uk.org.ogsadai.common.properties
Class CallbackSelfNotifyingProperty

java.lang.Object
  |
  +--java.util.Observable
        |
        +--uk.org.ogsadai.common.properties.Property
              |
              +--uk.org.ogsadai.common.properties.CallbackSelfNotifyingProperty

public class CallbackSelfNotifyingProperty

extends Property

A property that automatically notifies its observers whenever its value changes state.

The value object must be Observable and each time it is notified of a change, any observers of the property will also be notified. In other words, a chain is formed between the observable value and the property observers. The observable value will be passed as the argument to the property's notifiyObservers method.

Note that the value object of a property of this type cannot be changed after construction so the setValue method raises an UnsupportedOperationException.

Author:

The OGSA-DAI Project Team

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE
private java.util.Observable	mObservable
private PropertyValue	mValueCallback

Fields inherited from class uk.org.ogsadai.common.properties.Property

mName, mSecurityContext

Fields inherited from class java.util.Observable

Constructor Summary

CallbackSelfNotifyingProperty(javax.xml.namespace.QName name, java.util.Observable observable, PropertyValue value)
Create a new property with the specified name and observable value.

Method Summary

protected java.util.Observer	createObserver() Creates and returns an observer that will automatically notify observers of the property whenever the property value changes state.
java.lang.Object	getValue() Return the property value.
void	setValue(java.lang.Object value) Set the property value.

Methods inherited from class uk.org.ogsadai.common.properties.Property

getName, setName, setSecurityContext

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Field Detail

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

See Also:

Constant Field Values

mObservable

private final java.util.Observable mObservable

mValueCallback

private final PropertyValue mValueCallback

Constructor Detail

CallbackSelfNotifyingProperty

public CallbackSelfNotifyingProperty(javax.xml.namespace.QName name,
                                     java.util.Observable observable,
                                     PropertyValue value)

Create a new property with the specified name and observable value. When the state of the value changes, any observers of this property object will be notified.

Parameters:

name - The name of the property.

observable - The observed value.

value - The value of the property.

Method Detail

createObserver

protected java.util.Observer createObserver()

Creates and returns an observer that will automatically notify observers of the property whenever the property value changes state.

Returns:

observer.

getValue

public java.lang.Object getValue()
                          throws PropertyValueException

Description copied from class: Property

Return the property value.

Specified by:

getValue in class Property

Returns:

the value for the property or null if it has not been set.

Throws:

PropertyValueException - if an error occurs when obtaining the value.

setValue

public void setValue(java.lang.Object value)

Description copied from class: Property

Set the property value.

Specified by:

setValue in class Property

Parameters:

value - Property value.