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java.lang.Objectorg.jdesktop.beansbinding.Property<S,V>
org.jdesktop.beansbinding.PropertyHelper<S,V>
org.jdesktop.beansbinding.BeanProperty<S,V>
S - the type of source object that this BeanProperty operates onV - the type of value that this BeanProperty representspublic final class BeanProperty<S,V>
An implementation of Property that uses a simple dot-separated path
syntax to address Java Beans properties of source objects. For example, to
create a property representing the firstName property of an obect:
BeanProperty.create("firstName");
Or to create a property representing the firstName property of
an object's mother property:
BeanProperty.create("mother.firstName");
An instance of BeanProperty is immutable and can be used with
different source objects. When a PropertyStateListener is added to
a BeanProperty for a given source object, the BeanProperty
starts listening to all objects along the path (based on that source object)
for change notification, and reflects any changes by notifying the
listener associated with the property for that source object. So, in the second
example above, if a PropertyStateListener is added to the property
for an object Duke, the PropertyStateListener is notified
when either Duke's mother changes (if the new mother's name is
different), or Duke's mother's firstName changes.
It is very important that any bean properties addressed via a BeanProperty
follow the Java Beans specification, including firing property change notification;
otherwise, BeanProperty cannot respond to change. As some beans outside
of your control may not follow the Java Beans specification, BeanProperty
always checks the BeanAdapterFactory to
see if a delegate provider has been registered to provide a delegate bean to take
the place of an object for a given property. See the
ext package level documentation for more
details.
When there are no PropertyStateListeners installed on a BeanProperty
for a given source, all Property methods act by traversing the entire
path from the source to the end point, thereby always providing "live" information.
On the contrary, when there are PropertyStateListeners installed, the beans
along the path (including the final value) are cached, and only updated upon
notification of change from a bean. Again, this makes it very important that any
bean property that could change along the path fires property change notification.
Readability of a BeanProperty for a given source is defined as follows:
A BeanProperty is readable for a given source if and only if
a) each bean in the path, starting with the source, defines a Java Beans getter
method for the the property to be read on it AND b) each bean in the path,
starting with the source and ending with the bean on which we read the final
property, is non-null. The final value being null does not
affect the readability.
So, in the second example given earlier, the BeanProperty is readable for (@code Duke} when all
of the following are true: Duke defines a Java Beans getter for
mother, Duke's mother defines a Java Beans getter for
firstName, Duke is non-null, Duke's mother
is non-null. The BeanProperty is therefore unreadable when
any of the following is true: Duke does not define a Java Beans
getter for mother, Duke's mother does not define a Java
Beans getter for firstName, Duke is null,
Duke's mother is null.
Writeability of a BeanProperty for a given source is defined as follows:
A BeanProperty is writeable for a given source if and only if
a) each bean in the path, starting with the source and ending with the bean on
which we set the final property, defines a Java Beans getter method for the
property to be read on it AND b) the bean on which we set the final property
defines a Java Beans setter for the property to be set on it AND c) each bean
in the path, starting with the source and ending with the bean on which we
set the final property, is non-null. The final value being null
does not affect the writeability.
So, in the second example given earlier, the BeanProperty is writeable for Duke when all
of the following are true: Duke defines a Java Beans getter for
mother, Duke's mother defines a Java Beans setter for
firstName, Duke is non-null, Duke's mother
is non-null. The BeanProperty is therefore unreadable when
any of the following is true: Duke does not define a Java Beans
getter for mother, Duke's mother does not define a Java
Beans setter for firstName, Duke is null,
Duke's mother is null.
In addition to working on Java Beans properties, any object in the path
can be an instance of Map. In this case, the Map's get
method is used with the property name as the getter, and the
Map's put method is used with the property name as the setter.
BeanProperty can only respond to changes in Maps
if they are instances of ObservableMap.
Some methods in this class document that they can throw
PropertyResolutionException if an exception occurs while trying
to resolve the path. The throwing of this exception represents an abnormal
condition and if listeners are installed for the given source object,
leaves the BeanProperty in an inconsistent state for that source object.
