containing the listeners registered for the given source.
    abstract V
    getValue(S source)
    Returns the value of this Property for the given source.
    abstract Class<? extends V>
    getWriteType(S source)
    Returns the type of object that is suitable for setting as the value of this Property by calls to setValue.
    final boolean
    isListening(S source)
    Returns whether or not there are any PropertyStateListeners installed for the given source object.
    abstract boolean
    isReadable(S source)
    Returns whether or not the Property is readable for the given source.
    abstract boolean
    isWriteable(S source)
    Returns whether or not the Property is writeable for the given source.
    protected void
    listeningStarted(S source)
    Called when this PropertyHelper changes from having no listeners installed for the given source object to having listeners installed for the given source object.
    protected void
    listeningStopped(S source)
    Called when this PropertyHelper changes from having listeners installed for the given source object to having no listeners installed for the given source object.
    final void
    removePropertyStateListener(S source, PropertyStateListener listener)
    Removes a PropertyStateListener for the given source.
    abstract void
    setValue(S source, V value)
    Sets the value of this Property for the given source.

    Methods inherited from class Object

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

  • Constructor Details

    • PropertyHelper

      public PropertyHelper()
      Create a PropertyHelper that manages listeners for multiple source objects.

    • PropertyHelper

      public PropertyHelper(boolean ignoresSource)
      Create a PropertyHelper, specifying whether it manages listeners for multiple source objects, or ignores the source object argument when dealing with listeners
      Parameters:
      ignoresSource - whether or not the source argument is ignored when dealing with listeners

  • Method Details

    • getWriteType

      public abstract Class<? extends V> getWriteType(S source)
      Returns the type of object that is suitable for setting as the value of this Property by calls to setValue.
      Specified by:
      getWriteType in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      Returns:
      the type of object suitable for setting as the value
      Throws:
      UnsupportedOperationException - if the Property is not writeable for the given source
      See Also:

    • getValue

      public abstract V getValue(S source)
      Returns the value of this Property for the given source.
      Specified by:
      getValue in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      Returns:
      the value of this Property for the given source
      Throws:
      UnsupportedOperationException - if the Property is not readable for the given source
      See Also:

    • setValue

      public abstract void setValue(S source, V value)
      Sets the value of this Property for the given source.
      Specified by:
      setValue in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      value - the new value for the Property
      Throws:
      UnsupportedOperationException - if the Property is not writeable for the given source
      See Also:

    • isReadable

      public abstract boolean isReadable(S source)
      Returns whether or not the Property is readable for the given source.
      Specified by:
      isReadable in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      Returns:
      whether or not the Property is readable for the given source.
      See Also:

    • isWriteable

      public abstract boolean isWriteable(S source)
      Returns whether or not the Property is writeable for the given source.
      Specified by:
      isWriteable in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      Returns:
      whether or not the Property is writeable for the given source.
      See Also:

    • listeningStarted

      protected void listeningStarted(S source)
      Called when this PropertyHelper changes from having no listeners installed for the given source object to having listeners installed for the given source object. This is the ideal time for subclasses to install any listeners needed to track change on the source object.
      See Also:

    • listeningStopped

      protected void listeningStopped(S source)
      Called when this PropertyHelper changes from having listeners installed for the given source object to having no listeners installed for the given source object. This is the ideal time for subclasses to remove any listeners that they've installed to track changes on the source object.
      See Also:

    • addPropertyStateListener

      public final void addPropertyStateListener(S source, PropertyStateListener listener)
      Adds a PropertyStateListener to be notified when the state of the Property changes with respect to the given source. Does nothing if the listener is null. If a listener is added more than once, notifications are sent to that listener once for every time that it has been added. The ordering of listener notification is unspecified.
      Specified by:
      addPropertyStateListener in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      listener - the listener to be notified

    • removePropertyStateListener

      public final void removePropertyStateListener(S source, PropertyStateListener listener)
      Removes a PropertyStateListener for the given source. Does nothing if the listener is null or is not one of those registered for this source object. If the listener being removed was registered more than once, only one occurrence of the listener is removed from the list of listeners. The ordering of listener notification is unspecified.
      Specified by:
      removePropertyStateListener in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      listener - the listener to be removed
      See Also:

    • getPropertyStateListeners

      public final PropertyStateListener[] getPropertyStateListeners(S source)
      Returns an arry containing the listeners registered for the given source. Order is undefined. Returns an empty array if there are no listeners.
      Specified by:
      getPropertyStateListeners in class Property<S,V>
      Parameters:
      source - the source object on which to operate
      Returns:
      the set of listeners registered for the given source
      See Also:

    • firePropertyStateChange

      protected final void firePropertyStateChange(PropertyStateEvent pse)
      Notify listeners that the state of this property has changed, as characterized by the given PropertyStateEvent. If this PropertyHelper is managing listeners for multiple sources, only the listeners associated with the object returned by the PropertyStateEvent's getSourceObject() method are notified.
      Parameters:
      pse - the PropertyStateEvent characterizing the state change

    • isListening

      public final boolean isListening(S source)
      Returns whether or not there are any PropertyStateListeners installed for the given source object.
      Parameters:
      source - the source object of interest
      Returns:
      whether or not there are any PropertyStateListeners installed for the given source object