A BeanProperty should not be used again for that same source object
after such an exception without first removing all listeners associated with
the BeanProperty for that source object.
| Method Summary | ||
|---|---|---|
static
|
create(Property<S,?> baseProperty,
java.lang.String path)
Creates an instance of BeanProperty for the given base property
and path. |
|
static
|
create(java.lang.String path)
Creates an instance of BeanProperty for the given path. |
|
V |
getValue(S source)
Returns the value of this Property for the given source. |
|
java.lang.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. |
|
boolean |
isReadable(S source)
Returns whether or not the Property is readable for the given source. |
|
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. |
|
void |
setValue(S source,
V value)
Sets the value of this Property for the given source. |
|
java.lang.String |
toString()
Returns a string representation of the BeanProperty. |
|
| Methods inherited from class org.jdesktop.beansbinding.PropertyHelper |
|---|
addPropertyStateListener, firePropertyStateChange, getPropertyStateListeners, isListening, removePropertyStateListener |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
| Method Detail |
|---|
public static final <S,V> BeanProperty<S,V> create(java.lang.String path)
BeanProperty for the given path.
path - the path
BeanProperty for the given path
java.lang.IllegalArgumentException - if the path is null, or contains
no property names
public static final <S,V> BeanProperty<S,V> create(Property<S,?> baseProperty,
java.lang.String path)
BeanProperty for the given base property
and path. The path is relative to the value of the base property.
baseProperty - the base propertypath - the path
BeanProperty for the given base property and path
java.lang.IllegalArgumentException - if the path is null, or contains
no property namespublic java.lang.Class<? extends V> getWriteType(S source)
Property by calls to setValue.
See the class level documentation for the definition of writeability.
getWriteType in class PropertyHelper<S,V>source - the source object on which to operate
java.lang.UnsupportedOperationException - if the Property is not
writeable for the given source
PropertyResolutionException - if an exception occurs while resolving the pathsetValue(S, V),
isWriteable(S)public V getValue(S source)
Property for the given source.
See the class level documentation for the definition of readability.
getValue in class PropertyHelper<S,V>source - the source object on which to operate
Property for the given source
java.lang.UnsupportedOperationException - if the Property is not
readable for the given source
PropertyResolutionException - if an exception occurs while resolving the pathisReadable(S)
public void setValue(S source,
V value)
Property for the given source.
See the class level documentation for the definition of writeability.
setValue in class PropertyHelper<S,V>source - the source object on which to operatevalue - the new value for the Property
java.lang.UnsupportedOperationException - if the Property is not
writeable for the given source
PropertyResolutionException - if an exception occurs while resolving the pathisWriteable(S),
getWriteType(S)public boolean isReadable(S source)
Property is readable for the given source.
See the class level documentation for the definition of readability.
isReadable in class PropertyHelper<S,V>source - the source object on which to operate
Property is readable for the given source.
java.lang.UnsupportedOperationException
PropertyResolutionException - if an exception occurs while resolving the pathisWriteable(S)public boolean isWriteable(S source)
Property is writeable for the given source.
See the class level documentation for the definition of writeability.
isWriteable in class PropertyHelper<S,V>source - the source object on which to operate
Property is writeable for the given source.
java.lang.UnsupportedOperationException
PropertyResolutionException - if an exception occurs while resolving the pathisReadable(S)protected final void listeningStarted(S source)
PropertyHelperPropertyHelper 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.
listeningStarted in class PropertyHelper<S,V>PropertyHelper.listeningStopped(S)protected final void listeningStopped(S source)
PropertyHelperPropertyHelper 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.
listeningStopped in class PropertyHelper<S,V>PropertyHelper.listeningStopped(S)public java.lang.String toString()
BeanProperty. This
method is intended to be used for debugging purposes only, and
the content and format of the returned string may vary between
implementations. The returned string may be empty but may not
be null.
toString in class java.lang.ObjectBeanProperty
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